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      1 /***************************************************************************/
      2 /*                                                                         */
      3 /*  afloader.c                                                             */
      4 /*                                                                         */
      5 /*    Auto-fitter glyph loading routines (body).                           */
      6 /*                                                                         */
      7 /*  Copyright 2003-2015 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 #include "afglobal.h"
     20 #include "afloader.h"
     21 #include "afhints.h"
     22 #include "aferrors.h"
     23 #include "afmodule.h"
     24 #include "afpic.h"
     25 
     26 
     27   /* Initialize glyph loader. */
     28 
     29   FT_LOCAL_DEF( void )
     30   af_loader_init( AF_Loader      loader,
     31                   AF_GlyphHints  hints )
     32   {
     33     FT_ZERO( loader );
     34 
     35     loader->hints = hints;
     36   }
     37 
     38 
     39   /* Reset glyph loader and compute globals if necessary. */
     40 
     41   FT_LOCAL_DEF( FT_Error )
     42   af_loader_reset( AF_Loader  loader,
     43                    AF_Module  module,
     44                    FT_Face    face )
     45   {
     46     FT_Error  error = FT_Err_Ok;
     47 
     48 
     49     loader->face    = face;
     50     loader->globals = (AF_FaceGlobals)face->autohint.data;
     51 
     52     if ( loader->globals == NULL )
     53     {
     54       error = af_face_globals_new( face, &loader->globals, module );
     55       if ( !error )
     56       {
     57         face->autohint.data =
     58           (FT_Pointer)loader->globals;
     59         face->autohint.finalizer =
     60           (FT_Generic_Finalizer)af_face_globals_free;
     61       }
     62     }
     63 
     64     return error;
     65   }
     66 
     67 
     68   /* Finalize glyph loader. */
     69 
     70   FT_LOCAL_DEF( void )
     71   af_loader_done( AF_Loader  loader )
     72   {
     73     loader->face    = NULL;
     74     loader->globals = NULL;
     75     loader->hints   = NULL;
     76   }
     77 
     78 
     79   /* Do the main work of `af_loader_load_glyph'.  Note that we never   */
     80   /* have to deal with composite glyphs as those get loaded into       */
     81   /* FT_GLYPH_FORMAT_OUTLINE by the recursed `FT_Load_Glyph' function. */
     82   /* In the rare cases where FT_LOAD_NO_RECURSE is set, it implies     */
     83   /* FT_LOAD_NO_SCALE and as such the auto-hinter is never called.     */
     84 
     85   static FT_Error
     86   af_loader_load_g( AF_Loader  loader,
     87                     AF_Scaler  scaler,
     88                     FT_UInt    glyph_index,
     89                     FT_Int32   load_flags )
     90   {
     91     FT_Error          error;
     92     FT_Face           face     = loader->face;
     93     AF_StyleMetrics   metrics  = loader->metrics;
     94     AF_GlyphHints     hints    = loader->hints;
     95     FT_GlyphSlot      slot     = face->glyph;
     96     FT_Slot_Internal  internal = slot->internal;
     97     FT_GlyphLoader    gloader  = internal->loader;
     98     FT_Int32          flags;
     99 
    100 
    101     flags = load_flags | FT_LOAD_LINEAR_DESIGN;
    102     error = FT_Load_Glyph( face, glyph_index, flags );
    103     if ( error )
    104       goto Exit;
    105 
    106     loader->transformed = internal->glyph_transformed;
    107     if ( loader->transformed )
    108     {
    109       FT_Matrix  inverse;
    110 
    111 
    112       loader->trans_matrix = internal->glyph_matrix;
    113       loader->trans_delta  = internal->glyph_delta;
    114 
    115       inverse = loader->trans_matrix;
    116       if ( !FT_Matrix_Invert( &inverse ) )
    117         FT_Vector_Transform( &loader->trans_delta, &inverse );
    118     }
    119 
    120     switch ( slot->format )
    121     {
    122     case FT_GLYPH_FORMAT_OUTLINE:
    123       /* translate the loaded glyph when an internal transform is needed */
    124       if ( loader->transformed )
    125         FT_Outline_Translate( &slot->outline,
    126                               loader->trans_delta.x,
    127                               loader->trans_delta.y );
    128 
    129       /* compute original horizontal phantom points (and ignore */
    130       /* vertical ones)                                         */
    131       loader->pp1.x = hints->x_delta;
    132       loader->pp1.y = hints->y_delta;
    133       loader->pp2.x = FT_MulFix( slot->metrics.horiAdvance,
    134                                  hints->x_scale ) + hints->x_delta;
    135       loader->pp2.y = hints->y_delta;
    136 
    137       /* be sure to check for spacing glyphs */
    138       if ( slot->outline.n_points == 0 )
    139         goto Hint_Metrics;
    140 
    141       /* now load the slot image into the auto-outline and run the */
    142       /* automatic hinting process                                 */
    143       {
    144 #ifdef FT_CONFIG_OPTION_PIC
    145         AF_FaceGlobals         globals = loader->globals;
    146 #endif
    147         AF_StyleClass          style_class = metrics->style_class;
    148         AF_WritingSystemClass  writing_system_class =
    149           AF_WRITING_SYSTEM_CLASSES_GET[style_class->writing_system];
    150 
    151 
    152         if ( writing_system_class->style_hints_apply )
    153           writing_system_class->style_hints_apply( hints,
    154                                                    &gloader->base.outline,
    155                                                    metrics );
    156       }
    157 
    158       /* we now need to adjust the metrics according to the change in */
    159       /* width/positioning that occurred during the hinting process   */
    160       if ( scaler->render_mode != FT_RENDER_MODE_LIGHT )
    161       {
    162         FT_Pos        old_rsb, old_lsb, new_lsb;
    163         FT_Pos        pp1x_uh, pp2x_uh;
    164         AF_AxisHints  axis  = &hints->axis[AF_DIMENSION_HORZ];
    165         AF_Edge       edge1 = axis->edges;         /* leftmost edge  */
    166         AF_Edge       edge2 = edge1 +
    167                               axis->num_edges - 1; /* rightmost edge */
    168 
    169 
    170         if ( axis->num_edges > 1 && AF_HINTS_DO_ADVANCE( hints ) )
    171         {
    172           old_rsb = loader->pp2.x - edge2->opos;
    173           old_lsb = edge1->opos;
    174           new_lsb = edge1->pos;
    175 
    176           /* remember unhinted values to later account */
    177           /* for rounding errors                       */
    178 
    179           pp1x_uh = new_lsb    - old_lsb;
    180           pp2x_uh = edge2->pos + old_rsb;
    181 
    182           /* prefer too much space over too little space */
    183           /* for very small sizes                        */
    184 
    185           if ( old_lsb < 24 )
    186             pp1x_uh -= 8;
    187 
    188           if ( old_rsb < 24 )
    189             pp2x_uh += 8;
    190 
    191           loader->pp1.x = FT_PIX_ROUND( pp1x_uh );
    192           loader->pp2.x = FT_PIX_ROUND( pp2x_uh );
    193 
    194           if ( loader->pp1.x >= new_lsb && old_lsb > 0 )
    195             loader->pp1.x -= 64;
    196 
    197           if ( loader->pp2.x <= edge2->pos && old_rsb > 0 )
    198             loader->pp2.x += 64;
    199 
    200           slot->lsb_delta = loader->pp1.x - pp1x_uh;
    201           slot->rsb_delta = loader->pp2.x - pp2x_uh;
    202         }
    203         else
    204         {
    205           FT_Pos  pp1x = loader->pp1.x;
    206           FT_Pos  pp2x = loader->pp2.x;
    207 
    208 
    209           loader->pp1.x = FT_PIX_ROUND( pp1x );
    210           loader->pp2.x = FT_PIX_ROUND( pp2x );
    211 
    212           slot->lsb_delta = loader->pp1.x - pp1x;
    213           slot->rsb_delta = loader->pp2.x - pp2x;
    214         }
    215       }
    216       else
    217       {
    218         FT_Pos  pp1x = loader->pp1.x;
    219         FT_Pos  pp2x = loader->pp2.x;
    220 
    221 
    222         loader->pp1.x = FT_PIX_ROUND( pp1x + hints->xmin_delta );
    223         loader->pp2.x = FT_PIX_ROUND( pp2x + hints->xmax_delta );
    224 
    225         slot->lsb_delta = loader->pp1.x - pp1x;
    226         slot->rsb_delta = loader->pp2.x - pp2x;
    227       }
    228 
    229       break;
    230 
    231     default:
    232       /* we don't support other formats (yet?) */
    233       error = FT_THROW( Unimplemented_Feature );
    234     }
    235 
    236   Hint_Metrics:
    237     {
    238       FT_BBox    bbox;
    239       FT_Vector  vvector;
    240 
    241 
    242       vvector.x = slot->metrics.vertBearingX - slot->metrics.horiBearingX;
    243       vvector.y = slot->metrics.vertBearingY - slot->metrics.horiBearingY;
    244       vvector.x = FT_MulFix( vvector.x, metrics->scaler.x_scale );
    245       vvector.y = FT_MulFix( vvector.y, metrics->scaler.y_scale );
    246 
    247       /* transform the hinted outline if needed */
    248       if ( loader->transformed )
    249       {
    250         FT_Outline_Transform( &gloader->base.outline, &loader->trans_matrix );
    251         FT_Vector_Transform( &vvector, &loader->trans_matrix );
    252       }
    253 #if 1
    254       /* we must translate our final outline by -pp1.x and compute */
    255       /* the new metrics                                           */
    256       if ( loader->pp1.x )
    257         FT_Outline_Translate( &gloader->base.outline, -loader->pp1.x, 0 );
    258 #endif
    259       FT_Outline_Get_CBox( &gloader->base.outline, &bbox );
    260 
    261       bbox.xMin = FT_PIX_FLOOR( bbox.xMin );
    262       bbox.yMin = FT_PIX_FLOOR( bbox.yMin );
    263       bbox.xMax = FT_PIX_CEIL(  bbox.xMax );
    264       bbox.yMax = FT_PIX_CEIL(  bbox.yMax );
    265 
    266       slot->metrics.width        = bbox.xMax - bbox.xMin;
    267       slot->metrics.height       = bbox.yMax - bbox.yMin;
    268       slot->metrics.horiBearingX = bbox.xMin;
    269       slot->metrics.horiBearingY = bbox.yMax;
    270 
    271       slot->metrics.vertBearingX = FT_PIX_FLOOR( bbox.xMin + vvector.x );
    272       slot->metrics.vertBearingY = FT_PIX_FLOOR( bbox.yMax + vvector.y );
    273 
    274       /* for mono-width fonts (like Andale, Courier, etc.) we need */
    275       /* to keep the original rounded advance width; ditto for     */
    276       /* digits if all have the same advance width                 */
    277 #if 0
    278       if ( !FT_IS_FIXED_WIDTH( slot->face ) )
    279         slot->metrics.horiAdvance = loader->pp2.x - loader->pp1.x;
    280       else
    281         slot->metrics.horiAdvance = FT_MulFix( slot->metrics.horiAdvance,
    282                                                x_scale );
    283 #else
    284       if ( scaler->render_mode != FT_RENDER_MODE_LIGHT                      &&
    285            ( FT_IS_FIXED_WIDTH( slot->face )                              ||
    286              ( af_face_globals_is_digit( loader->globals, glyph_index ) &&
    287                metrics->digits_have_same_width                          ) ) )
    288       {
    289         slot->metrics.horiAdvance = FT_MulFix( slot->metrics.horiAdvance,
    290                                                metrics->scaler.x_scale );
    291 
    292         /* Set delta values to 0.  Otherwise code that uses them is */
    293         /* going to ruin the fixed advance width.                   */
    294         slot->lsb_delta = 0;
    295         slot->rsb_delta = 0;
    296       }
    297       else
    298       {
    299         /* non-spacing glyphs must stay as-is */
    300         if ( slot->metrics.horiAdvance )
    301           slot->metrics.horiAdvance = loader->pp2.x - loader->pp1.x;
    302       }
    303 #endif
    304 
    305       slot->metrics.vertAdvance = FT_MulFix( slot->metrics.vertAdvance,
    306                                              metrics->scaler.y_scale );
    307 
    308       slot->metrics.horiAdvance = FT_PIX_ROUND( slot->metrics.horiAdvance );
    309       slot->metrics.vertAdvance = FT_PIX_ROUND( slot->metrics.vertAdvance );
    310 
    311 #if 0
    312       /* reassign all outline fields except flags to protect them */
    313       slot->outline.n_contours = internal->loader->base.outline.n_contours;
    314       slot->outline.n_points   = internal->loader->base.outline.n_points;
    315       slot->outline.points     = internal->loader->base.outline.points;
    316       slot->outline.tags       = internal->loader->base.outline.tags;
    317       slot->outline.contours   = internal->loader->base.outline.contours;
    318 #endif
    319 
    320       slot->format  = FT_GLYPH_FORMAT_OUTLINE;
    321     }
    322 
    323   Exit:
    324     return error;
    325   }
    326 
    327 
    328   /* Load a glyph. */
    329 
    330   FT_LOCAL_DEF( FT_Error )
    331   af_loader_load_glyph( AF_Loader  loader,
    332                         AF_Module  module,
    333                         FT_Face    face,
    334                         FT_UInt    gindex,
    335                         FT_Int32   load_flags )
    336   {
    337     FT_Error      error;
    338     FT_Size       size   = face->size;
    339     AF_ScalerRec  scaler;
    340 
    341 
    342     if ( !size )
    343       return FT_THROW( Invalid_Size_Handle );
    344 
    345     FT_ZERO( &scaler );
    346 
    347     scaler.face    = face;
    348     scaler.x_scale = size->metrics.x_scale;
    349     scaler.x_delta = 0;  /* XXX: TODO: add support for sub-pixel hinting */
    350     scaler.y_scale = size->metrics.y_scale;
    351     scaler.y_delta = 0;  /* XXX: TODO: add support for sub-pixel hinting */
    352 
    353     scaler.render_mode = FT_LOAD_TARGET_MODE( load_flags );
    354     scaler.flags       = 0;  /* XXX: fix this */
    355 
    356     error = af_loader_reset( loader, module, face );
    357     if ( !error )
    358     {
    359       AF_StyleMetrics  metrics;
    360       FT_UInt          options = AF_STYLE_NONE_DFLT;
    361 
    362 
    363 #ifdef FT_OPTION_AUTOFIT2
    364       /* XXX: undocumented hook to activate the latin2 writing system */
    365       if ( load_flags & ( 1UL << 20 ) )
    366         options = AF_STYLE_LTN2_DFLT;
    367 #endif
    368 
    369       error = af_face_globals_get_metrics( loader->globals, gindex,
    370                                            options, &metrics );
    371       if ( !error )
    372       {
    373 #ifdef FT_CONFIG_OPTION_PIC
    374         AF_FaceGlobals         globals = loader->globals;
    375 #endif
    376         AF_StyleClass          style_class = metrics->style_class;
    377         AF_WritingSystemClass  writing_system_class =
    378           AF_WRITING_SYSTEM_CLASSES_GET[style_class->writing_system];
    379 
    380 
    381         loader->metrics = metrics;
    382 
    383         if ( writing_system_class->style_metrics_scale )
    384           writing_system_class->style_metrics_scale( metrics, &scaler );
    385         else
    386           metrics->scaler = scaler;
    387 
    388         load_flags |=  FT_LOAD_NO_SCALE | FT_LOAD_IGNORE_TRANSFORM;
    389         load_flags &= ~FT_LOAD_RENDER;
    390 
    391         if ( writing_system_class->style_hints_init )
    392         {
    393           error = writing_system_class->style_hints_init( loader->hints,
    394                                                           metrics );
    395           if ( error )
    396             goto Exit;
    397         }
    398 
    399         error = af_loader_load_g( loader, &scaler, gindex, load_flags );
    400       }
    401     }
    402   Exit:
    403     return error;
    404   }
    405 
    406 
    407 /* END */
    408