libraries/freetype-2.0.5/include/ttobjs.h

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  ttobjs.h                                                               */
   4 /*                                                                         */
   5 /*    Objects manager (specification).                                     */
   6 /*                                                                         */
   7 /*  Copyright 1996-2001 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 <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     FT_Long        loop;
  87     FT_F26Dot6     minimum_distance;
  88     FT_Int         round_state;
  89
  90     FT_Bool        auto_flip;
  91     FT_F26Dot6     control_value_cutin;
  92     FT_F26Dot6     single_width_cutin;
  93     FT_F26Dot6     single_width_value;
  94     FT_Short       delta_base;
  95     FT_Short       delta_shift;
  96
  97     FT_Byte        instruct_control;
  98     FT_Bool        scan_control;
  99     FT_Int         scan_type;
 100
 101     FT_UShort      gep0;
 102     FT_UShort      gep1;
 103     FT_UShort      gep2;
 104
 105   } TT_GraphicsState;
 106
 107
 108 #ifdef TT_CONFIG_OPTION_BYTECODE_INTERPRETER
 109
 110   FT_LOCAL void
 111   TT_Done_GlyphZone( TT_GlyphZone*  zone );
 112
 113   FT_LOCAL FT_Error
 114   TT_New_GlyphZone( FT_Memory      memory,
 115                     FT_UShort      maxPoints,
 116                     FT_Short       maxContours,
 117                     TT_GlyphZone*  zone );
 118
 119 #endif /* TT_CONFIG_OPTION_BYTECODE_INTERPRETER */
 120
 121
 122
 123   /*************************************************************************/
 124   /*                                                                       */
 125   /*  EXECUTION SUBTABLES                                                  */
 126   /*                                                                       */
 127   /*  These sub-tables relate to instruction execution.                    */
 128   /*                                                                       */
 129   /*************************************************************************/
 130
 131
 132 #define TT_MAX_CODE_RANGES  3
 133
 134
 135   /*************************************************************************/
 136   /*                                                                       */
 137   /* There can only be 3 active code ranges at once:                       */
 138   /*   - the Font Program                                                  */
 139   /*   - the CVT Program                                                   */
 140   /*   - a glyph's instructions set                                        */
 141   /*                                                                       */
 142   typedef enum  TT_CodeRange_Tag_
 143   {
 144     tt_coderange_none = 0,
 145     tt_coderange_font,
 146     tt_coderange_cvt,
 147     tt_coderange_glyph
 148
 149   } TT_CodeRange_Tag;
 150
 151
 152   typedef struct  TT_CodeRange_
 153   {
 154     FT_Byte*  base;
 155     FT_ULong  size;
 156
 157   } TT_CodeRange;
 158
 159   typedef TT_CodeRange  TT_CodeRangeTable[TT_MAX_CODE_RANGES];
 160
 161
 162   /*************************************************************************/
 163   /*                                                                       */
 164   /* Defines a function/instruction definition record.                     */
 165   /*                                                                       */
 166   typedef struct  TT_DefRecord_
 167   {
 168     FT_Int   range;      /* in which code range is it located? */
 169     FT_Long  start;      /* where does it start?               */
 170     FT_UInt  opc;        /* function #, or instruction code    */
 171     FT_Bool  active;     /* is it active?                      */
 172
 173   } TT_DefRecord, *TT_DefArray;
 174
 175
 176   /*************************************************************************/
 177   /*                                                                       */
 178   /* Subglyph transformation record.                                       */
 179   /*                                                                       */
 180   typedef struct  TT_Transform_
 181   {
 182     FT_Fixed    xx, xy;     /* transformation matrix coefficients */
 183     FT_Fixed    yx, yy;
 184     FT_F26Dot6  ox, oy;     /* offsets        */
 185
 186   } TT_Transform;
 187
 188
 189   /*************************************************************************/
 190   /*                                                                       */
 191   /* Subglyph loading record.  Used to load composite components.          */
 192   /*                                                                       */
 193   typedef struct  TT_SubglyphRec_
 194   {
 195     FT_Long       index;        /* subglyph index; initialized with -1 */
 196     FT_Bool       is_scaled;    /* is the subglyph scaled?             */
 197     FT_Bool       is_hinted;    /* should it be hinted?                */
 198     FT_Bool       preserve_pps; /* preserve phantom points?            */
 199
 200     FT_Long       file_offset;
 201
 202     FT_BBox       bbox;
 203     FT_Pos        left_bearing;
 204     FT_Pos        advance;
 205
 206     TT_GlyphZone  zone;
 207
 208     FT_Long       arg1;         /* first argument                      */
 209     FT_Long       arg2;         /* second argument                     */
 210
 211     FT_UShort     element_flag; /* current load element flag           */
 212
 213     TT_Transform  transform;    /* transformation matrix               */
 214
 215     FT_Vector     pp1, pp2;     /* phantom points                      */
 216
 217   } TT_SubGlyphRec, *TT_SubGlyph_Stack;
 218
 219
 220   /*************************************************************************/
 221   /*                                                                       */
 222   /* A note regarding non-squared pixels:                                  */
 223   /*                                                                       */
 224   /* (This text will probably go into some docs at some time; for now, it  */
 225   /*  is kept here to explain some definitions in the TIns_Metrics         */
 226   /*  record).                                                             */
 227   /*                                                                       */
 228   /* The CVT is a one-dimensional array containing values that control     */
 229   /* certain important characteristics in a font, like the height of all   */
 230   /* capitals, all lowercase letter, default spacing or stem width/height. */
 231   /*                                                                       */
 232   /* These values are found in FUnits in the font file, and must be scaled */
 233   /* to pixel coordinates before being used by the CVT and glyph programs. */
 234   /* Unfortunately, when using distinct x and y resolutions (or distinct x */
 235   /* and y pointsizes), there are two possible scalings.                   */
 236   /*                                                                       */
 237   /* A first try was to implement a `lazy' scheme where all values were    */
 238   /* scaled when first used.  However, while some values are always used   */
 239   /* in the same direction, some others are used under many different      */
 240   /* circumstances and orientations.                                       */
 241   /*                                                                       */
 242   /* I have found a simpler way to do the same, and it even seems to work  */
 243   /* in most of the cases:                                                 */
 244   /*                                                                       */
 245   /* - All CVT values are scaled to the maximum ppem size.                 */
 246   /*                                                                       */
 247   /* - When performing a read or write in the CVT, a ratio factor is used  */
 248   /*   to perform adequate scaling.  Example:                              */
 249   /*                                                                       */
 250   /*     x_ppem = 14                                                       */
 251   /*     y_ppem = 10                                                       */
 252   /*                                                                       */
 253   /*   We choose ppem = x_ppem = 14 as the CVT scaling size.  All cvt      */
 254   /*   entries are scaled to it.                                           */
 255   /*                                                                       */
 256   /*     x_ratio = 1.0                                                     */
 257   /*     y_ratio = y_ppem/ppem (< 1.0)                                     */
 258   /*                                                                       */
 259   /*   We compute the current ratio like:                                  */
 260   /*                                                                       */
 261   /*   - If projVector is horizontal,                                      */
 262   /*       ratio = x_ratio = 1.0                                           */
 263   /*                                                                       */
 264   /*   - if projVector is vertical,                                        */
 265   /*       ratio = y_ratio                                                 */
 266   /*                                                                       */
 267   /*   - else,                                                             */
 268   /*       ratio = sqrt( (proj.x * x_ratio) ^ 2 + (proj.y * y_ratio) ^ 2 ) */
 269   /*                                                                       */
 270   /*   Reading a cvt value returns                                         */
 271   /*     ratio * cvt[index]                                                */
 272   /*                                                                       */
 273   /*   Writing a cvt value in pixels:                                      */
 274   /*     cvt[index] / ratio                                                */
 275   /*                                                                       */
 276   /*   The current ppem is simply                                          */
 277   /*     ratio * ppem                                                      */
 278   /*                                                                       */
 279   /*************************************************************************/
 280
 281
 282   /*************************************************************************/
 283   /*                                                                       */
 284   /* Metrics used by the TrueType size and context objects.                */
 285   /*                                                                       */
 286   typedef struct  TT_Size_Metrics_
 287   {
 288     /* for non-square pixels */
 289     FT_Long     x_ratio;
 290     FT_Long     y_ratio;
 291
 292     FT_UShort   ppem;               /* maximum ppem size              */
 293     FT_Long     ratio;              /* current ratio                  */
 294     FT_Fixed    scale;
 295
 296     FT_F26Dot6  compensations[4];   /* device-specific compensations  */
 297
 298     FT_Bool     valid;
 299
 300     FT_Bool     rotated;            /* `is the glyph rotated?'-flag   */
 301     FT_Bool     stretched;          /* `is the glyph stretched?'-flag */
 302
 303   } TT_Size_Metrics;
 304
 305
 306   /*************************************************************************/
 307   /*                                                                       */
 308   /* TrueType size class.                                                  */
 309   /*                                                                       */
 310   typedef struct  TT_SizeRec_
 311   {
 312     FT_SizeRec         root;
 313
 314     TT_Size_Metrics    ttmetrics;
 315
 316 #ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
 317
 318     FT_UInt            strike_index;    /* 0xFFFF to indicate invalid */
 319     FT_Size_Metrics    strike_metrics;  /* current strike's metrics   */
 320
 321 #endif
 322
 323 #ifdef TT_CONFIG_OPTION_BYTECODE_INTERPRETER
 324
 325     FT_UInt            num_function_defs; /* number of function definitions */
 326     FT_UInt            max_function_defs;
 327     TT_DefArray        function_defs;     /* table of function definitions  */
 328
 329     FT_UInt            num_instruction_defs;  /* number of ins. definitions */
 330     FT_UInt            max_instruction_defs;
 331     TT_DefArray        instruction_defs;      /* table of ins. definitions  */
 332
 333     FT_UInt            max_func;
 334     FT_UInt            max_ins;
 335
 336     TT_CodeRangeTable  codeRangeTable;
 337
 338     TT_GraphicsState   GS;
 339
 340     FT_ULong           cvt_size;      /* the scaled control value table */
 341     FT_Long*           cvt;
 342
 343     FT_UShort          storage_size; /* The storage area is now part of */
 344     FT_Long*           storage;      /* the instance                    */
 345
 346     TT_GlyphZone       twilight;     /* The instance's twilight zone    */
 347
 348     /* debugging variables */
 349
 350     /* When using the debugger, we must keep the */
 351     /* execution context tied to the instance    */
 352     /* object rather than asking it on demand.   */
 353
 354     FT_Bool            debug;
 355     TT_ExecContext     context;
 356
 357 #endif /* TT_CONFIG_OPTION_BYTECODE_INTERPRETER */
 358
 359   } TT_SizeRec;
 360
 361
 362   /*************************************************************************/
 363   /*                                                                       */
 364   /* TrueType driver class.                                                */
 365   /*                                                                       */
 366   typedef struct  TT_DriverRec_
 367   {
 368     FT_DriverRec    root;
 369     TT_ExecContext  context;  /* execution context        */
 370     TT_GlyphZone    zone;     /* glyph loader points zone */
 371
 372     void*           extension_component;
 373
 374   } TT_DriverRec;
 375
 376
 377   /*************************************************************************/
 378   /*                                                                       */
 379   /* Face functions                                                        */
 380   /*                                                                       */
 381   FT_LOCAL FT_Error
 382   TT_Init_Face( FT_Stream      stream,
 383                 TT_Face        face,
 384                 FT_Int         face_index,
 385                 FT_Int         num_params,
 386                 FT_Parameter*  params );
 387
 388   FT_LOCAL void
 389   TT_Done_Face( TT_Face  face );
 390
 391
 392   /*************************************************************************/
 393   /*                                                                       */
 394   /* Size functions                                                        */
 395   /*                                                                       */
 396   FT_LOCAL FT_Error
 397   TT_Init_Size( TT_Size  size );
 398
 399   FT_LOCAL void
 400   TT_Done_Size( TT_Size  size );
 401
 402   FT_LOCAL FT_Error
 403   TT_Reset_Size( TT_Size  size );
 404
 405
 406   /*************************************************************************/
 407   /*                                                                       */
 408   /* Driver functions                                                      */
 409   /*                                                                       */
 410   FT_LOCAL FT_Error
 411   TT_Init_Driver( TT_Driver  driver );
 412
 413   FT_LOCAL void
 414   TT_Done_Driver( TT_Driver  driver );
 415
 416
 417 FT_END_HEADER
 418
 419 #endif /* __TTOBJS_H__ */
 420
 421
 422 /* END */