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; 105 106 } TT_CallRec, *TT_CallStack; 107 108 109 /*************************************************************************/ 110 /* */ 111 /* The main structure for the interpreter which collects all necessary */ 112 /* variables and states. */ 113 /* */ 114 typedef struct TT_ExecContextRec_ 115 { 116 TT_Face face; 117 TT_Size size; 118 FT_Memory memory; 119 120 /* instructions state */ 121 122 FT_Error error; /* last execution error */ 123 124 FT_Long top; /* top of exec. stack */ 125 126 FT_UInt stackSize; /* size of exec. stack */ 127 FT_Long* stack; /* current exec. stack */ 128 129 FT_Long args; 130 FT_UInt new_top; /* new top after exec. */ 131 132 TT_GlyphZoneRec zp0, /* zone records */ 133 zp1, 134 zp2, 135 pts, 136 twilight; 137 138 FT_Size_Metrics metrics; 139 TT_Size_Metrics tt_metrics; /* size metrics */ 140 141 TT_GraphicsState GS; /* current graphics state */ 142 143 FT_Int curRange; /* current code range number */ 144 FT_Byte* code; /* current code range */ 145 FT_Long IP; /* current instruction pointer */ 146 FT_Long codeSize; /* size of current range */ 147 148 FT_Byte opcode; /* current opcode */ 149 FT_Int length; /* length of current opcode */ 150 151 FT_Bool step_ins; /* true if the interpreter must */ 152 /* increment IP after ins. exec */ 153 FT_ULong cvtSize; 154 FT_Long* cvt; 155 156 FT_UInt glyphSize; /* glyph instructions buffer size */ 157 FT_Byte* glyphIns; /* glyph instructions buffer */ 158 159 FT_UInt numFDefs; /* number of function defs */ 160 FT_UInt maxFDefs; /* maximum number of function defs */ 161 TT_DefArray FDefs; /* table of FDefs entries */ 162 163 FT_UInt numIDefs; /* number of instruction defs */ 164 FT_UInt maxIDefs; /* maximum number of ins defs */ 165 TT_DefArray IDefs; /* table of IDefs entries */ 166 167 FT_UInt maxFunc; /* maximum function index */ 168 FT_UInt maxIns; /* maximum instruction index */ 169 170 FT_Int callTop, /* top of call stack during execution */ 171 callSize; /* size of call stack */ 172 TT_CallStack callStack; /* call stack */ 173 174 FT_UShort maxPoints; /* capacity of this context's `pts' */ 175 FT_Short maxContours; /* record, expressed in points and */ 176 /* contours. */ 177 178 TT_CodeRangeTable codeRangeTable; /* table of valid code ranges */ 179 /* useful for the debugger */ 180 181 FT_UShort storeSize; /* size of current storage */ 182 FT_Long* storage; /* storage area */ 183 184 FT_F26Dot6 period; /* values used for the */ 185 FT_F26Dot6 phase; /* `SuperRounding' */ 186 FT_F26Dot6 threshold; 187 188 #if 0 189 /* this seems to be unused */ 190 FT_Int cur_ppem; /* ppem along the current proj vector */ 191 #endif 192 193 FT_Bool instruction_trap; /* If `True', the interpreter will */ 194 /* exit after each instruction */ 195 196 TT_GraphicsState default_GS; /* graphics state resulting from */ 197 /* the prep program */ 198 FT_Bool is_composite; /* true if the glyph is composite */ 199 FT_Bool pedantic_hinting; /* true if pedantic interpretation */ 200 201 /* latest interpreter additions */ 202 203 FT_Long F_dot_P; /* dot product of freedom and projection */ 204 /* vectors */ 205 TT_Round_Func func_round; /* current rounding function */ 206 207 TT_Project_Func func_project, /* current projection function */ 208 func_dualproj, /* current dual proj. function */ 209 func_freeProj; /* current freedom proj. func */ 210 211 TT_Move_Func func_move; /* current point move function */ 212 TT_Move_Func func_move_orig; /* move original position function */ 213 214 TT_Get_CVT_Func func_read_cvt; /* read a cvt entry */ 215 TT_Set_CVT_Func func_write_cvt; /* write a cvt entry (in pixels) */ 216 TT_Set_CVT_Func func_move_cvt; /* incr a cvt entry (in pixels) */ 217 218 FT_Bool grayscale; /* are we hinting for grayscale? */ 219 220 } TT_ExecContextRec; 221 222 223 extern const TT_GraphicsState tt_default_graphics_state; 224 225 226 FT_LOCAL( FT_Error ) 227 TT_Goto_CodeRange( TT_ExecContext exec, 228 FT_Int range, 229 FT_Long IP ); 230 231 FT_LOCAL( FT_Error ) 232 TT_Set_CodeRange( TT_ExecContext exec, 233 FT_Int range, 234 void* base, 235 FT_Long length ); 236 237 FT_LOCAL( FT_Error ) 238 TT_Clear_CodeRange( TT_ExecContext exec, 239 FT_Int range ); 240 241 242 FT_LOCAL( FT_Error ) 243 Update_Max( FT_Memory memory, 244 FT_ULong* size, 245 FT_Long multiplier, 246 void* _pbuff, 247 FT_ULong new_max ); 248 249 250 /*************************************************************************/ 251 /* */ 252 /* <Function> */ 253 /* TT_New_Context */ 254 /* */ 255 /* <Description> */ 256 /* Queries the face context for a given font. Note that there is */ 257 /* now a _single_ execution context in the TrueType driver which is */ 258 /* shared among faces. */ 259 /* */ 260 /* <Input> */ 261 /* face :: A handle to the source face object. */ 262 /* */ 263 /* <Return> */ 264 /* A handle to the execution context. Initialized for `face'. */ 265 /* */ 266 /* <Note> */ 267 /* Only the glyph loader and debugger should call this function. */ 268 /* */ 269 FT_EXPORT( TT_ExecContext ) 270 TT_New_Context( TT_Driver driver ); 271 272 FT_LOCAL( FT_Error ) 273 TT_Done_Context( TT_ExecContext exec ); 274 275 FT_LOCAL( FT_Error ) 276 TT_Load_Context( TT_ExecContext exec, 277 TT_Face face, 278 TT_Size size ); 279 280 FT_LOCAL( FT_Error ) 281 TT_Save_Context( TT_ExecContext exec, 282 TT_Size ins ); 283 284 FT_LOCAL( FT_Error ) 285 TT_Run_Context( TT_ExecContext exec, 286 FT_Bool debug ); 287 288 289 /*************************************************************************/ 290 /* */ 291 /* <Function> */ 292 /* TT_RunIns */ 293 /* */ 294 /* <Description> */ 295 /* Executes one or more instruction in the execution context. This */ 296 /* is the main function of the TrueType opcode interpreter. */ 297 /* */ 298 /* <Input> */ 299 /* exec :: A handle to the target execution context. */ 300 /* */ 301 /* <Return> */ 302 /* FreeType error code. 0 means success. */ 303 /* */ 304 /* <Note> */ 305 /* Only the object manager and debugger should call this function. */ 306 /* */ 307 /* This function is publicly exported because it is directly */ 308 /* invoked by the TrueType debugger. */ 309 /* */ 310 FT_EXPORT( FT_Error ) 311 TT_RunIns( TT_ExecContext exec ); 312 313 314 FT_END_HEADER 315 316 #endif /* __TTINTERP_H__ */ 317 318 319 /* END */ 320