1 /***************************************************************************/ 2 /* */ 3 /* ttinterp.h */ 4 /* */ 5 /* TrueType bytecode interpreter (specification). */ 6 /* */ 7 /* Copyright 1996-2007, 2010, 2012-2013 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 __TTINTERP_H__ 20 #define __TTINTERP_H__ 21 22 #include <ft2build.h> 23 #include "ttobjs.h" 24 25 26 FT_BEGIN_HEADER 27 28 29 #ifndef TT_CONFIG_OPTION_STATIC_INTERPRETER /* indirect implementation */ 30 31 #define EXEC_OP_ TT_ExecContext exc, 32 #define EXEC_OP TT_ExecContext exc 33 #define EXEC_ARG_ exc, 34 #define EXEC_ARG exc 35 36 #else /* static implementation */ 37 38 #define EXEC_OP_ /* void */ 39 #define EXEC_OP /* void */ 40 #define EXEC_ARG_ /* void */ 41 #define EXEC_ARG /* void */ 42 43 #endif /* TT_CONFIG_OPTION_STATIC_INTERPRETER */ 44 45 46 /*************************************************************************/ 47 /* */ 48 /* Rounding mode constants. */ 49 /* */ 50 #define TT_Round_Off 5 51 #define TT_Round_To_Half_Grid 0 52 #define TT_Round_To_Grid 1 53 #define TT_Round_To_Double_Grid 2 54 #define TT_Round_Up_To_Grid 4 55 #define TT_Round_Down_To_Grid 3 56 #define TT_Round_Super 6 57 #define TT_Round_Super_45 7 58 59 60 /*************************************************************************/ 61 /* */ 62 /* Function types used by the interpreter, depending on various modes */ 63 /* (e.g. the rounding mode, whether to render a vertical or horizontal */ 64 /* line etc). */ 65 /* */ 66 /*************************************************************************/ 67 68 /* Rounding function */ 69 typedef FT_F26Dot6 70 (*TT_Round_Func)( EXEC_OP_ FT_F26Dot6 distance, 71 FT_F26Dot6 compensation ); 72 73 /* Point displacement along the freedom vector routine */ 74 typedef void 75 (*TT_Move_Func)( EXEC_OP_ TT_GlyphZone zone, 76 FT_UShort point, 77 FT_F26Dot6 distance ); 78 79 /* Distance projection along one of the projection vectors */ 80 typedef FT_F26Dot6 81 (*TT_Project_Func)( EXEC_OP_ FT_Pos dx, 82 FT_Pos dy ); 83 84 /* reading a cvt value. Take care of non-square pixels if necessary */ 85 typedef FT_F26Dot6 86 (*TT_Get_CVT_Func)( EXEC_OP_ FT_ULong idx ); 87 88 /* setting or moving a cvt value. Take care of non-square pixels */ 89 /* if necessary */ 90 typedef void 91 (*TT_Set_CVT_Func)( EXEC_OP_ FT_ULong idx, 92 FT_F26Dot6 value ); 93 94 95 /*************************************************************************/ 96 /* */ 97 /* This structure defines a call record, used to manage function calls. */ 98 /* */ 99 typedef struct TT_CallRec_ 100 { 101 FT_Int Caller_Range; 102 FT_Long Caller_IP; 103 FT_Long Cur_Count; 104 FT_Long Cur_Restart; 105 FT_Long Cur_End; 106 107 } TT_CallRec, *TT_CallStack; 108 109 110 #ifdef TT_CONFIG_OPTION_SUBPIXEL_HINTING 111 112 /*************************************************************************/ 113 /* */ 114 /* These structures define rules used to tweak subpixel hinting for */ 115 /* various fonts. "", 0, "", NULL value indicates to match any value. */ 116 /* */ 117 118 #define SPH_MAX_NAME_SIZE 32 119 #define SPH_MAX_CLASS_MEMBERS 100 120 121 typedef struct SPH_TweakRule_ 122 { 123 const char family[SPH_MAX_NAME_SIZE]; 124 const FT_UInt ppem; 125 const char style[SPH_MAX_NAME_SIZE]; 126 const FT_ULong glyph; 127 128 } SPH_TweakRule; 129 130 131 typedef struct SPH_ScaleRule_ 132 { 133 const char family[SPH_MAX_NAME_SIZE]; 134 const FT_UInt ppem; 135 const char style[SPH_MAX_NAME_SIZE]; 136 const FT_ULong glyph; 137 const FT_ULong scale; 138 139 } SPH_ScaleRule; 140 141 142 typedef struct SPH_Font_Class_ 143 { 144 const char name[SPH_MAX_NAME_SIZE]; 145 const char member[SPH_MAX_CLASS_MEMBERS][SPH_MAX_NAME_SIZE]; 146 147 } SPH_Font_Class; 148 149 #endif /* TT_CONFIG_OPTION_SUBPIXEL_HINTING */ 150 151 152 /*************************************************************************/ 153 /* */ 154 /* The main structure for the interpreter which collects all necessary */ 155 /* variables and states. */ 156 /* */ 157 typedef struct TT_ExecContextRec_ 158 { 159 TT_Face face; 160 TT_Size size; 161 FT_Memory memory; 162 163 /* instructions state */ 164 165 FT_Error error; /* last execution error */ 166 167 FT_Long top; /* top of exec. stack */ 168 169 FT_UInt stackSize; /* size of exec. stack */ 170 FT_Long* stack; /* current exec. stack */ 171 172 FT_Long args; 173 FT_UInt new_top; /* new top after exec. */ 174 175 TT_GlyphZoneRec zp0, /* zone records */ 176 zp1, 177 zp2, 178 pts, 179 twilight; 180 181 FT_Size_Metrics metrics; 182 TT_Size_Metrics tt_metrics; /* size metrics */ 183 184 TT_GraphicsState GS; /* current graphics state */ 185 186 FT_Int curRange; /* current code range number */ 187 FT_Byte* code; /* current code range */ 188 FT_Long IP; /* current instruction pointer */ 189 FT_Long codeSize; /* size of current range */ 190 191 FT_Byte opcode; /* current opcode */ 192 FT_Int length; /* length of current opcode */ 193 194 FT_Bool step_ins; /* true if the interpreter must */ 195 /* increment IP after ins. exec */ 196 FT_ULong cvtSize; 197 FT_Long* cvt; 198 199 FT_UInt glyphSize; /* glyph instructions buffer size */ 200 FT_Byte* glyphIns; /* glyph instructions buffer */ 201 202 FT_UInt numFDefs; /* number of function defs */ 203 FT_UInt maxFDefs; /* maximum number of function defs */ 204 TT_DefArray FDefs; /* table of FDefs entries */ 205 206 FT_UInt numIDefs; /* number of instruction defs */ 207 FT_UInt maxIDefs; /* maximum number of ins defs */ 208 TT_DefArray IDefs; /* table of IDefs entries */ 209 210 FT_UInt maxFunc; /* maximum function index */ 211 FT_UInt maxIns; /* maximum instruction index */ 212 213 FT_Int callTop, /* top of call stack during execution */ 214 callSize; /* size of call stack */ 215 TT_CallStack callStack; /* call stack */ 216 217 FT_UShort maxPoints; /* capacity of this context's `pts' */ 218 FT_Short maxContours; /* record, expressed in points and */ 219 /* contours. */ 220 221 TT_CodeRangeTable codeRangeTable; /* table of valid code ranges */ 222 /* useful for the debugger */ 223 224 FT_UShort storeSize; /* size of current storage */ 225 FT_Long* storage; /* storage area */ 226 227 FT_F26Dot6 period; /* values used for the */ 228 FT_F26Dot6 phase; /* `SuperRounding' */ 229 FT_F26Dot6 threshold; 230 231 #if 0 232 /* this seems to be unused */ 233 FT_Int cur_ppem; /* ppem along the current proj vector */ 234 #endif 235 236 FT_Bool instruction_trap; /* If `True', the interpreter will */ 237 /* exit after each instruction */ 238 239 TT_GraphicsState default_GS; /* graphics state resulting from */ 240 /* the prep program */ 241 FT_Bool is_composite; /* true if the glyph is composite */ 242 FT_Bool pedantic_hinting; /* true if pedantic interpretation */ 243 244 /* latest interpreter additions */ 245 246 FT_Long F_dot_P; /* dot product of freedom and projection */ 247 /* vectors */ 248 TT_Round_Func func_round; /* current rounding function */ 249 250 TT_Project_Func func_project, /* current projection function */ 251 func_dualproj, /* current dual proj. function */ 252 func_freeProj; /* current freedom proj. func */ 253 254 TT_Move_Func func_move; /* current point move function */ 255 TT_Move_Func func_move_orig; /* move original position function */ 256 257 TT_Get_CVT_Func func_read_cvt; /* read a cvt entry */ 258 TT_Set_CVT_Func func_write_cvt; /* write a cvt entry (in pixels) */ 259 TT_Set_CVT_Func func_move_cvt; /* incr a cvt entry (in pixels) */ 260 261 FT_Bool grayscale; /* are we hinting for grayscale? */ 262 263 #ifdef TT_CONFIG_OPTION_SUBPIXEL_HINTING 264 TT_Round_Func func_round_sphn; /* subpixel rounding function */ 265 266 FT_Bool grayscale_hinting; /* Using grayscale hinting? */ 267 FT_Bool subpixel_hinting; /* Using subpixel hinting? */ 268 FT_Bool native_hinting; /* Using native hinting? */ 269 FT_Bool ignore_x_mode; /* Standard rendering mode for */ 270 /* subpixel hinting. On if gray */ 271 /* or subpixel hinting is on ) */ 272 273 /* The following 4 aren't fully implemented but here for MS rasterizer */ 274 /* compatibility. */ 275 FT_Bool compatible_widths; /* compatible widths? */ 276 FT_Bool symmetrical_smoothing; /* symmetrical_smoothing? */ 277 FT_Bool bgr; /* bgr instead of rgb? */ 278 FT_Bool subpixel_positioned; /* subpixel positioned */ 279 /* (DirectWrite ClearType)? */ 280 281 FT_Int rasterizer_version; /* MS rasterizer version */ 282 283 FT_Bool iup_called; /* IUP called for glyph? */ 284 285 FT_ULong sph_tweak_flags; /* flags to control */ 286 /* hint tweaks */ 287 288 FT_ULong sph_in_func_flags; /* flags to indicate if in */ 289 /* special functions */ 290 291 #endif /* TT_CONFIG_OPTION_SUBPIXEL_HINTING */ 292 293 } TT_ExecContextRec; 294 295 296 extern const TT_GraphicsState tt_default_graphics_state; 297 298 299 #ifdef TT_USE_BYTECODE_INTERPRETER 300 FT_LOCAL( FT_Error ) 301 TT_Goto_CodeRange( TT_ExecContext exec, 302 FT_Int range, 303 FT_Long IP ); 304 305 FT_LOCAL( FT_Error ) 306 TT_Set_CodeRange( TT_ExecContext exec, 307 FT_Int range, 308 void* base, 309 FT_Long length ); 310 311 FT_LOCAL( FT_Error ) 312 TT_Clear_CodeRange( TT_ExecContext exec, 313 FT_Int range ); 314 315 316 FT_LOCAL( FT_Error ) 317 Update_Max( FT_Memory memory, 318 FT_ULong* size, 319 FT_Long multiplier, 320 void* _pbuff, 321 FT_ULong new_max ); 322 #endif /* TT_USE_BYTECODE_INTERPRETER */ 323 324 325 /*************************************************************************/ 326 /* */ 327 /* <Function> */ 328 /* TT_New_Context */ 329 /* */ 330 /* <Description> */ 331 /* Queries the face context for a given font. Note that there is */ 332 /* now a _single_ execution context in the TrueType driver which is */ 333 /* shared among faces. */ 334 /* */ 335 /* <Input> */ 336 /* face :: A handle to the source face object. */ 337 /* */ 338 /* <Return> */ 339 /* A handle to the execution context. Initialized for `face'. */ 340 /* */ 341 /* <Note> */ 342 /* Only the glyph loader and debugger should call this function. */ 343 /* */ 344 FT_EXPORT( TT_ExecContext ) 345 TT_New_Context( TT_Driver driver ); 346 347 348 #ifdef TT_USE_BYTECODE_INTERPRETER 349 FT_LOCAL( FT_Error ) 350 TT_Done_Context( TT_ExecContext exec ); 351 352 FT_LOCAL( FT_Error ) 353 TT_Load_Context( TT_ExecContext exec, 354 TT_Face face, 355 TT_Size size ); 356 357 FT_LOCAL( FT_Error ) 358 TT_Save_Context( TT_ExecContext exec, 359 TT_Size ins ); 360 361 FT_LOCAL( FT_Error ) 362 TT_Run_Context( TT_ExecContext exec, 363 FT_Bool debug ); 364 #endif /* TT_USE_BYTECODE_INTERPRETER */ 365 366 367 /*************************************************************************/ 368 /* */ 369 /* <Function> */ 370 /* TT_RunIns */ 371 /* */ 372 /* <Description> */ 373 /* Executes one or more instruction in the execution context. This */ 374 /* is the main function of the TrueType opcode interpreter. */ 375 /* */ 376 /* <Input> */ 377 /* exec :: A handle to the target execution context. */ 378 /* */ 379 /* <Return> */ 380 /* FreeType error code. 0 means success. */ 381 /* */ 382 /* <Note> */ 383 /* Only the object manager and debugger should call this function. */ 384 /* */ 385 /* This function is publicly exported because it is directly */ 386 /* invoked by the TrueType debugger. */ 387 /* */ 388 FT_EXPORT( FT_Error ) 389 TT_RunIns( TT_ExecContext exec ); 390 391 392 FT_END_HEADER 393 394 #endif /* __TTINTERP_H__ */ 395 396 397 /* END */ 398
