1 /***************************************************************************/ 2 /* */ 3 /* ttobjs.h */ 4 /* */ 5 /* Objects manager (specification). */ 6 /* */ 7 /* Copyright 1996-2009, 2011 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 <plugin/FT_fontsys/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_UInt opc; /* function #, or instruction code */ 179 FT_Bool active; /* is it active? */ 180 181 } TT_DefRecord, *TT_DefArray; 182 183 184 /*************************************************************************/ 185 /* */ 186 /* Subglyph transformation record. */ 187 /* */ 188 typedef struct TT_Transform_ 189 { 190 FT_Fixed xx, xy; /* transformation matrix coefficients */ 191 FT_Fixed yx, yy; 192 FT_F26Dot6 ox, oy; /* offsets */ 193 194 } TT_Transform; 195 196 197 /*************************************************************************/ 198 /* */ 199 /* A note regarding non-squared pixels: */ 200 /* */ 201 /* (This text will probably go into some docs at some time; for now, it */ 202 /* is kept here to explain some definitions in the TT_Size_Metrics */ 203 /* record). */ 204 /* */ 205 /* The CVT is a one-dimensional array containing values that control */ 206 /* certain important characteristics in a font, like the height of all */ 207 /* capitals, all lowercase letter, default spacing or stem width/height. */ 208 /* */ 209 /* These values are found in FUnits in the font file, and must be scaled */ 210 /* to pixel coordinates before being used by the CVT and glyph programs. */ 211 /* Unfortunately, when using distinct x and y resolutions (or distinct x */ 212 /* and y pointsizes), there are two possible scalings. */ 213 /* */ 214 /* A first try was to implement a `lazy' scheme where all values were */ 215 /* scaled when first used. However, while some values are always used */ 216 /* in the same direction, some others are used under many different */ 217 /* circumstances and orientations. */ 218 /* */ 219 /* I have found a simpler way to do the same, and it even seems to work */ 220 /* in most of the cases: */ 221 /* */ 222 /* - All CVT values are scaled to the maximum ppem size. */ 223 /* */ 224 /* - When performing a read or write in the CVT, a ratio factor is used */ 225 /* to perform adequate scaling. Example: */ 226 /* */ 227 /* x_ppem = 14 */ 228 /* y_ppem = 10 */ 229 /* */ 230 /* We choose ppem = x_ppem = 14 as the CVT scaling size. All cvt */ 231 /* entries are scaled to it. */ 232 /* */ 233 /* x_ratio = 1.0 */ 234 /* y_ratio = y_ppem/ppem (< 1.0) */ 235 /* */ 236 /* We compute the current ratio like: */ 237 /* */ 238 /* - If projVector is horizontal, */ 239 /* ratio = x_ratio = 1.0 */ 240 /* */ 241 /* - if projVector is vertical, */ 242 /* ratio = y_ratio */ 243 /* */ 244 /* - else, */ 245 /* ratio = sqrt( (proj.x * x_ratio) ^ 2 + (proj.y * y_ratio) ^ 2 ) */ 246 /* */ 247 /* Reading a cvt value returns */ 248 /* ratio * cvt[index] */ 249 /* */ 250 /* Writing a cvt value in pixels: */ 251 /* cvt[index] / ratio */ 252 /* */ 253 /* The current ppem is simply */ 254 /* ratio * ppem */ 255 /* */ 256 /*************************************************************************/ 257 258 259 /*************************************************************************/ 260 /* */ 261 /* Metrics used by the TrueType size and context objects. */ 262 /* */ 263 typedef struct TT_Size_Metrics_ 264 { 265 /* for non-square pixels */ 266 FT_Long x_ratio; 267 FT_Long y_ratio; 268 269 FT_UShort ppem; /* maximum ppem size */ 270 FT_Long ratio; /* current ratio */ 271 FT_Fixed scale; 272 273 FT_F26Dot6 compensations[4]; /* device-specific compensations */ 274 275 FT_Bool valid; 276 277 FT_Bool rotated; /* `is the glyph rotated?'-flag */ 278 FT_Bool stretched; /* `is the glyph stretched?'-flag */ 279 280 } TT_Size_Metrics; 281 282 283 /*************************************************************************/ 284 /* */ 285 /* TrueType size class. */ 286 /* */ 287 typedef struct TT_SizeRec_ 288 { 289 FT_SizeRec root; 290 291 /* we have our own copy of metrics so that we can modify */ 292 /* it without affecting auto-hinting (when used) */ 293 FT_Size_Metrics metrics; 294 295 TT_Size_Metrics ttmetrics; 296 297 FT_ULong strike_index; /* 0xFFFFFFFF to indicate invalid */ 298 299 #ifdef TT_USE_BYTECODE_INTERPRETER 300 301 FT_UInt num_function_defs; /* number of function definitions */ 302 FT_UInt max_function_defs; 303 TT_DefArray function_defs; /* table of function definitions */ 304 305 FT_UInt num_instruction_defs; /* number of ins. definitions */ 306 FT_UInt max_instruction_defs; 307 TT_DefArray instruction_defs; /* table of ins. definitions */ 308 309 FT_UInt max_func; 310 FT_UInt max_ins; 311 312 TT_CodeRangeTable codeRangeTable; 313 314 TT_GraphicsState GS; 315 316 FT_ULong cvt_size; /* the scaled control value table */ 317 FT_Long* cvt; 318 319 FT_UShort storage_size; /* The storage area is now part of */ 320 FT_Long* storage; /* the instance */ 321 322 TT_GlyphZoneRec twilight; /* The instance's twilight zone */ 323 324 /* debugging variables */ 325 326 /* When using the debugger, we must keep the */ 327 /* execution context tied to the instance */ 328 /* object rather than asking it on demand. */ 329 330 FT_Bool debug; 331 TT_ExecContext context; 332 333 FT_Bool bytecode_ready; 334 FT_Bool cvt_ready; 335 336 #endif /* TT_USE_BYTECODE_INTERPRETER */ 337 338 } TT_SizeRec; 339 340 341 /*************************************************************************/ 342 /* */ 343 /* TrueType driver class. */ 344 /* */ 345 typedef struct TT_DriverRec_ 346 { 347 FT_DriverRec root; 348 TT_ExecContext context; /* execution context */ 349 TT_GlyphZoneRec zone; /* glyph loader points zone */ 350 351 void* extension_component; 352 353 } TT_DriverRec; 354 355 356 /* Note: All of the functions below (except tt_size_reset()) are used */ 357 /* as function pointers in a FT_Driver_ClassRec. Therefore their */ 358 /* parameters are of types FT_Face, FT_Size, etc., rather than TT_Face, */ 359 /* TT_Size, etc., so that the compiler can confirm that the types and */ 360 /* number of parameters are correct. In all cases the FT_xxx types are */ 361 /* cast to their TT_xxx counterparts inside the functions since FreeType */ 362 /* will always use the TT driver to create them. */ 363 364 365 /*************************************************************************/ 366 /* */ 367 /* Face functions */ 368 /* */ 369 FT_LOCAL( FT_Error ) 370 tt_face_init( FT_Stream stream, 371 FT_Face ttface, /* TT_Face */ 372 FT_Int face_index, 373 FT_Int num_params, 374 FT_Parameter* params ); 375 376 FT_LOCAL( void ) 377 tt_face_done( FT_Face ttface ); /* TT_Face */ 378 379 380 /*************************************************************************/ 381 /* */ 382 /* Size functions */ 383 /* */ 384 FT_LOCAL( FT_Error ) 385 tt_size_init( FT_Size ttsize ); /* TT_Size */ 386 387 FT_LOCAL( void ) 388 tt_size_done( FT_Size ttsize ); /* TT_Size */ 389 390 #ifdef TT_USE_BYTECODE_INTERPRETER 391 392 FT_LOCAL( FT_Error ) 393 tt_size_run_fpgm( TT_Size size, 394 FT_Bool pedantic ); 395 396 FT_LOCAL( FT_Error ) 397 tt_size_run_prep( TT_Size size, 398 FT_Bool pedantic ); 399 400 FT_LOCAL( FT_Error ) 401 tt_size_ready_bytecode( TT_Size size, 402 FT_Bool pedantic ); 403 404 #endif /* TT_USE_BYTECODE_INTERPRETER */ 405 406 FT_LOCAL( FT_Error ) 407 tt_size_reset( TT_Size size ); 408 409 410 /*************************************************************************/ 411 /* */ 412 /* Driver functions */ 413 /* */ 414 FT_LOCAL( FT_Error ) 415 tt_driver_init( FT_Module ttdriver ); /* TT_Driver */ 416 417 FT_LOCAL( void ) 418 tt_driver_done( FT_Module ttdriver ); /* TT_Driver */ 419 420 421 /*************************************************************************/ 422 /* */ 423 /* Slot functions */ 424 /* */ 425 FT_LOCAL( FT_Error ) 426 tt_slot_init( FT_GlyphSlot slot ); 427 428 429 FT_END_HEADER 430 431 #endif /* __TTOBJS_H__ */ 432 433 434 /* END */ 435