src/freetype/truetype/ttinterp.h

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  ttinterp.h                                                             */
   4 /*                                                                         */
   5 /*    TrueType bytecode interpreter (specification).                       */
   6 /*                                                                         */
   7 /*  Copyright 1996-2000 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
  23 #ifdef FT_FLAT_COMPILE
  24
  25 #include "ttobjs.h"
  26
  27 #else
  28
  29 #include <truetype/ttobjs.h>
  30
  31 #endif
  32
  33
  34 #ifdef __cplusplus
  35   extern "C" {
  36 #endif
  37
  38
  39 #ifndef TT_CONFIG_OPTION_STATIC_INTEPRETER  /* indirect implementation */
  40
  41 #define EXEC_OP_   TT_ExecContext  exc,
  42 #define EXEC_OP    TT_ExecContext  exc
  43 #define EXEC_ARG_  exc,
  44 #define EXEC_ARG   exc
  45
  46 #else                                       /* static implementation */
  47
  48 #define EXEC_OP_   /* void */
  49 #define EXEC_OP    /* void */
  50 #define EXEC_ARG_  /* void */
  51 #define EXEC_ARG   /* void */
  52
  53 #endif /* TT_CONFIG_OPTION_STATIC_INTERPRETER */
  54
  55
  56   /*************************************************************************/
  57   /*                                                                       */
  58   /* Rounding mode constants.                                              */
  59   /*                                                                       */
  60 #define TT_Round_Off             5
  61 #define TT_Round_To_Half_Grid    0
  62 #define TT_Round_To_Grid         1
  63 #define TT_Round_To_Double_Grid  2
  64 #define TT_Round_Up_To_Grid      4
  65 #define TT_Round_Down_To_Grid    3
  66 #define TT_Round_Super           6
  67 #define TT_Round_Super_45        7
  68
  69
  70   /*************************************************************************/
  71   /*                                                                       */
  72   /* Function types used by the interpreter, depending on various modes    */
  73   /* (e.g. the rounding mode, whether to render a vertical or horizontal   */
  74   /* line etc).                                                            */
  75   /*                                                                       */
  76   /*************************************************************************/
  77
  78   /* Rounding function */
  79   typedef FT_F26Dot6  (*TT_Round_Func)( EXEC_OP_ FT_F26Dot6  distance,
  80                                                  FT_F26Dot6  compensation );
  81
  82   /* Point displacement along the freedom vector routine */
  83   typedef void  (*TT_Move_Func)( EXEC_OP_ TT_GlyphZone*  zone,
  84                                           FT_UInt        point,
  85                                           FT_F26Dot6     distance );
  86
  87   /* Distance projection along one of the projection vectors */
  88   typedef FT_F26Dot6  (*TT_Project_Func)( EXEC_OP_ FT_Vector*  v1,
  89                                                    FT_Vector*  v2 );
  90
  91   /* reading a cvt value.  Take care of non-square pixels if necessary */
  92   typedef FT_F26Dot6  (*TT_Get_CVT_Func)( EXEC_OP_ FT_ULong  index );
  93
  94   /* setting or moving a cvt value.  Take care of non-square pixels  */
  95   /* if necessary                                                    */
  96   typedef void  (*TT_Set_CVT_Func)( EXEC_OP_ FT_ULong    index,
  97                                              FT_F26Dot6  value );
  98
  99
 100   /*************************************************************************/
 101   /*                                                                       */
 102   /* This structure defines a call record, used to manage function calls.  */
 103   /*                                                                       */
 104   typedef struct  TT_CallRec_
 105   {
 106     FT_Int   Caller_Range;
 107     FT_Long  Caller_IP;
 108     FT_Long  Cur_Count;
 109     FT_Long  Cur_Restart;
 110
 111   } TT_CallRec, *TT_CallStack;
 112
 113
 114   /*************************************************************************/
 115   /*                                                                       */
 116   /* The main structure for the interpreter which collects all necessary   */
 117   /* variables and states.                                                 */
 118   /*                                                                       */
 119   typedef struct  TT_ExecContextRec_
 120   {
 121     TT_Face         face;
 122     TT_Size         size;
 123     FT_Memory       memory;
 124
 125     /* instructions state */
 126
 127     FT_Error        error;      /* last execution error */
 128
 129     FT_Long         top;        /* top of exec. stack   */
 130
 131     FT_UInt         stackSize;  /* size of exec. stack  */
 132     FT_Long*        stack;      /* current exec. stack  */
 133
 134     FT_Long         args;
 135     FT_UInt         new_top;    /* new top after exec.  */
 136
 137     TT_GlyphZone    zp0,        /* zone records */
 138                     zp1,
 139                     zp2,
 140                     pts,
 141                     twilight;
 142
 143     FT_Size_Metrics  metrics;
 144     TT_Size_Metrics  tt_metrics; /* size metrics */
 145
 146     TT_GraphicsState  GS;         /* current graphics state */
 147
 148     FT_Int          curRange;  /* current code range number   */
 149     FT_Byte*        code;      /* current code range          */
 150     FT_Long         IP;        /* current instruction pointer */
 151     FT_Long         codeSize;  /* size of current range       */
 152
 153     FT_Byte         opcode;    /* current opcode              */
 154     FT_Int          length;    /* length of current opcode    */
 155
 156     FT_Bool         step_ins;  /* true if the interpreter must */
 157                                /* increment IP after ins. exec */
 158     FT_Long         cvtSize;
 159     FT_Long*        cvt;
 160
 161     FT_UInt         glyphSize; /* glyph instructions buffer size */
 162     FT_Byte*        glyphIns;  /* glyph instructions buffer */
 163
 164     FT_UInt         numFDefs;  /* number of function defs         */
 165     FT_UInt         maxFDefs;  /* maximum number of function defs */
 166     TT_DefArray     FDefs;     /* table of FDefs entries          */
 167
 168     FT_UInt         numIDefs;  /* number of instruction defs */
 169     FT_UInt         maxIDefs;  /* maximum number of ins defs */
 170     TT_DefArray     IDefs;     /* table of IDefs entries     */
 171
 172     FT_UInt         maxFunc;   /* maximum function index     */
 173     FT_UInt         maxIns;    /* maximum instruction index  */
 174
 175     FT_Int          callTop,    /* top of call stack during execution */
 176                     callSize;   /* size of call stack */
 177     TT_CallStack    callStack;  /* call stack */
 178
 179     FT_UShort       maxPoints;    /* capacity of this context's `pts' */
 180     FT_Short        maxContours;  /* record, expressed in points and  */
 181                                   /* contours.                        */
 182
 183     TT_CodeRangeTable  codeRangeTable;  /* table of valid code ranges */
 184                                         /* useful for the debugger   */
 185
 186     FT_UShort       storeSize;  /* size of current storage */
 187     FT_Long*        storage;    /* storage area            */
 188
 189     FT_F26Dot6      period;     /* values used for the */
 190     FT_F26Dot6      phase;      /* `SuperRounding'     */
 191     FT_F26Dot6      threshold;
 192
 193 #if 0
 194     /* this seems to be unused */
 195     FT_Int          cur_ppem;       /* ppem along the current proj vector */
 196 #endif
 197
 198     FT_Bool         instruction_trap;  /* If `True', the interpreter will */
 199                                        /* exit after each instruction     */
 200
 201     TT_GraphicsState  default_GS;      /* graphics state resulting from    */
 202                                        /* the prep program                 */
 203     FT_Bool          is_composite;     /* true if the glyph is composite   */
 204     FT_Bool          pedantic_hinting; /* true for pedantic interpretation */
 205
 206     /* latest interpreter additions */
 207
 208     FT_Long            F_dot_P;    /* dot product of freedom and projection */
 209                                    /* vectors                               */
 210     TT_Round_Func      func_round; /* current rounding function             */
 211
 212     TT_Project_Func    func_project,   /* current projection function */
 213                        func_dualproj,  /* current dual proj. function */
 214                        func_freeProj;  /* current freedom proj. func  */
 215
 216     TT_Move_Func       func_move;      /* current point move function */
 217
 218     TT_Get_CVT_Func    func_read_cvt;  /* read a cvt entry              */
 219     TT_Set_CVT_Func    func_write_cvt; /* write a cvt entry (in pixels) */
 220     TT_Set_CVT_Func    func_move_cvt;  /* incr a cvt entry (in pixels)  */
 221
 222     FT_ULong           loadSize;
 223     TT_SubGlyph_Stack  loadStack;      /* loading subglyph stack */
 224
 225   } TT_ExecContextRec;
 226
 227
 228   extern const TT_GraphicsState  tt_default_graphics_state;
 229
 230
 231   LOCAL_DEF
 232   FT_Error  TT_Goto_CodeRange( TT_ExecContext  exec,
 233                                FT_Int          range,
 234                                FT_Long         IP );
 235
 236   LOCAL_DEF
 237   FT_Error  TT_Set_CodeRange( TT_ExecContext  exec,
 238                               FT_Int          range,
 239                               void*           base,
 240                               FT_Long         length );
 241
 242   LOCAL_DEF
 243   FT_Error  TT_Clear_CodeRange( TT_ExecContext  exec,
 244                                 FT_Int          range );
 245
 246   FT_EXPORT_DEF( TT_ExecContext )  TT_New_Context( TT_Face  face );
 247
 248   LOCAL_DEF
 249   FT_Error  TT_Done_Context( TT_ExecContext  exec );
 250
 251   LOCAL_DEF
 252   FT_Error  TT_Destroy_Context( TT_ExecContext  exec,
 253                                 FT_Memory       memory );
 254
 255   LOCAL_DEF
 256   FT_Error  TT_Load_Context( TT_ExecContext  exec,
 257                              TT_Face         face,
 258                              TT_Size         size );
 259
 260   LOCAL_DEF
 261   FT_Error  TT_Save_Context( TT_ExecContext  exec,
 262                              TT_Size         ins );
 263
 264   LOCAL_DEF
 265   FT_Error  TT_Run_Context( TT_ExecContext  exec,
 266                             FT_Bool         debug );
 267
 268   FT_EXPORT_DEF( FT_Error )  TT_RunIns( TT_ExecContext  exec );
 269
 270
 271 #ifdef __cplusplus
 272   }
 273 #endif
 274
 275 #endif /* TTINTERP_H */
 276
 277
 278 /* END */