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      1 /***************************************************************************/
      2 /*                                                                         */
      3 /*  ftgloadr.c                                                             */
      4 /*                                                                         */
      5 /*    The FreeType glyph loader (body).                                    */
      6 /*                                                                         */
      7 /*  Copyright 2002, 2003, 2004, 2005, 2006, 2010 by                        */
      8 /*  David Turner, Robert Wilhelm, and Werner Lemberg                       */
      9 /*                                                                         */
     10 /*  This file is part of the FreeType project, and may only be used,       */
     11 /*  modified, and distributed under the terms of the FreeType project      */
     12 /*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
     13 /*  this file you indicate that you have read the license and              */
     14 /*  understand and accept it fully.                                        */
     15 /*                                                                         */
     16 /***************************************************************************/
     17 
     18 
     19 #include <ft2build.h>
     20 #include FT_INTERNAL_GLYPH_LOADER_H
     21 #include FT_INTERNAL_MEMORY_H
     22 #include FT_INTERNAL_OBJECTS_H
     23 
     24 #undef  FT_COMPONENT
     25 #define FT_COMPONENT  trace_gloader
     26 
     27 
     28   /*************************************************************************/
     29   /*************************************************************************/
     30   /*************************************************************************/
     31   /*****                                                               *****/
     32   /*****                                                               *****/
     33   /*****                    G L Y P H   L O A D E R                    *****/
     34   /*****                                                               *****/
     35   /*****                                                               *****/
     36   /*************************************************************************/
     37   /*************************************************************************/
     38   /*************************************************************************/
     39 
     40   /*************************************************************************/
     41   /*                                                                       */
     42   /* The glyph loader is a simple object which is used to load a set of    */
     43   /* glyphs easily.  It is critical for the correct loading of composites. */
     44   /*                                                                       */
     45   /* Ideally, one can see it as a stack of abstract `glyph' objects.       */
     46   /*                                                                       */
     47   /*   loader.base     Is really the bottom of the stack.  It describes a  */
     48   /*                   single glyph image made of the juxtaposition of     */
     49   /*                   several glyphs (those `in the stack').              */
     50   /*                                                                       */
     51   /*   loader.current  Describes the top of the stack, on which a new      */
     52   /*                   glyph can be loaded.                                */
     53   /*                                                                       */
     54   /*   Rewind          Clears the stack.                                   */
     55   /*   Prepare         Set up `loader.current' for addition of a new glyph */
     56   /*                   image.                                              */
     57   /*   Add             Add the `current' glyph image to the `base' one,    */
     58   /*                   and prepare for another one.                        */
     59   /*                                                                       */
     60   /* The glyph loader is now a base object.  Each driver used to           */
     61   /* re-implement it in one way or the other, which wasted code and        */
     62   /* energy.                                                               */
     63   /*                                                                       */
     64   /*************************************************************************/
     65 
     66 
     67   /* create a new glyph loader */
     68   FT_BASE_DEF( FT_Error )
     69   FT_GlyphLoader_New( FT_Memory        memory,
     70                       FT_GlyphLoader  *aloader )
     71   {
     72     FT_GlyphLoader  loader = NULL;
     73     FT_Error        error;
     74 
     75 
     76     if ( !FT_NEW( loader ) )
     77     {
     78       loader->memory = memory;
     79       *aloader       = loader;
     80     }
     81     return error;
     82   }
     83 
     84 
     85   /* rewind the glyph loader - reset counters to 0 */
     86   FT_BASE_DEF( void )
     87   FT_GlyphLoader_Rewind( FT_GlyphLoader  loader )
     88   {
     89     FT_GlyphLoad  base    = &loader->base;
     90     FT_GlyphLoad  current = &loader->current;
     91 
     92 
     93     base->outline.n_points   = 0;
     94     base->outline.n_contours = 0;
     95     base->num_subglyphs      = 0;
     96 
     97     *current = *base;
     98   }
     99 
    100 
    101   /* reset the glyph loader, frees all allocated tables */
    102   /* and starts from zero                               */
    103   FT_BASE_DEF( void )
    104   FT_GlyphLoader_Reset( FT_GlyphLoader  loader )
    105   {
    106     FT_Memory memory = loader->memory;
    107 
    108 
    109     FT_FREE( loader->base.outline.points );
    110     FT_FREE( loader->base.outline.tags );
    111     FT_FREE( loader->base.outline.contours );
    112     FT_FREE( loader->base.extra_points );
    113     FT_FREE( loader->base.subglyphs );
    114 
    115     loader->base.extra_points2 = NULL;
    116 
    117     loader->max_points    = 0;
    118     loader->max_contours  = 0;
    119     loader->max_subglyphs = 0;
    120 
    121     FT_GlyphLoader_Rewind( loader );
    122   }
    123 
    124 
    125   /* delete a glyph loader */
    126   FT_BASE_DEF( void )
    127   FT_GlyphLoader_Done( FT_GlyphLoader  loader )
    128   {
    129     if ( loader )
    130     {
    131       FT_Memory memory = loader->memory;
    132 
    133 
    134       FT_GlyphLoader_Reset( loader );
    135       FT_FREE( loader );
    136     }
    137   }
    138 
    139 
    140   /* re-adjust the `current' outline fields */
    141   static void
    142   FT_GlyphLoader_Adjust_Points( FT_GlyphLoader  loader )
    143   {
    144     FT_Outline*  base    = &loader->base.outline;
    145     FT_Outline*  current = &loader->current.outline;
    146 
    147 
    148     current->points   = base->points   + base->n_points;
    149     current->tags     = base->tags     + base->n_points;
    150     current->contours = base->contours + base->n_contours;
    151 
    152     /* handle extra points table - if any */
    153     if ( loader->use_extra )
    154     {
    155       loader->current.extra_points  = loader->base.extra_points +
    156                                       base->n_points;
    157 
    158       loader->current.extra_points2 = loader->base.extra_points2 +
    159                                       base->n_points;
    160     }
    161   }
    162 
    163 
    164   FT_BASE_DEF( FT_Error )
    165   FT_GlyphLoader_CreateExtra( FT_GlyphLoader  loader )
    166   {
    167     FT_Error   error;
    168     FT_Memory  memory = loader->memory;
    169 
    170 
    171     if ( !FT_NEW_ARRAY( loader->base.extra_points, 2 * loader->max_points ) )
    172     {
    173       loader->use_extra          = 1;
    174       loader->base.extra_points2 = loader->base.extra_points +
    175                                    loader->max_points;
    176 
    177       FT_GlyphLoader_Adjust_Points( loader );
    178     }
    179     return error;
    180   }
    181 
    182 
    183   /* re-adjust the `current' subglyphs field */
    184   static void
    185   FT_GlyphLoader_Adjust_Subglyphs( FT_GlyphLoader  loader )
    186   {
    187     FT_GlyphLoad  base    = &loader->base;
    188     FT_GlyphLoad  current = &loader->current;
    189 
    190 
    191     current->subglyphs = base->subglyphs + base->num_subglyphs;
    192   }
    193 
    194 
    195   /* Ensure that we can add `n_points' and `n_contours' to our glyph.      */
    196   /* This function reallocates its outline tables if necessary.  Note that */
    197   /* it DOESN'T change the number of points within the loader!             */
    198   /*                                                                       */
    199   FT_BASE_DEF( FT_Error )
    200   FT_GlyphLoader_CheckPoints( FT_GlyphLoader  loader,
    201                               FT_UInt         n_points,
    202                               FT_UInt         n_contours )
    203   {
    204     FT_Memory    memory  = loader->memory;
    205     FT_Error     error   = FT_Err_Ok;
    206     FT_Outline*  base    = &loader->base.outline;
    207     FT_Outline*  current = &loader->current.outline;
    208     FT_Bool      adjust  = 0;
    209 
    210     FT_UInt      new_max, old_max;
    211 
    212 
    213     /* check points & tags */
    214     new_max = base->n_points + current->n_points + n_points;
    215     old_max = loader->max_points;
    216 
    217     if ( new_max > old_max )
    218     {
    219       new_max = FT_PAD_CEIL( new_max, 8 );
    220 
    221       if ( new_max > FT_OUTLINE_POINTS_MAX )
    222         return FT_Err_Array_Too_Large;
    223 
    224       if ( FT_RENEW_ARRAY( base->points, old_max, new_max ) ||
    225            FT_RENEW_ARRAY( base->tags,   old_max, new_max ) )
    226         goto Exit;
    227 
    228       if ( loader->use_extra )
    229       {
    230         if ( FT_RENEW_ARRAY( loader->base.extra_points,
    231                              old_max * 2, new_max * 2 ) )
    232           goto Exit;
    233 
    234         FT_ARRAY_MOVE( loader->base.extra_points + new_max,
    235                        loader->base.extra_points + old_max,
    236                        old_max );
    237 
    238         loader->base.extra_points2 = loader->base.extra_points + new_max;
    239       }
    240 
    241       adjust = 1;
    242       loader->max_points = new_max;
    243     }
    244 
    245     /* check contours */
    246     old_max = loader->max_contours;
    247     new_max = base->n_contours + current->n_contours +
    248               n_contours;
    249     if ( new_max > old_max )
    250     {
    251       new_max = FT_PAD_CEIL( new_max, 4 );
    252 
    253       if ( new_max > FT_OUTLINE_CONTOURS_MAX )
    254         return FT_Err_Array_Too_Large;
    255 
    256       if ( FT_RENEW_ARRAY( base->contours, old_max, new_max ) )
    257         goto Exit;
    258 
    259       adjust = 1;
    260       loader->max_contours = new_max;
    261     }
    262 
    263     if ( adjust )
    264       FT_GlyphLoader_Adjust_Points( loader );
    265 
    266   Exit:
    267     return error;
    268   }
    269 
    270 
    271   /* Ensure that we can add `n_subglyphs' to our glyph. this function */
    272   /* reallocates its subglyphs table if necessary.  Note that it DOES */
    273   /* NOT change the number of subglyphs within the loader!            */
    274   /*                                                                  */
    275   FT_BASE_DEF( FT_Error )
    276   FT_GlyphLoader_CheckSubGlyphs( FT_GlyphLoader  loader,
    277                                  FT_UInt         n_subs )
    278   {
    279     FT_Memory     memory = loader->memory;
    280     FT_Error      error  = FT_Err_Ok;
    281     FT_UInt       new_max, old_max;
    282 
    283     FT_GlyphLoad  base    = &loader->base;
    284     FT_GlyphLoad  current = &loader->current;
    285 
    286 
    287     new_max = base->num_subglyphs + current->num_subglyphs + n_subs;
    288     old_max = loader->max_subglyphs;
    289     if ( new_max > old_max )
    290     {
    291       new_max = FT_PAD_CEIL( new_max, 2 );
    292       if ( FT_RENEW_ARRAY( base->subglyphs, old_max, new_max ) )
    293         goto Exit;
    294 
    295       loader->max_subglyphs = new_max;
    296 
    297       FT_GlyphLoader_Adjust_Subglyphs( loader );
    298     }
    299 
    300   Exit:
    301     return error;
    302   }
    303 
    304 
    305   /* prepare loader for the addition of a new glyph on top of the base one */
    306   FT_BASE_DEF( void )
    307   FT_GlyphLoader_Prepare( FT_GlyphLoader  loader )
    308   {
    309     FT_GlyphLoad  current = &loader->current;
    310 
    311 
    312     current->outline.n_points   = 0;
    313     current->outline.n_contours = 0;
    314     current->num_subglyphs      = 0;
    315 
    316     FT_GlyphLoader_Adjust_Points   ( loader );
    317     FT_GlyphLoader_Adjust_Subglyphs( loader );
    318   }
    319 
    320 
    321   /* add current glyph to the base image - and prepare for another */
    322   FT_BASE_DEF( void )
    323   FT_GlyphLoader_Add( FT_GlyphLoader  loader )
    324   {
    325     FT_GlyphLoad  base;
    326     FT_GlyphLoad  current;
    327 
    328     FT_UInt       n_curr_contours;
    329     FT_UInt       n_base_points;
    330     FT_UInt       n;
    331 
    332 
    333     if ( !loader )
    334       return;
    335 
    336     base    = &loader->base;
    337     current = &loader->current;
    338 
    339     n_curr_contours = current->outline.n_contours;
    340     n_base_points   = base->outline.n_points;
    341 
    342     base->outline.n_points =
    343       (short)( base->outline.n_points + current->outline.n_points );
    344     base->outline.n_contours =
    345       (short)( base->outline.n_contours + current->outline.n_contours );
    346 
    347     base->num_subglyphs += current->num_subglyphs;
    348 
    349     /* adjust contours count in newest outline */
    350     for ( n = 0; n < n_curr_contours; n++ )
    351       current->outline.contours[n] =
    352         (short)( current->outline.contours[n] + n_base_points );
    353 
    354     /* prepare for another new glyph image */
    355     FT_GlyphLoader_Prepare( loader );
    356   }
    357 
    358 
    359   FT_BASE_DEF( FT_Error )
    360   FT_GlyphLoader_CopyPoints( FT_GlyphLoader  target,
    361                              FT_GlyphLoader  source )
    362   {
    363     FT_Error  error;
    364     FT_UInt   num_points   = source->base.outline.n_points;
    365     FT_UInt   num_contours = source->base.outline.n_contours;
    366 
    367 
    368     error = FT_GlyphLoader_CheckPoints( target, num_points, num_contours );
    369     if ( !error )
    370     {
    371       FT_Outline*  out = &target->base.outline;
    372       FT_Outline*  in  = &source->base.outline;
    373 
    374 
    375       FT_ARRAY_COPY( out->points, in->points,
    376                      num_points );
    377       FT_ARRAY_COPY( out->tags, in->tags,
    378                      num_points );
    379       FT_ARRAY_COPY( out->contours, in->contours,
    380                      num_contours );
    381 
    382       /* do we need to copy the extra points? */
    383       if ( target->use_extra && source->use_extra )
    384       {
    385         FT_ARRAY_COPY( target->base.extra_points, source->base.extra_points,
    386                        num_points );
    387         FT_ARRAY_COPY( target->base.extra_points2, source->base.extra_points2,
    388                        num_points );
    389       }
    390 
    391       out->n_points   = (short)num_points;
    392       out->n_contours = (short)num_contours;
    393 
    394       FT_GlyphLoader_Adjust_Points( target );
    395     }
    396 
    397     return error;
    398   }
    399 
    400 
    401 /* END */
    402