1 /****************************************************************************
   2  *
   3  * ftgloadr.c
   4  *
   5  *   The FreeType glyph loader (body).
   6  *
   7  * Copyright (C) 2002-2019 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_DEBUG_H
  21 #include FT_INTERNAL_GLYPH_LOADER_H
  22 #include FT_INTERNAL_MEMORY_H
  23 #include FT_INTERNAL_OBJECTS_H
  24 
  25 #undef  FT_COMPONENT
  26 #define FT_COMPONENT  gloader
  27 
  28 
  29   /*************************************************************************/
  30   /*************************************************************************/
  31   /*************************************************************************/
  32   /*****                                                               *****/
  33   /*****                                                               *****/
  34   /*****                    G L Y P H   L O A D E R                    *****/
  35   /*****                                                               *****/
  36   /*****                                                               *****/
  37   /*************************************************************************/
  38   /*************************************************************************/
  39   /*************************************************************************/
  40 
  41   /**************************************************************************
  42    *
  43    * The glyph loader is a simple object which is used to load a set of
  44    * glyphs easily.  It is critical for the correct loading of composites.
  45    *
  46    * Ideally, one can see it as a stack of abstract `glyph' objects.
  47    *
  48    *   loader.base     Is really the bottom of the stack.  It describes a
  49    *                   single glyph image made of the juxtaposition of
  50    *                   several glyphs (those `in the stack').
  51    *
  52    *   loader.current  Describes the top of the stack, on which a new
  53    *                   glyph can be loaded.
  54    *
  55    *   Rewind          Clears the stack.
  56    *   Prepare         Set up `loader.current' for addition of a new glyph
  57    *                   image.
  58    *   Add             Add the `current' glyph image to the `base' one,
  59    *                   and prepare for another one.
  60    *
  61    * The glyph loader is now a base object.  Each driver used to
  62    * re-implement it in one way or the other, which wasted code and
  63    * energy.
  64    *
  65    */
  66 
  67 
  68   /* create a new glyph loader */
  69   FT_BASE_DEF( FT_Error )
  70   FT_GlyphLoader_New( FT_Memory        memory,
  71                       FT_GlyphLoader  *aloader )
  72   {
  73     FT_GlyphLoader  loader = NULL;
  74     FT_Error        error;
  75 
  76 
  77     if ( !FT_NEW( loader ) )
  78     {
  79       loader->memory = memory;
  80       *aloader       = loader;
  81     }
  82     return error;
  83   }
  84 
  85 
  86   /* rewind the glyph loader - reset counters to 0 */
  87   FT_BASE_DEF( void )
  88   FT_GlyphLoader_Rewind( FT_GlyphLoader  loader )
  89   {
  90     FT_GlyphLoad  base    = &loader->base;
  91     FT_GlyphLoad  current = &loader->current;
  92 
  93 
  94     base->outline.n_points   = 0;
  95     base->outline.n_contours = 0;
  96     base->num_subglyphs      = 0;
  97 
  98     *current = *base;
  99   }
 100 
 101 
 102   /* reset glyph loader, free all allocated tables, */
 103   /* and start from zero                            */
 104   FT_BASE_DEF( void )
 105   FT_GlyphLoader_Reset( FT_GlyphLoader  loader )
 106   {
 107     FT_Memory  memory = loader->memory;
 108 
 109 
 110     FT_FREE( loader->base.outline.points );
 111     FT_FREE( loader->base.outline.tags );
 112     FT_FREE( loader->base.outline.contours );
 113     FT_FREE( loader->base.extra_points );
 114     FT_FREE( loader->base.subglyphs );
 115 
 116     loader->base.extra_points2 = NULL;
 117 
 118     loader->max_points    = 0;
 119     loader->max_contours  = 0;
 120     loader->max_subglyphs = 0;
 121 
 122     FT_GlyphLoader_Rewind( loader );
 123   }
 124 
 125 
 126   /* delete a glyph loader */
 127   FT_BASE_DEF( void )
 128   FT_GlyphLoader_Done( FT_GlyphLoader  loader )
 129   {
 130     if ( loader )
 131     {
 132       FT_Memory  memory = loader->memory;
 133 
 134 
 135       FT_GlyphLoader_Reset( loader );
 136       FT_FREE( loader );
 137     }
 138   }
 139 
 140 
 141   /* re-adjust the `current' outline fields */
 142   static void
 143   FT_GlyphLoader_Adjust_Points( FT_GlyphLoader  loader )
 144   {
 145     FT_Outline*  base    = &loader->base.outline;
 146     FT_Outline*  current = &loader->current.outline;
 147 
 148 
 149     current->points   = base->points   + base->n_points;
 150     current->tags     = base->tags     + base->n_points;
 151     current->contours = base->contours + base->n_contours;
 152 
 153     /* handle extra points table - if any */
 154     if ( loader->use_extra )
 155     {
 156       loader->current.extra_points  = loader->base.extra_points +
 157                                       base->n_points;
 158 
 159       loader->current.extra_points2 = loader->base.extra_points2 +
 160                                       base->n_points;
 161     }
 162   }
 163 
 164 
 165   FT_BASE_DEF( FT_Error )
 166   FT_GlyphLoader_CreateExtra( FT_GlyphLoader  loader )
 167   {
 168     FT_Error   error;
 169     FT_Memory  memory = loader->memory;
 170 
 171 
 172     if ( !FT_NEW_ARRAY( loader->base.extra_points, 2 * loader->max_points ) )
 173     {
 174       loader->use_extra          = 1;
 175       loader->base.extra_points2 = loader->base.extra_points +
 176                                    loader->max_points;
 177 
 178       FT_GlyphLoader_Adjust_Points( loader );
 179     }
 180     return error;
 181   }
 182 
 183 
 184   /* re-adjust the `current' subglyphs field */
 185   static void
 186   FT_GlyphLoader_Adjust_Subglyphs( FT_GlyphLoader  loader )
 187   {
 188     FT_GlyphLoad  base    = &loader->base;
 189     FT_GlyphLoad  current = &loader->current;
 190 
 191 
 192     current->subglyphs = base->subglyphs + base->num_subglyphs;
 193   }
 194 
 195 
 196   /* Ensure that we can add `n_points' and `n_contours' to our glyph.      */
 197   /* This function reallocates its outline tables if necessary.  Note that */
 198   /* it DOESN'T change the number of points within the loader!             */
 199   /*                                                                       */
 200   FT_BASE_DEF( FT_Error )
 201   FT_GlyphLoader_CheckPoints( FT_GlyphLoader  loader,
 202                               FT_UInt         n_points,
 203                               FT_UInt         n_contours )
 204   {
 205     FT_Memory    memory  = loader->memory;
 206     FT_Error     error   = FT_Err_Ok;
 207     FT_Outline*  base    = &loader->base.outline;
 208     FT_Outline*  current = &loader->current.outline;
 209     FT_Bool      adjust  = 0;
 210 
 211     FT_UInt      new_max, old_max;
 212 
 213 
 214     /* check points & tags */
 215     new_max = (FT_UInt)base->n_points + (FT_UInt)current->n_points +
 216               n_points;
 217     old_max = loader->max_points;
 218 
 219     if ( new_max > old_max )
 220     {
 221       new_max = FT_PAD_CEIL( new_max, 8 );
 222 
 223       if ( new_max > FT_OUTLINE_POINTS_MAX )
 224         return FT_THROW( Array_Too_Large );
 225 
 226       if ( FT_RENEW_ARRAY( base->points, old_max, new_max ) ||
 227            FT_RENEW_ARRAY( base->tags,   old_max, new_max ) )
 228         goto Exit;
 229 
 230       if ( loader->use_extra )
 231       {
 232         if ( FT_RENEW_ARRAY( loader->base.extra_points,
 233                              old_max * 2, new_max * 2 ) )
 234           goto Exit;
 235 
 236         FT_ARRAY_MOVE( loader->base.extra_points + new_max,
 237                        loader->base.extra_points + old_max,
 238                        old_max );
 239 
 240         loader->base.extra_points2 = loader->base.extra_points + new_max;
 241       }
 242 
 243       adjust = 1;
 244       loader->max_points = new_max;
 245     }
 246 
 247     /* check contours */
 248     old_max = loader->max_contours;
 249     new_max = (FT_UInt)base->n_contours + (FT_UInt)current->n_contours +
 250               n_contours;
 251     if ( new_max > old_max )
 252     {
 253       new_max = FT_PAD_CEIL( new_max, 4 );
 254 
 255       if ( new_max > FT_OUTLINE_CONTOURS_MAX )
 256         return FT_THROW( Array_Too_Large );
 257 
 258       if ( FT_RENEW_ARRAY( base->contours, old_max, new_max ) )
 259         goto Exit;
 260 
 261       adjust = 1;
 262       loader->max_contours = new_max;
 263     }
 264 
 265     if ( adjust )
 266       FT_GlyphLoader_Adjust_Points( loader );
 267 
 268   Exit:
 269     if ( error )
 270       FT_GlyphLoader_Reset( loader );
 271 
 272     return error;
 273   }
 274 
 275 
 276   /* Ensure that we can add `n_subglyphs' to our glyph. this function */
 277   /* reallocates its subglyphs table if necessary.  Note that it DOES */
 278   /* NOT change the number of subglyphs within the loader!            */
 279   /*                                                                  */
 280   FT_BASE_DEF( FT_Error )
 281   FT_GlyphLoader_CheckSubGlyphs( FT_GlyphLoader  loader,
 282                                  FT_UInt         n_subs )
 283   {
 284     FT_Memory     memory = loader->memory;
 285     FT_Error      error  = FT_Err_Ok;
 286     FT_UInt       new_max, old_max;
 287 
 288     FT_GlyphLoad  base    = &loader->base;
 289     FT_GlyphLoad  current = &loader->current;
 290 
 291 
 292     new_max = base->num_subglyphs + current->num_subglyphs + n_subs;
 293     old_max = loader->max_subglyphs;
 294     if ( new_max > old_max )
 295     {
 296       new_max = FT_PAD_CEIL( new_max, 2 );
 297       if ( FT_RENEW_ARRAY( base->subglyphs, old_max, new_max ) )
 298         goto Exit;
 299 
 300       loader->max_subglyphs = new_max;
 301 
 302       FT_GlyphLoader_Adjust_Subglyphs( loader );
 303     }
 304 
 305   Exit:
 306     return error;
 307   }
 308 
 309 
 310   /* prepare loader for the addition of a new glyph on top of the base one */
 311   FT_BASE_DEF( void )
 312   FT_GlyphLoader_Prepare( FT_GlyphLoader  loader )
 313   {
 314     FT_GlyphLoad  current = &loader->current;
 315 
 316 
 317     current->outline.n_points   = 0;
 318     current->outline.n_contours = 0;
 319     current->num_subglyphs      = 0;
 320 
 321     FT_GlyphLoader_Adjust_Points   ( loader );
 322     FT_GlyphLoader_Adjust_Subglyphs( loader );
 323   }
 324 
 325 
 326   /* add current glyph to the base image -- and prepare for another */
 327   FT_BASE_DEF( void )
 328   FT_GlyphLoader_Add( FT_GlyphLoader  loader )
 329   {
 330     FT_GlyphLoad  base;
 331     FT_GlyphLoad  current;
 332 
 333     FT_Int        n_curr_contours;
 334     FT_Int        n_base_points;
 335     FT_Int        n;
 336 
 337 
 338     if ( !loader )
 339       return;
 340 
 341     base    = &loader->base;
 342     current = &loader->current;
 343 
 344     n_curr_contours = current->outline.n_contours;
 345     n_base_points   = base->outline.n_points;
 346 
 347     base->outline.n_points =
 348       (short)( base->outline.n_points + current->outline.n_points );
 349     base->outline.n_contours =
 350       (short)( base->outline.n_contours + current->outline.n_contours );
 351 
 352     base->num_subglyphs += current->num_subglyphs;
 353 
 354     /* adjust contours count in newest outline */
 355     for ( n = 0; n < n_curr_contours; n++ )
 356       current->outline.contours[n] =
 357         (short)( current->outline.contours[n] + n_base_points );
 358 
 359     /* prepare for another new glyph image */
 360     FT_GlyphLoader_Prepare( loader );
 361   }
 362 
 363 
 364 /* END */