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Method for authoring hints for a font using a graphical user interface

1. U S Patent Apr 22 2003 Sheet 16 of 17 US 6 552 727 B2 FIG 11A FIG 11B yu U S Patent Apr 22 2003 Sheet 17 of 17 US 6 552 727 B2 FIG 11C 1100 FIG 11D E IE E Db Tp d US 6 552 727 B2 1 METHOD FOR AUTHORING HINTS FOR A FONT USING A GRAPHICAL USER INTERFACE CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation of prior application Ser No 09 049 633 filed Mar 27 1998 now abandoned which is incorporated herein by reference herein FIELD OF THE INVENTION This invention relates in general to authoring hints for a font and in particular to authoring hints for a font using a graphical user interface BACKGROUND OF THE INVENTION A font is a particular style of typeface such as Arial Times New Roman or Courier Fonts which conform to the Tru eType Open font standard promulgated by Microsoft Corporation assignee of the present invention are com monly referred to as TrueType fonts TrueType fonts contain font tables that include data such as glyph outlines metrics bitmaps and mapping information A glyph outline is a set of mathematical data that describes the shape of the glyph A glyph is a representation of one or more characters A single glyph may represent a single character such as the lowercase letter or a single glyph may represent a string of characters such as the ligature fi To displ
2. 63 3 1908 now dot 09049633 Aled Mar 74 Attorney Agent or Firm Banner amp Witcoff Ltd 51 Int Cl sess GO6T 11 00 57 ABSTRACT 2 6 oe S oe h Qu EM 47 ae Authoring hints for a font using a graphical user interface 58 Field o T 047 048 Graphical hints may be dragged and dropped on a displayed 469 P 2 T 2 glyph using a graphical user interface A graphical hint is 56 References Cited specified by selecting a hinting tool and selecting one or U S PATENT DOCUMENTS 5 155 805 A 10 1992 Kaasila 5 325 479 A 6 1994 Kaasila 5 583 978 A 12 1996 Collins et al 5 586 241 A 5 673 371 A 12 1996 9 1997 Bauermester et al Koopman et al 202 more points that define the glyph outline such as a control point A graphical hint is represented by a graphical element displayed on the glyph The graphical hint can be automati cally compiled and included in a font table The compiled graphical hint is used to display the hinted glyph 57 Claims 17 Drawing Sheets 2 200 Times Regular gana e e 80 char 0460 LOWERCASE 12 pt 16 ppen grid fitted pixels device units 220 222 InnmnonomoommmThe quick brown fox jumps over the lazy dog 206 InnmnonomoommmThe quick brown fox jumps over the lazy dog E 204 224 H 226 228 230 711 2327 2347T
3. 23671 2387T 24071 208 24221 244 E 246 24871 gt 2507 25277 EE V 25677 25871 2607 26271 264 210 266 EE L ommmmmmmmmmmmmmmmmummmm mm 26877 E Bin 16 18 2 26 8 30 32 38 24 ri ie 5 US 6 552 727 2 Sheet 1 of 17 Apr 22 2003 U S Patent YALNd WOO 310N3H YOLINOW LV Sis MHOMLAN SNVvu9Oud SNOILVONMddV 96 JOVdH3lNI MYOMLAN ASNOW dildV Vv vlvd S3 INGOW NOILYOFIddV ONLLNIH NOILVOMddV WALSAS ONIL Vd3dO 86 LE U S Patent Apr 22 2003 Sheet 2 of 17 US 6 552 727 B2 am FIG 2 SIS 220 220 224 22677 ME 228 230 ND Oo IN Oc E ES 264 E 16 18 00 202 4 6 05 30 32 34 U S Patent Apr 22 2003 Sheet 3 of 17 US 6 552 727 B2 FIG 3A US 6 552 727 2 Sheet 4 of 17 Apr 22 2003 U S Patent mi SNOILdO SONVLSIC 5 NOILOSYIG A i
4. 724 and 726 728 730 with rounded arrowheads at the child control points 704 706 and 710 712 and a rounded tail at the parent control points 702 708 and 702 714 An alignment can be modified to specify a different parent control point or a different child control point To specify a new parent control point the typographer selects the align tool selects the tail of the arrow associated with the parent control point and drags the tail of the arrow to a new parent control point To specify a new child control point the typographer selects the align tool selects the arrowhead of the arrow associated with the child control point and drags the arrowhead to a new child control point To delete an align the typographer drags the rounded arrowhead off the child control point The Angle Tool The angle tool allows the typographer to specify the stroke angle for an italic font To specify a stroke angle the typographer selects the angle tool 236 of FIG 2 from the toolbar Typically once the angle tool is selected the cursor changes into a protractor The typographer selects a point usually the left side bearing point and a straight line appears The straight line rotates as the typographer drags the angle tool to specify the desired angle The stroke is represented by a graphical character such as a sloped line 802 as shown in FIG 8 FIG 8 shows the stroke angle of an italic lowercase 800 Exception Tools At some point
5. A first graphical element is displayed in step 1056 For the stroke the first graphical element is an arrow connecting the first control point and the second control point The typographer then selects a third control point in step 1058 and drags the stroke tool to select a fourth control point in step 1060 The third control point and the fourth control point are equivalent to the second parent child pair discussed above in connec tion with the stroke tool A second graphical element is displayed in step 1062 For the stroke the second graphical element is an arrow connecting the third control point and the fourth control point A third graphical element is then displayed in step 1064 For a stroke the third graphical element is a series of parallel lines between the two arrows FIG 10E corresponds to a hint involving a single control point such as a move exception or a delta exception As shown in FIG 10E the typographer selects a hinting tool in step 1070 For example the typographer can select the delta exception hinting tool from the toolbar If the typographer selects the delta exception tool the cursor changes into a double headed arrow as discussed above in connection with the delta exception tool The typographer selects the first control point in step 1072 A graphical element is displayed in step 1074 For the delta exception the graphical element is a triangle located near the first control point In summary the present inve
6. arrow having a tail and an arrowhead the tail connected to the first selected control point and the arrow head connected to the second selected control point and wherein the step of receiving a modified graphical hint comprises receiving a selection of the arrowhead of the arrow and a third selected control point and displaying a modified graphical element representing the modified graphical hint connecting the first selected control point and the third selected control point US 6 552 727 B2 21 31 The method of claim 24 wherein the step of receiving a graphical hint further comprises receiving a control value associated with the graphical hint 32 A method for graphically authoring hints for a font using a graphical user interface comprising the steps of displaying a glyph of the font the glyph having a plurality of control points receiving a hinting function by receiving a selection of a displayed graphical hinting function receiving a selection of a first displayed control point of the glyph and a selection of a second displayed control point of the glyph displaying a first graphical element connecting the first control point and the second control point on the displayed glyph wherein changes in a control value associated with the graphical hinting function can be automatically coded and compiled receiving a selection of a third displayed control point of the glyph displaying a second graphical element r
7. hinting function 56 A method for graphically authoring hints for a font using a graphical user interface comprising the steps of displaying a glyph receiving a graphical hint by receiving a selection of a displayed graphical hinting tool displaying a graphical element representing the graphical hint on the glyph that indicates a flexibility associated with the graphical hint receiving an option for the graphical hint wherein changes to a control value associated with the graphical hint can be automatically coded and compiled displaying a component of the graphical element repre senting the option applying the graphical hint and the option to the glyph and displaying the glyph showing the application of the graphical hint and the option 57 The method of claim 56 wherein the option is a control value option
8. in FIG 4A a band 402 appears connecting the two parent control points 404 406 The typographer selects the band 402 and drags the band to the child control point 408 Once the child control point 408 is selected the band 402 changes into a graphical element representing the interpolation For example the interpolation shown in FIG 4B is represented by a pair of arrows 410 412 Each arrow has a tail at the parent control point and an arrowhead at the child control point The arrows are white to indicate the highly flexible nature of the interpolation An existing interpolation can be modified to specify different parent control point s or different child control point s To modify a parent control point the typographer selects the interpolate tool selects the tail of the arrow associated with the parent control point and drags the tail of the arrow to a new parent control point To modify a child control point the typographer selects the interpolate tool selects an arrowhead associated with the child control point and drags the arrowhead to a new child control point The arrowhead of the other arrow is automatically moved to the new child control point Automatically moving the arrow head to the new child control point prevents the illegal interpolation of a child control point with only a single parent control point To delete an interpolation the typographer selects the interpolate tool from the toolbar selects the arrowhead of
9. specified by editing the stem start and stem stop fields of a menu One drawback of the Fontographer program is that the hinting tools are limited The TrueType instruction set includes many hinting instructions which are not supported by the Fontographer program For example the Fontogra pher program does not support interpolations or alignments Another drawback of the hinting tools provided by the Fontographer program is that hints must be specified in coordinates For a TrueType font it is more efficient to specify a hint using a control value A control value is a value for a dominant width length or angle of a group of features such as the stem width or serif length Control values are stored in a font table commonly referred to as a control value table cvt Some control values are specific to certain glyphs while other control values apply to the entire font Requiring hints to refer to control values makes it easier to preserve regularity between the glyphs of the font Yet another drawback of the Fontographer program is that it displays hints outside the glyph outline Displaying hints outside the glyph outline makes it difficult to identify the control points associated with a hint Furthermore Fontog rapher does not have a built in rasterizer so a typographer cannot immediately see how a hint affects the appearance of a rendered glyph The lack of a built in rasterizer makes it difficult to fine tune pixel patterns and
10. stroke weights Accordingly there is a need in the art for a method for authoring hints for a glyph using a graphical user interface US 6 552 727 B2 3 There is also a need in the art for a graphical method for authoring hints using control point values SUMMARY OF THE INVENTION The present invention meets the needs described above by permitting a typographer to drag and drop graphical hints on a displayed glyph using a graphical user interface The graphical user interface provides the typographer with a number of hinting tools which correspond to hinting func tions The typographer specifies a graphical hint by selecting a hinting tool and selecting one or more points that define the glyph outline such as a control point The graphical hints are represented by graphical elements displayed on the glyph The shape and color of the graphical elements indicate the type of hinting function Options for the graphical hints are represented by graphical components The graphical hints are compiled and placed in the font tables without requiring that the typographer manually code the hints Once the graphical hints for a glyph are compiled the hinted glyph is displayed If the appearance of the hinted glyph is not satisfactory then the typographer can modify the existing graphical hints or add additional graphical hints until the appearance of the hinted glyph is satisfactory The typographer can modify an existing graphical hint by selec
11. 012 the hinted glyph is displayed Typically the selected glyph is displayed using the bitmap display option The hinted glyph is reviewed in step 1014 If the appearance of the hinted glyph is not acceptable then the No branch is followed from step 1014 back to step 1008 Steps 1008 1010 and 1012 are repeated until the appearance of the hinted glyph is acceptable The typographer may add addi tional hints or modify or delete the existing hints to achieve the desired appearance Once the appearance of the hinted glyph is acceptable the method proceeds along the Yes branch from step 1014 to step 1016 In step 1016 a 10 15 20 25 30 35 40 45 50 55 60 65 16 determination is made as to whether the font is completely hinted If additional glyphs of the font need to be hinted then the method follows the No branch back to step 1006 and another glyph is selected Glyphs are selected until all the glyphs of the font are hinted Once the determination in step 1016 is that all the glyphs of the font are hinted then the method follows the Yes branch and the method ends at step 1018 The steps for hinting a font are shown in FIG 10A The method begins at step 1000 and proceeds to step 1002 In step 1002 the font is loaded Loading the font typically includes loading the necessary font data and stripping any hints previously created Once the font is loaded the typog rapher completes the cvt in step 1004 The st
12. 6a other program modules 37 and program data 38 A user may enter commands and information into the personal computer 20 through a keyboard 40 and pointing device such as a mouse 42 Other input devices not shown may include a microphone joystick game pad satellite dish scanner or the like These and other input devices are often connected to the processing unit 21 through a serial port interface 46 that 15 coupled to the system bus but may be connected by other interfaces such as a game port or a universal serial bus USB A monitor 47 or other type of display device is also connected to the system bus 23 via an interface such as a video adapter 48 In addition to the monitor personal computers typically include other periph eral output devices not shown such as speakers or printers The personal computer 20 may operate in a networked environment using logical connections to one or more remote computers such as a remote computer 49 The remote computer 49 may be a server a router a peer device or other common network node and typically includes many or all of the elements described relative to the personal computer 20 although only a hard disk drive 50 has been illustrated in FIG 1 The logical connections depicted in FIG I include local area network LAN 51 and a wide area network WAN 52 Such networking environments are commonplace in offices enterprise wide computer networks intranets and the In
13. Attributes and relationships are typically represented by graphical elements For example a link can be represented by an arrow The graphical element provides the typographer with information about the hint Preferably the head of the arrow is connected to a child control point and the tail of the arrow is connected to a parent control point The color of a graphical element indicates the flexibility of the relation ship For example a white arrow indicates a high degree of flexibility an arrow filled with lines indicates a medium level of flexibility and a solid arrow indicates a low degree of flexibility The orientation of the graphical element indi cates the hinting direction For example an arrow with a horizontal arrowhead indicates that the hint is applied in the x direction whereas an arrow with a vertical arrowhead indicates that the hint is applied in the y direction Addi tional information regarding options for the graphical hint is provided by graphical components For example a graphical component can indicate the cvt number associated with the hint or the minimum distance option associated with the hint The typographer can modify the attributes relationships or options using the graphical element and or the graphical components For example selecting the head of the arrow representing a hint allows the typographer to select a new child control point Selecting the tail of the arrow represent ing a hint allows the typ
14. Ay Ka a H 5 all sU 2 m 2 9 2 E SNOILdO 3ONVISIO 5 NOILOAYId X d U S Patent Apr 22 2003 Sheet 5 of 17 US 6 552 727 B2 U S Patent Apr 22 2003 Sheet 6 of 17 US 6 552 727 B2 X DIRECTION Y DIRECTION ROUNDING ROUNDING OPTIONS OPTIONS U S Patent Apr 22 2003 Sheet 7 of 17 US 6 552 727 B2 U S Patent Apr 22 2003 Sheet 8 of 17 US 6 552 727 B2 FIG 7 702 700 U S Patent Apr 22 2003 Sheet 9 of 17 US 6 552 727 B2 FIG 8 802 800 U S Patent Apr 22 2003 Sheet 10 of 17 US 6 552 727 B2 U S Patent Apr 22 2003 Sheet 11 of 17 US 6 552 727 B2 1000 FIG 10A 1004 COMPLETE CVT 1006 SELECT A GLYPH 1008 HINT SELECTED GLYPH 1010 1002 COMPILE HINT S 1012 DISPLAY HINTED GLYPH 1014 APPEARANCE OF HINTED GLYPH SATISFACTORY YES NO IS FONT 1016 COMPLETELY HINTED YES END 1018 U S Patent Apr 22 2003 Sheet 12 of 17 US 6 552 727 B2 FIG 10B U S Patent Apr 22 2003 Sheet 13 of 17 US 6 552 727 B2 1042 SELECT FIRST CONTROL POINT SELECT SECOND CONTROL POINT GRAPHICAL ELEMENT IS DISPLAYED U S Patent Apr 22 2003 Sheet 14 of 17 US 6 552 727 B2 FIG 10D SELECT HINTING TOOL 1050 i T m U S Patent Apr 22 2003 Sheet 15 of 17 US 6 552 727 B2
15. The size run 210 displays the selected glyph at different point sizes The selected glyph may be displayed using a variety of glyph display options The glyph display options include displaying the glyph outline displaying the control points and or displaying the pixels for the selected glyph The glyph outline the control points the glyph bitmap the pixels and the pixel centers are displayed for the selected glyph shown in FIG 2 The toolbar shown in FIG 2 contains viewing tools control point tools hinting tools and display tools The tools are program modules that are associated with the hinting application program 36a of FIG 1 The display tools include snap shot 264 jump back 266 and size run 268 tools The viewing tools include tools for panning 220 measuring 226 and zooming 222 224 The control point tools include tools for moving 228 swapping 230 deleting 232 or adding 234 a control point The hinting tools include tools for linking 238 240 shifting 242 244 interpolating 246 248 aligning 250 moving 256 258 and deltaing 260 262 as well as tools for specifying an angle 236 and a stroke 252 The tools also may be accessed via menus not shown or keystroke combinations For example the display tools can be accessed via menus and the viewing tools can be accessed via keystroke combinations Additional tools and options are also available via menus For example the typographer can control which graphical hints
16. US006552727B2 United States Patent 12 10 Patent No US 6 552 727 B2 Stamm 45 Date of Patent Apr 22 2003 54 METHOD FOR AUTHORING HINTS FOR A 5 710 880 A 1 1998 Howlett et al FONT USING A GRAPHICAL USER 5 715 473 A 2 1998 Reed INTERFACE 5 777 627 A 7 1998 Takazawa 6 144 765 11 2000 Tamura et al 345 467 75 Inventor Beat Stamm Kirkland WA US OTHER PUBLICATIONS signee Microsoft Corp Redmond ontLab Powr typography Copyright ontLab Devel 73 Assi Mi ft C Redmond WA US FontLab P hy C ight 1997 FontLab Devel opers Group pp 110 111 135 137 361 143 145 Notice Subject to any disclaimer the term of this 185 188 197 198 225 240 and 255 328 patent is extended or adjusted under 35 Macromedia Fontographer user s Manual Version 4 1 374 U S C 154 b by 0 days Ed Copyright 1996 by Macromedia Inc pp 123 351 296 314 332 and 357 359 21 Appl No 09 961 418 Microsoft True Type Editor TTED Ted User Guide Ted Talk Language Guide Revision 1 0 Copyright 1996 22 Filed Sep 25 2001 Microsoft Corporation pp 1 74 65 Prior Publication Data IBM Technical Disclosure Bulletin article titled User Inter face 2 level Selectable Error Message Display during Drag US 2002 0033824 A1 Mar 21 2002 Drop vol 37 No 8 Aug 1994 Related U S Application Data cited by examiner iiu Bags Primary Examiner Mano Padmanabhan 63 Continuat f lication No 09 049 633 filed Mar
17. a toolbar and a selected glyph in accordance with an embodiment of the present invention FIG 3A is an illustration of links applied to a selected glyph in accordance with an embodiment of the present invention US 6 552 727 B2 5 FIG 3B is an illustration of the x direction and y direction stroke and minimum distance options in accor dance with an embodiment of the present invention FIGS 4A and 4B are illustrations of an interpolation applied to a selected glyph in accordance with an embodi ment of the present invention FIG 5 is an illustration of the x direction and y direction rounding options in accordance with an embodiment of the present invention FIG 6 is an illustration of strokes applied to a selected glyph in accordance with an embodiment of the present invention FIG 7 is an illustration of alignments applied to a selected glyph in accordance with an embodiment of the present invention FIG 8 is an illustration of an angle applied to a selected glyph in accordance with an embodiment of the present invention FIG 9 is an illustration of a delta exception applied to a selected glyph in accordance with an embodiment of the present invention FIGS 10A 10B 10C 10D and 10E are flow diagrams illustrating the steps for hinting a font using a graphical user interface FIGS 11A 11B 11C and 11D are illustrations of the application of the steps of FIG 10A and 10B in accordance with an embod
18. a vertical line with opposite pointing arrowheads on either side of the line e g 358 365 For the option of ignoring a minimum distance when the default option would maintain a minimum distance the elevator door symbol is a close door symbol a vertical line with arrowheads on either side of the line that point towards the line e g 366 373 The minimum distance override option can be represented by a graphical component dis US 6 552 727 B2 11 played near the graphical element for the link Typically the graphical component is an elevator door symbol In addition to specifying a stroke category option and a minimum distance option the menus shown in FIG 3B also permit the typographer to specify a cvt value for the link To specify a cvt value the typographer selects an option that includes a highway sign e g 352 357 360 365 and 368 373 If the link does not refer to cvt value then the typographer selects an option without a highway sign e g 350 351 To indicate that the link refers to a cvt value a graphical component such as a highway sign is displayed For example as shown in FIG 3B links 302 304 306 308 310 and 312 include highway signs 330 332 334 336 338 and 340 displaying the cvt numbers for the links If the link does not refer to a cvt value then the link is a distance A distance does not relate to any other glyph in the font Because a distance does not refer to a value the graphical el
19. are displayed on the selected glyph The typographer can choose to display only x direction hints or only y direction hints Typically a typographer hints in one direction at a time so limiting the displayed hints to only the x direction hints or only the y direction hints makes it easier for the typographer to see the existing hints Display Tools The display tools control what is displayed in the main window 200 The snap shot tool 264 creates a copy of the main window which is unaffected by subsequent changes to the selected glyph 208 The jump back tool 266 allows the typographer to switch between the last two glyphs selected using the Go to Glyph Character command Typically the Go to Glyph Character command is available via a menu The size run tool 268 allows the typographer to enable or disable the display of the size run 210 and the sample text 206 10 15 20 25 30 35 40 45 50 55 60 65 8 Viewing Tools The viewing tools allow the typographer to control the view of the selected glyph The panning tool 220 allows the typographer to precisely control the distance the selected glyph 208 is moved The zoom in tool 222 and the zoom out tool 224 allow the typographer to resize the view of the selected glyph 208 The zoom in tool 222 may be used to enlarge the view of the selected glyph 208 and the zoom out tool 224 may be used to reduce the view of the selected glyph 208 The measuring tool 226 may be u
20. ase 1100 As shown in FIG the bitmap has dent in both the upper and lower bowls of the The dent in the upper bowl is attributed to the activation of pixel 1101 and the dent in the lower bowl is attributed to the activation of pixel 1103 To eliminate the dent in the lower bowl the typographer hints the selected glyph by interpolating as shown in FIG 11B and 11C The typogra pher interpolates by selecting a first control point 1104 and second control point 1106 Once the typographer selects the two control points a band 1102 appears between the two control points 1104 1106 as shown in FIG The typographer selects the band and drags the band to the third control point 1108 Once the third control point 1108 is selected the band changes into a pair of arrows 1110 1112 as shown in FIG 11C Although FIG 11B and 11C show the typographer hinting the glyph outline the typographer could choose to hint the bitmapped glyph instead To see the effect of the interpolation the hint must be compiled Once the hint is compiled the bitmap of the hinted glyph 15 displayed as shown in FIG 11D The bitmap shown in FIG 11D shows that the interpolation eliminated the dent in the lower bowl by deactivating pixel 1103 as well as eliminating the dent in the upper bowl by deactivating pixel 1101 FIG 10C corresponds to creating a relationship between two control points such as a link or a shift As shown in FIG 10C th
21. at least one control value associated with the graphical hint can be automatically coded and com piled displaying a component of the graphical element repre senting the option applying the graphical hint and the option to the glyph and displaying the glyph showing the application of the graphical hint and the option 37 The method of claim 36 wherein the graphical element comprises an arrow having an arrowhead and wherein the step of receiving an option for the graphical hint comprises detecting an input comprising a shift key in combination with the arrowhead and receiving the option 10 15 20 25 30 35 40 45 50 55 60 65 22 38 The method of claim 37 wherein the option is a stroke category option 39 The method of claim 37 wherein the option is a minimum distance option 40 The method of claim 36 further comprising the step of modifying the option by detecting an input comprising a shift key in combina tion with the component and receiving a modified option 41 The method of claim 40 wherein the option is a control value option 42 The method of claim 36 wherein the graphical element comprises an arrow connecting a first control point and a second control point the arrow having an arrowhead at the second control point and wherein the step of receiving an option for the graphical hint comprises detecting an input comprising a shift key in combination with the s
22. ay or print a glyph the glyph outline is first scaled to the selected font size and the resolution of the output device The scaled glyph outline is then digitized or scan converted to create a bitmap Finally the bitmap is rendered on an output device such as a monitor or a printer using a regularly spaced grid of picture elements pixels Scaling the glyph outline may not produce satisfactory results at all point sizes At small point sizes a low resolution device may not have enough pixels to fill in the outline accurately To compensate for the lack of pixels hints or font instruc tions are added to the font to improve the appearance of the glyph Hints typically control distances proportions and pixel patterns For a TrueType font a typographer may specify hints for the entire font or for individual glyphs using an assembly type language The typographer may use the low level TrueType Instruction Set or a high level abstraction of the TrueType Instruction Set such as Type Man Talk Creating hints using one of the TrueType languages is often a tedious process To begin creating hints for a glyph the typographer typically prints a glyph outline for the glyph The glyph outline includes control points which define the shape of the glyph The typographer uses the glyph outline to visualize critical relationships between the control points such as the distance in the x direction between two control points or the distance in the
23. bles Typically the typographer then hints the refined glyphs US 6 552 727 B2 9 During the hinting process if the typographer decides to further refine a glyph outline then the typographer can use the control point tools to modify the control points of the glyph Hinting Tools The hinting tools allow the typographer to author hints by dragging and dropping graphical hints on a selected glyph Dragging and dropping graphical hints on the selected glyph is similar to hinting by drawing critical relationships on a printed glyph using colored pencils The typographer uses an input device such as a mouse to drag and drop graphical elements representing hints As explained in more detail below the typographer typically selects a hinting tool from the toolbar using the mouse and then drags the selected tool between control points The tool represents a particular hinting function such as a link or an interpolation The hinting tools permit the typographer to add hints in the x direction and or the y direction The possible hinting functions are defined by the font format The hinting func tions discussed herein are supported by a TrueType font Once the hinting tool and the control points are selected the hint is represented by a graphical element displayed on the glyph The hinting tools allow the typographer to define attributes for control points such as a rounding method and relationships between control points such as a link
24. e category options shown in FIG 3B include a pointed arrowhead 350 351 352 353 358 359 360 361 366 367 368 369 to indicate that the link refers to a stroke that is neither straight nor rounded a blunt arrowhead 354 355 362 363 370 371 to indicate that the link refers to a straight stroke and a rounded arrowhead 356 357 364 365 372 373 to indicate that the link refers to a round stroke The shape of the arrowhead of the graphical element indicates the stroke category option associated with the link For example the arrowhead of link 304 of FIG 3A is rounded indicating that link 304 refers to a round stroke The typographer also may specify a minimum distance option for the link or distance using the menus shown in FIG 3B The default minimum distance option instructs the rasterizer to maintain a minimum distance between the parent control point and the child control point in certain situations The typographer can override the default option and instruct the rasterizer to maintain a minimum distance when the default option would not maintain a minimum distance or to ignore a minimum distance when the default option would maintain a minimum distance The options in the menu include the default option no symbol and the override options elevator door symbols For the option of maintaining a minimum distance when the default option would not maintain a minimum distance the elevator door symbol is an open door symbol
25. e typographer selects a hinting tool in step 1040 For example the typographer can select the link hinting tool from the toolbar If the typographer selects the link tool the US 6 552 727 B2 17 cursor changes into an arrow as discussed above in connec tion with the link tool The typographer selects the first control point in step 1042 and drags the link tool to select the second control point in step 1044 The first control point is equivalent to the parent control point and the second control point is equivalent to the child control point discussed above in connection with the link tool A graphical element is displayed in step 1046 For the link the graphical element is an arrow connecting the first control point and the second control point FIG 10D corresponds to creating a relationship between two pairs of control points such as a stroke As shown in FIG 10D the typographer selects a hinting tool in step 1050 For example the typographer can select the stroke hinting tool from the toolbar If the typographer selects the stroke hinting tool the cursor changes into a pair of parallel arrowheads as discussed above in connection with the stroke tool The typographer selects the first control point in step 1052 and drags the stroke tool to select the second control point in step 1054 The first control point and the second control point are equivalent to the first parent child pair discussed above in connection with the stroke tool
26. econd control point and receiving the option 43 The method of claim 41 wherein the option is a rounding option 44 A method for graphically authoring hints for a font using a graphical user interface comprising the steps of a displaying a selected glyph by displaying a glyph outline for the selected glyph b receiving a selection of a displayed graphical hinting tool corresponding to a selected hinting function c receiving a selection of a first displayed point on the glyph outline and a selection of a second displayed point on the glyph outline d applying the selected hinting function to the selected glyph wherein changes in a control value for the hinting function can be automatically coded and com piled and e displaying the selected glyph with the hinting function applied 45 The method of claim 44 further comprising the step of repeating steps b e with a second selected hinting tool corresponding to a second selected hinting function and a selected off curve control point 46 The method of claim 44 wherein the first point is located on and identifies one side of a stem of the selected glyph and the second point is located on and identifies the opposite side of the stem of the selected glyph and wherein the step of applying the selected hinting function comprises positioning the side of the stem identified by the second point relative to the side of the stem identified by the first point 47 The me
27. ection or the y direction grid lines The remaining rounding options shown in FIG 5 round the control point relative to the main stroke angle or to the adjusted italic angle The selected rounding option is represented by a graphical component For example the graphical component may correspond to the graphical components displayed in the rounding menus shown in FIG 5 To modify a rounding option the typographer depresses the shift key selects the control point and selects a different one of the rounding methods from the menu To delete a rounding option the typographer depresses the shift key selects the control point and selects the option to fit the control point to the grid without rounding from the menu Stroke Tool The stroke tool is used to hint glyphs with diagonal strokes such as an uppercase A or italic glyphs The stroke tool ensures a uniform width of a diagonal stroke by linking a first parent child control point pair to a second parent child control point pair FIG 6 illustrates two strokes 630 and 632 defining the widths of the diagonals of an uppercase A 600 To create a stroke the typographer selects the stroke tool 252 of FIG 2 from the toolbar Typically once the stroke tool is selected the cursor changes into a pair of parallel arrowheads pointing in opposite directions To create stroke 630 the typographer selects the first parent control point 610 and drags the stroke tool to the first child con
28. ed to uppercase black round strokes in the x direction Typically the typographer completes the cvt before the typographer begins hinting The typographer may complete the cvt by opening the cvt using a menu and then editing the entries of the cvt Once the typographer completes the cvt the cvt values may be used to hint the font Hinting the font using cvt values helps the typographer obtain consistency between glyphs of the font Control Point Tools The control point tools may be used to refine the glyph outline by adding deleting or moving control points Refin ing the glyph outline should reduce the amount of hinting required Typically the typographer selects one of the con trol point tools from the toolbar and then selects a control point on the glyph outline For example to add a control point the typographer selects the add point tool 234 from the tool bar and then selects the location for the new control point To delete a control point the typographer selects the delete point tool 232 from the toolbar and then selects the control point to be deleted To move a control point the typographer selects the move point tool 228 from the tool bar and selects the control point to be moved The typog rapher then drags the selected control point to new location Once the typographer refines the glyph outlines using the control point tools the typographer compiles the font so that the refined glyph outlines are stored in the font ta
29. ement for the distance does not include a high way sign with a cvt number As the typographer hints the glyph the typographer may decide to modify or to delete a link To modify a link to specify a different parent control point the typographer selects the link tool selects the tail of the arrow and drags the tail to a new parent control point To modify a link to specify a different child control point the typographer selects the link tool selects the arrowhead and drags the arrowhead to a new child control point To delete a link the typographer selects the link tool from the toolbar selects the arrowhead of the link to be deleted and drags the arrowhead off the child control point The typographer may modify the stroke category the minimum distance or the cvt value options associated with a link To modify the stroke category option associated with the link the typographer depresses the shift key selects the arrowhead and then selects a new stroke category To modify the minimum distance option applied to the link the typographer depresses the shift key selects the elevator door symbol and then selects a new minimum distance option To modify the cvt value associated with the link the typogra pher depresses the shift key selects the highway sign and then selects a new cvt value An advantage of hinting a glyph using a graphical user interface is that a typographer can see the hints applied to the glyph and can recognize h
30. ep of complet ing the cvt typically includes measuring a number of rep resentative glyphs using the measuring tool and using the most common values to complete the cvt Once the cvt is completed the typographer selects a glyph to hint in step 1006 The typographer hints the selected glyph in step 1008 by dragging and dropping graphical hint s on the selected glyph The steps for hinting the selected glyph are discussed below in connection with FIGS 10 10 In step 1010 the hint s are compiled If the automatic compile option is enable then each hint is compiled as it is added If the automatic complied option is not enabled then the hint is not compiled until the typographer initiates the compilation The automatic compile option allows the typographer to imme diately see the effect of a hint on the glyph However in some instances the typographer may choose not to enable the automatic compile option because the automatic compile option can make it difficult to add multiple hints Additional details on compiling graphical hints is described in the commonly assigned U S patent application Ser No 09 049 777 for A System and Method for Representing Graphical Font Data and for Converting the Font Data to Font Instruc tions which is incorporated herein by reference FIGS 11A 11D may be used to illustrate an exemplary application of steps 1008 1010 and 1012 of FIG 10A and the steps of FIG 10B FIG 11A shows a bitmap for an upperc
31. epresenting the hinting function connecting the first control point the second control point and the third control point on the displayed glyph and displaying the glyph with the hinting function applied to the glyph 33 The method of claim 32 wherein the hinting function is an interpolation the first graphical element is a band and the second graphical element is a pair of arrows one arrow connecting the first control point and the third control point and another arrow connecting the second control point and the third control point 34 The method of claim 32 wherein the hinting function is an alignment the first graphical element is an arrow and the second graphical element is a pair of arrows one arrow connecting the first control point and the third control point and another arrow connecting the second control point and the third control point 35 The method of claim 32 wherein the step of display ing the glyph with the hinting function applied comprises displaying a bitmap of the glyph 36 A method for graphically authoring hints for a font using a graphical user interface comprising the steps of displaying a glyph displaying a plurality of graphical hinting tools receiving a graphical hint by receiving a selection of one of the displayed graphical hinting tool displaying a graphical element representing the graphical hint on the displayed glyph receiving an option for the graphical hint wherein changes in
32. he hints are to be compiled into a language that specifies hints using control points such as the TrueType language then the hinting program could resolve the selected point into a control point One way for the hinting program to resolve the selected point into a control point would be to select the control point located closest to the selected point Additional alternative embodiments will become apparent to those skilled in the art to which the present invention pertains without departing from its spirit and scope Accordingly the scope of the present invention is described by the appended claims and is supported by the foregoing description What is claimed is 1 A method for graphically authoring hints for a font using a graphical user interface comprising the steps of a loading the font b receiving control values for the font c displaying a glyph of the font having a plurality of control points with each control point based upon at least one control value d receiving a graphical hint by receiving a selection of a displayed graphical hinting tool corresponding to a hinting function and a selection of a first displayed control point for the glyph wherein changes in a control value associated with the graphical hint can be automatically coded and compiled applying the graphical hint to the glyph and f displaying the hinted glyph 2 The method of claim 1 wherein the step of receiving a graphical hint compri
33. he link tool from the parent control point 320 to the child control point 322 As shown in FIG 3A the link is represented by a graphical element such as an arrow 302 on the displayed glyph The arrow 302 has a tail that is connected to the parent control point 320 and an arrowhead that is connected to the child control point 322 The arrow 302 is filled with lines to indicate the flexible nature of the link If the link is in the x direction the arrow is filled with horizontal lines If the link is in the y direction the arrow is filled with vertical lines The arrow 302 is filled with horizontal lines indicating that the link is applied in the x direction Typically a typographer specifies a stroke category option a minimum distance option and possibly a cvt value for the link The stroke category option indicates the type of stroke straight round or other The minimum distance option indicates the minimum distance between the parent control point and the child control point The cvt value indicates the cvt number that is associated with the link To specify the stroke category the minimum distance and the value options the typographer selects the link tool depresses the shift key selects the arrowhead of the graphi cal element for the link and then selects the desired options from a menu A typical horizontal menu and a typical vertical menu of stroke category and minimum distance options are shown in FIG 3B The strok
34. iment of the present invention DETAILED DESCRIPTION The present invention is directed to a method for author ing hints for a font using a graphical user interface In one embodiment the invention is incorporated into the Visual TrueType program marketed by Microsoft Corporation of Redmond Wash Briefly described the graphical user inter face of the Visual TrueType program permits a typogra pher to drag and drop graphical hints on a displayed glyph which can be automatically compiled into a font table The typographer specifies a graphical hint by selecting a hinting tool which corresponds to a hinting function and selecting one or more points along the glyph outline such as a control point The graphical hints are represented by graphical elements displayed on the glyph Options for the hints are represented by graphical components displayed with the graphical elements The graphical hints are compiled and placed in the font tables without requiring that the typog rapher manually code the hints Once the graphical hints for a glyph are compiled the hinted glyph is displayed The typographer can determine if the appearance of the hinted glyph is acceptable If the appearance of the hinted glyph is not acceptable then the typographer can add additional hints or modify the existing hints Exemplary Operating Environment FIG 1 and the following discussion are intended to provide a brief general description of a suitable com
35. in the step of receiving a graphical hint for the glyph comprises displaying a graphical element representing the graphical hint about the first control point 10 The method of claim 9 wherein the selected hinting tool is a delta exception tool and the hinting function is a delta exception 11 The method of claim 1 wherein the step of receiving a graphical hint for the glyph comprises receiving a selection of a second displayed control point displaying a first graphical element connecting the first control point and the second control point receiving selection of a third displayed control point and a selection of a fourth displayed control point displaying a second graphical element connecting the third control point and the fourth control point and displaying a third graphical element representing the graphical hint the third graphical element connecting the first graphical element and the second graphical element 12 The method of claim 11 wherein the selected hinting tool is a stroke tool and the hinting function is a stroke 13 The method of claim 1 further comprising the step of repeating steps c f for a second glyph of the font 14 The method of claim 1 further comprising the step of repeating steps d f for a second graphical hint 15 A computer readable medium having computer executable instructions comprising the steps of a displaying a selected glyph having a plurality of control points with one
36. inting errors For example links cannot be circular If the typographer mistakenly specifies circular links then the graphical elements representing the links will be interconnected It is easier for the typographer to recognize the interconnected graphical elements dis played on the glyph than to recognize the lines of assembly type code which represent the circular links Shift Tool The shift tool is similar to the link tool but the shift tool creates a rigid relationship between a parent control point and a child control point The same relative distance is maintained between the two control points even if the parent control point is moved due to other hinting A shift is useful for defining a unique relationship between a parent control point and a child control point To create a shift the typographer selects the shift tool from the toolbar Typically once the shift tool is selected the cursor changes into an arrowhead If the x direction shift tool 242 of FIG 2 is selected then the cursor changes into a horizontal arrowhead If the y direction shift tool 244 of FIG 2 is selected then the cursor changes into a vertical arrowhead The typographer drags the arrowhead from the parent control point to the child control point The shift is represented by a graphical element such as an arrow 10 15 20 25 30 35 40 45 50 55 60 65 12 Typically the arrow is solid to distinguish the shift from a
37. link and to indicate the rigid relationship defined by the shift To modify an existing shift the typographer selects the shift tool and selects either the parent control point or the child control point To change the parent control point the typographer drags the tail of the arrow to the new parent control point To change the child control point the typog rapher drags the arrowhead to the new child control point To delete a shift the typographer selects the shift tool and drags the arrowhead off the child control point Interpolate Tool The interpolate tool controls the proportions of a glyph by maintaining the relative position of one or more child control points that fall between two parent control points The proportions are controlled in either the x direction or the y direction FIGS 4A and 4B illustrate an interpolation for an uppercase B 400 To create a interpolation the typog rapher selects the interpolate tool from the toolbar Typically once the interpolate tool is selected the cursor changes into a pair of arrowheads pointing towards a point If the x direction interpolate tool 246 of FIG 2 is selected then the cursor changes into a horizontal pair of arrowheads If the y direction interpolate tool 248 of FIG 2 is selected then the cursor changes into a vertical pair of arrowheads The typographer connects the parent control points typi cally by dragging the interpolate tool between the two points As shown
38. n of a second displayed control point and displaying a graphical element representing the graphical hint connecting the first control point and the second control point on the displayed glyph 26 The method of claim 24 wherein the step of receiving the graphical hint further comprises receiving a selection of a second displayed control point and a selection of a third displayed control point and displaying a graphical element representing the graphical hint connecting the first control point the second control point and the third control point 27 The method of claim 24 wherein the step of receiving the graphical hint further comprises displaying a graphical element representing the hinting function about the first control point 28 The method of claim 25 further comprising the step of receiving a modified graphical hint 29 The method of claim 28 wherein the graphical element is an arrow having a tail and an arrowhead the tail connected to the first selected control point and the arrow head connected to the second selected control point and wherein the step of receiving a modified graphical hint comprises receiving a selection of the tail of the arrow and a third selected control point and displaying a modified graphical element representing the modified graphical hint connecting the third selected control point and the second selected control point 30 The method of claim 28 wherein the graphical element is an
39. nt table defining the dominant width length or angle of a group of features such as the stem width or the serif length Completing the cvt typically includes measuring a number of representative glyphs using the measuring tool and using the most common values to complete the cvt The typogra pher can specify cvt values when hinting a glyph The ability to specify cvt values helps the typographer achieve consis tency across the glyphs of the font Once the cvt is completed the typographer selects a glyph to hint The typographer hints the selected glyph by dragging and dropping graphical hints on the selected glyph For example to specify a link the typographer selects the link tool The typographer then drags the link tool between a first control point and a second control point A graphical element such as an arrow appears between the two control points The tail of the arrow is connected to the parent 10 15 25 30 35 40 45 50 55 60 65 4 control point and the arrowhead is connected to the child control point The typographer can specify options for the link such as a stroke category option a minimum distance option or a cvt value by selecting the desired options from a menu The selected stroke category option is represented by the shape of the arrowhead of the graphical element representing the link The selected minimum distance option and the selected cvt value are represented by graphical compone
40. ntion is directed toward a method for creating hints for a font using a graphical user interface Although the present invention has been described using specific hinting tools and specific graphical elements those skilled in the art will appreciate that alternative hinting tools and graphical elements may be used For example to hint a non TrueType font the hinting tools would need to be modified to support the types of hinting permitted by the font Alternative graphical elements such as color may be used to differentiate hints For example a link and an interpolation may be represented by different colors rather than or in addition to different graphical elements Although the display tools viewing tools control point tools and hinting tools have been described as being accessed from a toolbar the tools may also be accessed using a combination of keystrokes or a menu Although the present invention has been described in connection with an embodi ment wherein a typographer selects a hinting tool and one or more control points as will be apparent to those skilled in the art the present invention may also be used in an 10 15 20 25 30 40 45 50 55 60 65 18 embodiment that does not require the selection of a control point For example the typographer could hint a glyph by selecting any point on the glyph outline or an off curve control point not just a control point located on the glyph outline If t
41. nts displayed with the graphical element The graphical user interface can be used to specify other types of hints including an interpolation To specify an interpolation the typographer selects the interpolate tool The typographer then drags the interpolate tool between a first control point and a second control point A graphical element such as a band appears between the two control points The band indicates that the two control points are the parent control points for the interpolation The typographer selects the band and drags the band to a third control point The graphical element changes from a band to a pair of arrows The tail of one of the arrows is connected to the first control point and the arrowhead is connected to the third control point The tail of the other arrow is connected to the second control point and the arrowhead is connected to the third control point The pair of arrows is a graphical repre sentation of the interpolation of the third control point between the first control point and the second control point The graphical element and the graphical components can be used to modify the graphical hints By selecting different portions of the graphical element different aspects of the hint are modified For example selecting the tail of the arrow representing a link or an interpolation allows the typographer to select a new parent control point Selecting a graphical component representing the minimum distance opti
42. ographer to select a new parent control point Selecting the graphical component that cor responds to an option such as the cvt number allows the typographer to modify the option Link and Distance Tools link connects two control points over a flexible distance in either the x direction or the y direction A link begins at parent control point and ends at a child control point A link determines the location of the child control point relative to the parent control point FIG 3A illustrates six links for an uppercase B 300 One link 312 connects the left side bearing point and a control point on the vertical stem of the Another link 306 connects the right side bearing point and a control point on the lower bowl of the B The width of the vertical stem is specified by links 308 and 310 and the width of the round strokes are specified by links 302 and 304 10 15 20 25 30 35 40 45 50 55 60 65 10 To create link the typographer selects the link tool from the toolbar and then selects a parent control point and a child control point Typically once the link tool is selected the cursor changes into an arrow with a highway sign If the x direction link tool 238 of FIG 2 is selected then the cursor changes into a horizontal arrow If the y direction link tool 240 of FIG 2 is selected then the cursor changes into a vertical arrow To create link 302 the typographer drags t
43. on allows the typographer to select a new minimum distance option If the automatic compile option is enabled then the hints are automatically compiled as the glyph is hinted The automatic compile option allows the typographer to imme diately see the effect of a hint on the glyph If the automatic compile option is not enabled then a hint is not compiled until the typographer compiles the hint typically by select ing a compile option from a menu Once the hints are compiled the selected glyph is redis played Typically the selected glyph is displayed using the bitmap display option If the appearance of the hinted glyph is not acceptable then the typographer modifies or deletes the existing hints or adds additional hints until the appear ance of the hinted glyph is acceptable Once the appearance of the hinted glyph is acceptable the typographer can hint another glyph Additional glyphs are selected until all the glyphs of the font are hinted These and other aspects features and advantages of the present invention may be more clearly understood and appreciated from a review of the following detailed descrip tion of the disclosed embodiments and by reference to the appended drawings and claims BRIEF DESCRIPTION OF THE DRAWINGS FIG 1 is a block diagram of a personal computer illus trating the operating environment for an embodiment of the present invention FIG 2 is an illustration of a graphical user interface including
44. one of the arrows representing the interpolation and drags the arrowhead off the child control point The arrowhead of the other arrow is automatically deleted Automatically deleting the arrowhead prevents the illegal interpolation of a child control point with only a single parent control point Rounding Tools The rounding tools are used to specify the position of a control point relative to the grid lines The typographer may specify rounding options for a control point when applying a hint such as a link shift or interpolation To specify a rounding option the typographer depresses the shift key selects a control point and selects the desired rounding option from a menu Typical horizontal rounding options and vertical rounding options are shown in FIG 5 The rounding options include 1 fit the control point to the grid US 6 552 727 B2 13 without rounding it 500 501 2 fit the control point to the nearest grid line round to grid 502 503 3 fit the control point halfway between two grid lines round to halfgrid 504 505 4 fit the control point to the nearest grid line or halfway between two grid lines whichever is closer round to double grid 506 507 5 fit the control point to the next lower grid line round down to grid 508 509 and 6 fit the control point to the next higher grid line round up to grid 510 511 Rounding options 500 511 round the control point relative to the x dir
45. or more control values associ ated with each control point b displaying a plurality of graphical hinting tools c receiving a selection of one of the displayed graphical hinting tools the selected graphical hinting tool corre sponding to a selected hinting function d receiving a selection of one of the displayed control points of the selected glyph applying the selected hinting function to the selected control point wherein changes in a corresponding value can be automatically coded and compiled and displaying the selected glyph with the selected hinting function applied 16 The computer readable medium of claim 15 further comprising the step of repeating steps b f with a second selected hinting tool corresponding to a second selected hinting function and a second selected control point 17 The computer readable medium of claim 15 further comprising the step of receiving a selection of a second displayed selected control point 18 The computer readable medium of claim 17 wherein the step of applying the selected hinting function comprises positioning the second selected control point relative to the selected control point 19 The computer readable medium of claim 15 further comprising the step of displaying a graphical element corresponding to the selected hinting function on the selected glyph 20 The computer readable medium of claim 19 wherein the step of displaying the graphical element compri
46. puting environment in which the present invention may be imple mented While the invention will be described in the general context of a hinting application program used in connection with an operating system running on a personal computer those skilled in the art will recognize that the invention also may be implemented in combination with other program modules Generally program modules include routines programs components data structures etc that perform particular tasks or implement particular abstract data types Moreover those skilled in the art will appreciate that the invention may be practiced with other computer system 10 15 20 25 30 35 40 45 50 55 60 65 6 configurations including hand held devices multiprocessor systems microprocessor based or programmable consumer electronics minicomputers mainframe computers and the like The invention may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a com munications network In a distributed computing environment program modules may be located in both local and remote memory storage devices With reference to FIG 1 an exemplary system for imple menting the invention includes a conventional personal computer 20 including a processing unit 21 a system memory 22 and a system bus 23 that couples the system memory to the processing unit 21 The system memo
47. rowhead off the child control point The typog rapher then selects the other child control point and drags the arrowhead off that child control point The Align Tool The align tool allows the typographer to specify that three or more control points should be kept along the same line 10 15 20 25 30 35 40 45 50 55 60 65 14 The align tool keeps the child control points aligned even though other hints are applied to the parent control points If the child control points are not aligned then the child control points may become distorted once other hints are applied to the parent control points FIG 7 shows two aligns 740 and 742 applied to an uppercase A 700 To create an alignment the typographer selects the align tool 250 of FIG 2 from the toolbar Typically once the align tool is selected the cursor changes into two diagonal arrowheads pointing towards each other To create alignment 740 the typographer selects the first parent control point 702 and drags the align tool to the second parent control point 708 A headless arrow is displayed with a rounded tail at each parent point The typographer drags the shaft of the arrow to one or more child control points 704 706 located between the two parent control points 702 and 708 The align 740 is represented by a graphical element such as a set of arrows connecting all the aligned control points Each align is represented by a set of arrows 720 722
48. ry 22 includes read only memory ROM 24 and random access memory RAM 25 A basic input output system 26 BIOS containing the basic routines that help to transfer information between elements within the personal computer 20 such as during start up is stored in ROM 24 The personal computer 20 further includes a hard disk drive 27 a magnetic disk drive 28 e g to read from or write to a removable disk 29 and an optical disk drive 30 e g for reading a CD ROM disk 31 or to read from or write to other optical media The hard disk drive 27 magnetic disk drive 28 and optical disk drive 30 are connected to the system bus 23 by a hard disk drive interface 32 a magnetic disk drive interface 33 and an optical drive interface 34 respectively The drives and their associated computer readable media provide nonvolatile storage for the personal computer 20 Although the description of computer readable media above refers to a hard disk a removable magnetic disk and a CD ROM disk it should be appreciated by those skilled in the art that other types of media which are readable by a computer such as magnetic cassettes flash memory cards digital video disks Bernoulli cartridges and the like may also be used in the exemplary operating environment A number of program modules may be stored in the drives and RAM 25 including an operating system 35 one or more application programs 36 including a hinting application program 3
49. sed to measure various distances on the selected glyph 208 typographer may use the measuring tool 226 to measure a set of representative glyphs to determine the initial values for the control value table cvt The cvt is a font table defining the dominant width length or angle of a group of features such as stem width or serif length Some cvt values are specific to certain glyphs but other cvt values apply to the entire font The cvt specifies cvt values for the different character groups of the font such as uppercase lowercase figure and other Each entry in the cvt includes a cvt number a cvt value and a comment field A typical entry in the cvt is shown below 287 212 Uppercase Black X Round cyt number is a sequential number identifying the entry in the cvt In the entry shown above the cvt number is 287 A cvt value gives the dominant length or width of a feature measured in font units Font units are units of measure that are independent of the device grid During the scaling process the cvt values are scaled to the device grid so that the cvt values are appropriate for the ppem size at issue The term ppem refers to pixel per em An em is a unit of measure which is the square of the point size In the entry shown above the cvt value is 212 The comment field provides information about the application of the cvt value For example in the entry shown above the comment field indicates that the cvt value is appli
50. ses receiving a selection of a second displayed control point and displaying a graphical element representing the graphical hint connecting the first control point and the second control point on the displayed glyph 3 The method of claim 2 further comprising the steps of receiving an option for the graphical hint displaying a graphical component representing the option with the graphical element and applying the option to the glyph 4 The method of claim 3 wherein the option associates a selected one of the control values with the graphical hint 5 The method of claim 2 wherein the selected hinting tool is a link tool and the hinting function is a link 6 The method of claim 1 wherein the step of receiving a graphical hint comprises receiving a selection of a second displayed control point displaying a first graphical element that connects the first control point and the second control point receiving a selection of a third displayed control point and displaying a second graphical element representing the graphical hint connecting the first control point the second control point and the third control point 7 The method of claim 6 wherein the selected hinting tool is an interpolate tool and the hinting function is an interpolation 8 The method of claim 6 wherein the selected hinting tool is an align tool and the hinting function is an alignment US 6 552 727 B2 19 9 The method of claim 1 where
51. ses displaying the graphical element using a color the color indicating a flexibility associated with the selected hinting function 21 The computer readable medium of claim 15 wherein the hinting function is applied to a plurality of point sizes of the glyph 10 15 20 25 30 40 45 50 55 60 65 20 22 The computer readable medium of claim 15 wherein the hinting function is applied to a selected point size of the glyph 23 The computer readable medium of claim 15 wherein the step of displaying the selected glyph with the hinting function applied comprises displaying a bitmap for the selected glyph 24 A method for graphically authoring hints for a Tru eType font using a graphical user interface comprising the steps of receiving a selected glyph having a plurality of control points wherein each control point has one or more associated control values displaying the selected glyph and the plurality of control points receiving a graphical hint by receiving a selection of a displayed graphical hinting tool and a selection of a first displayed control point wherein changes in a corresponding control value can be automatically coded and compiled applying the graphical hint to the selected glyph and displaying the selected glyph showing the application of the graphical hint 25 The method of claim 24 wherein the step of receiving the graphical hint further comprises receiving a selectio
52. sizes the typographer may need to create an exception to the global hinting to improve the pixel pattern around the round parts of a glyph Two types of exceptions may be applied to a control point a delta exception and a move exception A delta exception moves the control point a set number of pixel s based on the ppem size A delta exception applies only to a particular point size A move exception moves a control point a set number of pixel s regardless of the ppem size of the glyph To create an exception the typographer selects one of the exception tools from the toolbar and then selects a control point Typically if the delta exception tool is selected the cursor changes into a double headed arrow with pointed arrowheads If the x direction delta exception tool 260 FIG 2 is selected then the cursor changes into a horizontal arrow If the y direction delta exception tool 262 FIG 2 is selected then the cursor changes into a vertical arrow If the move exception tool is selected then the cursor changes into a double headed arrow with rounded arrowheads If the x direction move exception tool 256 FIG 2 is selected then the cursor changes into a horizontal arrow If the US 6 552 727 B2 15 y direction move exception tool 258 FIG 2 is selected then the cursor changes into a vertical arrow Once the exception tool and the control point are selected a ruler is displayed The ruler is horizontal for a horizontal excep
53. t ing a portion of the graphical element and modifying the aspect of the hint that corresponds to that portion of the graphical element For example the typographer can modify the parent control point of a link by selecting the tail of an arrow representing the link and dragging the tail to a new parent control point A number of tools are provided by the graphical user interface including viewing tools control point tools hint ing tools and display tools The display tools include snap shot jump back and size run tools The viewing tools include tools for panning measuring and zooming The control point tools include tools for moving swapping deleting or adding a control point The hinting tools include tools for linking shifting interpolating aligning and moving as well as tools for specifying an angle and a stroke The hinting tools allow the typographer to specify a hinting function Typically the typographer selects a hinting tool and then drags the selected tool between control points Once the hinting tool and the control points are selected the graphical hint is represented by a graphical element such as an arrow displayed on the glyph To hint a font using a graphical user interface the typographer loads a font Loading the font typically includes loading the necessary font data and stripping any hints previously created Once the font is loaded the typographer completes the control value table or cvt The cvt is a fo
54. ter readable medium of claim 49 wherein the step of displaying the graphical element comprises displaying the graphical element using a color the color indicating a flexibility associated with the selected hinting function 52 The computer readable medium of claim 49 wherein the step of displaying the selected glyph with the hinting function applied comprises displaying a bitmap for the selected glyph 53 A method for graphically authoring hints for a font using a graphical user interface comprising the steps of receiving a selected glyph having a plurality of control points displaying the selected glyph receiving a graphical hint by receiving a selection of a displayed graphical hinting tool and a selection of a first displayed control point 10 15 20 30 24 displaying a graphical element representing the hinting function about the first control point that indicates a hinting direction for the graphical hint applying the graphical hint to the selected glyph and displaying the selected glyph showing the application of the graphical hint to the selected glyph 54 The method of claim 53 wherein the step of receiving a graphical hint further comprises receiving a control value associated with the graphical hint 55 The method of claim 53 wherein the step of display ing a graphical element comprises displaying the graphical element using a color the color indicating a flexibility associated with the selected
55. ternet When used in a LAN networking environment the per sonal computer 20 is connected to the LAN 51 through a US 6 552 727 B2 7 network interface 53 When used in a WAN networking environment the personal computer 20 typically includes a modem 54 or other means for establishing communications over the WAN 52 such as the Internet The modem 54 which may be internal or external is connected to the system bus 23 via the serial port interface 46 In a networked environment program modules depicted relative to the personal computer 20 or portions thereof may be stored in the remote memory storage device It will be appreciated that the network connections shown are exemplary and other means of establishing a communications link between the computers may be used User Interface FIG 2 illustrates the main window 200 of an exemplary graphical user interface for authoring hints for a font As shown in FIG 2 the main window includes a toolbar 202 a status bar 204 sample text for the font 206 a selected glyph 208 and a size run 210 In FIG 2 the selected glyph is a lowercase m 208 The status bar 204 displays infor mation about the selected glyph For example the status bar shown in FIG 2 includes the glyph s sequential number in the font the glyph s Unicode number and the glyph s case as well as other information The sample text 206 provides the typographer with an indication of the overall look of the font
56. thod of claim 44 further comprising the step of displaying a graphical element corresponding to the selected hinting function on the selected glyph 48 The method of claim 47 wherein the step of display ing the graphical element comprises displaying the graphical element using a color the color indicating a flexibility associated with the selected hinting function 49 A computer readable medium having computer executable instructions comprising the steps of displaying a selected glyph having a plurality of control points receiving a selection of a displayed graphical hinting tool corresponding to a selected hinting function and a hinting direction US 6 552 727 B2 23 receiving a selection of one of the displayed control points displaying a graphical element corresponding to the selected hinting function and indicating the hinting direction on the selected glyph applying the selected hinting function to the selected control point wherein changes in a selected control value associated with the selected hinting function can be automatically coded and compiled and displaying the selected glyph with the selected hinting function applied 50 The computer readable medium of claim 49 wherein receiving a selection of a displayed graphical hinting tool includes receiving a selected control value further compris ing the step of associating the selected control value with the selected hinting function 51 The compu
57. tion tool and vertical for a vertical exception tool The typographer drags the cursor to the desired value on the ruler The ruler has a range of plus or minus eight pixels with increments as fine as 6 pixel or as coarse as one pixel The typographer can change the displayed range of the ruler and the displayed increments The selected control point is moved in accordance with the value selected on the ruler An exception is represented by a graphical element such as a pointed triangle delta exception or a round tip triangle move exception located about the selected control point FIG 9 shows two delta exceptions 902 904 applied to an uppercase O 900 As shown in FIG 9 the graphical element 902 904 is positioned near the affected control point 901 903 To delete an exception the typographer selects the excep tion tool delta or move selects the control point and selects the value zero 0 on the ruler Method for Hinting a Font The typographer may hint a font such as a True Type font that was created using an outline editor Before beginning to hint the font the typographer can select the resolution of the target output device The resolution of the target output device determines the number of pixels available to render the glyphs of the font The steps for hinting a font are shown in FIG 10A The method begins at step 1000 and proceeds to step 1002 In step 1002 the font is loaded Loading the font typically incl
58. trol point 612 Typically an arrow 602 is displayed beginning at the first parent control point 610 and ending at the first child control point 612 The typographer then selects the second parent control point 616 and drags the stroke tool to the second child control point 618 A second arrow 604 is displayed beginning at the second parent control point 616 and ending at the second child control point 618 The area between the first parent child pair and the second parent child pair is filled with parallel lines indicating that the two arrows define a stroke If the stroke is within forty five degrees 45 of vertical then the lines are horizontal otherwise the lines are vertical The stroke 630 is represented by the graphical element including the arrows 602 and 604 and the horizontal lines A stroke can be modified to specify a different parent control point or a different child control point To specify a new parent control point the typographer selects the stroke tool selects the tail of the arrow associated with the parent control point and drags the tail of the arrow to a new parent control point To specify a new child control point the typographer selects the stroke tool selects the arrowhead of the arrow associated with the child control point and drags the arrowhead to a new child control point To delete a stroke the typographer selects the stroke tool from the toolbar selects one of the child control points and drags the ar
59. uction is not inserted in the correct sequence then the font instructions will not be correctly applied For the majority of typographers it would be easier to hint a glyph if the relationships drawn on the glyph outline could be translated into font instructions without the typographer s intervention In addition it is easier to prevent or debug hinting errors if the font instructions are shown on the glyph outline For example it is easier for the typographer to recognize a circular relationship if the circular relationship is shown graphically on the glyph outline than if the circular relationship is only apparent from the font instructions One proposed solution to the hinting problem is provided by the Fontographer program marketed by Macromedia of San Francisco Calif The Fontographer program assists a typographer in designing a font by providing tools to support glyph outline design The Fontographer program also pro vides some rudimentary hinting tools The Fontographer program allows a typographer to specify horizontal and vertical serif hints horizontal and vertical stem hints and diagonal hints For example to specify a vertical stem hint the typographer selects two points which define the vertical stem and then selects the make vertical stem command from the hints menu The typographer may control the width of the vertical stem by specifying the x coordinates of the stem Typically the x coordinates of the stem are
60. udes loading the necessary font data and stripping any hints previously created Once the font is loaded the typog rapher completes the cvt in step 1004 The step of complet ing the cvt typically includes measuring a number of rep resentative glyphs using the measuring tool and using the most common values to complete the cvt Once the cvt is completed the typographer selects a glyph to hint in step 1006 The typographer hints the selected glyph in step 1008 by dragging and dropping graphical hint s on the selected glyph The steps for hinting the selected glyph are discussed below in connection with FIGS 10B 10E In step 1010 the hint s are compiled If the automatic compile option is enabled then each hint is compiled as it is added If the automatic compile option is not enabled then the hint is not compiled until the typographer initiates the compilation The automatic compile option allows the typographer to imme diately see the effect of a hint on the glyph However in some instances the typographer may choose not to enable the automatic compile option because the automatic compile option can make it difficult to add multiple hints Additional details on compiling graphical hints is described in the commonly assigned U S patent application Ser No 09 049 777 for System and Method for Representing Graphical Font Data and for Converting the Font Data to Font Instruc tions which is incorporated herein by reference In step 1
61. y direction between two control points The typographer then draws these relationships on the glyph outline using colored pencils Once the typographer draws the relationships on the glyph outline the typographer translates the colored pencil mark ings into font instructions The translation requires that the typographer not only convert the relationships into the proper TrueType commands but also requires that the typographer order the commands according to the command sequence requirements of the TrueType Instruction Set Once the typographer translates the relationships into font instructions the font instructions are compiled and the 10 15 20 25 30 35 40 45 50 55 60 65 2 compiled font instructions are used to display a bitmap for the glyph The typographer reviews the bitmap to determine whether the appearance of the hinted glyph is satisfactory If the appearance of the hinted glyph is not satisfactory then the typographer must modify the font instructions or add additional font instructions The typographer must repeat these steps until the appearance of the hinted glyph is satisfactory If the typographer adds an additional font instruction then the typographer must determine where to insert the font instruction Because the TrueType Instruction Set requires certain command sequences determining where to insert the additional font instruction is not usually obvi ous If the additional font instr

Method for authoring hints for a font using a graphical user interface

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