1 /***************************************************************************/ 2 /* */ 3 /* ftmm.h */ 4 /* */ 5 /* FreeType Multiple Master font interface (specification). */ 6 /* */ 7 /* Copyright 1996-2015 by */ 8 /* David Turner, Robert Wilhelm, and Werner Lemberg. */ 9 /* */ 10 /* This file is part of the FreeType project, and may only be used, */ 11 /* modified, and distributed under the terms of the FreeType project */ 12 /* license, LICENSE.TXT. By continuing to use, modify, or distribute */ 13 /* this file you indicate that you have read the license and */ 14 /* understand and accept it fully. */ 15 /* */ 16 /***************************************************************************/ 17 18 19 #ifndef __FTMM_H__ 20 #define __FTMM_H__ 21 22 23 #include <ft2build.h> 24 #include FT_TYPE1_TABLES_H 25 26 27 FT_BEGIN_HEADER 28 29 30 /*************************************************************************/ 31 /* */ 32 /* <Section> */ 33 /* multiple_masters */ 34 /* */ 35 /* <Title> */ 36 /* Multiple Masters */ 37 /* */ 38 /* <Abstract> */ 39 /* How to manage Multiple Masters fonts. */ 40 /* */ 41 /* <Description> */ 42 /* The following types and functions are used to manage Multiple */ 43 /* Master fonts, i.e., the selection of specific design instances by */ 44 /* setting design axis coordinates. */ 45 /* */ 46 /* George Williams has extended this interface to make it work with */ 47 /* both Type~1 Multiple Masters fonts and GX distortable (var) */ 48 /* fonts. Some of these routines only work with MM fonts, others */ 49 /* will work with both types. They are similar enough that a */ 50 /* consistent interface makes sense. */ 51 /* */ 52 /*************************************************************************/ 53 54 55 /*************************************************************************/ 56 /* */ 57 /* <Struct> */ 58 /* FT_MM_Axis */ 59 /* */ 60 /* <Description> */ 61 /* A simple structure used to model a given axis in design space for */ 62 /* Multiple Masters fonts. */ 63 /* */ 64 /* This structure can't be used for GX var fonts. */ 65 /* */ 66 /* <Fields> */ 67 /* name :: The axis's name. */ 68 /* */ 69 /* minimum :: The axis's minimum design coordinate. */ 70 /* */ 71 /* maximum :: The axis's maximum design coordinate. */ 72 /* */ 73 typedef struct FT_MM_Axis_ 74 { 75 FT_String* name; 76 FT_Long minimum; 77 FT_Long maximum; 78 79 } FT_MM_Axis; 80 81 82 /*************************************************************************/ 83 /* */ 84 /* <Struct> */ 85 /* FT_Multi_Master */ 86 /* */ 87 /* <Description> */ 88 /* A structure used to model the axes and space of a Multiple Masters */ 89 /* font. */ 90 /* */ 91 /* This structure can't be used for GX var fonts. */ 92 /* */ 93 /* <Fields> */ 94 /* num_axis :: Number of axes. Cannot exceed~4. */ 95 /* */ 96 /* num_designs :: Number of designs; should be normally 2^num_axis */ 97 /* even though the Type~1 specification strangely */ 98 /* allows for intermediate designs to be present. */ 99 /* This number cannot exceed~16. */ 100 /* */ 101 /* axis :: A table of axis descriptors. */ 102 /* */ 103 typedef struct FT_Multi_Master_ 104 { 105 FT_UInt num_axis; 106 FT_UInt num_designs; 107 FT_MM_Axis axis[T1_MAX_MM_AXIS]; 108 109 } FT_Multi_Master; 110 111 112 /*************************************************************************/ 113 /* */ 114 /* <Struct> */ 115 /* FT_Var_Axis */ 116 /* */ 117 /* <Description> */ 118 /* A simple structure used to model a given axis in design space for */ 119 /* Multiple Masters and GX var fonts. */ 120 /* */ 121 /* <Fields> */ 122 /* name :: The axis's name. */ 123 /* Not always meaningful for GX. */ 124 /* */ 125 /* minimum :: The axis's minimum design coordinate. */ 126 /* */ 127 /* def :: The axis's default design coordinate. */ 128 /* FreeType computes meaningful default values for MM; it */ 129 /* is then an integer value, not in 16.16 format. */ 130 /* */ 131 /* maximum :: The axis's maximum design coordinate. */ 132 /* */ 133 /* tag :: The axis's tag (the GX equivalent to `name'). */ 134 /* FreeType provides default values for MM if possible. */ 135 /* */ 136 /* strid :: The entry in `name' table (another GX version of */ 137 /* `name'). */ 138 /* Not meaningful for MM. */ 139 /* */ 140 typedef struct FT_Var_Axis_ 141 { 142 FT_String* name; 143 144 FT_Fixed minimum; 145 FT_Fixed def; 146 FT_Fixed maximum; 147 148 FT_ULong tag; 149 FT_UInt strid; 150 151 } FT_Var_Axis; 152 153 154 /*************************************************************************/ 155 /* */ 156 /* <Struct> */ 157 /* FT_Var_Named_Style */ 158 /* */ 159 /* <Description> */ 160 /* A simple structure used to model a named style in a GX var font. */ 161 /* */ 162 /* This structure can't be used for MM fonts. */ 163 /* */ 164 /* <Fields> */ 165 /* coords :: The design coordinates for this style. */ 166 /* This is an array with one entry for each axis. */ 167 /* */ 168 /* strid :: The entry in `name' table identifying this style. */ 169 /* */ 170 typedef struct FT_Var_Named_Style_ 171 { 172 FT_Fixed* coords; 173 FT_UInt strid; 174 175 } FT_Var_Named_Style; 176 177 178 /*************************************************************************/ 179 /* */ 180 /* <Struct> */ 181 /* FT_MM_Var */ 182 /* */ 183 /* <Description> */ 184 /* A structure used to model the axes and space of a Multiple Masters */ 185 /* or GX var distortable font. */ 186 /* */ 187 /* Some fields are specific to one format and not to the other. */ 188 /* */ 189 /* <Fields> */ 190 /* num_axis :: The number of axes. The maximum value is~4 for */ 191 /* MM; no limit in GX. */ 192 /* */ 193 /* num_designs :: The number of designs; should be normally */ 194 /* 2^num_axis for MM fonts. Not meaningful for GX */ 195 /* (where every glyph could have a different */ 196 /* number of designs). */ 197 /* */ 198 /* num_namedstyles :: The number of named styles; only meaningful for */ 199 /* GX that allows certain design coordinates to */ 200 /* have a string ID (in the `name' table) */ 201 /* associated with them. The font can tell the */ 202 /* user that, for example, Weight=1.5 is `Bold'. */ 203 /* */ 204 /* axis :: An axis descriptor table. */ 205 /* GX fonts contain slightly more data than MM. */ 206 /* */ 207 /* namedstyle :: A named style table. */ 208 /* Only meaningful with GX. */ 209 /* */ 210 typedef struct FT_MM_Var_ 211 { 212 FT_UInt num_axis; 213 FT_UInt num_designs; 214 FT_UInt num_namedstyles; 215 FT_Var_Axis* axis; 216 FT_Var_Named_Style* namedstyle; 217 218 } FT_MM_Var; 219 220 221 /*************************************************************************/ 222 /* */ 223 /* <Function> */ 224 /* FT_Get_Multi_Master */ 225 /* */ 226 /* <Description> */ 227 /* Retrieve the Multiple Master descriptor of a given font. */ 228 /* */ 229 /* This function can't be used with GX fonts. */ 230 /* */ 231 /* <Input> */ 232 /* face :: A handle to the source face. */ 233 /* */ 234 /* <Output> */ 235 /* amaster :: The Multiple Masters descriptor. */ 236 /* */ 237 /* <Return> */ 238 /* FreeType error code. 0~means success. */ 239 /* */ 240 FT_EXPORT( FT_Error ) 241 FT_Get_Multi_Master( FT_Face face, 242 FT_Multi_Master *amaster ); 243 244 245 /*************************************************************************/ 246 /* */ 247 /* <Function> */ 248 /* FT_Get_MM_Var */ 249 /* */ 250 /* <Description> */ 251 /* Retrieve the Multiple Master/GX var descriptor of a given font. */ 252 /* */ 253 /* <Input> */ 254 /* face :: A handle to the source face. */ 255 /* */ 256 /* <Output> */ 257 /* amaster :: The Multiple Masters/GX var descriptor. */ 258 /* Allocates a data structure, which the user must free. */ 259 /* */ 260 /* <Return> */ 261 /* FreeType error code. 0~means success. */ 262 /* */ 263 FT_EXPORT( FT_Error ) 264 FT_Get_MM_Var( FT_Face face, 265 FT_MM_Var* *amaster ); 266 267 268 /*************************************************************************/ 269 /* */ 270 /* <Function> */ 271 /* FT_Set_MM_Design_Coordinates */ 272 /* */ 273 /* <Description> */ 274 /* For Multiple Masters fonts, choose an interpolated font design */ 275 /* through design coordinates. */ 276 /* */ 277 /* This function can't be used with GX fonts. */ 278 /* */ 279 /* <InOut> */ 280 /* face :: A handle to the source face. */ 281 /* */ 282 /* <Input> */ 283 /* num_coords :: The number of available design coordinates. If it */ 284 /* is larger than the number of axes, ignore the excess */ 285 /* values. If it is smaller than the number of axes, */ 286 /* use default values for the remaining axes. */ 287 /* */ 288 /* coords :: An array of design coordinates. */ 289 /* */ 290 /* <Return> */ 291 /* FreeType error code. 0~means success. */ 292 /* */ 293 FT_EXPORT( FT_Error ) 294 FT_Set_MM_Design_Coordinates( FT_Face face, 295 FT_UInt num_coords, 296 FT_Long* coords ); 297 298 299 /*************************************************************************/ 300 /* */ 301 /* <Function> */ 302 /* FT_Set_Var_Design_Coordinates */ 303 /* */ 304 /* <Description> */ 305 /* For Multiple Master or GX Var fonts, choose an interpolated font */ 306 /* design through design coordinates. */ 307 /* */ 308 /* <InOut> */ 309 /* face :: A handle to the source face. */ 310 /* */ 311 /* <Input> */ 312 /* num_coords :: The number of available design coordinates. If it */ 313 /* is larger than the number of axes, ignore the excess */ 314 /* values. If it is smaller than the number of axes, */ 315 /* use default values for the remaining axes. */ 316 /* */ 317 /* coords :: An array of design coordinates. */ 318 /* */ 319 /* <Return> */ 320 /* FreeType error code. 0~means success. */ 321 /* */ 322 FT_EXPORT( FT_Error ) 323 FT_Set_Var_Design_Coordinates( FT_Face face, 324 FT_UInt num_coords, 325 FT_Fixed* coords ); 326 327 328 /*************************************************************************/ 329 /* */ 330 /* <Function> */ 331 /* FT_Set_MM_Blend_Coordinates */ 332 /* */ 333 /* <Description> */ 334 /* For Multiple Masters and GX var fonts, choose an interpolated font */ 335 /* design through normalized blend coordinates. */ 336 /* */ 337 /* <InOut> */ 338 /* face :: A handle to the source face. */ 339 /* */ 340 /* <Input> */ 341 /* num_coords :: The number of available design coordinates. If it */ 342 /* is larger than the number of axes, ignore the excess */ 343 /* values. If it is smaller than the number of axes, */ 344 /* use default values for the remaining axes. */ 345 /* */ 346 /* coords :: The design coordinates array (each element must be */ 347 /* between 0 and 1.0). */ 348 /* */ 349 /* <Return> */ 350 /* FreeType error code. 0~means success. */ 351 /* */ 352 FT_EXPORT( FT_Error ) 353 FT_Set_MM_Blend_Coordinates( FT_Face face, 354 FT_UInt num_coords, 355 FT_Fixed* coords ); 356 357 358 /*************************************************************************/ 359 /* */ 360 /* <Function> */ 361 /* FT_Set_Var_Blend_Coordinates */ 362 /* */ 363 /* <Description> */ 364 /* This is another name of @FT_Set_MM_Blend_Coordinates. */ 365 /* */ 366 FT_EXPORT( FT_Error ) 367 FT_Set_Var_Blend_Coordinates( FT_Face face, 368 FT_UInt num_coords, 369 FT_Fixed* coords ); 370 371 /* */ 372 373 374 FT_END_HEADER 375 376 #endif /* __FTMM_H__ */ 377 378 379 /* END */ 380
