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1. Interface This function receives one const int for input This integer is the index of a particular row in the matrix of coordinates that has been predefined This will simply set the member Current_Dir to be whatever direction the user sends in Issues An invalid direction could be sent in If this happens the program will try to access memory that does not exist This will either cause the game to not draw a sprite on the screen or could cause the system to crash Constraints There should be a test within this function to ensure that the direction sent in is indeed a valid direction If not simply keep the current direction If so update the current direction to the specified direction 51 Update_Frame Narrative This function receives no inputs This simply increments the index of the column in the coordinate matrix to point to the next frame of animation Once the last frame has been reached the index is reset to Zero Diagram Increment Index Interface This function receives no inputs Internally the member Current_Frame is incremented to the next frame If after incrementing the index exceeds the number of frames defined the frame will be reset to zero to begin the animation again Issues This does not allow for different patterns of animation Each animation will load in succession as they were defined in the data file If the user wants to repeat a certain frame they will have to either edit the da
2. 100 Logic_Random Narrative This function receives the X and Y velocities of the current sprite and a seed for the randomizer The seed is used more as a delimiter for the randomizer It will limit the actual value spit out by the randomizer to be below that number Using the randomizer function a new X and Y velocity are calculated and are returned from this function Diagram Seed Return Velocities Sprite Velocities gt Randomizer Generate Velocities Interface This function receives three const int as input The first two integers represent the current SPRITE_OBJ s X and Y velocities The last integer is the number to use when calling the randomize function to limit the output of the randomizer The value returned by the randomizer is set to the X and Y velocities and they are returned Issues If the seed sent in for use in the randomizer is very large the current sprite will most likely jump off of the screen This is because a very high number could be set to be the X or Y velocity and the sprite s position after the next game loop would be somewhere off the screen If the sprite s random flag is not set this function will have no bearing on the sprite s position Constraints Negative numbers for the randomizer seed are not acceptable If a negative number is sent in to the randomizer it will be converted to its absolute value instead 101 Logic_Kill_Player Nar
3. Consistency of display Efficient assimilation of information by the user Minimize memory load Compatibility between data entry and display Flexibility of user control 118 Menu Guidelines 1 2 3 DEA a Shallow wide menus preferred over tall deep menus User has access to all relevant items without referencing a manual Logical item presentation sequence a Numeric b Alphabetic Icons are harder to recognize than text during visual search Don t assume the user will notice cues like color or border changes Allow key presses for frequent users Ensure consistent navigation Screen Formatting Guidelines 1 DA ER S Focus on readability and user acceptability Don t clutter the screen white space is free Choose pleasing color combinations Use full width of the screen Keep only relevant info on the screen Use device codes to move cursor clear lines etc Guidelines for Effective Use of Color 1 SEE Use color to group similar items Use colors with connotation if reasonable red means stop etc Limit the total number of colors 7 2 Watch out for bad color combinations red blue blue black Keep in mind people may view it in monochrome Prompt and Response Guidelines SD OE Oo Use upper lower case letters for emphasis as needed Tasks should be interruptible without loss Give user a means of controlling multiple screens Allow user to verify and edit responses Give user a reasonable a
4. s of the sprite are updated From here the collision detection algorithm is called to determine if that movement caused the sprite to collide with any other object If not the function returns If so velocities are re calculated and tested again Player Position Global Generate Velocities Sprite Position Update Sprite Position Player Within Range Collision Detector Collision Found Return Coordinate Diagram Interface This function receives a const POINT as input The POINT contains the X and Y position of the current sprite These values are tested against the player character s X and Y positions and it is determined which direction the current sprite will have to move to avoid the player Once determined an X velocity and Y velocity will be calculated The velocities will be used to update the sprites X and Y position The new X and Y position s will be tested with the collision detector function to determine is the movement caused a collision If a collision is not detected the new position is valid and the function exits If a collision is detected new velocities are calculated bearing in mind what direction caused the collision This is sort of a bump and turn routine A direction is tested if it works then exit if not change the direction Issues None Constraints Closed areas may create some difficulty in generating the correct movement for t
5. This receives no input and simply sends the Alias back to wherever this function was called from Return type is a const char Issues An attempt to call Get_Alias for a SOUND_OBJ that has no Alias set may crash the program because it would attempt to play a sound that is not created yet This should not be allowed Constraints This function must check to see if the Alias for the current SOUND_OBJ has been set before trying to send back undefined information Get_Path Narrative This function simply returns the path of the SOUND_OBJ The path is the filename and path of the desired WAV file to load to the sound surface Diagram Path p Interface This function receives no input and simply sends back the path the wherever this function was called from Return type is a const char Issues If no path yet exists for the current SOUND_OBJ an empty string will be returned This path is used in loading the WAV to the sound surface If the path is NULL there will be no path to load to the surface and the program may crash Constraints Possibly set a default sound so that the program does not crash if the path has not been set Or possibly make the sound loading function not kill the program and instead continue processing 78 Get_Surface Narrative This function simply returns the sound surface pointer of the SOUND_OBJ The surface pointer is the pointer to the surface that will be loaded with the specified WAV file
6. This surface will be used to grab portions of when animating sprites within the game The IMAGE _OBJ member Surface is simply set to point to the temporary surface sent in Diagram Surface Interface This function receives a const LPDIRECTDRAWSURFACE7 as its input type The Surface member within the current IMAGE_OBJ is simply set to point to the same memory location as that of the surface sent in Issues Users that do not have DirectX 7 installed on their machine will not be able to compile nor run this particular function Constraints None 36 OBJ_ HANDLER Create_Window Narrative This function receives as input the name of the event handler and the handle to the instance of the game application Using these inputs and several predefine macros found in defines h the actual window for the game is created First several things are defined such as background color and application icon Once all is set the window is registered After the window is registered the window is then created Once created the cursor is hidden and the window is set into focus Diagram Window Handle Message Handler Attach Message Handler Register Create Window Window Interface The functions inputs are two void types One is the handle to the event handler and the other is the handle to the application instance Once the event handler has been attached to the window being created the window is registe
7. Database Sears Data Files Sprite User Interface Data Level User Input Logic Data User Interface User Input i Spri prite Map Editor Define Logic Data Level Data User Input User Interface P Define Level Map Editor 12 Component Descriptions INTERFACE Scrollbar_Change Narrative Receives no input It s job is to scroll the object that it is attached to in a the direction the user chooses Any time the user clicks on the scrollbar this function handles how the user is interacting with the scrollbar Scrolling up moves the data up scrolling down moves the data down This is done by interpreting how the user is interacting with the scrollbar and changing the top and left coordinates of the image by some pixel value depending on how much the user moves the bar Diagram ScrollBar Direction of Movement New Position Interface The function interfaces with the object that the scrollbar is linked to It changes the way the information is displayed in that particular object Issues If the function is not handled correctly the data in the object linked to the scrollbar may not be displayed in the manner intended Constraints All scrollbars must be associated with the proper object s or the proper output may not be displayed 13 Scrollbar_Scroll Narrative Receives no input It s job is to scroll the object that it is attached to in a the direction the user chooses Any time the user clicks on the scr
8. During each iteration the current sprite is queried to see if their frame of animation needs updating If it does need updating checked by time passed or frame count the source coordinate for the sprite are changed so that when the sprite is drawn the image will be different than it was on the previous frame Issues While it s not necessary to update the frame information for sprites off screen this will be done anyway The reason is simply because it does not take that much processing power to do so and it s easier to do all of the sprites instead of keeping track of which ones are on screen and which are off Constraints Some objects animation patterns will vary greatly as the game moves on Other objects animation patterns will have to be based on user input and not by or in addition to timer or frame count 48 Update_Dest Narrative This function receives no inputs Its duty is to update the screen position of every sprite that needs repositioning Querying each sprite to see how each one moves will do this Some will be user controlled others will have their own simple AI routines and others will simply not move Diagram Loops until all Sprites accounted for Query Sprite Interface This function has no inputs It contains a for loop that loops until each sprite has been accounted for During each iteration the sprite is queried to determine how to update the screen destination if at all Each spri
9. If any of the past steps failed the mouse will not work correctly or at all during the game Issues The user must have the device the game expects attached to the computer prior to running the game or the game will not work correctly Constraints The cooperative level should be set fairly low so that if the user ALT TAB s out of the game Windows will regain control of the mouse If this were not done its very possible that Windows would lock up 85 Key_Handler Narrative This function receives the current x and y velocities of the sprite in question The role of this function is to detect what key is being pressed and if the key is one of the keys defined by the user as an input key take the appropriate action Since there is no way to define all possible actions the user may want the keystroke to represent only a few actions will be predefined The predefined actions will consist of strictly moving the object up down left and right respectively Any other keystroke that has been defined by the user as an important key will be passed back to the main program so its logic can be handled there Diagram Interface This function receives two const int as input The integers are the current x and y velocities The keyboard will be queried to see what key or keys is are being pressed at the moment It will check if the key is one predefined by the user as an action key defined in the GUI builder If the key is an act
10. Wizard Iof xi Define Collision Area Top Top 30 a Left f Right B E Bottom Size a 35x12 117 Objects and Actions Treeview Control The Treeview Control will be used to allow the user to see what sprites are currently loaded into the application The sprites will be categorized and be divided into different branches that can be expanded or collapsed When a particular user selects one of the loaded sprites the user will be able to position the image associated with that sprite MiniMap The MiniMap will allow the user to see what portion of the overall level currently being edited is in view It will also allow the user to move quickly to any portion of the level regardless of level size Surface Selector The Surface Selector is a combobox that will allow the user to display only the surfaces of the type that is selected in the combobox This is useful when designing the level because there may be multiple surfaces on the screen in a particular area To be able to edit view individual objects it will be necessary to have the surface of that type selected Interface Design Rules Eight Golden Rules of Dialog Design SOON Se Strive for consistency Short cuts for frequent users Design dialogs to yield closure Offer information feedback Offer simple error handling Permit easy reversal of actions Support internal focus of control Reduce short term memory load Data Display Guidelines ie ASS
11. able to compile nor run this particular function Constraints None 82 INPUT_HANDLER DInput_Init Narrative This function receives a window handle and an instance handle The window and the instance are used to create the DirectInput object The DirectInput object is what is used by the game to attach input devices to The input devices i e mouse keyboard and joystick will be used to gather input from the game player to manipulate objects on the screen If the creation of the object fails an error message is output Diagram Wadow Handle DirectInputCreate Instance Handle Interface This function receives a const HWND and a const HINSTANCE Both data members are used to create the DirectInput object The object is created by accessing a few DirectX 7 functions The object is what all input devices will be attached to Issues If the user does not have DirectX 7 installed on their system this function will not compile correctly nor will it run It should be noted in the help files that DirectX 7 is needed Constraints The hwnd and hinstance from the actual window creation will have to be saved and sent into this function for it to work correctly 83 Keyboard_Init Narrative This function receives no input Its duty is to query the keyboard as one of the input devices for use in the game The keyboard can then be used as an input device to interact with objects in the game SetDataFormat SetCooperati
12. and cause problems in loading sprites correctly 41 If the user decided to move the BMP files the a different path or filename the data file would have no way of knowing this and would either have to be hand edited by the user or would have to be re edited by the GUI builder If the user wants to hand edit the data file they will have to be aware of the correct syntax expected by this function Complete syntax knowledge with examples should be easily accessible in the help files The string handling in C is something left to be desired With a more flexible language the data files could be more fault tolerant than they will be but with the limited string handling and file streaming of C the data files will have to be very correct Constraints The file handling part will have to be somewhat flexible to allow for added white space This is essential All users have different ideas of how separate items should be spaced and therefore this function will have to take that into account Init_All Narrative This function accepts no inputs Its duty is to simply call the functions that will in turn create the DD DS and DI objects Diagram Interface This function makes a call to Draw DDraw_Init Sound DSound_Init and Input DInput_Init Each of these functions are DirectX 7 functions that will create the draw sound and input objects to be used in the game Issues If the user does not have DirectX 7 installed on their sys
13. detection function is called to determine if the current SPRITE_OBJ is already colliding with another solid SPRITE_OBJ from the top If a collision is detected the function exits with no change to the SPRITE_OBJ s position If a collision is not detected the Y coordinate is updated by a predefine velocity that represents the acceleration due to gravity Issues If the collision detection algorithm is not working correctly sprites may continue falling until the fall right off of the screen Also sprites may stop falling even if they are not colliding with another sprite If the acceleration due to gravity is too high upon the next game loop the sprite may pass clear through solid objects sprites that are too small may be overlooked Constraints Sprites will most likely have to contain a mass data member Using the mass it can be calculated how fast the sprite should 97 accelerate downward This can be done without using a mass data member simply be limiting the acceleration due to gravity to a constant This may make more sense 98 Logic_Bounce Narrative This function receives the X and Y coordinate and velocity of the current sprite Based on the position and the velocity a new position for the sprite is determined This position is tested for a collision in the collision detection function If there is not collision then the function exits If there is a collision depending on the direction the collision was ca
14. from Path Diagram Surface p Interface This function receives no input and simply returns a surface pointer to wherever this function was called from Return type is a const LPDIRECTSOUNDSURFACE7 Issues Any sound effect or music in the game rely upon these surfaces for use in playing the sounds If the surface was not loaded correctly the game output will either not work at all or not work correctly Constraints None 79 Set_Alias Narrative This function receives as input a string The string is the user defined name that will represent this sound surface This is so each sprite defined can be pointed to whichever sound surface needed via their alias Diagram Alias Allocate Memor Interface This function receive as input a const char containing the user defined alias to the current sound surface First memory is allocated to contain the string then the string is copied in using strcpy found in string h Issues Resetting an alias may cause problems when using strcpy The alias may end up being not what was originally sent in Constraints The alias should be kept short but this will not be enforced as it will be simpler to just let it be the size it wants to be Since the alias is user defined and used within the data files most users will see that by creating a long alias to begin with just makes them have to type more later on 80 Set_Path Narrative This function rec
15. in the file will not be loaded correctly This could end up in undefined TEXT_OBJ s and cause problems in loading the text sprites correctly or at all 46 If the user wants to hand edit the data file they will have to be aware of the correct syntax expected by this function Complete syntax knowledge with examples should be easily accessible in the help files The string handling in C is something left to be desired With a more flexible language the data files could be more fault tolerant than they will be but with the limited string handling and file streaming of C the data files will have to be very correct Constraints The file handling part will have to be somewhat flexible to allow for added white space This is essential All users have different ideas of how separate items should be spaced and therefore this function will have to take that into account Update_Frame Narrative This function accepts no inputs Its duty is to update each sprite s that has more than one frame of animation frame of animation This will be done either by using a millisecond timer or by setting a frame rate for each particular sprite This function contains a for loop that will query each sprite and determine whether their frame needs updating Diagram Loops until all Sprites accounted for Query Sprite Interface This function has no inputs It contains a for loop that loops until all sprites have been accounted for
16. of directions the current sprite will have i e 1 2 4 8 and the number of frames of animation per direction i e 1 2 3 4 If the input values have a value of 4 for directions and 3 for frames that means this sprite has 4 directions N W E S and per each direction there are 3 animations associated with it This function has two loops inside The outer loop will loop as until all directions have been accounted for and the inner loop will loop until all frames per direction are accounted for During each iteration new memory is created as a placeholder for coordinates that will be defined in a later function Issues The total number of frames directions frames will have to be known at this time If the user decides to add another frame direction to the data file they will also have to change the number of directions or the number of frames This should be outlined in the help file Constraints This will have to be flexible enough to allow for vast differences in numbers A user may want to have 64 animations per direction and so the array cannot simply be a static array it will have to be dynamically allocated to allow for this 50 Update_Dir Narrative This function receives a direction to set the sprite to The direction is simply an integer used to look op the correct row in the matrix or coordinates that was defined earlier This function will be called any time the sprite changes directions Diagram Direction o
17. on the screen or off the screen The integer is simply set to the data member X_Velocity Issues If the velocity sent in is very large the sprite itself may not appear after its first frame This would be because the sprite shot off the screen at a very large rate that it would only appear onscreen for the first few frames Constraints Negative and positive velocities should be allowed Negative will move the sprite to the left positive to the right Set_Y_ Velocity Narrative This function receives a velocity as input The velocity is simple the number of pixels up or down that the sprite will move This should default to zero The velocity sent in will simply be set to the data member Y_Velocity Diagram Y_Velocity Interface This function receives a const int as input The integer represents the number of pixels to offset the current SPRITE_OBJ by on the screen or off the screen The integer is simply set to the data member Y_Velocity 56 Issues If the velocity sent in is very large the sprite itself may not appear after its first frame This would be because the sprite shot off the screen at a very large rate that it would only appear onscreen for the first few frames Constraints Negative and positive velocities should be allowed Negative will move the sprite up positive down Set_Height Narrative This function receives as in put an integer The integer is the height of the sprite itself It will be us
18. screen Constraints None 63 Get_Frame_Rate Narrative This function receives no input Its duty is to simply return the data member Frame_Rate to wherever this function was called from Frame_Rate Interface This function receives no input and simply returns the current SPRITE_OBJ s frame rate to wherever this function was called from Diagram Issues If the frame rate is set too high the sprite will appear to have no animation if too low it will animate too fast Constraints None Get_Rate_Count Narrative This function receives no input Its duty is to simply return the data member Rate_Count to wherever this function was called from Diagram Rate_Count Interface This function receives no input and simply returns the current SPRITE_OBJ s rate count to wherever this function was called from Issues None Constraints The rate count should fall somewhere between zero and the frame rate A check should be made to make sure that the value does indeed fall within this range 64 TEXT_OBJ Set_Dest Narrative This function receives a destination coordinate as input The coordinate is the pixel on the screen to draw the TEXT_OBJ at The coordinate sent in is simply set to the data member Dest_Coord Diagram Dest Interface This function receives a const POINT as input The POINT is actually a pixel coordinate of where to draw the TEXT_OBJ on screen The coordinate sent in is simply set to
19. screen are accounted for During each iteration of the loop the current SPRITE_OBJ is queried to see what attributes have been set for it Based upon these attributes logic functions are called to manipulate the sprite s position on screen For example if the current sprite is a moving sprite meaning another creature in the game and is a solid sprite meaning when its collision area is overlapping with another this object will stop and is affected by gravity meaning this object is drawn downward then the appropriate logic functions will be called In this instance the calls go to the function that handles gravity followed by the collision detection function If a collision is found the sprite stops moving downward if not it continues Issues If the sprite being tested has no attributes defined for it most of the logic functions will have no affect on that sprite This should be outlined in the help files Constraints Moving sprites creatures will have to be tested against every other sprite and collision area for the current level The more creatures there are the slower the game will move It should be considered to put a creature limit for each level If the logic function calls are not called in the correct order undesirable effects may occur Special care should be taken when determining which logic function has priority The function should also be thoroughly tested to ensure that it works without any problems 92 Lo
20. sprite Using these velocities a new velocity is generated Meaning that the velocity returned from this function will be smaller than the velocity sent into the function This is so that during each game loop the sprite in question will slow down and finally come to a stop The new velocities are returned Diagram Return Sprite Velocities 3 p Coordinate Decrement Velocities Interface This function receives two const int as input The integers represent the X and Y velocities of the current SPRITE_OBJ New velocities are calculated which will be smaller in value than those sent in Each game loop the velocities get smaller and smaller until they finally hit zero Once at zero the SPRITE_OBJ comes to a complete stop The new velocities are returned Issues If a sprite s friction flag is not set this function will not have any bearing on the sprite s movement The sprite will simply never stop moving until the game is over This function will also have no affect on the player sprite so long as the player is using the input device to control the sprite Once the player stops using the device the player sprite will eventually come to a stop assuming the player sprite s friction flag is set Constraints This should be a fairly simple function The real physics equation for calculating friction could be used but on large levels with more creatures this may cause the game to take a serious performance hit
21. sprite this function will determine if the two objects are colliding If they are colliding a predefined constant is returned representing what direction the collision occurred from Diagram Sprite 1 Position Width and Height Sprite 2 Position Width and Height Return 1 Return Compare Position And Zones Sprites Overlapping Return Bottom From Bottom Return Right Return Left Interface This function receives two const POINT and four const int as input The two POINTs are the position coordinates of the SPRITE_OBJ being tested and the SPRITE_OBJ its being tested against The four integers are the width and height values of each SPRITE_OBJ Using these values this function will test if the first SPRITE_OBJ is overlapping with the second SPRITE_OBJ s collision area If it is overlapping a constant representing top bottom left and right is returned The return type is a const int Issues If the collision zones are very small and the velocity of the current sprite is very large the sprite may pass right through another sprite This is because the current velocity makes the current sprite step right over the sprite its being tested against 108 Constraints There definitely should be a way of determining what side of the object the collision took place on In some games a collision from the top kills the enemy and a collision from the side kills the player This is im
22. surfaces are then checked to make sure that their memory wasn t overwritten If the surfaces were lost DirectX 7 will restore the surfaces Diagram Primary Surface Back Buffer Interface No input is sent into this function The primary surface and the back buffer are used here The back buffer is queried to see if a past Flip is still in progress Once determined it either continues or cancels the function If it continues a call to flip the primary surface with the back buffer is made The flip routine simply switches the pointer to the Primary surface to be swapped with that of the pointer to the back buffer This flips what s being drawn in memory to the screen and vice versa Issues If not done correctly the surfaces could be lost if this were to happen the screen would bomb out and nothing but the last known surface would be displayed on screen Constraints To avoid losing the surfaces once the surfaces are flipped they should be checked to see whether they we lost If so the surfaces need to be restore 28 Restore Narrative Restore receives no input It simply checks to see if a DirectX 7 Object exists and if so restore all surfaces This is needed in case the surfaces get lost This can happen when the user ALT TABs out of the program and back in again Diagram Draw Restore Interface There is no input to this function The DirectX 7 Object is checked to see whether it exists or not If it does
23. the Height of the SPRITE_OBJ The height is the size in pixels of the sprite in question Diagram Height Interface This function receives no input and simply sends back the Height to wherever this function was called from Issues If a call is made to Get_Height and no height has been defined the program will attempt to draw regardless This will not be a problem unless somehow the Height was by default a negative number which could have undesired affects This may cause the program to crash If the height specified exceeds the height of the BMP file itself the game will most likely produce undesired output Constraints A check has to be made to make sure that the surface in question does have a width associated with it and that the width be a positive integer and smaller than the image itself Get_Width Narrative This function simply returns the Width of the SPRITE_OBJ The width is the size in pixels of the surface in question Diagram Source Interface This function receives no input and simply sends back the width to wherever this function was called from Issues If a call is made to Get_Width and no height has been defined the program will attempt to draw regardless This will not be a problem unless somehow the width was by default a negative number which could have undesired affects This may cause the program to crash If the width specified exceeds the width of the BMP file itself the g
24. the data member Dest_Coord Issues Since TEXT_OBJ s can be positioned off screen the user may mistakenly put the wrong coordinates for an object This means text that they expect to see on screen will not be at all This is unavoidable The user will have to move the coordinates of the text in the GUI builder or simply change the data file Constraints Some TEXT_OBJ s should be able to have coordinates off screen This will allow for objects to move onto the screen at a later time This means that a clipper will have to be attached so that unnecessary drawing if off screen TEXT_OBJ s is not done This also means pixel values that do not fit within the current screen resolution ARE valid entries 65 Set_Message Narrative This function receives a message as input The message is an actual text message the will be output to the screen The message is copied into the data member Message Once the message is set the length of the message is determined and set to the data member Length Diagram Message Allocate Memo Interface This function receives a const char as input The function first allocates memory the size of the string sent in Once allocated the function uses strcpy string h to copy the string into the data member Message Once the message is set strlen string h is called to determine the length of the message The length is then set to the data member Length Issues None Constraints
25. Design Specification Introduction Goals and Objectives GameForge is a graphical tool used to aid in the design and creation of video games It attempts to bring game development down to a level that any computer savvy user can understand without requiring masterful programming ability A user with limited Microsoft DirectX and or Visual C programming knowledge will be able to construct a basic 2 D arcade game GameForge limits the amount of actual code written by the user if not eliminating it completely It will also assist experienced programmers in generating the Microsoft DirectX and Microsoft Windows9x overhead necessary for basic game construction allowing them to concentrate on more detailed game design issues and implementation Project Scope GameForge is a graphical tool used to aid in the design and creation of video games A user with limited Microsoft DirectX and or Visual C programming knowledge will be able to construct a basic 2D arcade game The idea is to limit the amount of actual code written by the user It will also assist experienced programmers in generating the Microsoft DirectX and Microsoft Windows9x overhead necessary for basic game construction allowing them to concentrate on more detailed game design issues and implementation The software will consist of a number of inputs graphically assisting the user in creating on screen objects including the following e User Created Objects player character crea
26. Exit_Click Narrative Receives no input Its job is to close all files and exit the program Any cosmetic closing effects are also included here and the main program is unloaded from memory Diagram File Saved Program Terminates Interface This function will need to interface with the save as dialog Because if it doesn t the user s files will be closed and changes will not be saved Issues The user should be prompted to save their files to disk or else they will be closed and changes will not be saved The user should be asked to confirm the desire to exit the program Constraints If this function interfaces with the SaveAs Function the Microsoft Common Dialog controls will need to be included 18 SpriteLoader Narrative Receives no input Its job is to pass the filename of the sprite into the image loader Diagram SpriteLoader alls Open CommonDialog User Selects Image File ImageLoader Interface The function interfaces with the ImageLoader function and the Open common dialog Imageloader is the function that loads the images into a particular object Issues The file chosen must be a bitmap Constraints Without the ImageLoader function and the common dialog control the user will not be able to choose the file to open The common dialog control is included in the Visual Basic application wizard 19 ImageLoader Narrative Receives the filename to display as inpu
27. Microsoft DirectX up to version 3 0 DirectInput had not been implemented at this time making this version of DirectX very limited Microsoft Windows 2000 should also be compatible GameForge also requires Microsoft DirectX 7 0 or above Users may also want to obtain the DirectX 7 0 SDK if they plan on expanding the GameForge library files beyond their original scope GameForge also requires the Microsoft Visual C 6 0 compiler GameForge s VC code may be compilable using Borland or some other VC compiler but functionality is not guaranteed Management and Technical Constraints GameForge has a drop dead delivery date of 04 17 00 PA Software will be using the Rapid Prototyping model during design and implementation Prototype GUI Prototype GUI Requirements Design List of Revisions Prototype Engine Prototype Engine Requirements Design Prototype System Deliver GameForge GameForge Requirements Data Design Internal Software Data Structures Sprites Sprites consist of the following attributes Name Primary Key Name of the sprite Image Name of the Image file displayed representing the sprite Width The width of the sprite in pixels Height The height of the sprite in pixels DestinationX The X coordinate for the destination of the placement of the sprite DestinationY The Y coordinate for the destination of the placement of the sprite Framerate The fr
28. OBJ that will be within the game The filename given will be opened If the file does not exist the function will open a file for output and will output an error message to a log file If the file opening was successful the function will continue to loop until all data from the file has been read in Within the loop the file is parsed and each piece of information is used to load an TEXT_OBJ with all of the correct information it needs When the file is empty the file is closed Diagram R Text Data Filename G gt KRA Interface This function receives a const char as input The string is the handle to a filename that contains all of the information needed to fill an TEXT_OBJ object An attempt to open that file is made If the file exists in the specified path the program will continue If not an output file is opened and an error message is output Once a valid file is opened each line of data is read in one by one Each line will consist of an operation and an operator The operand is parsed off and the operator tells what function to use to set the data with Once an end operation has been read the image counter is incremented and a new TEXT_OBJ is created After all TEXT_OBJ are read in from the file the loop ends and the file is closed Issues If the data file s contents are not set up correctly by the GUI builder or if the user edits the data file incorrectly some or all of the information
29. Sound 7 Object is the base object for all other sound surfaces to be attached to After the object is created it can be used for playing sounds using calls defined within the DirectSound 7 object Issues If the user does not have DirectX 7 installed on his her machine and their compiler is not linking to the correct DirectX 7 files this function will not even compile Constraints The GUI builder will have to determine which files are small enough to load into memory and which files should be streamed from the hard drive 75 Play_Sound Narrative Receives a surface a sample rate and a sample quality The surface is the surface that will be used for the sound file itself The surface has a WAV loaded onto it so that using the sample rate and quality sent in the sound could be played If the sound clip is too large to fit into memory the sound clip will be streamed in piece by piece off of the hard drive Diagram Sound Surface Sample Rate Sample Quality Play Sound Interface A DirectSound 7 surface is sent in as well as two const int The DirectSound 7 surface contains a specific WAV file already loaded onto it If the sound file is too large to fit into system memory this function will have to stream the file off of the hard disk Issues The more sounds being played at once the harder it will be to distinguish one sound from the other If one of the sounds being played represents an important role in the
30. When reading in the message from the data file the file handler has to be able to accept spaces in the message This should be done using the getline function fstream h 66 Set_Color Narrative This function receives a color as input The color is used to specify what color the text message will be drawn on the screen with The color is copied into the data member Color Diagram Color Interface This function receives a const COLORREF as input The COLORREF is a Windows data type that holds an RBG color value The color is set to the data member Color Issues If the game is running at a color depth other than 16 bit Windows will automatically attempt to adjust the color for the correct color depth Constraints None Set_BkColor Narrative This function receives a color as input The color is used to specify with what color the text message will have as its background color The color is copied into the data member BkColor Diagram BkColor Interface This function receives a const COLORREF as input The COLORREF is a Windows data type that holds an RBG color value The color is set to the data member BkColor Issues If the game is running at a color depth other than 16 bit Windows will automatically attempt to adjust the color for the correct color depth Constraints None 67 Set_Trans Narrative This function receives a flag as its input The flag is used to specify whether or not the backgroun
31. a where that image can be placed on the screen onto any of the particular backgrounds that the user has chosen There will be a standard menu bar that is present on nearly every Microsoft Windows application along with a toolbar for quicker access to the commands embedded under the various menu options 111 Screen Images The Level Editor GameForge File Edit Create Help Ci te Ble tea x 40 Background Layer 7 Player Creatures Bowser Background E S k Objects gt Sts fF 332PM 112 New Sprite Wizard Attributes a m m a a a m a x New Sprite Wizard Movement EEIE a Storica nang J Bounces gt Randomize Movement fa Follows Rlayer Vv Vv M m a M E x 113 New Sprite Wizard Animation main screen Animation Wizard Define Attach Bitmap BouAding Bay Add Frame Delete Frame 114 New Sprite Wizard Animation Select BMP Selection Zoom Options Save Cancel Restore Original Settings 175x160 Top Top d QS Left Right sad fo a Bp O m 141 Bottom i al Size 141 5 136x137 115 New Sprite Wizard Animation Main Screen with BMP Define Bounding Box Animate Kenny a Add Remove Animation Animation Selection_ Animation Frames Final Animation 116 New Sprite Wizard Set Collision Area w Collision Area
32. ace in question does have a width associated with it Get_Path Narrative This function simply returns the path of the IMAGE_OBJ The path is the filename and path of the desired BMP file to load to the surface Path Interface This function receives no input and simply sends back the path the wherever this function was called from Diagram Issues If no path yet exists for the current IMAGE_OBJ an empty string will be returned This path is used in loading the BMP to the surface If the path is NULL there will be no path to load to the surface and the program will crash Constraints Possibly set a default image so that the program does not crash if the path has not been set Or possibly make the image loading function not kill the program and instead continue processing 32 Get_Surface Narrative This function simply returns the surface pointer of the IMAGE_OBJ The surface pointer is the pointer to the surface that will be loaded with the specified BMP file from Path Diagram Surface Interface This function receives no input and simply returns a surface pointer to wherever this function was called from Issues The sprites in the game rely upon these surfaces for use in drawing If the surface was not loaded correctly the game output will either not work at all or not work correctly Constraints None Set_Alias Narrative This function receives as input a string The string is the user de
33. ame will most likely produce undesired output Constraints A check has to be made to make sure that the surface in question does have a width associated with it and that the width be a positive integer and smaller than the image itself 62 Get_X_Velocity Narrative This function receives no inputs Its duty is to simply return the data member X_Velocity to wherever this function was called from Diagram X_Velocity Interface This function receives no inputs and simply sends back the current SPRITE_OBJ s x velocity to wherever this function was called from Issues The velocity could be set to a very large number If this happened and the number was returned it would be used to update the current SPRITE_OBJ s x position on the screen This may in fact move the sprite so much that it would no longer be on the screen Constraints None Get_Y_Velocity Narrative This function receives no inputs Its duty is to simply return the data member Y_Velocity to wherever this function was called from Diagram Y_Velocity Interface This function receives no inputs and simply sends back the current SPRITE_OBJ s y velocity to wherever this function was called from Issues The velocity could be set to a very large number If this happened and the number was returned it would be used to update the current SPRITE_OBJ s y position on the screen This may in fact move the sprite so much that it would no longer be on the
34. amerate of the sprite NumOfDir The number of directions the sprite has NumOfFrames The number of frames per direction Solid Whether or not the sprite is a solid object KillsPlayer Whether or not the sprite kills the player PlayerCanKill Whether or not the player can kill this sprite OtherCanKill Whether or not other sprites other than the player can kill this sprite Obtainable Whether or not the sprite can be picked up Visible Whether or not the sprite is visible on the screen AffectsScore Whether or not the sprite has an effect on the score SoundAttached Index of the sound is attached to this sprite ReactsToGravity Whether or not the sprite is affected by gravity ReactsToFriction Whether or not the sprite is affected by Friction ReactionToPlayer Index determining how the sprite reacts to the player s position Bounces Whether or not the sprite changes direction when contacting another sprite Random Whether or not the sprite has random movement Surfaces Surface consist of the following attributes Alias Primary Key The filename of the image Path The directory that the image is found in Height The height of the image in pixels Width The width of the image in pixels Messages Messages consist of the following attributes String Primary Key The actual text to be displayed DestX The X coordinate for the destination of where th
35. andle the event manually Diagram User Defined Event Handled Window Handle Message Parameters No Windows Auto Handle Interface This function receives a HWND a UINT a WPARAM and a LPARAM The function is an event handler The UINT is the message generated by a keystroke or automatically by Windows Based on the UINT message the appropriate actions take place Once this is done the function returns out and then returns to the exact place that the program jumped out of the handle this message Issues Windows will automatically handle Any Windows message that is not defined Most messages will never be explicitly handled by our program and will let Windows act appropriately Constraints Most predefined Windows handler functions are suitable for use in any application If there is no need to specifically make a change or addition to any occurring event it s suggested to let Windows handle it automatically 91 Logic_Handler Narrative This function receives no inputs Its duty is to query a specific object s attributes to see what kind of game logic it is defined to have and call a specific function for handling that logic This will be done as many times as there are objects Diagram Loops Number of Sprites Times Query Sprite Logic Router gt Interface This function receives no inputs Within the function is a for loop that continues until all sprites onscreen or off
36. application to crash This should be outlined in the help files so that the user knows to only include valid data files Constraints DirectDraw DirectInput and DirectSound MUST be initialized prior to initializing any of the game objects If the reverse were to occur the application would crash 89 Main_State Narrative This function receives no input This is the main game loop The game will loop into this function and repeat every call within so long as the game is running Any function that manipulates the objects on screen is put in here The function calls for drawing playing sounds handling game logic and handling user input are all within this function This allows for the game to be constantly updated until the game is over Object Draw_Sprites Object Draw_Text Diagram g Object Flip Logic_Handler Object Play_Sounds pan Interface This function receives no input The function is called repeatedly and as often as possible though the frame rate will be limited to 30 frames per second The first function call is to draw all the sprites and text messages on the screen that should be on the screen Once this is done the surfaces are flipped so that the user will see the next frame of animation After this is done the game logic functions are called These will update the screen positions of all objects also the player based on input This will also call the collision handler to make sure that no o
37. as complete as possible to assist advanced GameForge users seeking specific solutions Tutorials must be clear and complete and must not assume anything of the user Graphical cues may be helpful The GameForge help system must include a menu structure for more casual searching as well as a competent search engine too allow users access to specific data Flawless exporting to engine All files exported from the level builder must be free of errors Any errors generated at this point may result in code that is not executable Performance Requirements Avg FPS Games utilizing the GameForge engine must retain an average number of frames per second number to be finalized at a later time using the minimum requirements Mem usage Due to the costly memory usage of uncompressed bitmaps and wave files which GameForge uses unused memory must be freed properly once it is no longer being used File paging from the hard drive is unacceptable if the user has the minimum system requirements 123 Identification Errorless_ compilation of code There should be zero errors when compiling code that has been exported from the GameForge level builder This only includes code that has been compiled immediately after being exported from the level builder It is the user s responsibility to care for their code after they have altered it Errorless Low error execution of code without alteration Some ambitious game designs may not run per
38. ate some blitting problems Get_Dest Narrative This function receives no input Its duty is to simply return the current SPRITE_OBJ s destination coordinate drawing coordinate to wherever it was called from Dest Interface This function simply returns the data member Dest_Coord to wherever it was called from This coordinate is used to blit the sprite to the screen Diagram Issues If the destination coordinate is not defined the sprite may be drawn in odd coordinates on the screen or may not be drawn at all Constraints The data member Dest_Coord should have a default value of 0 0 This will ensure that all objects will be drawn although not at the right place if not specified 60 Get_Source Narrative This function receives no input Its duty is to simply return the current SPRITE_OBJ s current source coordinate where to blit from to wherever this function was called from Diagram Source Interface This function simply returns the data member Source_Coord at the current index determined by Current_Dir and Current_Frame This coordinate is used to determine what frame to blit to the screen Issues If Current_Dir and Current_Frame are undefined the desired output will not be displayed and may cause the game to crash Care has to be taken that Set_Source is called prior to any call to this function Constraints None 61 Get_Height Narrative This function simply returns
39. ation is gathered a call to Draw Draw_Surface is called which actually draws the surface by blitting to the back buffer Issues The more sprites that exist on screen the more often the function Draw Draw_Surface has to be called Draw Draw_Surface when called too often with surfaces that are large WILL eventually cause the games graphics to stutter Constraints Limit the total number of sprite to a suitable number so that the call to Draw Draw_Surface is minimized 38 Draw_Text Narrative This function receives no input Its function is to draw all text objects on the screen in the position that they are supposed to be drawn at It contains a loop then continues until all text objects are drawn Diagram Loops of Text Messages Times Draw Draw_Text S Interface This function receives no input This is a fairly simple function in that all it does is loop until all TEXT_OBJ s have been accounted for Within the loop is a call to Draw Draw_Text which actually does the drawing Issues If all TEXT_OBJ are define as invisible this will loop through each object anyway This of course eats up some processor time and will produce no output Constraints None 39 Error Flip Narrative Error is a very simple function that receives a string and outputs a text box to the screen specifying the error and shuts down the game Diagram Window Handle Display Message Message and Quit Program Messag
40. bjects are overlapping and will trigger any events associated with the objects that are colliding Once complete and sounds or music that need playing are played At this point the time is checked and the function sits here until 30 milliseconds have passed What this does is ensure that if the game is run on a vastly faster machine than it was designed for the game speed will not change and will remain at roughly 30 frames per second Issues This function does not ensure that on old machines slower machines that the frame rate will achieve 30 frames per second This is simply set up so that faster computers will not exceed 30 frames per second 90 Constraints The drawing and page flipping should be done first and as immediately as possible This is to ensure that the animation runs smoothly Message_Handler Narrative This function receives the window handle a message and two parameters Based upon the message and the parameters this function acts accordingly For a simple example if the player hits ALT TAB on the keyboard the event WM_ACTIVATEAPP will be sent immediately to this function A global variable is then set to be one of the parameters sent in If the parameter is false this means the user wishes to return to windows and unlock the primary surface and back buffer so that Windows will regain control of the screen Any user event or others can be handled here however most often we chose to bypass this routine and h
41. coordinate of where to draw the object on screen The coordinate sent in is simply set to the member Dest_Coord Issues Since sprites can be positioned off screen the user may mistakenly put the wrong coordinates for an object This means a sprite that they expect to see on screen will not be at all This is unavoidable The user will have to move the coordinates of the sprite in the GUI builder or simply change the data file Constraints Some sprites should be able to have coordinates off screen This will allow for objects to move onto the screen at a later time This means that a clipper will have to be attached so that unnecessary drawing if off screen sprites is not done This also means pixel values that do not fit within the current screen resolution ARE valid entries Set_Source Narrative This function receives a coordinate as input The coordinate is used to determine what pixel on the specified BMP file to start blitting from Some sprites will have more than one frame of animation and therefore this function will have to set the correct index in the array of coordinates Diagram Source o Interface This function receives a const POINT as input The POINT is a pixel position on the BMP file that will be used during the blit operation 54 to grab a certain portion of the BMP file This function will set the current index of the source coordinate array to be the coordinate sent in and will also increment the index o
42. d and appropriate Program Groups and Icons will be created as per the user s request GameForge will also include an uninstall feature to remove itself from any local machines Product Manual GameForge will ship with a detailed user manual covering the following topics e Installation Removal e Introduction to the software e General usage instructions e A tutorial detailing the creation of a simple game from start to finish 126 The GameForge software package in conjunction with the website will include an extensive list of help files and tutorials The manual is not meant to be a replacement for these facilities especially where troubleshooting and question lookup are concerned but is instead intended to assist the user in quickly familiarizing themselves with GameForge Product Packaging and Distribution GameForge will ship with a visually pleasing CD jewelcase containing the GameForge logo and at a glance information about GameForge The manual will fit nicely into the CD jewelcase cover The manual and packaging artwork are only available when ordering from the GameForge website for a nominal fee GameForge will be distributed via the GameForge website where it will be available for free download The software itself will have a splash screen that can only be bypassed after an undetermined number of seconds This screen can be bypassed if the copy of GameForge is licensed via the GameForge website for a
43. d of the text message is transparent or opaque The flag is copied as a Boolean value into the data member Transparent Trans Diagram Interface This function receives a const int as its input The integer can be set at one or zero which determines if the background of the current TEXT_OBJ is transparent or opaque The integer is copied into the data member Transparent Issues The background color BkColor is unnecessarily set if this flag is set to transparent The background color will never be seen unless this flag is reset to opaque Constraints Values other than one or zero should be weeded out prior to calling this function 68 Set_Visibility Narrative This function receives a flag as its input The flag is used to specify whether or not the text message is actually displayed on the screen or not This can be useful for turning on or off a text message The flag is copied as a Boolean value into the data member Visible Diagram Visibility Interface This function receives a const int as its input The integer can be set at one or zero which determines if the current TEXT _OBJ is visible or invisible The integer is copied into the data member Visible Issues A TEXT_OBJ that has a default value of invisible will not appear on the screen unless this flag is reset to visible This may cause some confusion for the user and should be outlined in the help files Constraints Values other than on
44. data or if the saving is not done automatically 15 MnuFileOpen_Click Narrative Receives no input Its job is to load the correct project files into memory that the user chooses The user will then be able to work with the project Diagram MnuFileOpen Calls Open CommonDialog User Selects Project ProjectOpened Interface The function interfaces with the common dialog control that is the standard Open box associated with most Microsoft Windows applications The user will choose a file displayed in this control Issues The file chosen must be a data file that is in a format supported by GameForge Constraints Without the common dialog control the user will not be able to choose the file to open This is included in the application wizard 16 MnuFileClose_Click Narrative Receives no input Its job is to close all files Any cosmetic closing effects are also included here Diagram File Saved MnhuFileClose Program Returns to Start State Interface The function interfaces with the common dialog control that is the standard Close choice associated with most Microsoft Windows applications Issues None Constraints Without the common dialog control the user will not be able to choose this command This is included in the application wizard The user should be prompted to save their files to disk or else they will be closed and changes will not be saved 17 MenuFile
45. e for output and will output an error message to a log file If the file opening was successful the function will continue to loop until all data from the file has been read in Within the loop the file is parsed and each piece of information is used to load an IMAGE OBJ with all of the correct information it needs When the file is empty the file is closed Ce Diagram Image Data Filename Set_Width Set_Path Set_Alias KHH Interface This function receives a const char as input The string is the handle to a filename that contains all of the information needed to fill an IMAGE_OBJ object An attempt to open that file is made If the file exists in the specified path the program will continue If not an output file is opened and an error message is output Once a valid file is opened each line of data is read in one by one Each line will consist of an operation and an operator The operand is parsed off and the operator tells what function to use to set the data with Once an end operation has been read the image counter is incremented and a new IMAGE _OB J is created After all IMAGE_OBJ are read in from the file the loop ends and the file is closed Issues If the data file s contents are not set up correctly by the GUI builder or if the user edits the data file incorrectly some or all of the information in the file will not be loaded correctly This could end up in undefined IMAGE_OBJ s
46. e or zero should be weeded out prior to calling this function Get_Dest Narrative This function receives no input Its duty is to simply return the current TEXT_OBJ s destination coordinate drawing coordinate to wherever it was called from Diagram Dest Interface This function simply returns the data member Dest_Coord to wherever it was called from This coordinate is used to draw the text message to the screen The type returned is a const POINT Issues If the destination coordinate is not defined the text message may be drawn in odd coordinates on the screen or may not be drawn at all Constraints The data member Dest_Coord should have a default value of 0 0 This will ensure that all objects will be drawn although not at the right place if not specified 69 Get_Color Narrative This function receives no input Its duty is to simply return the current TEXT_OBJ s foreground color to wherever this function was called from Diagram Color Interface This function simply returns the data member Color to wherever this function was called from The color is used as the foreground color of the text message to be drawn The return type is a const COLORREF Issues If the color depth of the game is anything but 16 bit color Windows will automatically convert the color to fit the specified color space Constraints Default color should be set to 255 255 255 so that by default the message will appear
47. e string will be placed DestY The Y coordinate for the destination of where the string will be placed ForeRGB The RGB value of the foreground color of the text BackRGB The RGB value of the background color of the text Transparent The background of the text can be made transparent Visible Whether or not the text is visible on the screen Sounds Sounds consist of the following attributes Alias Primary Key The filename of the sound Path The directory that the sound is found in Buffer The buffer to load the sound onto Notifications Breaks up sound into pieces for streaming State Determines play state playing not playing looping Levels Levels consist of the following attributes Name Primary Key The name of the level Width Overall width of the level in pixels Height Overall height of the level in pixels GoalSprite Index of the goal sprite GoalScore Value of the goal score Global Data Structures Object Handler Object Handler is the only global structure It contains the following Object Array Array of non moving sprites Creature Array Array of moving sprites Background Array Array of background sprites Player Player Sprite Message Array Array of text messages Surface Array Array of surfaces Game Contains game information Logic Contains all game logic DirectSound Handles all sound logic DirectDraw Handle
48. eBox gt Interface The only input is a const char containing the error message to put on screen Once on the screen the user has to click on the OK button or hit enter Once clicked the function posts a quit message and the window callback function kills the application Issues This of course causes the game to crash because it shuts down the program automatically Another function should be made to have a similar function but not shut down the program for minor errors Constraints Possibly allow the user to attempt to continue running the program in spite of the error that happened Narrative Flip receives no input Its function is simply a pipeline to the Draw Flip function that actually does the page flipping animation Diagram Interface This function is a way to be able to flip the surfaces from the main program without directly interacting with the Draw object The Draw object is contained within the OBJ_HANDLER and so therefore is a private member The only way to use Draw s internal function is to have a function in the OBJLHANDLER to call the specified Draw function Issues None Constraints None 40 Load_Image Narrative This function receives a string as input That string is the handle to a filename that is a data file containing information about every IMAGE_OBJ that will be within the game The filename given will be opened If the file does not exist the function will open a fil
49. ed so that the sprite will remain at its correct size and proportion when blitting to the screen This will also be used to determine how much of the BMP file to blit Diagram Height o ae Interface This function receives a const int as its input The integer is simply set to the current SPRITE_OBJ s Height member Issues This will only accept integers as a value because the integer represents the number of pixels tall the image to be loaded will be Constraints None 57 Set_Width Narrative This function receives as in put an integer The integer is the height of the sprite itself It will be used so that the sprite will remain at its correct size and proportion when blitting to the screen This will also be used to determine how much of the BMP file to blit Diagram Width a Interface This function receives a const int as its input The integer is simply set to the current SPRITE_OBJ s Width member Issues This will only accept integers as a value because the integer represents the number of pixels wide the image to be loaded will be Constraints None 58 Set_Frame_Rate Narrative This function receives a frame rate as its only input The frame rate is the timer that will be used to determine when a sprite s frame of animation needs to be updated Without this the sprite s frames would rapidly flip through too fast for the user to see Diagram Frame_Rate Interface This
50. eives as input a string The string the filename and path of the filename of the WAV file to be loaded onto the surface The string is set to the SOUND_OBJ data member Path Diagram Path Allocate i stre Memo py Path Interface This function receives a const char as its input First enough memory is allocated to contain the string Then the string is simply set to the current SOUND_OBJ s data member Path This will be used later to load the surface with the specified filename Issues Resetting a path may cause problems when using strcpy The path may end up being not what was originally sent in This may in turn cause problems when loading the WAV file to the surface Constraints The path should contain a WAV extension If the path specified does not contain WAV then the path is invalid and an error should be output 81 Set_Surface Narrative This function receives as input a pointer to a DirectSound 7 surface This surface will be used to play a specified WAV file when the game logic specifies to do so The SOUND_OBJ member Surface is simply set to point to the temporary surface sent in Diagram Surface Interface This function receives a const LPDIRECTSOUNDSURFACE7 as its input type The Surface member within the current SOUND_OBJ is simply set to point to the same memory location as that of the surface sent in Issues Users that do not have DirectX 7 installed on their machine will not be
51. ent sprite it will not Constraints It might be considered to first query all sprites to determine which actually could harm other sprites Once they are determined call the collision detection function to see if a collision occurred This may speed the algorithm up a bit 106 Randomizer Narrative This function receives a seed for its input The seed is used to limit the number returned from this function The function makes a call to rand defined in stdlib h That function generates a large positive random number The seed sent in to our function will take the modulus of that number with the seed to cut down the range of the number The new number is returned Diagram Seed Return Modulus Integer By Seed Interface This function receives a const int as its input The integer is used to limit the range of the random number generated by the rand function rand is found in stdlib h Using the modulus operation with regard to the integer sent in cuts down the number returned from rand The calculated number is returned out of the function as a const int Issues None Constraints None 107 Collision Narrative This function receives two X and Y coordinates two widths and two heights The first coordinate is the position coordinate of the current sprite being tested The second it the position coordinate of the sprite its being tested against Based on these coordinates and the width and height for each
52. es with the either the SaveAs or the AttriubuteDefiner functions Data is saved to the Database after the user is done selecting attributes Issues The database must be working properly Constraints Without the SaveDB function the changes will be lost 22 DRAW_HANDLER Create_Surface Narrative Receives as input a filename and width and a height Based on the width and height the appropriate DirectX 7 calls are made to allocate memory for surface creation and once the memory is set the filename is used to load the specified BMP file onto the DirectX 7 surface The width and height are the full size of the actual image itself Once completed creating and loading the surface the surface is returned Diagram BMP Filename Width Height DirectX 7 New Surface BMP Loaded Surface Object Loader Interface The function receives a filename const char and a width and a height both const int Using these the function interfaces with the DirectX 7 Object DDObjectNew to create a new DirectX 7 surface capable of holding a BMP file Once the new surface has been created the function opens up the specified BMP file using filename and makes a call to a DirectX 7 SDK defined function that loads the specified BMP onto the new surface Once complete the new surface is returned Issues This function is not capable of determining how much video system memory is left available Assuming that the user loads too ma
53. exist make a call to the restore routine defined within the DirectX 7 object to restore the surfaces Issues Older versions of DX made you restore each surface individually which was both time consuming for the programmer and the system itself DirectX 7 fixes this problem with one call to its RestoreAllSurfaces function Constraints It should be determined whether the DirectX 7 Object still exists If one tied to restore surfaces that do not exist it may cause the program to crash 29 Unlock Narrative This function simply unlocks the Primary surface and the back buffer This is used so that the game has the ability to be ALT TABbed out of By unlocking both surfaces it gives control of the video buffer back to Windows Diagram Interface This function calls the UnLock functions defined within the primary surface and the back buffer By doing so it frees up control of the video buffer so that Windows can write to the screen Issues Unlocking the surfaces during a page flip may cause a slight animation hiccup Most of the time the user will never see this because it will happen as they are hitting ALT TAB Constraints None 30 IMAGE _ OBJ Get_Alias Narrative This function simply returns the Alias of the IMAGE_OBJ The Alias is the user given name to the surface in question Diagram Alias Interface This receives no input and simply sends the Alias back to wherever this function was called from Is
54. f the array so that the next call if there is a next call will place the new coordinate in the correct index Issues Init_Source allocates enough memory to hold a certain range of source coordinates The number of directions and the number of frames determine this If the user decides to input an additional source coordinate frame of animation without changing the number of frames member the system will attempt to load the coordinate but will fail Constraints None Set_Name Narrative This function receives a name as input The name is used to distinguish between sprites This is primary used in the GUI builder but could be used in the game itself as well The name is copied into the member Name Name Allocate Memor Diagram Interface This function receives a const char as input The function first allocates memory the size of the string sent in Once allocated the function uses strcpy string h to copy the string into the data member Name Issues None Constraints None 55 Set_X_ Velocity Narrative This function receives a velocity as input The velocity is simple the number of pixels to the left or right that the sprite will move This should default to zero The velocity sent in will simply be set to the data member X_Velocity Diagram X_Velocity o Interface This function receives a const int as input The integer represents the number of pixels to offset the current SPRITE_OBJ by
55. fectly or with all features intact after being exported from the GameForge level builder However the code should still be executable with reasonable results of Critical Components Interface Engine Main Level Editor This is the main interface and displays a graphical representation of the game level a user is designing A tree view of all created objects is also represented here All wizards and other functions can be accessed from this interface Input Wizards There are a number of wizards provided to guide the novice user through the necessary steps for game development They range from sprite generation to game logic to input devices The wizards interact directly with the user interface Exporting GameForge Files gmf Files are stored with a unique extension used exclusively by the GameForge system These files are similar to cpp files but will not be compilable They are intended as a temporary storage during game creation They are generated by the user interface Exporting VC Files cpp Finished projects can be saved as cpp files that can be compiled with Microsoft s Visual C compiler to create an executable file for the game The VC engine runs these files Object Handling The Object handler is the hub of the engine and controls all data flow through the program Draw Handling The Draw Handler controls all image processing All surfaces are created here Sound Hand
56. fically for testing purposes The level builder will be tested to ensure proper communication between the interface and the database High Order Testing The High Order testing will be performed on the complete integrated system In house beta testing will take place at this time and PA Software staff members will attempt to construct fully functional games using GameForge Public Beta Testing Parties outside PA Software will be asked to help with the final testing phase Each beta tester will be given a copy of the software and the preliminary help files these will not be completed until immediately prior to GameForge s final build Beta testers will be expected to submit bug reports and any opinions they may have concerning the software especially the interface layout 122 Expected Software Response Interface Engine Some issues are expected for more complicated game designs Flawless exporting to engine Fair performance on PII and better machines Errorless compilation of code Errorless Low error execution of code without alteration Performance Bounds General Hardware Requirements Processor PII 200 MHz System Memory 32 MB RAM Video Memory 4 MB VRAM Interface Performance Requirements Engine Robust help and tutorial files The windows based help files must be detailed enough to assist users but written clearly enough to maximize understanding especially for novice users They must be
57. fined name that will represent this surface This is so each sprite defined can be pointed to whichever surface needed via their alias Diagram Alias Allocate Memo Interface This function receive as input a const char containing the user defined alias to the current surface First memory is allocated to contain the string and then the string is copied in using strcpy found in string h Issues Resetting an alias may cause problems when using strcpy The alias may end up being not what was originally sent in Constraints The alias should be kept short but this will not be enforced as it will be simpler to just let it be the size it wants to be Since the alias is user defined and used within the data files most users will see that by 33 creating a long alias to begin with just makes them have to type more later on Set_Height Narrative This function receives as in put an integer The integer is the height of the BMP file to be loaded onto the surface It will be used to correctly specify the size of the surface so that none of the image is lost Diagram Height Interface This function receives a const int as its input The integer is simply set to the current IMAGE_OBJ s Height member Issues This will only accept integers as a value because the integer represents the number of pixels tall the image to be loaded will be Constraints None Set_Width Narrative This function receives as in p
58. function receives a const int as its input The integer is the number of frames to wait until updating the sprite s source coordinates The integer is simply set to the data member Frame_Rate Issues This method of controlling animation will be directly coupled to the computer that the game is running on The better the computer the higher the frame rate of the game the higher the frame rate of the game the faster the animation will seem We might also include a true millisecond timer based animation cycle Constraints Negative numbers could possible be used to be a stop for the animation itself This may prove useful for user controlled sprites 59 Get_Image_Index Narrative This function receives no input Its duty is to simply return the SPRITE_OBJ s image index to wherever the function was called from The image index will be used when blitting the sprite to the screen Diagram Image_Index Interface The function does nothing more than return the data member Image_Index s value to wherever it was called form Issues If the image index is undefined this function will still return a value The value returned may not correspond to an image at all and may cause the game to crash upon attempting to blit this sprite Constraints This should definitely have a default value of zero That way more that likely the index will point to SOME BMP file even though it may not be the desired one This will help to elimin
59. g filename and loads the specified WAV onto the new surface Once complete the new surface is returned Issues This function is not capable of determining how much system memory is left available Assuming that the user loads too many sounds into memory the program will most likely crash Constraints Illegal sample rates and sample qualities should be discarded and a log file should reflect the problem In this instance a sample rate of 44MHz should be used and a sample quality of 16 should be used DirectX 7 will automatically convert the sound of lesser quality to fit these parameters 74 DSound_Init Narrative Receives a hwnd as input being the window handle Using the window handle and several other predefined macros defines found in a separate header file defines h the DirectSound object is first created Once created the Cooperative level is set how to share resources with Windows The Format of the sound buffer will be set and the Primary surface is created A secondary surface sound back buffer is created for use in streaming sound files and is attached to the primary surface Diagram Predefined Macros Window Handle DirectSoundCreate SetCooperativeLevel Create Primary and Secondary Surface Interface The input to the function is a const HWND The HWND is the handle to the window that was created in another function Using the window handle a DirectSound 7 object is created The Direct
60. game it may be drowned out by the other sounds playing Constraints Due to the above issue we might consider allowing a sample pitch to be used to control the loudness of the sound being played We should also think about the possibility of streaming all sound files instead of just some sound files This will most likely be easier to program and in the long run will probably work better 76 Error Narrative Error is a very simple function that receives a string and outputs a text box to the screen specifying the error and shuts down the game Diagram Window Handle Display Message Message and Quit Program MessageBox Interface The only input is a const char containing the error message to put on screen Once on the screen the user has to click on the OK button or hit enter Once clicked the function posts a quit message and the window callback function kills the application Issues This of course causes the game to crash because it shuts down the program automatically Another function should be made to have a similar function but not shut down the program for minor errors Constraints Possibly allow the user to attempt to continue running the program in spite of the error that occurred 77 SOUND_OBJ Get_Alias Narrative This function simply returns the Alias of the SOUND_OBJ The Alias is the user given name to the sound surface in question Diagram Alias Interface
61. gic_Follow Narrative This function is a simple AI routine used solely by other creatures Static sprites will not have use for this function This function receives the X and Y position of the current sprite Using the X and Y position of the current sprite and the X and Y position of the player character the current sprite will be instructed to head towards the player character Once determined where to move an X and Y velocity are calculated and the X and Y position s of the sprite are updated From here the collision detection algorithm is called to determine if that movement caused the sprite to collide with any other object If not the function returns If so velocities are re calculated and tested again Diagram Player Position Global Generate Velocities Update Sprite Position Sprite Position Player Within Range Collision Detector Collision Found Return Coordinate Interface This function receives a const POINT as input The POINT contains the X and Y position of the current sprite These values are tested against the player character s X and Y positions and it is determined which direction the current sprite will have to move to intercept the player Once determined an X velocity and Y velocity will be calculated The velocities will be used to update the sprites X and Y position The new X and Y position s will be tested with the collision detector functio
62. he sprite Older arcade games used a similar 95 routine to have creatures hunt the player Their solution was to specify to the level designers that no closed areas are allowed for the level This should be outlined in the help files since the GUI builder user is developing the level they should be aware of this Another method to fixing this problem would be to allow the creature to back up This may or may not be more difficult than the previous solution and both ideas should be tried and tested 96 Logic_Gravity Narrative This function is a simple AI routine used solely by other creatures Static sprites will not have use for this function This function receives the X and Y position of the current sprite Based on that position the collision detection function will be called and will determine whether or not the current sprite is already colliding with a solid object from the top If so the function exits If not using the Y coordinate sent in and a predefined constant for gravity the new Y position of the sprite is calculated Diagram Until Sprites Depleted No Sprite Position Collision Collision Detector Found No Collisions Found Return Coordinate Generate Velocities Update Sprite Position Interface This function receives a const POINT as its input The POINT contains the X and Y coordinates of the current SPRITE_OBJ Using these coordinates the collision
63. ints None 71 Get_Length Narrative This function receives no input Its duty is to simply return the length of the current TEXT_OBJ to wherever this function was called from Diagram Length Interface This function simply returns the data member Length to wherever this function was called from The length is used when drawing the text message to the screen The return type is a const int Issues If the data member Length were to somehow get corrupted or was not set correctly the message when displayed on the screen could be cut short because the length would imply that the message is shorter than it actually is Constraints None Get_Visibility Narrative This function receives no input Its duty is to simply return the visibility of the current TEXT_OBJ to wherever this function was called from Diagram Visibility Interface This function simply returns the data member Visible to wherever this function was called from The visibility flag is used to determine when drawing if the text message will appear on the screen or not The return type is a const int Issues If the data member is set to invisible the text no matter if it should be on the screen or not will not be drawn on the screen Constraints None 72 Get_Trans Narrative This function receives no input Its duty is to simply return the transparency of the current TEXT_OBJ to wherever this function was called from Diag
64. ion key and represents character movement on the screen the appropriate calculations will be made using the x and y velocities If the key being pressed is an action key but does not have a predefined function the keystroke is returned to the main program so that the keystroke can be handled there Issues These predefined functions for certain keystrokes are necessary However the results they produce may not be what the user had planned on Constraints Special care has to be taken to allow for GREAT flexibility when defining the actions of the keystrokes This will be a fairly large function and should be thoroughly tested 86 Mouse_Handler Narrative This function receives the current x and y velocities of the sprite in question The role of this function is to detect how the mouse is moving and what button s is are being pressed If the mouse movement is predefined by the user as an action the appropriate action must be taken Since there is no way to define all possible actions the user may want the mouse to represent only a few actions will be predefined The predefined actions will consist of strictly moving the object up down left and right respectively Any other mouse movement that has been defined by the user as an important will be passed back to the main program so its logic can be handled there Diagram Yes Query Keyboard No Return Action Interface This function receives two const int as in
65. ling The Sound Handler controls all sound processing All sound is done in a streaming fashion 124 Input Handling The Input Handler controls all input processing All user defined movement controls are defined here Logic Handling The Logic Handler controls all game logic Sprite attributes are passed into the logic handler and are interpreted based on world attributes This includes collision detection gravity pathing etc 125 Appendices Requirements Traceability Matrix Requirement Interface easy to use by novices and advanced users Design The interface has been designed for maximum functionality but with the user s comfort in mind Requirement Creature AI reasonably advanced Design The new Logic Handler includes pathing and attribute functions that simulate creature AI Requirement Exported code from the level builder is immediately compilable Design All exported code will be compilable and most code will be executable as well for less complicated game designs Packaging and Installation Issues Installation Package GameForge will utilize Wise Installer 8 0 from Wise Solutions Inc as its software installation package Wise Installer was chosen because of the design team s familiarity with the software Licensing negotiations are still underway and should they fall through PA Software currently retains a software license for InstallShield Installation of GameForge will be completely automate
66. me The filename given will be opened If the file does not exist the function will open a file for output and will output an error message to a log file If the file opening was successful the function will continue to loop until all data from the file has been read in Within the loop the file is parsed and each piece of information is used to load an SPRITE_OBJ with all of the correct information it needs When the file is empty the file is closed No Yes Diagram Sprite Data Filename File Done Set_Attribs Set_Destination Set_Height HH Set_Width Set_Path Set_Alias Set_Name Interface This function receives a const char as input The string is the handle to a filename that contains all of the information needed to fill a SPRITE_OBJ object An attempt to open that file is made If the file exists in the specified path the program will continue If not an output file is opened and an error message is output Once a valid file is opened each line of data is read in one by one Each line will consist of an operation and an operator The operand is parsed off and the operator tells what function to use to set the data with Once an end operation has 44 been read the image counter is incremented and a new SPRITE_OBJ is created After all SPRITE_OBJ are read in from the file the loop ends and the file is closed Issues If the data file s contents are not set up correctl
67. mount of time to respond Compose in screen rather than lines When long delays are inevitable put up an indicator 119 Components Available See the MSDN Library for Microsoft Visual Basic 6 0 for a complete list of all components available UIDS description Microsoft Visual Basic 6 0 is a programming language that allows the user to quickly create complex applications for Windows without all of the overhead required using other languages It allows the user to pick from a list of practically thousands of controls and draw them on the screen These controls then have certain events methods and properties that can be set When a particular event fires the code associated with that event is executed See the MSDN Library for Microsoft Visual Basic 6 0 for a complete list of all components available including each component s properties methods and events 120 Restrictions Limitations and Constraints Performance Behavior Issues GameForge is designed to be compatible with the Microsoft Windows 9x operating system Microsoft Windows NT 4 0 and earlier versions will not be supported Windows NT only supports Microsoft DirectX up to version 3 0 DirectInput had not been implemented at this time making this version of DirectX very limited Microsoft Windows 2000 should also be compatible but is not directly supported GameForge also requires Microsoft DirectX 7 0 or above Users may also want to obtain the DirectX 7 0 SDK if
68. n Found Sprite Position Collision gt Detector Harmed By Player Interface This function receives two const int as input The integers are the X and Y position of the current SPRITE_OBJ The player s position is tested to see if it s colliding with this SPRITE_OBJ If the player sprite is colliding with the current sprite test that sprite to see if the player can harm it If so hide the current sprite by setting its visibility flag to false and set the sprite s solid flag to false as well so that the user cannot interact with is by accident Issues If the sprite that the player sprite is colliding with does not have its solid flag set there will be no way to detect if that sprite is colliding with the player sprite So regardless of whether the player should harm the current sprite it will not Constraints It might be considered to first query all sprites to determine which actually could harm other sprites Once they are determined call the collision detection function to see if a collision occurred This may speed the algorithm up a bit It may also be considered to destroy the sprite instead of simply hiding it from view This will free up memory and speed up certain processes collision detection etc 104 Logic_Score Narrative This function receives the X and Y position of the current sprite The collision detection function is called to see whether or not the playe
69. n to determine is the movement caused a collision If a collision is not detected the new position is valid and the function exits If a collision is detected new velocities are calculated bearing in mind what direction caused the collision This is sort of a bump and turn routine A direction is tested if it works then exit if not change the direction Issues None Constraints Closed areas may create some difficulty in generating the correct movement for the sprite Older arcade games used a similar 93 routine to have creatures hunt the player Their solution was to specify to the level designers that no closed areas are allowed for the level This should be outlined in the help files since the GUI builder user is developing the level they should be aware of this Another method to fixing this problem would be to allow the creature to back up This may or may not be more difficult than the previous solution and both ideas should be tried and tested 94 Logic_Flee Narrative This function is a simple AI routine used solely by other creatures Static sprites will not have use for this function This function receives the X and Y position of the current sprite Using the X and Y position of the current sprite and the X and Y position of the player character the current sprite will be instructed to move away the player character Once determined where to move an X and Y velocity are calculated and the X and Y position
70. nominal good will donation Design Metrics to Be Used PA Software will utilize two design metrics during the GameForge development process e Function Point e CoCoMo These will be used in estimating costs and development time For more detailed information regarding these estimates see the Software Project Plan document Supplementary Information Additional Information can be found at GameForge website www patheticattempts com gameforge Pathetic Attempts website www patheticattempts com 127
71. ny images into memory the program will most likely crash Constraints The function should be able to automatically convert a different bit depth BMP to the one specified when creating the DirectX 7 object 23 Ddraw_Init Narrative Receives a hwnd as input being the window handle Using the window handle and several other predefined macros defines found in a separate header file defines h the DirectDraw object is first created Once created the Cooperative level is set how to share resources with Windows The display mode is set i e 800 X 600 X 16 bit and the Primary surface is created A secondary surface back buffer is created for use in page flipping animation and is attached to the primary surface A color key is set to allow for transparent colors Finally a clipper is attached Diagram Predefined Macros Window Handle SetCooperativeLevel SetDisplayMode Create Primary and Attach Clipper Secondary Surface Interface The input to the function is a const HWND The HWND is the handle to the window that was created in another function Using the window handle a DirectDraw 7 object is created The DirectDraw 7 Object is the base object for all other drawing surfaces to be attached to After the object is created it can be used for drawing and animation using calls defined within the DirectDraw 7 object Issues If the user does not have DirectX 7 installed on his her machine and their c
72. ollbar this function handles how the user is interacting with the scrollbar Scrolling up moves the data up scrolling down moves the data down This is done by interpreting how the user is interacting with the scrollbar and changing the top and left coordinates of the image by some pixel value depending on how much the user moves the bar Diagram ScrollBar Direction of Movement New Position Interface The function interfaces with the object that the scrollbar is linked to It changes the way the information is displayed in that particular object Issues If the function is not handled correctly the data in the object linked to the scrollbar may not be displayed in the manner intended Constraints All scrollbars must be associated with the proper object s or the proper output may not be displayed 14 MnuFileNew_Click Narrative Receives no input It s job is to load the correct interface wizard to allow the user to create a new project The user will then be able to use this new interface to input data that the program will use to create the final product Diagram Interface The function interfaces with the wizard that will prompt the user for the information needed to produce the final output of the program Issues The user should be ready to lose all information that GameForge currently has open Constraints All data currently open will be lost if the user is not prompted to save current open
73. ompiler is not linking to the correct DirectX 7 files this function will not even compile If the user tries to set the display mode to something odd the function will crash Constraints The GUI will have to limit the choices the user can make for the display mode so that no strange entries can be made that will make the system crash 24 Draw_Surface Narrative Receives a surface a point and a rectangle The surface is the surface that will be used for the graphic itself The image has a BMP loaded onto it so that using the rectangle sent in a portion of the BMP file can be grabbed at a time instead of using the entire image The point sent in is used to determine where on the screen will the chunk of the BMP file be drawn So essentially a chunk of the surface is grabbed and is repainted onto another surface at the specified coordinate Diagram Back Buffer Surface Point and Rectangle Interface A DirectDraw 7 surface is sent in as well as a const POINT and a const RECT The DirectDraw 7 surface contains a specific BMP file already loaded onto it Since only a portion of the BMP file is wanted the const RECT sent in specifies what portion of the BMP to draw The const POINT is used to reposition that portion to a specific area on the screen In order to do so this function has to interface with the back buffer we created in Ddraw_Init Issues The more sprites on the screen the more often this function
74. ows chooses the current font for use when drawing the text So only the current Windows font will be drawn Constraints Text should be drawn last over every other object on the screen This is so important information is not hidden behind an on screen sprite 26 Error Narrative Error is a very simple function that receives a string and outputs a text box to the screen specifying the error and shuts down the game Diagram Window Handle Display Message Message and Quit Program MessageBox Interface The only input is a const char containing the error message to put on screen Once on the screen the user has to click on the OK button or hit enter Once clicked the function posts a quit message and the window callback function kills the application Issues This of course causes the game to crash because it shuts down the program automatically Another function should be made to have a similar function but not shut down the program for minor errors Constraints Possibly allow the user to attempt to continue running the program in spite of the error that happened 27 Flip_Surfaces Narrative Flip_Surfaces simply flips the Primary buffer and the Back buffer This allows for smooth animation from frame to frame No input is sent into the function The function first checks if the past Flip call has finished if not it simply returns Once this is done the surfaces will be flipped The
75. possible to determine unless the direction of the collision is returned 109 Software Interface Description External Machine Interfaces We have no plans to support any external machine interfaces External System Interfaces We have no plans to support any external system interfaces Human Interface The interface that we have chosen to use will be designed in Microsoft Visual Basic Version 6 The interface will utilize many of the common controls included in Visual Basic and the majority of windows based applications The interface will be a graphical user interface that provides the user with a quick and easy way to position objects and design and build a two dimensional game For a more detailed description of the interface please refer to the User Interface Design section found below 110 User Interface Design Description of the User Interface Description The interface will have on the left side of the screen a treeview control which displays elements in a directory tree structure Placed in this treeview will be categories with which the sprites that user has input will be categorized The user will be able to click on these categories and see the expanded list of the sprites that are under that particular category In addition the user will be able to click on a particular sprite and bring up all of that sprite s properties When the sprite wizard is up the right side of the screen will be the sprite s image and an are
76. put The integers are the current x and y velocities The mouse will be queried to see what movement is happening with the mouse at the moment It will check if the movement is one predefined by the user as an action movement defined in the GUI builder If the movement is an action movement and represents character movement on the screen the appropriate calculations will be made using the x and y velocities If the movement is an action movement but does not have a predefined function the movement is returned to the main program so that it can be handled there Issues These predefined functions for certain mouse movements are necessary However the results they produce may not be what the user had planned on Constraints Special care has to be taken to allow for GREAT flexibility when defining the actions of the mouse movements This will be a fairly large function and should be thoroughly tested 87 Error Narrative Error is a very simple function that receives a string and outputs a text box to the screen specifying the error and shuts down the game Diagram Window Handle Display Message Message and Quit Program MessageBox Interface The only input is a const char containing the error message to put on screen Once on the screen the user has to click on the OK button or hit enter Once clicked the function posts a quit message and the window callback function kills the application Issue
77. query all sprites to determine which actually could harm the player Once they are determined call the collision detection function to see if a collision occurred This may speed the algorithm up a bit It may also be considered to destroy the sprite instead of simply hiding it from view This will free up memory and speed up certain processes collision detection etc 102 Logic_Killed_By_Other Narrative This function receives the X and Y position of the sprite The collision detection function is called to see whether or not the current sprite is colliding with any other sprites If so those sprites are queried to determine if they can be killed by other sprites If the sprite is not set to be harmed by another sprite then the function exits If the sprite is sensitive to other sprites simply set the sprite s visible flag to false and its solid flag to false This is so that the sprite no longer exists to the player Diagram Until Sprites Depleted Sprite Position Collision Collision Harmed By Detector Found Other No Collisions Detected Interface This function receives two const int as input The integers are the X and Y position of the current SPRITE_OBJ The sprite s position is tested to see if it s colliding with any other SPRITE_OBJs If the current sprite is colliding with another sprite test that sprite to see if it harms the current sprite If so hide the c
78. r is colliding with this sprite If so the current sprite is queried to determine if the player s score will be affected by it If the players score is not affected then the function exits If the player s score is affected the player s score is updated by some fixed amount Most likely this sprite will also be eliminated but that will not always happen Diagram Player s Position Global Collision Found Affects Player s Score Sprite Position Collision Detector Update Player s Score Interface This function receives two const int as input The integers are the X and Y position of the current SPRITE_OBJ The player s position is tested to see if it s colliding with this SPRITE_OBJ If the player sprite is colliding with the current sprite test that sprite to see if the player s score is affected by it If so update the player s score Issues If the sprite that the player sprite is colliding with does not have its solid flag set there will be no way to detect if that sprite is colliding with the player sprite So regardless of whether the player s score should be affected by colliding with the current sprite it will not Constraints It might be considered to first query all sprites to determine which actually could harm other sprites Once they are determined call the collision detection function to see if a collision occurred This may speed the algori
79. ram Trans Interface This function simply returns the data member Transparent to wherever this function was called from The transparency flag is used to determine when drawing if the text message will have a filled background opaque or a clear background transparent The return type is a const int Issues If the transparency is set to true the background color that was set will have no bearing on what is actually drawn on the screen The only time the background color of the TEXT_OBJ will be seen will be when this flag is set to false Constraints None 73 SOUND_HANDLER Create_Surface Narrative Receives as input a filename and sample rate and quality Based on the sample rate and quality the appropriate DirectX 7 calls are made to allocate memory for surface creation Once the memory is set the filename is used to load the specified WAV file onto the DirectSound 7 surface Once completed creating and loading the surface the surface is returned Diagram WAV Filename Sample Rate Sample Quality DirectX 7 New Surface WAV Loaded Surface Object Loader Interface The function receives a filename const char and a sample rate and quality both const int Using these the function interfaces with the DirectX 7 Object DDObjectNew to create a new DirectSound 7 surface capable of holding a WAV file Once the new surface has been created the function opens up the specified WAV file usin
80. rative This function receives the X and Y position of the player sprite The collision detection function is called to see whether or not the player is colliding with any other sprites If so those sprites are queried to determine if they will harm the player If the sprite does not harm the player then the function exits If the sprite does harm the player update the player alive state a global variable If the player alive state is zero during the next game loop the player will lose a life If the player s lives are all lost the game is over Diagram Player s Position Global Player Loses Life Harms the Player Collision Sprite Position Collision gt Found Detector Interface This function receives two const int as input The integers are the X and Y position of the player SPRITE_OBJ The player s position is tested to see if it s colliding with any other SPRITE_OBJs If the player is colliding with another sprite test that sprite to see if it harms the player If so decrement the global variable alive so that the appropriate action can be taken next game loop Issues If the sprite that the player is colliding with does not have its solid flag set there will be no way to detect if that sprite is colliding with the player sprite So regardless of whether the sprite should harm the player it will not Constraints It might be considered to first
81. red This attempts to register the window with Windows itself If successful the application window is then created If the creation of the window is successful the window is brought to focus and the function exits If the registering or creation of the window fail the program will not run Issues The predefined window that will be created will be a full screen popup window The window will have no close or minimize buttons so there must be a keystroke that will end the application Constraints This is the function that defines the window width and height and therefore must take into account different screen resolutions This can be solved by using predefine macros and simply having the GUI of the design application make changes to the macros 37 Draw_Sprites Narrative This function receives no input Its function is to draw all of the sprites currently created on the screen in the position that they are supposed to be drawn at It contains a loop that continues until all sprites have been drawn Diagram Loops of Sprites Times Draw Draw_Sprites Interface This function has no input It uses data members that are already defined within the OBJLHANDLER The function contains a for loop that continues to loop until its reached the number of sprites that are defined Within the loop are calls to the current sprite The calls get information about what part of the image to draw and where to draw it on screen Once that inform
82. s This of course causes the game to crash because it shuts down the program automatically Another function should be made to have a similar function but not shut down the program for minor errors Constraints Possibly allow the user to attempt to continue running the program in spite of the error that happened 88 Main Program Game_Init Narrative This function receives no input Its duty is to wrap all initialization functions into one function call In most games this will never change This is the function where all sprites text messages and surfaces are loaded This means that the data files that contain the information needed by the program to create the sprites text messages and surfaces is specified here Any other things that might need initializing like initializing DirectDraw etc are also put in here Diagram Object Init_All Object Load_Images Y Object Load_Sprites Object Load_Text w Interface This function receives no input All game initialization routines are called from within this function First DirectDraw DirectInput and DirectSound are all initialized Once this is complete the sprites text messages and surfaces are all initialized These are initialized by sending in data file filenames to the functions that will know how to read the data and use that data to create the game objects This function is called once per game Issues Undefined data files will most likely cause the
83. s all drawing logic Temporary Data Structures No temporary data structures are created Database Description The database we are using is a Microsoft Access Database It will be created using Microsoft Access 97 It will hold all of the information entered by the user during the design of the game This information will be stored in the tables that are listed above in the section titled Internal Software Data Structures Architectural and Component Level Design Program Structure Architecture Diagram Images Logic Handler Input Handler Sound Handler Background Object Handler Creatures Draw Handler Background Creatures Alternative Architecture It is important to note that the proper engine architecture breaks up the Sprite structure into a number of categories allowing each of these categories to communicate directly with the Object Handler Without this breakdown a significant amount of unnecessary data must be passed back and forth through the Object Handler to parse down the Sprite information With the current design the Object Handler can easily retrieve Sprite information after receiving data requests from the other Handlers with a minimum amount of parsing It is also important to note that DDraw DSound and DInput each require surfaces buffers and objects respectively By removing these structures from their subsequent functions we can increase modularity and allow easy updating of these struct
84. sues An attempt to Get_Alias an IMAGE_OBJ that has no alias set may crash the program this should not be allowed Constraints This function must check to see if the Alias for the current IMAGE_OBJ has been set before trying to send back undefined information Get_Height Narrative This function simply returns the Height of the IMAGE_OBJ The height is the size in pixels of the surface in question Diagram Height Interface This function receives no input and simply sends back the Height to wherever this function was called from Issues If a call is made to Get_Height and no height has been defined the program may try to load an image to a surface that does not have enough memory allocated to contain that image This may cause the program to crash Constraints A check has to be made to make sure that the surface in question does have a Height associated with it 31 Get_Width Narrative This function simply returns the Width of the IMAGE_OBJ The width is the size in pixels of the surface in question Diagram Width Interface This function receives no input and simply sends back the width to wherever this function was called from Issues If a call is made to Get_Width and no width has been defined the program may try to load an image to a surface that does not have enough memory allocated to contain that image This may cause the program to crash Constraints A check has to be made to make sure that the surf
85. t Its job is to load the correct sprite on the screen Diagram Filename ImageLoader Passes Filename to LoadPicture LoadPicture Method Picture Is Loaded Into ImageBox or PictureBox Control Interface The function interfaces with the SpriteLoader function and the Open common dialog SpriteLoader passes the filename to this function Issues The file chosen must be a bitmap and the SpriteLoader function must be implemented Constraints Without the SpriteLoader function and the common dialog control the file will not be displayed The common dialog control is included in the Visual Basic application wizard 20 AttributeDefiner Narrative Function is called after the ImageLoader is done This is where the user is allowed to determine all of the attributes that a particular sprite will have Diagram AttributeDefiner User Selects Attributes Sprite Attributes Saved In Database Interface The function interfaces with the SaveDB function Data is saved to the Database after the user is done selecting attributes Issues The database must be working properly Constraints Without the SaveDB function the attributes will be lost 21 SaveDB Narrative Function is called when the user chooses Save As from the file menu or after attributes are updated The data is written to the Access database Diagram AttributesDefiner Database Written To Disk Interface The function interfac
86. ta file and add the same coordinates twice or use the GUI builder the choose that repeated frame Constraints Make sure that the function is not attempting to draw a frame that does not exist This may simply cause a hiccup in animation or could possibly crash the system 52 Set_Image_Index Narrative This function receives an index to the IMAGE_OBJ array This is so that the sprite actually has a portion of a BMP file associated with it Without this image index no graphics would be drawn on screen The index sent in is simply set to be the member Image_Index Diagram Image_Index Interface This function receives a const int as input The integer is an index to the IMAGE _OBJ array The index points to a certain surface so that at run time a graphic will be associated with the sprite Issues If the index sent in is an invalid index the game will attempt to blit from and image that is not defined This will either cause the sprite to not be drawn at all or will cause the system to crash Constraints The image index will have to be pre processed to determine whether it is indeed a valid index 53 Set_Dest Narrative This function receives a destination coordinate as input The coordinate is the pixel on the screen to draw the sprite at The coordinate sent in is simply set to the member Dest_Coord Diagram Dest o Interface This function receives a const POINT as input The POINT is actually a pixel
87. te is updated to its new destination by a certain velocity also contained within the sprite Issues While it s not necessary to update the screen destination for sprites off screen this will be done anyway The reason is simply because it does not take that much processing power to do so and it s easier to do all of the sprites instead of keeping track of which ones are on screen and which are off Constraints Some objects motion patterns will vary different from others This will have to be taken into account when writing this function This may have to call separate AI routines to update each sprite s position accordingly 49 SPRITE_OBJ Init_Source Narrative This function receives the number of directions and number of frames of animation for the spite being defined These allow the function to allocated enough memory to contain the matrix of coordinates that will be defined in a later function For example if the sprite being defined has only 1 static image then this function will allocate enough memory for only 1 coordinate This function does not actually set the coordinates it simply creates enough room to store them later on Allocate is Memory Number of Frames Times Diagram A Number of Directions Times Number of Directions lt lt Allocate Memory Number of Frames v Interface This function receives two const int as input These integers represent the number
88. tem the functions being called will not compile nor run correctly Constraints None 42 Restore Narrative Restore receives no input Its function is simply a pipeline to the Draw Restore function that actually restores lost surfaces Diagram Draw Restore Interface This function is a way to be able to restore lost surfaces from the main program without directly interacting with the Draw object The Draw object is contained within the OBJ_HANDLER and so therefore is a private member The only way to use Draw s internal function is to have a function in the OBJ_HANDLER to call the specified Draw function Issues None Constraints None Unlock Narrative Unlock receives no input Its function is simply a pipeline to the Draw Unlock function that actually unlocks the primary surface and the back buffer Diagram Interface This function is a way to be able to unlock the primary surface and the back buffer main program without directly interacting with the Draw object The Draw object is contained within the OBJLHANDLER and so therefore is a private member The only way to use Draw s internal function is to have a function in the OBJLHANDLER to call the specified Draw function Issues None Constraints None 43 Load_Sprite Narrative This function receives a string as input That string is the handle to a filename that is a data file containing information about every SPRITE_OBJ that will be within the ga
89. they plan on expanding the GameForge library files beyond their original scope GameForge also requires the Microsoft Visual C 6 0 compiler GameForge s VC code may be compilable using Borland or some other VC compiler but functionality is not guaranteed Program Limitations GameForge does not directly support two players This includes two player simultaneous and two player turn based GameForge supports only limited mouse support Users will only be able to control player movement Users will not be able to select specific sprites to gain control over that sprite GameForge only supports 800 by 600 resolution and 640 by 480 resolution both at 16 bit color depth GameForge only supports WAV files for use in sound effects Any other type of audio file i e MIDI MP3 etc will have to be converted to WAV format for use in GameForge 121 Testing Issues Classes of Tests Unit Testing Individual engine components Draw Handler Sound Handler etc will be tested separately Do to the GameForge engine s modular design there is no need for test beds All components can be tested through the Object Handler The interface will be unit tested in three parts Level editor Wizards File exporting All unit testing will be done in White Box fashion Integration Testing Combined engine components will be tested as a whole To maintain maximum control over the testing criteria all data files will be made speci
90. thm up a bit It may also be considered to destroy the sprite instead of simply hiding it from view This will free up memory and speed up certain processes collision detection etc 105 Logic_Sound Narrative This function receives the X and Y position of the current sprite Based on these positions the collision detection function is called to determine if the player is colliding with the current sprite If so the Sprite is queried to see if the sound index has been set If it has been set the sound that the index corresponds to will be played Diagram Player s Position Global Sound Defined Collision Found Sprite Position Collision y Detector Interface This function receives a const POINT as its input The POINT is the X and Y coordinate of the current SPRITE_OBJ The collision detection function is called with respect to this coordinate to determine if the player is interacting with this SPRITE_OBJ If the player is colliding with the current sprite the sprite is queried to see if the sound index has been set Ifthe sound index has been set the sound corresponding to that index will be played The function then exists Issues If the sprite that the player sprite is colliding with does not have its solid flag set there will be no way to detect if that sprite is colliding with the player sprite So regardless of whether a sound should be played when colliding with the curr
91. tures static objects Bitmaps with animation Collision Detection Areas Movement Routines Additional Object Attributes e Backgrounds e Input Device Setup e Sound Events The software will also consist of a number of graphical processing functionalities including the following e Defining Editing Objects including characteristics e Object Positioning e Opening Closing Saving Game Project Files e Exporting Game Projects to compilable C Files Outputs include e User Created Sprite Objects Bitmaps Microsoft VC with DirectX code Files Game Project Files Text Files containing sprite attributes Database Files Software Context GameForge is being marketed as a CASE tool to allow software developers to build rather than code their game It is not necessary for developers to have prior knowledge with DirectX or Visual C as long as they have a good art team and high production values GameForge will be commercially distributed via the GameForge website for information regarding the URL see the Appendix GameForge will be available free for educational use It will be distributed for use in CIS 587 Computer Game Design and Implementation at the University of Michigan Dearborn Major Constraints Performance Behavior Issues GameForge is designed to be compatible with the Microsoft Windows 9x operating system Microsoft Windows NT 4 0 and earlier versions will not be supported Windows NT only supports
92. ures without affecting their functions Engine State Transition Diagram Collision User Input Invoke Update Invoke Logic Update Health Lives Read User Input Action From User Invoke Read Input Sprites Updated Handle Logic apies plated collisions etc lavoke Logic Logic Complete Invoke Output Player Death Invoke Player Death Output Complete Output Sprites Invoke Update Monitor and Speakers Update Sprites Reset to Menu Invoke Update Sprites Final Death Invoke Game Over Handle Player Death Lives Left Invoke Update Sprites Level Over Invoke Level Over Final Level Invoke Game Complete Reset to Menu Invoke Update Sprites Game Complete Levels Left Invoke Update Sprites Engine Data Flow Diagram Sprite Array Sprite and Game Data Sprites Images and Messages Flipped Surfaces Draw Handler Handle Logic 10 World Builder Entity Relationship Diagram ERD Frames c Ea Category W Are Is Contained Contained Image name a Sprite Creates lt j Spritelnstance W i Made a 11 World Builder Data Flow Diagram User Interface User Input Sprite Sprite Imagery Bitmaps Create Sprite Wave Files Sound FX and Music Ree Soe Database Database User Interface User Input Store in Info Datab Info Flat Text Game
93. urrent sprite by setting its visibility flag to false and set the sprite s solid flag to false as well so that the user cannot interact with is by accident Issues If the sprite that the current sprite is colliding with does not have its solid flag set there will be no way to detect if that sprite is colliding with the current sprite So regardless of whether the sprite should harm the current sprite it will not Constraints It might be considered to first query all sprites to determine which actually could harm other sprites Once they are determined call the collision detection function to see if a collision occurred This may speed the algorithm up a bit It may also be considered to destroy the sprite instead of simply hiding it from view This will free up memory and speed up certain processes collision detection etc 103 Logic_Killed_By_Player Narrative This function receives the X and Y position of the current sprite The collision detection function is called to see whether or not the player is colliding with this sprite If so the current sprite is queried to determine if the player will harm it If the player cannot harm the sprite then the function exits If the player can harm the sprite simply set the sprite s visible flag to false and its solid flag to false This is so that the sprite no longer exists to the player Diagram Player s Position Global Remove Sprite Collisio
94. used from the velocity will be reversed Once reversed the sprite s position is updated and the function exits Diagram Until Sprites Depleted Generate Velocities Collision Sprite Position Collision y Found Detector No Collisions Found Update Sprite Position Return Coordinate Interface This function receives a const POINT and a const int as its input The POINT contains the X and Y position of the current SPRITE_OBJ The integer is the relative velocity Based on the coordinate and the velocity a new X and Y position is calculated Once calculated the collision detection algorithm is called to see if the new coordinate caused a collision If not the function exits If so a new coordinate is calculated based on the negative velocity and the direction that caused the collision Once the new coordinate is calculated the function exits Issues If the collision detection algorithm is not functioning correctly this may falsely detect a collision and reverse the current sprite for no reason It may also not detect an actual collision and the sprite would pass through a solid object If somehow the sprite in question were to get caught inside of another sprite s collision area the current sprite would continue to bounce back and forth within the object Constraints None 99 Logic_Friction Narrative This function receives the X and Y velocity of the current
95. ut an integer The integer is the width of the BMP file to be loaded onto the surface It will be used to correctly specify the size of the surface so that none of the image is lost Diagram Width Interface This function receives a const int as its input The integer is simply set to the current IMAGE_OBJ s Width member Issues This will only accept integers as a value because the integer represents the number of pixels wide the image to be loaded will be Constraints None 34 Set_Path Narrative This function receives as input a string The string the filename and path of the filename of the BMP file to be loaded onto the surface The string is set to the IMAGE_OBJ Path member Diagram Path Allocate Memor Interface This function receives a const char as its input First enough memory is allocated to contain the string Then the string is simply set to the current IMAGE _OBJ s Path member This will be used later to load the surface with the specified filename Issues Resetting a path may cause problems when using strcpy The path may end up being not what was originally sent in This may in turn cause problems when loading the BMP file to the surface Constraints The path should contain a BMP extension If the path specified does not contain BMP then the path is invalid and an error should be output 35 Set_Surface Narrative This function receives as input a pointer to a DirectX 7 surface
96. veLevel O Interface This function attaches a keyboard device to the DirectInput object Once attached the keyboard can be used as input for the game First the input device is created specifying that the device type is a keyboard Once created the cooperative level is set Once that is set the keyboard is acquired Now the keyboard is ready for use If any of the past steps failed the keyboard will not work correctly or at all during the game Diagram Issues The user must have the device the game expects attached to the computer prior to running the game or the game will not work correctly Constraints The cooperative level should be set fairly low so that if the user ALT TAB s out of the game Windows will regain control of the keyboard If this were not done its very possible that Windows would lock up 84 Mouse_Init Narrative This function receives no input Its duty is to query the mouse as one of the input devices for use in the game The mouse can then be used as an input device to interact with objects in the game Diagram CreateDevice SetDataFormat SetCooperativeLevel Interface This function attaches a mouse device to the DirectInput object Once attached the mouse can be used as input for the game First the input device is created specifying that the device type is a mouse Once created the cooperative level is set Once that is set the mouse is acquired Now the mouse is ready for use
97. white on the screen This will only be a problem if the background color is specified as white as well Get_BkColor Narrative This function receives no input Its duty is to simply return the current TEXT_OBJ s background color to wherever this function was called from Diagram BkColor Interface This function simply returns the data member BkColor to wherever this function was called from The color is used as the background color of the text message to be drawn The return type is a const COLORREF Issues If the color depth of the game is anything but 16 bit color Windows will automatically convert the color to fit the specified color space Constraints Default color should be set to 0 0 0 so that by default the message will appear on a black background on the screen This will only be a problem if the foreground color is specified as black as well 70 Get_Message Narrative This function receives no input Its duty is to simply return the current TEXT_OBJ s message to wherever this function was called from Diagram Message Interface This function simply returns the data member Message to wherever this function was called from The message is the actual string that will be output to the screen The return type is a const char Issues If the data member Visible is set as false the text message returned will not actually appear on the screen actually it will not be drawn at all Constra
98. will be called Since this function is literally copying large chunks of memory from on surface to another this function is not the fastest So if there are an extreme number of sprites on screen the game itself may suffer from a performance hit Constraints Due to the above issue a clipper will have to be attached so that sprites outside of the screen will not be drawn and calls to this function will not happen nearly as often 25 Draw_Text Narrative Receives a Text Object as the only input Using information within the text object the message itself and the orientation on screen the text will be output to the back buffer surface A background color and a foreground color are also defined within the text object as well as whether the text is visible This allows the user to be able to turn off the text Diagram Back Buffer Message TEXT_OBJ Interfaces A TEXT_OBJ is sent in as the only parameter This function interfaces with that object in order to draw it to the back buffer Within the object itself are the message the background and foreground colors the coordinate to draw it at and whether the background is visible or whether the text is visible at all Once it is determined that the text is visible the text is drawn to the back buffer using a routine defined within the back buffer surface Issues This is a fairly limited text handler because one cannot change the font that it draws Wind
99. y by the GUI builder or if the user edits the data file incorrectly some or all of the information in the file will not be loaded correctly This could end up in undefined SPRITE_OBJ s and cause problems in loading sprites correctly or at all If the user decided to change the BMP files in any way i e resizing or changing position of entities within the data file would have no way of knowing this This means that the user would have to hand edit the data file to compensate for the changes or the data file would have to be re edited by the GUI builder If the user wants to hand edit the data file they will have to be aware of the correct syntax expected by this function Complete syntax knowledge with examples should be easily accessible in the help files The string handling in C is something left to be desired With a more flexible language the data files could be more fault tolerant than they will be but with the limited string handling and file streaming of C the data files will have to be very correct Constraints The file handling part will have to be somewhat flexible to allow for added white space This is essential All users have different ideas of how separate items should be spaced and therefore this function will have to take that into account 45 Load_Text Narrative This function receives a string as input That string is the handle to a filename that is a data file containing information about every TEXT_

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