1 /***************************************************************************/ 2 /* */ 3 /* ttinterp.h */ 4 /* */ 5 /* TrueType bytecode interpreter (specification). */ 6 /* */ 7 /* Copyright 1996-2001, 2002, 2003, 2004, 2005, 2006, 2007, 2010 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 /*************************************************************************/ 111 /* */ 112 /* The main structure for the interpreter which collects all necessary */ 113 /* variables and states. */ 114 /* */ 115 typedef struct TT_ExecContextRec_ 116 { 117 TT_Face face; 118 TT_Size size; 119 FT_Memory memory; 120 121 /* instructions state */ 122 123 FT_Error error; /* last execution error */ 124 125 FT_Long top; /* top of exec. stack */ 126 127 FT_UInt stackSize; /* size of exec. stack */ 128 FT_Long* stack; /* current exec. stack */ 129 130 FT_Long args; 131 FT_UInt new_top; /* new top after exec. */ 132 133 TT_GlyphZoneRec zp0, /* zone records */ 134 zp1, 135 zp2, 136 pts, 137 twilight; 138 139 FT_Size_Metrics metrics; 140 TT_Size_Metrics tt_metrics; /* size metrics */ 141 142 TT_GraphicsState GS; /* current graphics state */ 143 144 FT_Int curRange; /* current code range number */ 145 FT_Byte* code; /* current code range */ 146 FT_Long IP; /* current instruction pointer */ 147 FT_Long codeSize; /* size of current range */ 148 149 FT_Byte opcode; /* current opcode */ 150 FT_Int length; /* length of current opcode */ 151 152 FT_Bool step_ins; /* true if the interpreter must */ 153 /* increment IP after ins. exec */ 154 FT_ULong cvtSize; 155 FT_Long* cvt; 156 157 FT_UInt glyphSize; /* glyph instructions buffer size */ 158 FT_Byte* glyphIns; /* glyph instructions buffer */ 159 160 FT_UInt numFDefs; /* number of function defs */ 161 FT_UInt maxFDefs; /* maximum number of function defs */ 162 TT_DefArray FDefs; /* table of FDefs entries */ 163 164 FT_UInt numIDefs; /* number of instruction defs */ 165 FT_UInt maxIDefs; /* maximum number of ins defs */ 166 TT_DefArray IDefs; /* table of IDefs entries */ 167 168 FT_UInt maxFunc; /* maximum function index */ 169 FT_UInt maxIns; /* maximum instruction index */ 170 171 FT_Int callTop, /* top of call stack during execution */ 172 callSize; /* size of call stack */ 173 TT_CallStack callStack; /* call stack */ 174 175 FT_UShort maxPoints; /* capacity of this context's `pts' */ 176 FT_Short maxContours; /* record, expressed in points and */ 177 /* contours. */ 178 179 TT_CodeRangeTable codeRangeTable; /* table of valid code ranges */ 180 /* useful for the debugger */ 181 182 FT_UShort storeSize; /* size of current storage */ 183 FT_Long* storage; /* storage area */ 184 185 FT_F26Dot6 period; /* values used for the */ 186 FT_F26Dot6 phase; /* `SuperRounding' */ 187 FT_F26Dot6 threshold; 188 189 #if 0 190 /* this seems to be unused */ 191 FT_Int cur_ppem; /* ppem along the current proj vector */ 192 #endif 193 194 FT_Bool instruction_trap; /* If `True', the interpreter will */ 195 /* exit after each instruction */ 196 197 TT_GraphicsState default_GS; /* graphics state resulting from */ 198 /* the prep program */ 199 FT_Bool is_composite; /* true if the glyph is composite */ 200 FT_Bool pedantic_hinting; /* true if pedantic interpretation */ 201 202 /* latest interpreter additions */ 203 204 FT_Long F_dot_P; /* dot product of freedom and projection */ 205 /* vectors */ 206 TT_Round_Func func_round; /* current rounding function */ 207 208 TT_Project_Func func_project, /* current projection function */ 209 func_dualproj, /* current dual proj. function */ 210 func_freeProj; /* current freedom proj. func */ 211 212 TT_Move_Func func_move; /* current point move function */ 213 TT_Move_Func func_move_orig; /* move original position function */ 214 215 TT_Get_CVT_Func func_read_cvt; /* read a cvt entry */ 216 TT_Set_CVT_Func func_write_cvt; /* write a cvt entry (in pixels) */ 217 TT_Set_CVT_Func func_move_cvt; /* incr a cvt entry (in pixels) */ 218 219 FT_Bool grayscale; /* are we hinting for grayscale? */ 220 221 } TT_ExecContextRec; 222 223 224 extern const TT_GraphicsState tt_default_graphics_state; 225 226 227 FT_LOCAL( FT_Error ) 228 TT_Goto_CodeRange( TT_ExecContext exec, 229 FT_Int range, 230 FT_Long IP ); 231 232 FT_LOCAL( FT_Error ) 233 TT_Set_CodeRange( TT_ExecContext exec, 234 FT_Int range, 235 void* base, 236 FT_Long length ); 237 238 FT_LOCAL( FT_Error ) 239 TT_Clear_CodeRange( TT_ExecContext exec, 240 FT_Int range ); 241 242 243 FT_LOCAL( FT_Error ) 244 Update_Max( FT_Memory memory, 245 FT_ULong* size, 246 FT_Long multiplier, 247 void* _pbuff, 248 FT_ULong new_max ); 249 250 251 /*************************************************************************/ 252 /* */ 253 /* <Function> */ 254 /* TT_New_Context */ 255 /* */ 256 /* <Description> */ 257 /* Queries the face context for a given font. Note that there is */ 258 /* now a _single_ execution context in the TrueType driver which is */ 259 /* shared among faces. */ 260 /* */ 261 /* <Input> */ 262 /* face :: A handle to the source face object. */ 263 /* */ 264 /* <Return> */ 265 /* A handle to the execution context. Initialized for `face'. */ 266 /* */ 267 /* <Note> */ 268 /* Only the glyph loader and debugger should call this function. */ 269 /* */ 270 FT_EXPORT( TT_ExecContext ) 271 TT_New_Context( TT_Driver driver ); 272 273 FT_LOCAL( FT_Error ) 274 TT_Done_Context( TT_ExecContext exec ); 275 276 FT_LOCAL( FT_Error ) 277 TT_Load_Context( TT_ExecContext exec, 278 TT_Face face, 279 TT_Size size ); 280 281 FT_LOCAL( FT_Error ) 282 TT_Save_Context( TT_ExecContext exec, 283 TT_Size ins ); 284 285 FT_LOCAL( FT_Error ) 286 TT_Run_Context( TT_ExecContext exec, 287 FT_Bool debug ); 288 289 290 /*************************************************************************/ 291 /* */ 292 /* <Function> */ 293 /* TT_RunIns */ 294 /* */ 295 /* <Description> */ 296 /* Executes one or more instruction in the execution context. This */ 297 /* is the main function of the TrueType opcode interpreter. */ 298 /* */ 299 /* <Input> */ 300 /* exec :: A handle to the target execution context. */ 301 /* */ 302 /* <Return> */ 303 /* FreeType error code. 0 means success. */ 304 /* */ 305 /* <Note> */ 306 /* Only the object manager and debugger should call this function. */ 307 /* */ 308 /* This function is publicly exported because it is directly */ 309 /* invoked by the TrueType debugger. */ 310 /* */ 311 FT_EXPORT( FT_Error ) 312 TT_RunIns( TT_ExecContext exec ); 313 314 315 FT_END_HEADER 316 317 #endif /* __TTINTERP_H__ */ 318 319 320 /* END */ 321
