1 /***************************************************************************/ 2 /* */ 3 /* ttobjs.h */ 4 /* */ 5 /* Objects manager (specification). */ 6 /* */ 7 /* Copyright 1996-2009, 2011-2012 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 __TTOBJS_H__ 20 #define __TTOBJS_H__ 21 22 23 #include <ft2build.h> 24 #include FT_INTERNAL_OBJECTS_H 25 #include FT_INTERNAL_TRUETYPE_TYPES_H 26 27 28 FT_BEGIN_HEADER 29 30 31 /*************************************************************************/ 32 /* */ 33 /* <Type> */ 34 /* TT_Driver */ 35 /* */ 36 /* <Description> */ 37 /* A handle to a TrueType driver object. */ 38 /* */ 39 typedef struct TT_DriverRec_* TT_Driver; 40 41 42 /*************************************************************************/ 43 /* */ 44 /* <Type> */ 45 /* TT_Instance */ 46 /* */ 47 /* <Description> */ 48 /* A handle to a TrueType size object. */ 49 /* */ 50 typedef struct TT_SizeRec_* TT_Size; 51 52 53 /*************************************************************************/ 54 /* */ 55 /* <Type> */ 56 /* TT_GlyphSlot */ 57 /* */ 58 /* <Description> */ 59 /* A handle to a TrueType glyph slot object. */ 60 /* */ 61 /* <Note> */ 62 /* This is a direct typedef of FT_GlyphSlot, as there is nothing */ 63 /* specific about the TrueType glyph slot. */ 64 /* */ 65 typedef FT_GlyphSlot TT_GlyphSlot; 66 67 68 /*************************************************************************/ 69 /* */ 70 /* <Struct> */ 71 /* TT_GraphicsState */ 72 /* */ 73 /* <Description> */ 74 /* The TrueType graphics state used during bytecode interpretation. */ 75 /* */ 76 typedef struct TT_GraphicsState_ 77 { 78 FT_UShort rp0; 79 FT_UShort rp1; 80 FT_UShort rp2; 81 82 FT_UnitVector dualVector; 83 FT_UnitVector projVector; 84 FT_UnitVector freeVector; 85 86 #ifdef TT_CONFIG_OPTION_UNPATENTED_HINTING 87 FT_Bool both_x_axis; 88 #endif 89 90 FT_Long loop; 91 FT_F26Dot6 minimum_distance; 92 FT_Int round_state; 93 94 FT_Bool auto_flip; 95 FT_F26Dot6 control_value_cutin; 96 FT_F26Dot6 single_width_cutin; 97 FT_F26Dot6 single_width_value; 98 FT_Short delta_base; 99 FT_Short delta_shift; 100 101 FT_Byte instruct_control; 102 /* According to Greg Hitchcock from Microsoft, the `scan_control' */ 103 /* variable as documented in the TrueType specification is a 32-bit */ 104 /* integer; the high-word part holds the SCANTYPE value, the low-word */ 105 /* part the SCANCTRL value. We separate it into two fields. */ 106 FT_Bool scan_control; 107 FT_Int scan_type; 108 109 FT_UShort gep0; 110 FT_UShort gep1; 111 FT_UShort gep2; 112 113 } TT_GraphicsState; 114 115 116 #ifdef TT_USE_BYTECODE_INTERPRETER 117 118 FT_LOCAL( void ) 119 tt_glyphzone_done( TT_GlyphZone zone ); 120 121 FT_LOCAL( FT_Error ) 122 tt_glyphzone_new( FT_Memory memory, 123 FT_UShort maxPoints, 124 FT_Short maxContours, 125 TT_GlyphZone zone ); 126 127 #endif /* TT_USE_BYTECODE_INTERPRETER */ 128 129 130 131 /*************************************************************************/ 132 /* */ 133 /* EXECUTION SUBTABLES */ 134 /* */ 135 /* These sub-tables relate to instruction execution. */ 136 /* */ 137 /*************************************************************************/ 138 139 140 #define TT_MAX_CODE_RANGES 3 141 142 143 /*************************************************************************/ 144 /* */ 145 /* There can only be 3 active code ranges at once: */ 146 /* - the Font Program */ 147 /* - the CVT Program */ 148 /* - a glyph's instructions set */ 149 /* */ 150 typedef enum TT_CodeRange_Tag_ 151 { 152 tt_coderange_none = 0, 153 tt_coderange_font, 154 tt_coderange_cvt, 155 tt_coderange_glyph 156 157 } TT_CodeRange_Tag; 158 159 160 typedef struct TT_CodeRange_ 161 { 162 FT_Byte* base; 163 FT_ULong size; 164 165 } TT_CodeRange; 166 167 typedef TT_CodeRange TT_CodeRangeTable[TT_MAX_CODE_RANGES]; 168 169 170 /*************************************************************************/ 171 /* */ 172 /* Defines a function/instruction definition record. */ 173 /* */ 174 typedef struct TT_DefRecord_ 175 { 176 FT_Int range; /* in which code range is it located? */ 177 FT_Long start; /* where does it start? */ 178 FT_Long end; /* where does it end? */ 179 FT_UInt opc; /* function #, or instruction code */ 180 FT_Bool active; /* is it active? */ 181 182 } TT_DefRecord, *TT_DefArray; 183 184 185 /*************************************************************************/ 186 /* */ 187 /* Subglyph transformation record. */ 188 /* */ 189 typedef struct TT_Transform_ 190 { 191 FT_Fixed xx, xy; /* transformation matrix coefficients */ 192 FT_Fixed yx, yy; 193 FT_F26Dot6 ox, oy; /* offsets */ 194 195 } TT_Transform; 196 197 198 /*************************************************************************/ 199 /* */ 200 /* A note regarding non-squared pixels: */ 201 /* */ 202 /* (This text will probably go into some docs at some time; for now, it */ 203 /* is kept here to explain some definitions in the TT_Size_Metrics */ 204 /* record). */ 205 /* */ 206 /* The CVT is a one-dimensional array containing values that control */ 207 /* certain important characteristics in a font, like the height of all */ 208 /* capitals, all lowercase letter, default spacing or stem width/height. */ 209 /* */ 210 /* These values are found in FUnits in the font file, and must be scaled */ 211 /* to pixel coordinates before being used by the CVT and glyph programs. */ 212 /* Unfortunately, when using distinct x and y resolutions (or distinct x */ 213 /* and y pointsizes), there are two possible scalings. */ 214 /* */ 215 /* A first try was to implement a `lazy' scheme where all values were */ 216 /* scaled when first used. However, while some values are always used */ 217 /* in the same direction, some others are used under many different */ 218 /* circumstances and orientations. */ 219 /* */ 220 /* I have found a simpler way to do the same, and it even seems to work */ 221 /* in most of the cases: */ 222 /* */ 223 /* - All CVT values are scaled to the maximum ppem size. */ 224 /* */ 225 /* - When performing a read or write in the CVT, a ratio factor is used */ 226 /* to perform adequate scaling. Example: */ 227 /* */ 228 /* x_ppem = 14 */ 229 /* y_ppem = 10 */ 230 /* */ 231 /* We choose ppem = x_ppem = 14 as the CVT scaling size. All cvt */ 232 /* entries are scaled to it. */ 233 /* */ 234 /* x_ratio = 1.0 */ 235 /* y_ratio = y_ppem/ppem (< 1.0) */ 236 /* */ 237 /* We compute the current ratio like: */ 238 /* */ 239 /* - If projVector is horizontal, */ 240 /* ratio = x_ratio = 1.0 */ 241 /* */ 242 /* - if projVector is vertical, */ 243 /* ratio = y_ratio */ 244 /* */ 245 /* - else, */ 246 /* ratio = sqrt( (proj.x * x_ratio) ^ 2 + (proj.y * y_ratio) ^ 2 ) */ 247 /* */ 248 /* Reading a cvt value returns */ 249 /* ratio * cvt[index] */ 250 /* */ 251 /* Writing a cvt value in pixels: */ 252 /* cvt[index] / ratio */ 253 /* */ 254 /* The current ppem is simply */ 255 /* ratio * ppem */ 256 /* */ 257 /*************************************************************************/ 258 259 260 /*************************************************************************/ 261 /* */ 262 /* Metrics used by the TrueType size and context objects. */ 263 /* */ 264 typedef struct TT_Size_Metrics_ 265 { 266 /* for non-square pixels */ 267 FT_Long x_ratio; 268 FT_Long y_ratio; 269 270 FT_UShort ppem; /* maximum ppem size */ 271 FT_Long ratio; /* current ratio */ 272 FT_Fixed scale; 273 274 FT_F26Dot6 compensations[4]; /* device-specific compensations */ 275 276 FT_Bool valid; 277 278 FT_Bool rotated; /* `is the glyph rotated?'-flag */ 279 FT_Bool stretched; /* `is the glyph stretched?'-flag */ 280 281 } TT_Size_Metrics; 282 283 284 /*************************************************************************/ 285 /* */ 286 /* TrueType size class. */ 287 /* */ 288 typedef struct TT_SizeRec_ 289 { 290 FT_SizeRec root; 291 292 /* we have our own copy of metrics so that we can modify */ 293 /* it without affecting auto-hinting (when used) */ 294 FT_Size_Metrics metrics; 295 296 TT_Size_Metrics ttmetrics; 297 298 FT_ULong strike_index; /* 0xFFFFFFFF to indicate invalid */ 299 300 #ifdef TT_USE_BYTECODE_INTERPRETER 301 302 FT_UInt num_function_defs; /* number of function definitions */ 303 FT_UInt max_function_defs; 304 TT_DefArray function_defs; /* table of function definitions */ 305 306 FT_UInt num_instruction_defs; /* number of ins. definitions */ 307 FT_UInt max_instruction_defs; 308 TT_DefArray instruction_defs; /* table of ins. definitions */ 309 310 FT_UInt max_func; 311 FT_UInt max_ins; 312 313 TT_CodeRangeTable codeRangeTable; 314 315 TT_GraphicsState GS; 316 317 FT_ULong cvt_size; /* the scaled control value table */ 318 FT_Long* cvt; 319 320 FT_UShort storage_size; /* The storage area is now part of */ 321 FT_Long* storage; /* the instance */ 322 323 TT_GlyphZoneRec twilight; /* The instance's twilight zone */ 324 325 /* debugging variables */ 326 327 /* When using the debugger, we must keep the */ 328 /* execution context tied to the instance */ 329 /* object rather than asking it on demand. */ 330 331 FT_Bool debug; 332 TT_ExecContext context; 333 334 FT_Bool bytecode_ready; 335 FT_Bool cvt_ready; 336 337 #endif /* TT_USE_BYTECODE_INTERPRETER */ 338 339 } TT_SizeRec; 340 341 342 /*************************************************************************/ 343 /* */ 344 /* TrueType driver class. */ 345 /* */ 346 typedef struct TT_DriverRec_ 347 { 348 FT_DriverRec root; 349 TT_ExecContext context; /* execution context */ 350 TT_GlyphZoneRec zone; /* glyph loader points zone */ 351 352 void* extension_component; 353 354 } TT_DriverRec; 355 356 357 /* Note: All of the functions below (except tt_size_reset()) are used */ 358 /* as function pointers in a FT_Driver_ClassRec. Therefore their */ 359 /* parameters are of types FT_Face, FT_Size, etc., rather than TT_Face, */ 360 /* TT_Size, etc., so that the compiler can confirm that the types and */ 361 /* number of parameters are correct. In all cases the FT_xxx types are */ 362 /* cast to their TT_xxx counterparts inside the functions since FreeType */ 363 /* will always use the TT driver to create them. */ 364 365 366 /*************************************************************************/ 367 /* */ 368 /* Face functions */ 369 /* */ 370 FT_LOCAL( FT_Error ) 371 tt_face_init( FT_Stream stream, 372 FT_Face ttface, /* TT_Face */ 373 FT_Int face_index, 374 FT_Int num_params, 375 FT_Parameter* params ); 376 377 FT_LOCAL( void ) 378 tt_face_done( FT_Face ttface ); /* TT_Face */ 379 380 381 /*************************************************************************/ 382 /* */ 383 /* Size functions */ 384 /* */ 385 FT_LOCAL( FT_Error ) 386 tt_size_init( FT_Size ttsize ); /* TT_Size */ 387 388 FT_LOCAL( void ) 389 tt_size_done( FT_Size ttsize ); /* TT_Size */ 390 391 #ifdef TT_USE_BYTECODE_INTERPRETER 392 393 FT_LOCAL( FT_Error ) 394 tt_size_run_fpgm( TT_Size size, 395 FT_Bool pedantic ); 396 397 FT_LOCAL( FT_Error ) 398 tt_size_run_prep( TT_Size size, 399 FT_Bool pedantic ); 400 401 FT_LOCAL( FT_Error ) 402 tt_size_ready_bytecode( TT_Size size, 403 FT_Bool pedantic ); 404 405 #endif /* TT_USE_BYTECODE_INTERPRETER */ 406 407 FT_LOCAL( FT_Error ) 408 tt_size_reset( TT_Size size ); 409 410 411 /*************************************************************************/ 412 /* */ 413 /* Driver functions */ 414 /* */ 415 FT_LOCAL( FT_Error ) 416 tt_driver_init( FT_Module ttdriver ); /* TT_Driver */ 417 418 FT_LOCAL( void ) 419 tt_driver_done( FT_Module ttdriver ); /* TT_Driver */ 420 421 422 /*************************************************************************/ 423 /* */ 424 /* Slot functions */ 425 /* */ 426 FT_LOCAL( FT_Error ) 427 tt_slot_init( FT_GlyphSlot slot ); 428 429 430 FT_END_HEADER 431 432 #endif /* __TTOBJS_H__ */ 433 434 435 /* END */ 436
