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      1 /***************************************************************************/
      2 /*                                                                         */
      3 /*  ttgload.c                                                              */
      4 /*                                                                         */
      5 /*    TrueType Glyph Loader (body).                                        */
      6 /*                                                                         */
      7 /*  Copyright 1996-2011                                                    */
      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 #include <ft2build.h>
     20 #include FT_INTERNAL_DEBUG_H
     21 #include FT_INTERNAL_CALC_H
     22 #include FT_INTERNAL_STREAM_H
     23 #include FT_INTERNAL_SFNT_H
     24 #include FT_TRUETYPE_TAGS_H
     25 #include FT_OUTLINE_H
     26 
     27 #include "ttgload.h"
     28 #include "ttpload.h"
     29 
     30 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
     31 #include "ttgxvar.h"
     32 #endif
     33 
     34 #include "tterrors.h"
     35 
     36 
     37   /*************************************************************************/
     38   /*                                                                       */
     39   /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
     40   /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
     41   /* messages during execution.                                            */
     42   /*                                                                       */
     43 #undef  FT_COMPONENT
     44 #define FT_COMPONENT  trace_ttgload
     45 
     46 
     47   /*************************************************************************/
     48   /*                                                                       */
     49   /* Composite glyph flags.                                                */
     50   /*                                                                       */
     51 #define ARGS_ARE_WORDS             0x0001
     52 #define ARGS_ARE_XY_VALUES         0x0002
     53 #define ROUND_XY_TO_GRID           0x0004
     54 #define WE_HAVE_A_SCALE            0x0008
     55 /* reserved                        0x0010 */
     56 #define MORE_COMPONENTS            0x0020
     57 #define WE_HAVE_AN_XY_SCALE        0x0040
     58 #define WE_HAVE_A_2X2              0x0080
     59 #define WE_HAVE_INSTR              0x0100
     60 #define USE_MY_METRICS             0x0200
     61 #define OVERLAP_COMPOUND           0x0400
     62 #define SCALED_COMPONENT_OFFSET    0x0800
     63 #define UNSCALED_COMPONENT_OFFSET  0x1000
     64 
     65 
     66   /*************************************************************************/
     67   /*                                                                       */
     68   /* Return the horizontal metrics in font units for a given glyph.        */
     69   /*                                                                       */
     70   FT_LOCAL_DEF( void )
     71   TT_Get_HMetrics( TT_Face     face,
     72                    FT_UInt     idx,
     73                    FT_Short*   lsb,
     74                    FT_UShort*  aw )
     75   {
     76     ( (SFNT_Service)face->sfnt )->get_metrics( face, 0, idx, lsb, aw );
     77 
     78     FT_TRACE5(( "  advance width (font units): %d\n", *aw ));
     79     FT_TRACE5(( "  left side bearing (font units): %d\n", *lsb ));
     80   }
     81 
     82 
     83   /*************************************************************************/
     84   /*                                                                       */
     85   /* Return the vertical metrics in font units for a given glyph.          */
     86   /* Greg Hitchcock from Microsoft told us that if there were no `vmtx'    */
     87   /* table, typoAscender/Descender from the `OS/2' table would be used     */
     88   /* instead, and if there were no `OS/2' table, use ascender/descender    */
     89   /* from the `hhea' table.  But that is not what Microsoft's rasterizer   */
     90   /* apparently does: It uses the ppem value as the advance height, and    */
     91   /* sets the top side bearing to be zero.                                 */
     92   /*                                                                       */
     93   FT_LOCAL_DEF( void )
     94   TT_Get_VMetrics( TT_Face     face,
     95                    FT_UInt     idx,
     96                    FT_Short*   tsb,
     97                    FT_UShort*  ah )
     98   {
     99     if ( face->vertical_info )
    100       ( (SFNT_Service)face->sfnt )->get_metrics( face, 1, idx, tsb, ah );
    101 
    102 #if 1             /* Empirically determined, at variance with what MS said */
    103 
    104     else
    105     {
    106       *tsb = 0;
    107       *ah  = face->root.units_per_EM;
    108     }
    109 
    110 #else      /* This is what MS said to do.  It isn't what they do, however. */
    111 
    112     else if ( face->os2.version != 0xFFFFU )
    113     {
    114       *tsb = face->os2.sTypoAscender;
    115       *ah  = face->os2.sTypoAscender - face->os2.sTypoDescender;
    116     }
    117     else
    118     {
    119       *tsb = face->horizontal.Ascender;
    120       *ah  = face->horizontal.Ascender - face->horizontal.Descender;
    121     }
    122 
    123 #endif
    124 
    125     FT_TRACE5(( "  advance height (font units): %d\n", *ah ));
    126     FT_TRACE5(( "  top side bearing (font units): %d\n", *tsb ));
    127   }
    128 
    129 
    130   static void
    131   tt_get_metrics( TT_Loader  loader,
    132                   FT_UInt    glyph_index )
    133   {
    134     TT_Face  face = (TT_Face)loader->face;
    135 
    136     FT_Short   left_bearing = 0, top_bearing = 0;
    137     FT_UShort  advance_width = 0, advance_height = 0;
    138 
    139 
    140     TT_Get_HMetrics( face, glyph_index,
    141                      &left_bearing,
    142                      &advance_width );
    143     TT_Get_VMetrics( face, glyph_index,
    144                      &top_bearing,
    145                      &advance_height );
    146 
    147     loader->left_bearing = left_bearing;
    148     loader->advance      = advance_width;
    149     loader->top_bearing  = top_bearing;
    150     loader->vadvance     = advance_height;
    151 
    152     if ( !loader->linear_def )
    153     {
    154       loader->linear_def = 1;
    155       loader->linear     = advance_width;
    156     }
    157   }
    158 
    159 
    160 #ifdef FT_CONFIG_OPTION_INCREMENTAL
    161 
    162   static void
    163   tt_get_metrics_incr_overrides( TT_Loader  loader,
    164                                  FT_UInt    glyph_index )
    165   {
    166     TT_Face  face = (TT_Face)loader->face;
    167 
    168     FT_Short   left_bearing = 0, top_bearing = 0;
    169     FT_UShort  advance_width = 0, advance_height = 0;
    170 
    171 
    172     /* If this is an incrementally loaded font check whether there are */
    173     /* overriding metrics for this glyph.                              */
    174     if ( face->root.internal->incremental_interface                           &&
    175          face->root.internal->incremental_interface->funcs->get_glyph_metrics )
    176     {
    177       FT_Incremental_MetricsRec  metrics;
    178       FT_Error                   error;
    179 
    180 
    181       metrics.bearing_x = loader->left_bearing;
    182       metrics.bearing_y = 0;
    183       metrics.advance   = loader->advance;
    184       metrics.advance_v = 0;
    185 
    186       error = face->root.internal->incremental_interface->funcs->get_glyph_metrics(
    187                 face->root.internal->incremental_interface->object,
    188                 glyph_index, FALSE, &metrics );
    189       if ( error )
    190         goto Exit;
    191 
    192       left_bearing  = (FT_Short)metrics.bearing_x;
    193       advance_width = (FT_UShort)metrics.advance;
    194 
    195 #if 0
    196 
    197       /* GWW: Do I do the same for vertical metrics? */
    198       metrics.bearing_x = 0;
    199       metrics.bearing_y = loader->top_bearing;
    200       metrics.advance   = loader->vadvance;
    201 
    202       error = face->root.internal->incremental_interface->funcs->get_glyph_metrics(
    203                 face->root.internal->incremental_interface->object,
    204                 glyph_index, TRUE, &metrics );
    205       if ( error )
    206         goto Exit;
    207 
    208       top_bearing    = (FT_Short)metrics.bearing_y;
    209       advance_height = (FT_UShort)metrics.advance;
    210 
    211 #endif /* 0 */
    212 
    213       loader->left_bearing = left_bearing;
    214       loader->advance      = advance_width;
    215       loader->top_bearing  = top_bearing;
    216       loader->vadvance     = advance_height;
    217 
    218       if ( !loader->linear_def )
    219       {
    220         loader->linear_def = 1;
    221         loader->linear     = advance_width;
    222       }
    223     }
    224 
    225   Exit:
    226     return;
    227   }
    228 
    229 #endif /* FT_CONFIG_OPTION_INCREMENTAL */
    230 
    231 
    232   /*************************************************************************/
    233   /*                                                                       */
    234   /* Translates an array of coordinates.                                   */
    235   /*                                                                       */
    236   static void
    237   translate_array( FT_UInt     n,
    238                    FT_Vector*  coords,
    239                    FT_Pos      delta_x,
    240                    FT_Pos      delta_y )
    241   {
    242     FT_UInt  k;
    243 
    244 
    245     if ( delta_x )
    246       for ( k = 0; k < n; k++ )
    247         coords[k].x += delta_x;
    248 
    249     if ( delta_y )
    250       for ( k = 0; k < n; k++ )
    251         coords[k].y += delta_y;
    252   }
    253 
    254 
    255 #undef  IS_HINTED
    256 #define IS_HINTED( flags )  ( ( flags & FT_LOAD_NO_HINTING ) == 0 )
    257 
    258 
    259   /*************************************************************************/
    260   /*                                                                       */
    261   /* The following functions are used by default with TrueType fonts.      */
    262   /* However, they can be replaced by alternatives if we need to support   */
    263   /* TrueType-compressed formats (like MicroType) in the future.           */
    264   /*                                                                       */
    265   /*************************************************************************/
    266 
    267   FT_CALLBACK_DEF( FT_Error )
    268   TT_Access_Glyph_Frame( TT_Loader  loader,
    269                          FT_UInt    glyph_index,
    270                          FT_ULong   offset,
    271                          FT_UInt    byte_count )
    272   {
    273     FT_Error   error;
    274     FT_Stream  stream = loader->stream;
    275 
    276     /* for non-debug mode */
    277     FT_UNUSED( glyph_index );
    278 
    279 
    280     FT_TRACE4(( "Glyph %ld\n", glyph_index ));
    281 
    282     /* the following line sets the `error' variable through macros! */
    283     if ( FT_STREAM_SEEK( offset ) || FT_FRAME_ENTER( byte_count ) )
    284       return error;
    285 
    286     loader->cursor = stream->cursor;
    287     loader->limit  = stream->limit;
    288 
    289     return TT_Err_Ok;
    290   }
    291 
    292 
    293   FT_CALLBACK_DEF( void )
    294   TT_Forget_Glyph_Frame( TT_Loader  loader )
    295   {
    296     FT_Stream  stream = loader->stream;
    297 
    298 
    299     FT_FRAME_EXIT();
    300   }
    301 
    302 
    303   FT_CALLBACK_DEF( FT_Error )
    304   TT_Load_Glyph_Header( TT_Loader  loader )
    305   {
    306     FT_Byte*  p     = loader->cursor;
    307     FT_Byte*  limit = loader->limit;
    308 
    309 
    310     if ( p + 10 > limit )
    311       return TT_Err_Invalid_Outline;
    312 
    313     loader->n_contours = FT_NEXT_SHORT( p );
    314 
    315     loader->bbox.xMin = FT_NEXT_SHORT( p );
    316     loader->bbox.yMin = FT_NEXT_SHORT( p );
    317     loader->bbox.xMax = FT_NEXT_SHORT( p );
    318     loader->bbox.yMax = FT_NEXT_SHORT( p );
    319 
    320     FT_TRACE5(( "  # of contours: %d\n", loader->n_contours ));
    321     FT_TRACE5(( "  xMin: %4d  xMax: %4d\n", loader->bbox.xMin,
    322                                             loader->bbox.xMax ));
    323     FT_TRACE5(( "  yMin: %4d  yMax: %4d\n", loader->bbox.yMin,
    324                                             loader->bbox.yMax ));
    325     loader->cursor = p;
    326 
    327     return TT_Err_Ok;
    328   }
    329 
    330 
    331   FT_CALLBACK_DEF( FT_Error )
    332   TT_Load_Simple_Glyph( TT_Loader  load )
    333   {
    334     FT_Error        error;
    335     FT_Byte*        p          = load->cursor;
    336     FT_Byte*        limit      = load->limit;
    337     FT_GlyphLoader  gloader    = load->gloader;
    338     FT_Int          n_contours = load->n_contours;
    339     FT_Outline*     outline;
    340     TT_Face         face       = (TT_Face)load->face;
    341     FT_UShort       n_ins;
    342     FT_Int          n_points;
    343 
    344     FT_Byte         *flag, *flag_limit;
    345     FT_Byte         c, count;
    346     FT_Vector       *vec, *vec_limit;
    347     FT_Pos          x;
    348     FT_Short        *cont, *cont_limit, prev_cont;
    349     FT_Int          xy_size = 0;
    350 
    351 
    352     /* check that we can add the contours to the glyph */
    353     error = FT_GLYPHLOADER_CHECK_POINTS( gloader, 0, n_contours );
    354     if ( error )
    355       goto Fail;
    356 
    357     /* reading the contours' endpoints & number of points */
    358     cont       = gloader->current.outline.contours;
    359     cont_limit = cont + n_contours;
    360 
    361     /* check space for contours array + instructions count */
    362     if ( n_contours >= 0xFFF || p + ( n_contours + 1 ) * 2 > limit )
    363       goto Invalid_Outline;
    364 
    365     prev_cont = FT_NEXT_USHORT( p );
    366 
    367     if ( n_contours > 0 )
    368       cont[0] = prev_cont;
    369 
    370     for ( cont++; cont < cont_limit; cont++ )
    371     {
    372       cont[0] = FT_NEXT_USHORT( p );
    373       if ( cont[0] <= prev_cont )
    374       {
    375         /* unordered contours: this is invalid */
    376         error = TT_Err_Invalid_Table;
    377         goto Fail;
    378       }
    379       prev_cont = cont[0];
    380     }
    381 
    382     n_points = 0;
    383     if ( n_contours > 0 )
    384     {
    385       n_points = cont[-1] + 1;
    386       if ( n_points < 0 )
    387         goto Invalid_Outline;
    388     }
    389 
    390     /* note that we will add four phantom points later */
    391     error = FT_GLYPHLOADER_CHECK_POINTS( gloader, n_points + 4, 0 );
    392     if ( error )
    393       goto Fail;
    394 
    395     /* we'd better check the contours table right now */
    396     outline = &gloader->current.outline;
    397 
    398     for ( cont = outline->contours + 1; cont < cont_limit; cont++ )
    399       if ( cont[-1] >= cont[0] )
    400         goto Invalid_Outline;
    401 
    402     /* reading the bytecode instructions */
    403     load->glyph->control_len  = 0;
    404     load->glyph->control_data = 0;
    405 
    406     if ( p + 2 > limit )
    407       goto Invalid_Outline;
    408 
    409     n_ins = FT_NEXT_USHORT( p );
    410 
    411     FT_TRACE5(( "  Instructions size: %u\n", n_ins ));
    412 
    413     if ( n_ins > face->max_profile.maxSizeOfInstructions )
    414     {
    415       FT_TRACE0(( "TT_Load_Simple_Glyph: too many instructions (%d)\n",
    416                   n_ins ));
    417       error = TT_Err_Too_Many_Hints;
    418       goto Fail;
    419     }
    420 
    421     if ( ( limit - p ) < n_ins )
    422     {
    423       FT_TRACE0(( "TT_Load_Simple_Glyph: instruction count mismatch\n" ));
    424       error = TT_Err_Too_Many_Hints;
    425       goto Fail;
    426     }
    427 
    428 #ifdef TT_USE_BYTECODE_INTERPRETER
    429 
    430     if ( IS_HINTED( load->load_flags ) )
    431     {
    432       load->glyph->control_len  = n_ins;
    433       load->glyph->control_data = load->exec->glyphIns;
    434 
    435       FT_MEM_COPY( load->exec->glyphIns, p, (FT_Long)n_ins );
    436     }
    437 
    438 #endif /* TT_USE_BYTECODE_INTERPRETER */
    439 
    440     p += n_ins;
    441 
    442     /* reading the point tags */
    443     flag       = (FT_Byte*)outline->tags;
    444     flag_limit = flag + n_points;
    445 
    446     FT_ASSERT( flag != NULL );
    447 
    448     while ( flag < flag_limit )
    449     {
    450       if ( p + 1 > limit )
    451         goto Invalid_Outline;
    452 
    453       *flag++ = c = FT_NEXT_BYTE( p );
    454       if ( c & 8 )
    455       {
    456         if ( p + 1 > limit )
    457           goto Invalid_Outline;
    458 
    459         count = FT_NEXT_BYTE( p );
    460         if ( flag + (FT_Int)count > flag_limit )
    461           goto Invalid_Outline;
    462 
    463         for ( ; count > 0; count-- )
    464           *flag++ = c;
    465       }
    466     }
    467 
    468     /* reading the X coordinates */
    469 
    470     vec       = outline->points;
    471     vec_limit = vec + n_points;
    472     flag      = (FT_Byte*)outline->tags;
    473     x         = 0;
    474 
    475     if ( p + xy_size > limit )
    476       goto Invalid_Outline;
    477 
    478     for ( ; vec < vec_limit; vec++, flag++ )
    479     {
    480       FT_Pos   y = 0;
    481       FT_Byte  f = *flag;
    482 
    483 
    484       if ( f & 2 )
    485       {
    486         if ( p + 1 > limit )
    487           goto Invalid_Outline;
    488 
    489         y = (FT_Pos)FT_NEXT_BYTE( p );
    490         if ( ( f & 16 ) == 0 )
    491           y = -y;
    492       }
    493       else if ( ( f & 16 ) == 0 )
    494       {
    495         if ( p + 2 > limit )
    496           goto Invalid_Outline;
    497 
    498         y = (FT_Pos)FT_NEXT_SHORT( p );
    499       }
    500 
    501       x     += y;
    502       vec->x = x;
    503       /* the cast is for stupid compilers */
    504       *flag  = (FT_Byte)( f & ~( 2 | 16 ) );
    505     }
    506 
    507     /* reading the Y coordinates */
    508 
    509     vec       = gloader->current.outline.points;
    510     vec_limit = vec + n_points;
    511     flag      = (FT_Byte*)outline->tags;
    512     x         = 0;
    513 
    514     for ( ; vec < vec_limit; vec++, flag++ )
    515     {
    516       FT_Pos   y = 0;
    517       FT_Byte  f = *flag;
    518 
    519 
    520       if ( f & 4 )
    521       {
    522         if ( p + 1 > limit )
    523           goto Invalid_Outline;
    524 
    525         y = (FT_Pos)FT_NEXT_BYTE( p );
    526         if ( ( f & 32 ) == 0 )
    527           y = -y;
    528       }
    529       else if ( ( f & 32 ) == 0 )
    530       {
    531         if ( p + 2 > limit )
    532           goto Invalid_Outline;
    533 
    534         y = (FT_Pos)FT_NEXT_SHORT( p );
    535       }
    536 
    537       x     += y;
    538       vec->y = x;
    539       /* the cast is for stupid compilers */
    540       *flag  = (FT_Byte)( f & FT_CURVE_TAG_ON );
    541     }
    542 
    543     outline->n_points   = (FT_UShort)n_points;
    544     outline->n_contours = (FT_Short) n_contours;
    545 
    546     load->cursor = p;
    547 
    548   Fail:
    549     return error;
    550 
    551   Invalid_Outline:
    552     error = TT_Err_Invalid_Outline;
    553     goto Fail;
    554   }
    555 
    556 
    557   FT_CALLBACK_DEF( FT_Error )
    558   TT_Load_Composite_Glyph( TT_Loader  loader )
    559   {
    560     FT_Error        error;
    561     FT_Byte*        p       = loader->cursor;
    562     FT_Byte*        limit   = loader->limit;
    563     FT_GlyphLoader  gloader = loader->gloader;
    564     FT_SubGlyph     subglyph;
    565     FT_UInt         num_subglyphs;
    566 
    567 
    568     num_subglyphs = 0;
    569 
    570     do
    571     {
    572       FT_Fixed  xx, xy, yy, yx;
    573       FT_UInt   count;
    574 
    575 
    576       /* check that we can load a new subglyph */
    577       error = FT_GlyphLoader_CheckSubGlyphs( gloader, num_subglyphs + 1 );
    578       if ( error )
    579         goto Fail;
    580 
    581       /* check space */
    582       if ( p + 4 > limit )
    583         goto Invalid_Composite;
    584 
    585       subglyph = gloader->current.subglyphs + num_subglyphs;
    586 
    587       subglyph->arg1 = subglyph->arg2 = 0;
    588 
    589       subglyph->flags = FT_NEXT_USHORT( p );
    590       subglyph->index = FT_NEXT_USHORT( p );
    591 
    592       /* check space */
    593       count = 2;
    594       if ( subglyph->flags & ARGS_ARE_WORDS )
    595         count += 2;
    596       if ( subglyph->flags & WE_HAVE_A_SCALE )
    597         count += 2;
    598       else if ( subglyph->flags & WE_HAVE_AN_XY_SCALE )
    599         count += 4;
    600       else if ( subglyph->flags & WE_HAVE_A_2X2 )
    601         count += 8;
    602 
    603       if ( p + count > limit )
    604         goto Invalid_Composite;
    605 
    606       /* read arguments */
    607       if ( subglyph->flags & ARGS_ARE_WORDS )
    608       {
    609         subglyph->arg1 = FT_NEXT_SHORT( p );
    610         subglyph->arg2 = FT_NEXT_SHORT( p );
    611       }
    612       else
    613       {
    614         subglyph->arg1 = FT_NEXT_CHAR( p );
    615         subglyph->arg2 = FT_NEXT_CHAR( p );
    616       }
    617 
    618       /* read transform */
    619       xx = yy = 0x10000L;
    620       xy = yx = 0;
    621 
    622       if ( subglyph->flags & WE_HAVE_A_SCALE )
    623       {
    624         xx = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
    625         yy = xx;
    626       }
    627       else if ( subglyph->flags & WE_HAVE_AN_XY_SCALE )
    628       {
    629         xx = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
    630         yy = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
    631       }
    632       else if ( subglyph->flags & WE_HAVE_A_2X2 )
    633       {
    634         xx = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
    635         yx = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
    636         xy = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
    637         yy = (FT_Fixed)FT_NEXT_SHORT( p ) << 2;
    638       }
    639 
    640       subglyph->transform.xx = xx;
    641       subglyph->transform.xy = xy;
    642       subglyph->transform.yx = yx;
    643       subglyph->transform.yy = yy;
    644 
    645       num_subglyphs++;
    646 
    647     } while ( subglyph->flags & MORE_COMPONENTS );
    648 
    649     gloader->current.num_subglyphs = num_subglyphs;
    650 
    651 #ifdef TT_USE_BYTECODE_INTERPRETER
    652 
    653     {
    654       FT_Stream  stream = loader->stream;
    655 
    656 
    657       /* we must undo the FT_FRAME_ENTER in order to point */
    658       /* to the composite instructions, if we find some.   */
    659       /* We will process them later.                       */
    660       /*                                                   */
    661       loader->ins_pos = (FT_ULong)( FT_STREAM_POS() +
    662                                     p - limit );
    663     }
    664 
    665 #endif
    666 
    667     loader->cursor = p;
    668 
    669   Fail:
    670     return error;
    671 
    672   Invalid_Composite:
    673     error = TT_Err_Invalid_Composite;
    674     goto Fail;
    675   }
    676 
    677 
    678   FT_LOCAL_DEF( void )
    679   TT_Init_Glyph_Loading( TT_Face  face )
    680   {
    681     face->access_glyph_frame   = TT_Access_Glyph_Frame;
    682     face->read_glyph_header    = TT_Load_Glyph_Header;
    683     face->read_simple_glyph    = TT_Load_Simple_Glyph;
    684     face->read_composite_glyph = TT_Load_Composite_Glyph;
    685     face->forget_glyph_frame   = TT_Forget_Glyph_Frame;
    686   }
    687 
    688 
    689   static void
    690   tt_prepare_zone( TT_GlyphZone  zone,
    691                    FT_GlyphLoad  load,
    692                    FT_UInt       start_point,
    693                    FT_UInt       start_contour )
    694   {
    695     zone->n_points    = (FT_UShort)( load->outline.n_points - start_point );
    696     zone->n_contours  = (FT_Short) ( load->outline.n_contours -
    697                                        start_contour );
    698     zone->org         = load->extra_points + start_point;
    699     zone->cur         = load->outline.points + start_point;
    700     zone->orus        = load->extra_points2 + start_point;
    701     zone->tags        = (FT_Byte*)load->outline.tags + start_point;
    702     zone->contours    = (FT_UShort*)load->outline.contours + start_contour;
    703     zone->first_point = (FT_UShort)start_point;
    704   }
    705 
    706 
    707   /*************************************************************************/
    708   /*                                                                       */
    709   /* <Function>                                                            */
    710   /*    TT_Hint_Glyph                                                      */
    711   /*                                                                       */
    712   /* <Description>                                                         */
    713   /*    Hint the glyph using the zone prepared by the caller.  Note that   */
    714   /*    the zone is supposed to include four phantom points.               */
    715   /*                                                                       */
    716   static FT_Error
    717   TT_Hint_Glyph( TT_Loader  loader,
    718                  FT_Bool    is_composite )
    719   {
    720     TT_GlyphZone  zone = &loader->zone;
    721     FT_Pos        origin;
    722 
    723 #ifdef TT_USE_BYTECODE_INTERPRETER
    724     FT_UInt       n_ins;
    725 #else
    726     FT_UNUSED( is_composite );
    727 #endif
    728 
    729 
    730 #ifdef TT_USE_BYTECODE_INTERPRETER
    731     if ( loader->glyph->control_len > 0xFFFFL )
    732     {
    733       FT_TRACE1(( "TT_Hint_Glyph: too long instructions " ));
    734       FT_TRACE1(( "(0x%lx byte) is truncated\n",
    735                  loader->glyph->control_len ));
    736     }
    737     n_ins = (FT_UInt)( loader->glyph->control_len );
    738 #endif
    739 
    740     origin = zone->cur[zone->n_points - 4].x;
    741     origin = FT_PIX_ROUND( origin ) - origin;
    742     if ( origin )
    743       translate_array( zone->n_points, zone->cur, origin, 0 );
    744 
    745 #ifdef TT_USE_BYTECODE_INTERPRETER
    746     /* save original point position in org */
    747     if ( n_ins > 0 )
    748       FT_ARRAY_COPY( zone->org, zone->cur, zone->n_points );
    749 
    750     /* Reset graphics state. */
    751     loader->exec->GS = ((TT_Size)loader->size)->GS;
    752 
    753     /* XXX: UNDOCUMENTED! Hinting instructions of a composite glyph */
    754     /*      completely refer to the (already) hinted subglyphs.     */
    755     if ( is_composite )
    756     {
    757       loader->exec->metrics.x_scale = 1 << 16;
    758       loader->exec->metrics.y_scale = 1 << 16;
    759 
    760       FT_ARRAY_COPY( zone->orus, zone->cur, zone->n_points );
    761     }
    762     else
    763     {
    764       loader->exec->metrics.x_scale =
    765         ((TT_Size)loader->size)->metrics.x_scale;
    766       loader->exec->metrics.y_scale =
    767         ((TT_Size)loader->size)->metrics.y_scale;
    768     }
    769 #endif
    770 
    771     /* round pp2 and pp4 */
    772     zone->cur[zone->n_points - 3].x =
    773       FT_PIX_ROUND( zone->cur[zone->n_points - 3].x );
    774     zone->cur[zone->n_points - 1].y =
    775       FT_PIX_ROUND( zone->cur[zone->n_points - 1].y );
    776 
    777 #ifdef TT_USE_BYTECODE_INTERPRETER
    778 
    779     if ( n_ins > 0 )
    780     {
    781       FT_Bool   debug;
    782       FT_Error  error;
    783 
    784       FT_GlyphLoader  gloader         = loader->gloader;
    785       FT_Outline      current_outline = gloader->current.outline;
    786 
    787 
    788       error = TT_Set_CodeRange( loader->exec, tt_coderange_glyph,
    789                                 loader->exec->glyphIns, n_ins );
    790       if ( error )
    791         return error;
    792 
    793       loader->exec->is_composite = is_composite;
    794       loader->exec->pts          = *zone;
    795 
    796       debug = FT_BOOL( !( loader->load_flags & FT_LOAD_NO_SCALE ) &&
    797                        ((TT_Size)loader->size)->debug             );
    798 
    799       error = TT_Run_Context( loader->exec, debug );
    800       if ( error && loader->exec->pedantic_hinting )
    801         return error;
    802 
    803       /* store drop-out mode in bits 5-7; set bit 2 also as a marker */
    804       current_outline.tags[0] |=
    805         ( loader->exec->GS.scan_type << 5 ) | FT_CURVE_TAG_HAS_SCANMODE;
    806     }
    807 
    808 #endif
    809 
    810     /* save glyph phantom points */
    811     if ( !loader->preserve_pps )
    812     {
    813       loader->pp1 = zone->cur[zone->n_points - 4];
    814       loader->pp2 = zone->cur[zone->n_points - 3];
    815       loader->pp3 = zone->cur[zone->n_points - 2];
    816       loader->pp4 = zone->cur[zone->n_points - 1];
    817     }
    818 
    819     return TT_Err_Ok;
    820   }
    821 
    822 
    823   /*************************************************************************/
    824   /*                                                                       */
    825   /* <Function>                                                            */
    826   /*    TT_Process_Simple_Glyph                                            */
    827   /*                                                                       */
    828   /* <Description>                                                         */
    829   /*    Once a simple glyph has been loaded, it needs to be processed.     */
    830   /*    Usually, this means scaling and hinting through bytecode           */
    831   /*    interpretation.                                                    */
    832   /*                                                                       */
    833   static FT_Error
    834   TT_Process_Simple_Glyph( TT_Loader  loader )
    835   {
    836     FT_GlyphLoader  gloader = loader->gloader;
    837     FT_Error        error   = TT_Err_Ok;
    838     FT_Outline*     outline;
    839     FT_Int          n_points;
    840 
    841 
    842     outline  = &gloader->current.outline;
    843     n_points = outline->n_points;
    844 
    845     /* set phantom points */
    846 
    847     outline->points[n_points    ] = loader->pp1;
    848     outline->points[n_points + 1] = loader->pp2;
    849     outline->points[n_points + 2] = loader->pp3;
    850     outline->points[n_points + 3] = loader->pp4;
    851 
    852     outline->tags[n_points    ] = 0;
    853     outline->tags[n_points + 1] = 0;
    854     outline->tags[n_points + 2] = 0;
    855     outline->tags[n_points + 3] = 0;
    856 
    857     n_points += 4;
    858 
    859 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
    860 
    861     if ( ((TT_Face)loader->face)->doblend )
    862     {
    863       /* Deltas apply to the unscaled data. */
    864       FT_Vector*  deltas;
    865       FT_Memory   memory = loader->face->memory;
    866       FT_Int      i;
    867 
    868 
    869       error = TT_Vary_Get_Glyph_Deltas( (TT_Face)(loader->face),
    870                                         loader->glyph_index,
    871                                         &deltas,
    872                                         n_points );
    873       if ( error )
    874         return error;
    875 
    876       for ( i = 0; i < n_points; ++i )
    877       {
    878         outline->points[i].x += deltas[i].x;
    879         outline->points[i].y += deltas[i].y;
    880       }
    881 
    882       FT_FREE( deltas );
    883     }
    884 
    885 #endif /* TT_CONFIG_OPTION_GX_VAR_SUPPORT */
    886 
    887     if ( IS_HINTED( loader->load_flags ) )
    888     {
    889       tt_prepare_zone( &loader->zone, &gloader->current, 0, 0 );
    890 
    891       FT_ARRAY_COPY( loader->zone.orus, loader->zone.cur,
    892                      loader->zone.n_points + 4 );
    893     }
    894 
    895     /* scale the glyph */
    896     if ( ( loader->load_flags & FT_LOAD_NO_SCALE ) == 0 )
    897     {
    898       FT_Vector*  vec     = outline->points;
    899       FT_Vector*  limit   = outline->points + n_points;
    900       FT_Fixed    x_scale = ((TT_Size)loader->size)->metrics.x_scale;
    901       FT_Fixed    y_scale = ((TT_Size)loader->size)->metrics.y_scale;
    902 
    903 
    904       for ( ; vec < limit; vec++ )
    905       {
    906         vec->x = FT_MulFix( vec->x, x_scale );
    907         vec->y = FT_MulFix( vec->y, y_scale );
    908       }
    909 
    910       loader->pp1 = outline->points[n_points - 4];
    911       loader->pp2 = outline->points[n_points - 3];
    912       loader->pp3 = outline->points[n_points - 2];
    913       loader->pp4 = outline->points[n_points - 1];
    914     }
    915 
    916     if ( IS_HINTED( loader->load_flags ) )
    917     {
    918       loader->zone.n_points += 4;
    919 
    920       error = TT_Hint_Glyph( loader, 0 );
    921     }
    922 
    923     return error;
    924   }
    925 
    926 
    927   /*************************************************************************/
    928   /*                                                                       */
    929   /* <Function>                                                            */
    930   /*    TT_Process_Composite_Component                                     */
    931   /*                                                                       */
    932   /* <Description>                                                         */
    933   /*    Once a composite component has been loaded, it needs to be         */
    934   /*    processed.  Usually, this means transforming and translating.      */
    935   /*                                                                       */
    936   static FT_Error
    937   TT_Process_Composite_Component( TT_Loader    loader,
    938                                   FT_SubGlyph  subglyph,
    939                                   FT_UInt      start_point,
    940                                   FT_UInt      num_base_points )
    941   {
    942     FT_GlyphLoader  gloader    = loader->gloader;
    943     FT_Vector*      base_vec   = gloader->base.outline.points;
    944     FT_UInt         num_points = gloader->base.outline.n_points;
    945     FT_Bool         have_scale;
    946     FT_Pos          x, y;
    947 
    948 
    949     have_scale = FT_BOOL( subglyph->flags & ( WE_HAVE_A_SCALE     |
    950                                               WE_HAVE_AN_XY_SCALE |
    951                                               WE_HAVE_A_2X2       ) );
    952 
    953     /* perform the transform required for this subglyph */
    954     if ( have_scale )
    955     {
    956       FT_UInt  i;
    957 
    958 
    959       for ( i = num_base_points; i < num_points; i++ )
    960         FT_Vector_Transform( base_vec + i, &subglyph->transform );
    961     }
    962 
    963     /* get offset */
    964     if ( !( subglyph->flags & ARGS_ARE_XY_VALUES ) )
    965     {
    966       FT_UInt     k = subglyph->arg1;
    967       FT_UInt     l = subglyph->arg2;
    968       FT_Vector*  p1;
    969       FT_Vector*  p2;
    970 
    971 
    972       /* match l-th point of the newly loaded component to the k-th point */
    973       /* of the previously loaded components.                             */
    974 
    975       /* change to the point numbers used by our outline */
    976       k += start_point;
    977       l += num_base_points;
    978       if ( k >= num_base_points ||
    979            l >= num_points      )
    980         return TT_Err_Invalid_Composite;
    981 
    982       p1 = gloader->base.outline.points + k;
    983       p2 = gloader->base.outline.points + l;
    984 
    985       x = p1->x - p2->x;
    986       y = p1->y - p2->y;
    987     }
    988     else
    989     {
    990       x = subglyph->arg1;
    991       y = subglyph->arg2;
    992 
    993       if ( !x && !y )
    994         return TT_Err_Ok;
    995 
    996   /* Use a default value dependent on                                     */
    997   /* TT_CONFIG_OPTION_COMPONENT_OFFSET_SCALED.  This is useful for old TT */
    998   /* fonts which don't set the xxx_COMPONENT_OFFSET bit.                  */
    999 
   1000       if ( have_scale &&
   1001 #ifdef TT_CONFIG_OPTION_COMPONENT_OFFSET_SCALED
   1002            !( subglyph->flags & UNSCALED_COMPONENT_OFFSET ) )
   1003 #else
   1004             ( subglyph->flags & SCALED_COMPONENT_OFFSET ) )
   1005 #endif
   1006       {
   1007 
   1008 #if 0
   1009 
   1010   /*************************************************************************/
   1011   /*                                                                       */
   1012   /* This algorithm is what Apple documents.  But it doesn't work.         */
   1013   /*                                                                       */
   1014         int  a = subglyph->transform.xx > 0 ?  subglyph->transform.xx
   1015                                             : -subglyph->transform.xx;
   1016         int  b = subglyph->transform.yx > 0 ?  subglyph->transform.yx
   1017                                             : -subglyph->transform.yx;
   1018         int  c = subglyph->transform.xy > 0 ?  subglyph->transform.xy
   1019                                             : -subglyph->transform.xy;
   1020         int  d = subglyph->transform.yy > 0 ? subglyph->transform.yy
   1021                                             : -subglyph->transform.yy;
   1022         int  m = a > b ? a : b;
   1023         int  n = c > d ? c : d;
   1024 
   1025 
   1026         if ( a - b <= 33 && a - b >= -33 )
   1027           m *= 2;
   1028         if ( c - d <= 33 && c - d >= -33 )
   1029           n *= 2;
   1030         x = FT_MulFix( x, m );
   1031         y = FT_MulFix( y, n );
   1032 
   1033 #else /* 0 */
   1034 
   1035   /*************************************************************************/
   1036   /*                                                                       */
   1037   /* This algorithm is a guess and works much better than the above.       */
   1038   /*                                                                       */
   1039         FT_Fixed  mac_xscale = FT_SqrtFixed(
   1040                                  (FT_Int32)FT_MulFix( subglyph->transform.xx,
   1041                                                       subglyph->transform.xx ) +
   1042                                  (FT_Int32)FT_MulFix( subglyph->transform.xy,
   1043                                                       subglyph->transform.xy ) );
   1044         FT_Fixed  mac_yscale = FT_SqrtFixed(
   1045                                  (FT_Int32)FT_MulFix( subglyph->transform.yy,
   1046                                                       subglyph->transform.yy ) +
   1047                                  (FT_Int32)FT_MulFix( subglyph->transform.yx,
   1048                                                       subglyph->transform.yx ) );
   1049 
   1050 
   1051         x = FT_MulFix( x, mac_xscale );
   1052         y = FT_MulFix( y, mac_yscale );
   1053 
   1054 #endif /* 0 */
   1055 
   1056       }
   1057 
   1058       if ( !( loader->load_flags & FT_LOAD_NO_SCALE ) )
   1059       {
   1060         FT_Fixed  x_scale = ((TT_Size)loader->size)->metrics.x_scale;
   1061         FT_Fixed  y_scale = ((TT_Size)loader->size)->metrics.y_scale;
   1062 
   1063 
   1064         x = FT_MulFix( x, x_scale );
   1065         y = FT_MulFix( y, y_scale );
   1066 
   1067         if ( subglyph->flags & ROUND_XY_TO_GRID )
   1068         {
   1069           x = FT_PIX_ROUND( x );
   1070           y = FT_PIX_ROUND( y );
   1071         }
   1072       }
   1073     }
   1074 
   1075     if ( x || y )
   1076       translate_array( num_points - num_base_points,
   1077                        base_vec + num_base_points,
   1078                        x, y );
   1079 
   1080     return TT_Err_Ok;
   1081   }
   1082 
   1083 
   1084   /*************************************************************************/
   1085   /*                                                                       */
   1086   /* <Function>                                                            */
   1087   /*    TT_Process_Composite_Glyph                                         */
   1088   /*                                                                       */
   1089   /* <Description>                                                         */
   1090   /*    This is slightly different from TT_Process_Simple_Glyph, in that   */
   1091   /*    its sole purpose is to hint the glyph.  Thus this function is      */
   1092   /*    only available when bytecode interpreter is enabled.               */
   1093   /*                                                                       */
   1094   static FT_Error
   1095   TT_Process_Composite_Glyph( TT_Loader  loader,
   1096                               FT_UInt    start_point,
   1097                               FT_UInt    start_contour )
   1098   {
   1099     FT_Error     error;
   1100     FT_Outline*  outline;
   1101     FT_UInt      i;
   1102 
   1103 
   1104     outline = &loader->gloader->base.outline;
   1105 
   1106     /* make room for phantom points */
   1107     error = FT_GLYPHLOADER_CHECK_POINTS( loader->gloader,
   1108                                          outline->n_points + 4,
   1109                                          0 );
   1110     if ( error )
   1111       return error;
   1112 
   1113     outline->points[outline->n_points    ] = loader->pp1;
   1114     outline->points[outline->n_points + 1] = loader->pp2;
   1115     outline->points[outline->n_points + 2] = loader->pp3;
   1116     outline->points[outline->n_points + 3] = loader->pp4;
   1117 
   1118     outline->tags[outline->n_points    ] = 0;
   1119     outline->tags[outline->n_points + 1] = 0;
   1120     outline->tags[outline->n_points + 2] = 0;
   1121     outline->tags[outline->n_points + 3] = 0;
   1122 
   1123 #ifdef TT_USE_BYTECODE_INTERPRETER
   1124 
   1125     {
   1126       FT_Stream  stream = loader->stream;
   1127       FT_UShort  n_ins, max_ins;
   1128       FT_ULong   tmp;
   1129 
   1130 
   1131       /* TT_Load_Composite_Glyph only gives us the offset of instructions */
   1132       /* so we read them here                                             */
   1133       if ( FT_STREAM_SEEK( loader->ins_pos ) ||
   1134            FT_READ_USHORT( n_ins )           )
   1135         return error;
   1136 
   1137       FT_TRACE5(( "  Instructions size = %d\n", n_ins ));
   1138 
   1139       /* check it */
   1140       max_ins = ((TT_Face)loader->face)->max_profile.maxSizeOfInstructions;
   1141       if ( n_ins > max_ins )
   1142       {
   1143         /* acroread ignores this field, so we only do a rough safety check */
   1144         if ( (FT_Int)n_ins > loader->byte_len )
   1145         {
   1146           FT_TRACE1(( "TT_Process_Composite_Glyph: "
   1147                       "too many instructions (%d) for glyph with length %d\n",
   1148                       n_ins, loader->byte_len ));
   1149           return TT_Err_Too_Many_Hints;
   1150         }
   1151 
   1152         tmp = loader->exec->glyphSize;
   1153         error = Update_Max( loader->exec->memory,
   1154                             &tmp,
   1155                             sizeof ( FT_Byte ),
   1156                             (void*)&loader->exec->glyphIns,
   1157                             n_ins );
   1158         loader->exec->glyphSize = (FT_UShort)tmp;
   1159         if ( error )
   1160           return error;
   1161       }
   1162       else if ( n_ins == 0 )
   1163         return TT_Err_Ok;
   1164 
   1165       if ( FT_STREAM_READ( loader->exec->glyphIns, n_ins ) )
   1166         return error;
   1167 
   1168       loader->glyph->control_data = loader->exec->glyphIns;
   1169       loader->glyph->control_len  = n_ins;
   1170     }
   1171 
   1172 #endif
   1173 
   1174     tt_prepare_zone( &loader->zone, &loader->gloader->base,
   1175                      start_point, start_contour );
   1176 
   1177     /* Some points are likely touched during execution of  */
   1178     /* instructions on components.  So let's untouch them. */
   1179     for ( i = start_point; i < loader->zone.n_points; i++ )
   1180       loader->zone.tags[i] &= ~FT_CURVE_TAG_TOUCH_BOTH;
   1181 
   1182     loader->zone.n_points += 4;
   1183 
   1184     return TT_Hint_Glyph( loader, 1 );
   1185   }
   1186 
   1187 
   1188   /* Calculate the four phantom points.                     */
   1189   /* The first two stand for horizontal origin and advance. */
   1190   /* The last two stand for vertical origin and advance.    */
   1191 #define TT_LOADER_SET_PP( loader )                                          \
   1192           do {                                                              \
   1193             (loader)->pp1.x = (loader)->bbox.xMin - (loader)->left_bearing; \
   1194             (loader)->pp1.y = 0;                                            \
   1195             (loader)->pp2.x = (loader)->pp1.x + (loader)->advance;          \
   1196             (loader)->pp2.y = 0;                                            \
   1197             (loader)->pp3.x = 0;                                            \
   1198             (loader)->pp3.y = (loader)->top_bearing + (loader)->bbox.yMax;  \
   1199             (loader)->pp4.x = 0;                                            \
   1200             (loader)->pp4.y = (loader)->pp3.y - (loader)->vadvance;         \
   1201           } while ( 0 )
   1202 
   1203 
   1204   /*************************************************************************/
   1205   /*                                                                       */
   1206   /* <Function>                                                            */
   1207   /*    load_truetype_glyph                                                */
   1208   /*                                                                       */
   1209   /* <Description>                                                         */
   1210   /*    Loads a given truetype glyph.  Handles composites and uses a       */
   1211   /*    TT_Loader object.                                                  */
   1212   /*                                                                       */
   1213   static FT_Error
   1214   load_truetype_glyph( TT_Loader  loader,
   1215                        FT_UInt    glyph_index,
   1216                        FT_UInt    recurse_count,
   1217                        FT_Bool    header_only )
   1218   {
   1219     FT_Error        error        = TT_Err_Ok;
   1220     FT_Fixed        x_scale, y_scale;
   1221     FT_ULong        offset;
   1222     TT_Face         face         = (TT_Face)loader->face;
   1223     FT_GlyphLoader  gloader      = loader->gloader;
   1224     FT_Bool         opened_frame = 0;
   1225 
   1226 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
   1227     FT_Vector*      deltas       = NULL;
   1228 #endif
   1229 
   1230 #ifdef FT_CONFIG_OPTION_INCREMENTAL
   1231     FT_StreamRec    inc_stream;
   1232     FT_Data         glyph_data;
   1233     FT_Bool         glyph_data_loaded = 0;
   1234 #endif
   1235 
   1236 
   1237     /* some fonts have an incorrect value of `maxComponentDepth', */
   1238     /* thus we allow depth 1 to catch the majority of them        */
   1239     if ( recurse_count > 1                                   &&
   1240          recurse_count > face->max_profile.maxComponentDepth )
   1241     {
   1242       error = TT_Err_Invalid_Composite;
   1243       goto Exit;
   1244     }
   1245 
   1246     /* check glyph index */
   1247     if ( glyph_index >= (FT_UInt)face->root.num_glyphs )
   1248     {
   1249       error = TT_Err_Invalid_Glyph_Index;
   1250       goto Exit;
   1251     }
   1252 
   1253     loader->glyph_index = glyph_index;
   1254 
   1255     if ( ( loader->load_flags & FT_LOAD_NO_SCALE ) == 0 )
   1256     {
   1257       x_scale = ((TT_Size)loader->size)->metrics.x_scale;
   1258       y_scale = ((TT_Size)loader->size)->metrics.y_scale;
   1259     }
   1260     else
   1261     {
   1262       x_scale = 0x10000L;
   1263       y_scale = 0x10000L;
   1264     }
   1265 
   1266     tt_get_metrics( loader, glyph_index );
   1267 
   1268     /* Set `offset' to the start of the glyph relative to the start of */
   1269     /* the `glyf' table, and `byte_len' to the length of the glyph in  */
   1270     /* bytes.                                                          */
   1271 
   1272 #ifdef FT_CONFIG_OPTION_INCREMENTAL
   1273 
   1274     /* If we are loading glyph data via the incremental interface, set */
   1275     /* the loader stream to a memory stream reading the data returned  */
   1276     /* by the interface.                                               */
   1277     if ( face->root.internal->incremental_interface )
   1278     {
   1279       error = face->root.internal->incremental_interface->funcs->get_glyph_data(
   1280                 face->root.internal->incremental_interface->object,
   1281                 glyph_index, &glyph_data );
   1282       if ( error )
   1283         goto Exit;
   1284 
   1285       glyph_data_loaded = 1;
   1286       offset            = 0;
   1287       loader->byte_len  = glyph_data.length;
   1288 
   1289       FT_MEM_ZERO( &inc_stream, sizeof ( inc_stream ) );
   1290       FT_Stream_OpenMemory( &inc_stream,
   1291                             glyph_data.pointer, glyph_data.length );
   1292 
   1293       loader->stream = &inc_stream;
   1294     }
   1295     else
   1296 
   1297 #endif /* FT_CONFIG_OPTION_INCREMENTAL */
   1298 
   1299       offset = tt_face_get_location( face, glyph_index,
   1300                                      (FT_UInt*)&loader->byte_len );
   1301 
   1302     if ( loader->byte_len > 0 )
   1303     {
   1304 #ifdef FT_CONFIG_OPTION_INCREMENTAL
   1305       /* for the incremental interface, `glyf_offset' is always zero */
   1306       if ( !loader->glyf_offset                        &&
   1307            !face->root.internal->incremental_interface )
   1308 #else
   1309       if ( !loader->glyf_offset )
   1310 #endif /* FT_CONFIG_OPTION_INCREMENTAL */
   1311       {
   1312         FT_TRACE2(( "no `glyf' table but non-zero `loca' entry\n" ));
   1313         error = TT_Err_Invalid_Table;
   1314         goto Exit;
   1315       }
   1316 
   1317       error = face->access_glyph_frame( loader, glyph_index,
   1318                                         loader->glyf_offset + offset,
   1319                                         loader->byte_len );
   1320       if ( error )
   1321         goto Exit;
   1322 
   1323       opened_frame = 1;
   1324 
   1325       /* read glyph header first */
   1326       error = face->read_glyph_header( loader );
   1327       if ( error || header_only )
   1328         goto Exit;
   1329     }
   1330 
   1331     if ( loader->byte_len == 0 || loader->n_contours == 0 )
   1332     {
   1333       loader->bbox.xMin = 0;
   1334       loader->bbox.xMax = 0;
   1335       loader->bbox.yMin = 0;
   1336       loader->bbox.yMax = 0;
   1337 
   1338       if ( header_only )
   1339         goto Exit;
   1340 
   1341       /* must initialize points before (possibly) overriding */
   1342       /* glyph metrics from the incremental interface        */
   1343       TT_LOADER_SET_PP( loader );
   1344 
   1345 #ifdef FT_CONFIG_OPTION_INCREMENTAL
   1346       tt_get_metrics_incr_overrides( loader, glyph_index );
   1347 #endif
   1348 
   1349 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
   1350 
   1351       if ( ((TT_Face)(loader->face))->doblend )
   1352       {
   1353         /* this must be done before scaling */
   1354         FT_Memory  memory = loader->face->memory;
   1355 
   1356 
   1357         error = TT_Vary_Get_Glyph_Deltas( (TT_Face)(loader->face),
   1358                                           glyph_index, &deltas, 4 );
   1359         if ( error )
   1360           goto Exit;
   1361 
   1362         loader->pp1.x += deltas[0].x; loader->pp1.y += deltas[0].y;
   1363         loader->pp2.x += deltas[1].x; loader->pp2.y += deltas[1].y;
   1364         loader->pp3.x += deltas[2].x; loader->pp3.y += deltas[2].y;
   1365         loader->pp4.x += deltas[3].x; loader->pp4.y += deltas[3].y;
   1366 
   1367         FT_FREE( deltas );
   1368       }
   1369 
   1370 #endif
   1371 
   1372       if ( ( loader->load_flags & FT_LOAD_NO_SCALE ) == 0 )
   1373       {
   1374         loader->pp1.x = FT_MulFix( loader->pp1.x, x_scale );
   1375         loader->pp2.x = FT_MulFix( loader->pp2.x, x_scale );
   1376         loader->pp3.y = FT_MulFix( loader->pp3.y, y_scale );
   1377         loader->pp4.y = FT_MulFix( loader->pp4.y, y_scale );
   1378       }
   1379 
   1380       error = TT_Err_Ok;
   1381       goto Exit;
   1382     }
   1383 
   1384     /* must initialize points before (possibly) overriding */
   1385     /* glyph metrics from the incremental interface        */
   1386     TT_LOADER_SET_PP( loader );
   1387 
   1388 #ifdef FT_CONFIG_OPTION_INCREMENTAL
   1389     tt_get_metrics_incr_overrides( loader, glyph_index );
   1390 #endif
   1391 
   1392     /***********************************************************************/
   1393     /***********************************************************************/
   1394     /***********************************************************************/
   1395 
   1396     /* if it is a simple glyph, load it */
   1397 
   1398     if ( loader->n_contours > 0 )
   1399     {
   1400       error = face->read_simple_glyph( loader );
   1401       if ( error )
   1402         goto Exit;
   1403 
   1404       /* all data have been read */
   1405       face->forget_glyph_frame( loader );
   1406       opened_frame = 0;
   1407 
   1408       error = TT_Process_Simple_Glyph( loader );
   1409       if ( error )
   1410         goto Exit;
   1411 
   1412       FT_GlyphLoader_Add( gloader );
   1413     }
   1414 
   1415     /***********************************************************************/
   1416     /***********************************************************************/
   1417     /***********************************************************************/
   1418 
   1419     /* otherwise, load a composite! */
   1420     else if ( loader->n_contours == -1 )
   1421     {
   1422       FT_UInt   start_point;
   1423       FT_UInt   start_contour;
   1424       FT_ULong  ins_pos;  /* position of composite instructions, if any */
   1425 
   1426 
   1427       start_point   = gloader->base.outline.n_points;
   1428       start_contour = gloader->base.outline.n_contours;
   1429 
   1430       /* for each subglyph, read composite header */
   1431       error = face->read_composite_glyph( loader );
   1432       if ( error )
   1433         goto Exit;
   1434 
   1435       /* store the offset of instructions */
   1436       ins_pos = loader->ins_pos;
   1437 
   1438       /* all data we need are read */
   1439       face->forget_glyph_frame( loader );
   1440       opened_frame = 0;
   1441 
   1442 #ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
   1443 
   1444       if ( face->doblend )
   1445       {
   1446         FT_Int       i, limit;
   1447         FT_SubGlyph  subglyph;
   1448         FT_Memory    memory = face->root.memory;
   1449 
   1450 
   1451         /* this provides additional offsets */
   1452         /* for each component's translation */
   1453 
   1454         if ( ( error = TT_Vary_Get_Glyph_Deltas(
   1455                          face,
   1456                          glyph_index,
   1457                          &deltas,
   1458                          gloader->current.num_subglyphs + 4 )) != 0 )
   1459           goto Exit;
   1460 
   1461         subglyph = gloader->current.subglyphs + gloader->base.num_subglyphs;
   1462         limit    = gloader->current.num_subglyphs;
   1463 
   1464         for ( i = 0; i < limit; ++i, ++subglyph )
   1465         {
   1466           if ( subglyph->flags & ARGS_ARE_XY_VALUES )
   1467           {
   1468             /* XXX: overflow check for subglyph->{arg1,arg2}.   */
   1469             /* deltas[i].{x,y} must be within signed 16-bit,    */
   1470             /* but the restriction of summed delta is not clear */
   1471             subglyph->arg1 += (FT_Int16)deltas[i].x;
   1472             subglyph->arg2 += (FT_Int16)deltas[i].y;
   1473           }
   1474         }
   1475 
   1476         loader->pp1.x += deltas[i + 0].x; loader->pp1.y += deltas[i + 0].y;
   1477         loader->pp2.x += deltas[i + 1].x; loader->pp2.y += deltas[i + 1].y;
   1478         loader->pp3.x += deltas[i + 2].x; loader->pp3.y += deltas[i + 2].y;
   1479         loader->pp4.x += deltas[i + 3].x; loader->pp4.y += deltas[i + 3].y;
   1480 
   1481         FT_FREE( deltas );
   1482       }
   1483 
   1484 #endif /* TT_CONFIG_OPTION_GX_VAR_SUPPORT */
   1485 
   1486       if ( ( loader->load_flags & FT_LOAD_NO_SCALE ) == 0 )
   1487       {
   1488         loader->pp1.x = FT_MulFix( loader->pp1.x, x_scale );
   1489         loader->pp2.x = FT_MulFix( loader->pp2.x, x_scale );
   1490         loader->pp3.y = FT_MulFix( loader->pp3.y, y_scale );
   1491         loader->pp4.y = FT_MulFix( loader->pp4.y, y_scale );
   1492       }
   1493 
   1494       /* if the flag FT_LOAD_NO_RECURSE is set, we return the subglyph */
   1495       /* `as is' in the glyph slot (the client application will be     */
   1496       /* responsible for interpreting these data)...                   */
   1497       if ( loader->load_flags & FT_LOAD_NO_RECURSE )
   1498       {
   1499         FT_GlyphLoader_Add( gloader );
   1500         loader->glyph->format = FT_GLYPH_FORMAT_COMPOSITE;
   1501 
   1502         goto Exit;
   1503       }
   1504 
   1505       /*********************************************************************/
   1506       /*********************************************************************/
   1507       /*********************************************************************/
   1508 
   1509       {
   1510         FT_UInt      n, num_base_points;
   1511         FT_SubGlyph  subglyph       = 0;
   1512 
   1513         FT_UInt      num_points     = start_point;
   1514         FT_UInt      num_subglyphs  = gloader->current.num_subglyphs;
   1515         FT_UInt      num_base_subgs = gloader->base.num_subglyphs;
   1516 
   1517         FT_Stream    old_stream     = loader->stream;
   1518         FT_Int       old_byte_len   = loader->byte_len;
   1519 
   1520 
   1521         FT_GlyphLoader_Add( gloader );
   1522 
   1523         /* read each subglyph independently */
   1524         for ( n = 0; n < num_subglyphs; n++ )
   1525         {
   1526           FT_Vector  pp[4];
   1527 
   1528 
   1529           /* Each time we call load_truetype_glyph in this loop, the   */
   1530           /* value of `gloader.base.subglyphs' can change due to table */
   1531           /* reallocations.  We thus need to recompute the subglyph    */
   1532           /* pointer on each iteration.                                */
   1533           subglyph = gloader->base.subglyphs + num_base_subgs + n;
   1534 
   1535           pp[0] = loader->pp1;
   1536           pp[1] = loader->pp2;
   1537           pp[2] = loader->pp3;
   1538           pp[3] = loader->pp4;
   1539 
   1540           num_base_points = gloader->base.outline.n_points;
   1541 
   1542           error = load_truetype_glyph( loader, subglyph->index,
   1543                                        recurse_count + 1, FALSE );
   1544           if ( error )
   1545             goto Exit;
   1546 
   1547           /* restore subglyph pointer */
   1548           subglyph = gloader->base.subglyphs + num_base_subgs + n;
   1549 
   1550           if ( !( subglyph->flags & USE_MY_METRICS ) )
   1551           {
   1552             loader->pp1 = pp[0];
   1553             loader->pp2 = pp[1];
   1554             loader->pp3 = pp[2];
   1555             loader->pp4 = pp[3];
   1556           }
   1557 
   1558           num_points = gloader->base.outline.n_points;
   1559 
   1560           if ( num_points == num_base_points )
   1561             continue;
   1562 
   1563           /* gloader->base.outline consists of three parts:               */
   1564           /* 0 -(1)-> start_point -(2)-> num_base_points -(3)-> n_points. */
   1565           /*                                                              */
   1566           /* (1): exists from the beginning                               */
   1567           /* (2): components that have been loaded so far                 */
   1568           /* (3): the newly loaded component                              */
   1569           TT_Process_Composite_Component( loader, subglyph, start_point,
   1570                                           num_base_points );
   1571         }
   1572 
   1573         loader->stream   = old_stream;
   1574         loader->byte_len = old_byte_len;
   1575 
   1576         /* process the glyph */
   1577         loader->ins_pos = ins_pos;
   1578         if ( IS_HINTED( loader->load_flags ) &&
   1579 
   1580 #ifdef TT_USE_BYTECODE_INTERPRETER
   1581 
   1582              subglyph->flags & WE_HAVE_INSTR &&
   1583 
   1584 #endif
   1585 
   1586              num_points > start_point )
   1587           TT_Process_Composite_Glyph( loader, start_point, start_contour );
   1588 
   1589       }
   1590     }
   1591     else
   1592     {
   1593       /* invalid composite count (negative but not -1) */
   1594       error = TT_Err_Invalid_Outline;
   1595       goto Exit;
   1596     }
   1597 
   1598     /***********************************************************************/
   1599     /***********************************************************************/
   1600     /***********************************************************************/
   1601 
   1602   Exit:
   1603 
   1604     if ( opened_frame )
   1605       face->forget_glyph_frame( loader );
   1606 
   1607 #ifdef FT_CONFIG_OPTION_INCREMENTAL
   1608 
   1609     if ( glyph_data_loaded )
   1610       face->root.internal->incremental_interface->funcs->free_glyph_data(
   1611         face->root.internal->incremental_interface->object,
   1612         &glyph_data );
   1613 
   1614 #endif
   1615 
   1616     return error;
   1617   }
   1618 
   1619 
   1620   static FT_Error
   1621   compute_glyph_metrics( TT_Loader  loader,
   1622                          FT_UInt    glyph_index )
   1623   {
   1624     FT_BBox       bbox;
   1625     TT_Face       face = (TT_Face)loader->face;
   1626     FT_Fixed      y_scale;
   1627     TT_GlyphSlot  glyph = loader->glyph;
   1628     TT_Size       size = (TT_Size)loader->size;
   1629 
   1630 
   1631     y_scale = 0x10000L;
   1632     if ( ( loader->load_flags & FT_LOAD_NO_SCALE ) == 0 )
   1633       y_scale = size->root.metrics.y_scale;
   1634 
   1635     if ( glyph->format != FT_GLYPH_FORMAT_COMPOSITE )
   1636       FT_Outline_Get_CBox( &glyph->outline, &bbox );
   1637     else
   1638       bbox = loader->bbox;
   1639 
   1640     /* get the device-independent horizontal advance; it is scaled later */
   1641     /* by the base layer.                                                */
   1642     glyph->linearHoriAdvance = loader->linear;
   1643 
   1644     glyph->metrics.horiBearingX = bbox.xMin;
   1645     glyph->metrics.horiBearingY = bbox.yMax;
   1646     glyph->metrics.horiAdvance  = loader->pp2.x - loader->pp1.x;
   1647 
   1648     /* adjust advance width to the value contained in the hdmx table */
   1649     if ( !face->postscript.isFixedPitch  &&
   1650          IS_HINTED( loader->load_flags ) )
   1651     {
   1652       FT_Byte*  widthp;
   1653 
   1654 
   1655       widthp = tt_face_get_device_metrics( face,
   1656                                            size->root.metrics.x_ppem,
   1657                                            glyph_index );
   1658 
   1659       if ( widthp )
   1660         glyph->metrics.horiAdvance = *widthp << 6;
   1661     }
   1662 
   1663     /* set glyph dimensions */
   1664     glyph->metrics.width  = bbox.xMax - bbox.xMin;
   1665     glyph->metrics.height = bbox.yMax - bbox.yMin;
   1666 
   1667     /* Now take care of vertical metrics.  In the case where there is */
   1668     /* no vertical information within the font (relatively common),   */
   1669     /* create some metrics manually                                   */
   1670     {
   1671       FT_Pos  top;      /* scaled vertical top side bearing  */
   1672       FT_Pos  advance;  /* scaled vertical advance height    */
   1673 
   1674 
   1675       /* Get the unscaled top bearing and advance height. */
   1676       if ( face->vertical_info                   &&
   1677            face->vertical.number_Of_VMetrics > 0 )
   1678       {
   1679         top = (FT_Short)FT_DivFix( loader->pp3.y - bbox.yMax,
   1680                                    y_scale );
   1681 
   1682         if ( loader->pp3.y <= loader->pp4.y )
   1683           advance = 0;
   1684         else
   1685           advance = (FT_UShort)FT_DivFix( loader->pp3.y - loader->pp4.y,
   1686                                           y_scale );
   1687       }
   1688       else
   1689       {
   1690         FT_Pos  height;
   1691 
   1692 
   1693         /* XXX Compute top side bearing and advance height in  */
   1694         /*     Get_VMetrics instead of here.                   */
   1695 
   1696         /* NOTE: The OS/2 values are the only `portable' ones, */
   1697         /*       which is why we use them, if there is an OS/2 */
   1698         /*       table in the font.  Otherwise, we use the     */
   1699         /*       values defined in the horizontal header.      */
   1700 
   1701         height = (FT_Short)FT_DivFix( bbox.yMax - bbox.yMin,
   1702                                       y_scale );
   1703         if ( face->os2.version != 0xFFFFU )
   1704           advance = (FT_Pos)( face->os2.sTypoAscender -
   1705                               face->os2.sTypoDescender );
   1706         else
   1707           advance = (FT_Pos)( face->horizontal.Ascender -
   1708                               face->horizontal.Descender );
   1709 
   1710         top = ( advance - height ) / 2;
   1711       }
   1712 
   1713 #ifdef FT_CONFIG_OPTION_INCREMENTAL
   1714       {
   1715         FT_Incremental_InterfaceRec*  incr;
   1716         FT_Incremental_MetricsRec     metrics;
   1717         FT_Error                      error;
   1718 
   1719 
   1720         incr = face->root.internal->incremental_interface;
   1721 
   1722         /* If this is an incrementally loaded font see if there are */
   1723         /* overriding metrics for this glyph.                       */
   1724         if ( incr && incr->funcs->get_glyph_metrics )
   1725         {
   1726           metrics.bearing_x = 0;
   1727           metrics.bearing_y = top;
   1728           metrics.advance   = advance;
   1729 
   1730           error = incr->funcs->get_glyph_metrics( incr->object,
   1731                                                   glyph_index,
   1732                                                   TRUE,
   1733                                                   &metrics );
   1734           if ( error )
   1735             return error;
   1736 
   1737           top     = metrics.bearing_y;
   1738           advance = metrics.advance;
   1739         }
   1740       }
   1741 
   1742       /* GWW: Do vertical metrics get loaded incrementally too? */
   1743 
   1744 #endif /* FT_CONFIG_OPTION_INCREMENTAL */
   1745 
   1746       glyph->linearVertAdvance = advance;
   1747 
   1748       /* scale the metrics */
   1749       if ( !( loader->load_flags & FT_LOAD_NO_SCALE ) )
   1750       {
   1751         top     = FT_MulFix( top,     y_scale );
   1752         advance = FT_MulFix( advance, y_scale );
   1753       }
   1754 
   1755       /* XXX: for now, we have no better algorithm for the lsb, but it */
   1756       /*      should work fine.                                        */
   1757       /*                                                               */
   1758       glyph->metrics.vertBearingX = glyph->metrics.horiBearingX -
   1759                                       glyph->metrics.horiAdvance / 2;
   1760       glyph->metrics.vertBearingY = top;
   1761       glyph->metrics.vertAdvance  = advance;
   1762     }
   1763 
   1764     return 0;
   1765   }
   1766 
   1767 
   1768 #ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
   1769 
   1770   static FT_Error
   1771   load_sbit_image( TT_Size       size,
   1772                    TT_GlyphSlot  glyph,
   1773                    FT_UInt       glyph_index,
   1774                    FT_Int32      load_flags )
   1775   {
   1776     TT_Face             face;
   1777     SFNT_Service        sfnt;
   1778     FT_Stream           stream;
   1779     FT_Error            error;
   1780     TT_SBit_MetricsRec  metrics;
   1781 
   1782 
   1783     face   = (TT_Face)glyph->face;
   1784     sfnt   = (SFNT_Service)face->sfnt;
   1785     stream = face->root.stream;
   1786 
   1787     error = sfnt->load_sbit_image( face,
   1788                                    size->strike_index,
   1789                                    glyph_index,
   1790                                    (FT_Int)load_flags,
   1791                                    stream,
   1792                                    &glyph->bitmap,
   1793                                    &metrics );
   1794     if ( !error )
   1795     {
   1796       glyph->outline.n_points   = 0;
   1797       glyph->outline.n_contours = 0;
   1798 
   1799       glyph->metrics.width  = (FT_Pos)metrics.width  << 6;
   1800       glyph->metrics.height = (FT_Pos)metrics.height << 6;
   1801 
   1802       glyph->metrics.horiBearingX = (FT_Pos)metrics.horiBearingX << 6;
   1803       glyph->metrics.horiBearingY = (FT_Pos)metrics.horiBearingY << 6;
   1804       glyph->metrics.horiAdvance  = (FT_Pos)metrics.horiAdvance  << 6;
   1805 
   1806       glyph->metrics.vertBearingX = (FT_Pos)metrics.vertBearingX << 6;
   1807       glyph->metrics.vertBearingY = (FT_Pos)metrics.vertBearingY << 6;
   1808       glyph->metrics.vertAdvance  = (FT_Pos)metrics.vertAdvance  << 6;
   1809 
   1810       glyph->format = FT_GLYPH_FORMAT_BITMAP;
   1811 
   1812       if ( load_flags & FT_LOAD_VERTICAL_LAYOUT )
   1813       {
   1814         glyph->bitmap_left = metrics.vertBearingX;
   1815         glyph->bitmap_top  = metrics.vertBearingY;
   1816       }
   1817       else
   1818       {
   1819         glyph->bitmap_left = metrics.horiBearingX;
   1820         glyph->bitmap_top  = metrics.horiBearingY;
   1821       }
   1822     }
   1823 
   1824     return error;
   1825   }
   1826 
   1827 #endif /* TT_CONFIG_OPTION_EMBEDDED_BITMAPS */
   1828 
   1829 
   1830   static FT_Error
   1831   tt_loader_init( TT_Loader     loader,
   1832                   TT_Size       size,
   1833                   TT_GlyphSlot  glyph,
   1834                   FT_Int32      load_flags,
   1835                   FT_Bool       glyf_table_only )
   1836   {
   1837     TT_Face    face;
   1838     FT_Stream  stream;
   1839     FT_Bool    pedantic = FT_BOOL( load_flags & FT_LOAD_PEDANTIC );
   1840 
   1841 
   1842     face   = (TT_Face)glyph->face;
   1843     stream = face->root.stream;
   1844 
   1845     FT_MEM_ZERO( loader, sizeof ( TT_LoaderRec ) );
   1846 
   1847 #ifdef TT_USE_BYTECODE_INTERPRETER
   1848 
   1849     /* load execution context */
   1850     if ( IS_HINTED( load_flags ) && !glyf_table_only )
   1851     {
   1852       TT_ExecContext  exec;
   1853       FT_Bool         grayscale;
   1854 
   1855 
   1856       if ( !size->cvt_ready )
   1857       {
   1858         FT_Error  error = tt_size_ready_bytecode( size, pedantic );
   1859 
   1860 
   1861         if ( error )
   1862           return error;
   1863       }
   1864 
   1865       /* query new execution context */
   1866       exec = size->debug ? size->context
   1867                          : ( (TT_Driver)FT_FACE_DRIVER( face ) )->context;
   1868       if ( !exec )
   1869         return TT_Err_Could_Not_Find_Context;
   1870 
   1871       grayscale =
   1872         FT_BOOL( FT_LOAD_TARGET_MODE( load_flags ) != FT_RENDER_MODE_MONO );
   1873 
   1874       TT_Load_Context( exec, face, size );
   1875 
   1876       /* a change from mono to grayscale rendering (and vice versa) */
   1877       /* requires a re-execution of the CVT program                 */
   1878       if ( grayscale != exec->grayscale )
   1879       {
   1880         FT_UInt  i;
   1881 
   1882 
   1883         FT_TRACE4(( "tt_loader_init: grayscale change,"
   1884                     " re-executing `prep' table\n" ));
   1885 
   1886         exec->grayscale = grayscale;
   1887 
   1888         for ( i = 0; i < size->cvt_size; i++ )
   1889           size->cvt[i] = FT_MulFix( face->cvt[i], size->ttmetrics.scale );
   1890         tt_size_run_prep( size, pedantic );
   1891       }
   1892 
   1893       /* see whether the cvt program has disabled hinting */
   1894       if ( exec->GS.instruct_control & 1 )
   1895         load_flags |= FT_LOAD_NO_HINTING;
   1896 
   1897       /* load default graphics state -- if needed */
   1898       if ( exec->GS.instruct_control & 2 )
   1899         exec->GS = tt_default_graphics_state;
   1900 
   1901       exec->pedantic_hinting = FT_BOOL( load_flags & FT_LOAD_PEDANTIC );
   1902       loader->exec = exec;
   1903       loader->instructions = exec->glyphIns;
   1904     }
   1905 
   1906 #endif /* TT_USE_BYTECODE_INTERPRETER */
   1907 
   1908     /* seek to the beginning of the glyph table -- for Type 42 fonts     */
   1909     /* the table might be accessed from a Postscript stream or something */
   1910     /* else...                                                           */
   1911 
   1912 #ifdef FT_CONFIG_OPTION_INCREMENTAL
   1913 
   1914     if ( face->root.internal->incremental_interface )
   1915       loader->glyf_offset = 0;
   1916     else
   1917 
   1918 #endif
   1919 
   1920     {
   1921       FT_Error  error = face->goto_table( face, TTAG_glyf, stream, 0 );
   1922 
   1923 
   1924       if ( error == TT_Err_Table_Missing )
   1925         loader->glyf_offset = 0;
   1926       else if ( error )
   1927       {
   1928         FT_ERROR(( "tt_loader_init: could not access glyph table\n" ));
   1929         return error;
   1930       }
   1931       else
   1932         loader->glyf_offset = FT_STREAM_POS();
   1933     }
   1934 
   1935     /* get face's glyph loader */
   1936     if ( !glyf_table_only )
   1937     {
   1938       FT_GlyphLoader  gloader = glyph->internal->loader;
   1939 
   1940 
   1941       FT_GlyphLoader_Rewind( gloader );
   1942       loader->gloader = gloader;
   1943     }
   1944 
   1945     loader->load_flags = load_flags;
   1946 
   1947     loader->face   = (FT_Face)face;
   1948     loader->size   = (FT_Size)size;
   1949     loader->glyph  = (FT_GlyphSlot)glyph;
   1950     loader->stream = stream;
   1951 
   1952     return TT_Err_Ok;
   1953   }
   1954 
   1955 
   1956   /*************************************************************************/
   1957   /*                                                                       */
   1958   /* <Function>                                                            */
   1959   /*    TT_Load_Glyph                                                      */
   1960   /*                                                                       */
   1961   /* <Description>                                                         */
   1962   /*    A function used to load a single glyph within a given glyph slot,  */
   1963   /*    for a given size.                                                  */
   1964   /*                                                                       */
   1965   /* <Input>                                                               */
   1966   /*    glyph       :: A handle to a target slot object where the glyph    */
   1967   /*                   will be loaded.                                     */
   1968   /*                                                                       */
   1969   /*    size        :: A handle to the source face size at which the glyph */
   1970   /*                   must be scaled/loaded.                              */
   1971   /*                                                                       */
   1972   /*    glyph_index :: The index of the glyph in the font file.            */
   1973   /*                                                                       */
   1974   /*    load_flags  :: A flag indicating what to load for this glyph.  The */
   1975   /*                   FT_LOAD_XXX constants can be used to control the    */
   1976   /*                   glyph loading process (e.g., whether the outline    */
   1977   /*                   should be scaled, whether to load bitmaps or not,   */
   1978   /*                   whether to hint the outline, etc).                  */
   1979   /*                                                                       */
   1980   /* <Return>                                                              */
   1981   /*    FreeType error code.  0 means success.                             */
   1982   /*                                                                       */
   1983   FT_LOCAL_DEF( FT_Error )
   1984   TT_Load_Glyph( TT_Size       size,
   1985                  TT_GlyphSlot  glyph,
   1986                  FT_UInt       glyph_index,
   1987                  FT_Int32      load_flags )
   1988   {
   1989     TT_Face       face;
   1990     FT_Error      error;
   1991     TT_LoaderRec  loader;
   1992 
   1993 
   1994     face   = (TT_Face)glyph->face;
   1995     error  = TT_Err_Ok;
   1996 
   1997 #ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
   1998 
   1999     /* try to load embedded bitmap if any              */
   2000     /*                                                 */
   2001     /* XXX: The convention should be emphasized in     */
   2002     /*      the documents because it can be confusing. */
   2003     if ( size->strike_index != 0xFFFFFFFFUL      &&
   2004          ( load_flags & FT_LOAD_NO_BITMAP ) == 0 )
   2005     {
   2006       error = load_sbit_image( size, glyph, glyph_index, load_flags );
   2007       if ( !error )
   2008       {
   2009         FT_Face  root = &face->root;
   2010 
   2011 
   2012         if ( FT_IS_SCALABLE( root ) )
   2013         {
   2014           /* for the bbox we need the header only */
   2015           (void)tt_loader_init( &loader, size, glyph, load_flags, TRUE );
   2016           (void)load_truetype_glyph( &loader, glyph_index, 0, TRUE );
   2017           glyph->linearHoriAdvance = loader.linear;
   2018           glyph->linearVertAdvance = loader.top_bearing + loader.bbox.yMax -
   2019                                        loader.vadvance;
   2020         }
   2021 
   2022         return TT_Err_Ok;
   2023       }
   2024     }
   2025 
   2026 #endif /* TT_CONFIG_OPTION_EMBEDDED_BITMAPS */
   2027 
   2028     /* if FT_LOAD_NO_SCALE is not set, `ttmetrics' must be valid */
   2029     if ( !( load_flags & FT_LOAD_NO_SCALE ) && !size->ttmetrics.valid )
   2030       return TT_Err_Invalid_Size_Handle;
   2031 
   2032     if ( load_flags & FT_LOAD_SBITS_ONLY )
   2033       return TT_Err_Invalid_Argument;
   2034 
   2035     error = tt_loader_init( &loader, size, glyph, load_flags, FALSE );
   2036     if ( error )
   2037       return error;
   2038 
   2039     glyph->format        = FT_GLYPH_FORMAT_OUTLINE;
   2040     glyph->num_subglyphs = 0;
   2041     glyph->outline.flags = 0;
   2042 
   2043     /* main loading loop */
   2044     error = load_truetype_glyph( &loader, glyph_index, 0, FALSE );
   2045     if ( !error )
   2046     {
   2047       if ( glyph->format == FT_GLYPH_FORMAT_COMPOSITE )
   2048       {
   2049         glyph->num_subglyphs = loader.gloader->base.num_subglyphs;
   2050         glyph->subglyphs     = loader.gloader->base.subglyphs;
   2051       }
   2052       else
   2053       {
   2054         glyph->outline        = loader.gloader->base.outline;
   2055         glyph->outline.flags &= ~FT_OUTLINE_SINGLE_PASS;
   2056 
   2057         /* Translate array so that (0,0) is the glyph's origin.  Note  */
   2058         /* that this behaviour is independent on the value of bit 1 of */
   2059         /* the `flags' field in the `head' table -- at least major     */
   2060         /* applications like Acroread indicate that.                   */
   2061         if ( loader.pp1.x )
   2062           FT_Outline_Translate( &glyph->outline, -loader.pp1.x, 0 );
   2063       }
   2064 
   2065 #ifdef TT_USE_BYTECODE_INTERPRETER
   2066 
   2067       if ( IS_HINTED( load_flags ) )
   2068       {
   2069         if ( loader.exec->GS.scan_control )
   2070         {
   2071           /* convert scan conversion mode to FT_OUTLINE_XXX flags */
   2072           switch ( loader.exec->GS.scan_type )
   2073           {
   2074           case 0: /* simple drop-outs including stubs */
   2075             glyph->outline.flags |= FT_OUTLINE_INCLUDE_STUBS;
   2076             break;
   2077           case 1: /* simple drop-outs excluding stubs */
   2078             /* nothing; it's the default rendering mode */
   2079             break;
   2080           case 4: /* smart drop-outs including stubs */
   2081             glyph->outline.flags |= FT_OUTLINE_SMART_DROPOUTS |
   2082                                     FT_OUTLINE_INCLUDE_STUBS;
   2083             break;
   2084           case 5: /* smart drop-outs excluding stubs  */
   2085             glyph->outline.flags |= FT_OUTLINE_SMART_DROPOUTS;
   2086             break;
   2087 
   2088           default: /* no drop-out control */
   2089             glyph->outline.flags |= FT_OUTLINE_IGNORE_DROPOUTS;
   2090             break;
   2091           }
   2092         }
   2093         else
   2094           glyph->outline.flags |= FT_OUTLINE_IGNORE_DROPOUTS;
   2095       }
   2096 
   2097 #endif /* TT_USE_BYTECODE_INTERPRETER */
   2098 
   2099       compute_glyph_metrics( &loader, glyph_index );
   2100     }
   2101 
   2102     /* Set the `high precision' bit flag.                           */
   2103     /* This is _critical_ to get correct output for monochrome      */
   2104     /* TrueType glyphs at all sizes using the bytecode interpreter. */
   2105     /*                                                              */
   2106     if ( !( load_flags & FT_LOAD_NO_SCALE ) &&
   2107          size->root.metrics.y_ppem < 24     )
   2108       glyph->outline.flags |= FT_OUTLINE_HIGH_PRECISION;
   2109 
   2110     return error;
   2111   }
   2112 
   2113 
   2114 /* END */
   2115