thirdparty/freetype-2.3.12/src/cache/ftcsbits.c

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  ftcsbits.c                                                             */
   4 /*                                                                         */
   5 /*    FreeType sbits manager (body).                                       */
   6 /*                                                                         */
   7 /*  Copyright 2000-2001, 2002, 2003, 2004, 2005, 2006, 2009 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_CACHE_H
  21 #include "ftcsbits.h"
  22 #include FT_INTERNAL_OBJECTS_H
  23 #include FT_INTERNAL_DEBUG_H
  24 #include FT_ERRORS_H
  25
  26 #include "ftccback.h"
  27 #include "ftcerror.h"
  28
  29 #undef  FT_COMPONENT
  30 #define FT_COMPONENT  trace_cache
  31
  32
  33   /*************************************************************************/
  34   /*************************************************************************/
  35   /*****                                                               *****/
  36   /*****                     SBIT CACHE NODES                          *****/
  37   /*****                                                               *****/
  38   /*************************************************************************/
  39   /*************************************************************************/
  40
  41
  42   static FT_Error
  43   ftc_sbit_copy_bitmap( FTC_SBit    sbit,
  44                         FT_Bitmap*  bitmap,
  45                         FT_Memory   memory )
  46   {
  47     FT_Error  error;
  48     FT_Int    pitch = bitmap->pitch;
  49     FT_ULong  size;
  50
  51
  52     if ( pitch < 0 )
  53       pitch = -pitch;
  54
  55     size = (FT_ULong)( pitch * bitmap->rows );
  56
  57     if ( !FT_ALLOC( sbit->buffer, size ) )
  58       FT_MEM_COPY( sbit->buffer, bitmap->buffer, size );
  59
  60     return error;
  61   }
  62
  63
  64   FT_LOCAL_DEF( void )
  65   ftc_snode_free( FTC_Node   ftcsnode,
  66                   FTC_Cache  cache )
  67   {
  68     FTC_SNode  snode  = (FTC_SNode)ftcsnode;
  69     FTC_SBit   sbit   = snode->sbits;
  70     FT_UInt    count  = snode->count;
  71     FT_Memory  memory = cache->memory;
  72
  73
  74     for ( ; count > 0; sbit++, count-- )
  75       FT_FREE( sbit->buffer );
  76
  77     FTC_GNode_Done( FTC_GNODE( snode ), cache );
  78
  79     FT_FREE( snode );
  80   }
  81
  82
  83   FT_LOCAL_DEF( void )
  84   FTC_SNode_Free( FTC_SNode  snode,
  85                   FTC_Cache  cache )
  86   {
  87     ftc_snode_free( FTC_NODE( snode ), cache );
  88   }
  89
  90
  91   /*
  92    *  This function tries to load a small bitmap within a given FTC_SNode.
  93    *  Note that it returns a non-zero error code _only_ in the case of
  94    *  out-of-memory condition.  For all other errors (e.g., corresponding
  95    *  to a bad font file), this function will mark the sbit as `unavailable'
  96    *  and return a value of 0.
  97    *
  98    *  You should also read the comment within the @ftc_snode_compare
  99    *  function below to see how out-of-memory is handled during a lookup.
 100    */
 101   static FT_Error
 102   ftc_snode_load( FTC_SNode    snode,
 103                   FTC_Manager  manager,
 104                   FT_UInt      gindex,
 105                   FT_ULong    *asize )
 106   {
 107     FT_Error          error;
 108     FTC_GNode         gnode  = FTC_GNODE( snode );
 109     FTC_Family        family = gnode->family;
 110     FT_Memory         memory = manager->memory;
 111     FT_Face           face;
 112     FTC_SBit          sbit;
 113     FTC_SFamilyClass  clazz;
 114
 115
 116     if ( (FT_UInt)(gindex - gnode->gindex) >= snode->count )
 117     {
 118       FT_ERROR(( "ftc_snode_load: invalid glyph index" ));
 119       return FTC_Err_Invalid_Argument;
 120     }
 121
 122     sbit  = snode->sbits + ( gindex - gnode->gindex );
 123     clazz = (FTC_SFamilyClass)family->clazz;
 124
 125     sbit->buffer = 0;
 126
 127     error = clazz->family_load_glyph( family, gindex, manager, &face );
 128     if ( error )
 129       goto BadGlyph;
 130
 131     {
 132       FT_Int        temp;
 133       FT_GlyphSlot  slot   = face->glyph;
 134       FT_Bitmap*    bitmap = &slot->bitmap;
 135       FT_Pos        xadvance, yadvance; /* FT_GlyphSlot->advance.{x|y} */
 136
 137
 138       if ( slot->format != FT_GLYPH_FORMAT_BITMAP )
 139       {
 140         FT_TRACE0(( "ftc_snode_load:"
 141                     " glyph loaded didn't return a bitmap\n" ));
 142         goto BadGlyph;
 143       }
 144
 145       /* Check that our values fit into 8-bit containers!       */
 146       /* If this is not the case, our bitmap is too large       */
 147       /* and we will leave it as `missing' with sbit.buffer = 0 */
 148
 149 #define CHECK_CHAR( d )  ( temp = (FT_Char)d, temp == d )
 150 #define CHECK_BYTE( d )  ( temp = (FT_Byte)d, temp == d )
 151
 152       /* horizontal advance in pixels */
 153       xadvance = ( slot->advance.x + 32 ) >> 6;
 154       yadvance = ( slot->advance.y + 32 ) >> 6;
 155
 156       if ( !CHECK_BYTE( bitmap->rows  )     ||
 157            !CHECK_BYTE( bitmap->width )     ||
 158            !CHECK_CHAR( bitmap->pitch )     ||
 159            !CHECK_CHAR( slot->bitmap_left ) ||
 160            !CHECK_CHAR( slot->bitmap_top  ) ||
 161            !CHECK_CHAR( xadvance )          ||
 162            !CHECK_CHAR( yadvance )          )
 163         goto BadGlyph;
 164
 165       sbit->width     = (FT_Byte)bitmap->width;
 166       sbit->height    = (FT_Byte)bitmap->rows;
 167       sbit->pitch     = (FT_Char)bitmap->pitch;
 168       sbit->left      = (FT_Char)slot->bitmap_left;
 169       sbit->top       = (FT_Char)slot->bitmap_top;
 170       sbit->xadvance  = (FT_Char)xadvance;
 171       sbit->yadvance  = (FT_Char)yadvance;
 172       sbit->format    = (FT_Byte)bitmap->pixel_mode;
 173       sbit->max_grays = (FT_Byte)(bitmap->num_grays - 1);
 174
 175       /* copy the bitmap into a new buffer -- ignore error */
 176       error = ftc_sbit_copy_bitmap( sbit, bitmap, memory );
 177
 178       /* now, compute size */
 179       if ( asize )
 180         *asize = FT_ABS( sbit->pitch ) * sbit->height;
 181
 182     } /* glyph loading successful */
 183
 184     /* ignore the errors that might have occurred --   */
 185     /* we mark unloaded glyphs with `sbit.buffer == 0' */
 186     /* and `width == 255', `height == 0'               */
 187     /*                                                 */
 188     if ( error && error != FTC_Err_Out_Of_Memory )
 189     {
 190     BadGlyph:
 191       sbit->width  = 255;
 192       sbit->height = 0;
 193       sbit->buffer = NULL;
 194       error        = 0;
 195       if ( asize )
 196         *asize = 0;
 197     }
 198
 199     return error;
 200   }
 201
 202
 203   FT_LOCAL_DEF( FT_Error )
 204   FTC_SNode_New( FTC_SNode  *psnode,
 205                  FTC_GQuery  gquery,
 206                  FTC_Cache   cache )
 207   {
 208     FT_Memory   memory = cache->memory;
 209     FT_Error    error;
 210     FTC_SNode   snode  = NULL;
 211     FT_UInt     gindex = gquery->gindex;
 212     FTC_Family  family = gquery->family;
 213
 214     FTC_SFamilyClass  clazz = FTC_CACHE__SFAMILY_CLASS( cache );
 215     FT_UInt           total;
 216
 217
 218     total = clazz->family_get_count( family, cache->manager );
 219     if ( total == 0 || gindex >= total )
 220     {
 221       error = FT_Err_Invalid_Argument;
 222       goto Exit;
 223     }
 224
 225     if ( !FT_NEW( snode ) )
 226     {
 227       FT_UInt  count, start;
 228
 229
 230       start = gindex - ( gindex % FTC_SBIT_ITEMS_PER_NODE );
 231       count = total - start;
 232       if ( count > FTC_SBIT_ITEMS_PER_NODE )
 233         count = FTC_SBIT_ITEMS_PER_NODE;
 234
 235       FTC_GNode_Init( FTC_GNODE( snode ), start, family );
 236
 237       snode->count = count;
 238
 239       error = ftc_snode_load( snode,
 240                               cache->manager,
 241                               gindex,
 242                               NULL );
 243       if ( error )
 244       {
 245         FTC_SNode_Free( snode, cache );
 246         snode = NULL;
 247       }
 248     }
 249
 250   Exit:
 251     *psnode = snode;
 252     return error;
 253   }
 254
 255
 256   FT_LOCAL_DEF( FT_Error )
 257   ftc_snode_new( FTC_Node   *ftcpsnode,
 258                  FT_Pointer  ftcgquery,
 259                  FTC_Cache   cache )
 260   {
 261     FTC_SNode  *psnode = (FTC_SNode*)ftcpsnode;
 262     FTC_GQuery  gquery = (FTC_GQuery)ftcgquery;
 263
 264
 265     return FTC_SNode_New( psnode, gquery, cache );
 266   }
 267
 268
 269   FT_LOCAL_DEF( FT_Offset )
 270   ftc_snode_weight( FTC_Node   ftcsnode,
 271                     FTC_Cache  cache )
 272   {
 273     FTC_SNode  snode = (FTC_SNode)ftcsnode;
 274     FT_UInt    count = snode->count;
 275     FTC_SBit   sbit  = snode->sbits;
 276     FT_Int     pitch;
 277     FT_Offset  size;
 278
 279     FT_UNUSED( cache );
 280
 281
 282     FT_ASSERT( snode->count <= FTC_SBIT_ITEMS_PER_NODE );
 283
 284     /* the node itself */
 285     size = sizeof ( *snode );
 286
 287     for ( ; count > 0; count--, sbit++ )
 288     {
 289       if ( sbit->buffer )
 290       {
 291         pitch = sbit->pitch;
 292         if ( pitch < 0 )
 293           pitch = -pitch;
 294
 295         /* add the size of a given glyph image */
 296         size += pitch * sbit->height;
 297       }
 298     }
 299
 300     return size;
 301   }
 302
 303
 304 #if 0
 305
 306   FT_LOCAL_DEF( FT_Offset )
 307   FTC_SNode_Weight( FTC_SNode  snode )
 308   {
 309     return ftc_snode_weight( FTC_NODE( snode ), NULL );
 310   }
 311
 312 #endif /* 0 */
 313
 314
 315   FT_LOCAL_DEF( FT_Bool )
 316   ftc_snode_compare( FTC_Node    ftcsnode,
 317                      FT_Pointer  ftcgquery,
 318                      FTC_Cache   cache )
 319   {
 320     FTC_SNode   snode  = (FTC_SNode)ftcsnode;
 321     FTC_GQuery  gquery = (FTC_GQuery)ftcgquery;
 322     FTC_GNode   gnode  = FTC_GNODE( snode );
 323     FT_UInt     gindex = gquery->gindex;
 324     FT_Bool     result;
 325
 326
 327     result = FT_BOOL( gnode->family == gquery->family                    &&
 328                       (FT_UInt)( gindex - gnode->gindex ) < snode->count );
 329     if ( result )
 330     {
 331       /* check if we need to load the glyph bitmap now */
 332       FTC_SBit  sbit = snode->sbits + ( gindex - gnode->gindex );
 333
 334
 335       /*
 336        *  The following code illustrates what to do when you want to
 337        *  perform operations that may fail within a lookup function.
 338        *
 339        *  Here, we want to load a small bitmap on-demand; we thus
 340        *  need to call the `ftc_snode_load' function which may return
 341        *  a non-zero error code only when we are out of memory (OOM).
 342        *
 343        *  The correct thing to do is to use @FTC_CACHE_TRYLOOP and
 344        *  @FTC_CACHE_TRYLOOP_END in order to implement a retry loop
 345        *  that is capable of flushing the cache incrementally when
 346        *  an OOM errors occur.
 347        *
 348        *  However, we need to `lock' the node before this operation to
 349        *  prevent it from being flushed within the loop.
 350        *
 351        *  When we exit the loop, we unlock the node, then check the `error'
 352        *  variable.  If it is non-zero, this means that the cache was
 353        *  completely flushed and that no usable memory was found to load
 354        *  the bitmap.
 355        *
 356        *  We then prefer to return a value of 0 (i.e., NO MATCH).  This
 357        *  ensures that the caller will try to allocate a new node.
 358        *  This operation consequently _fail_ and the lookup function
 359        *  returns the appropriate OOM error code.
 360        *
 361        *  Note that `buffer == NULL && width == 255' is a hack used to
 362        *  tag `unavailable' bitmaps in the array.  We should never try
 363        *  to load these.
 364        *
 365        */
 366
 367       if ( sbit->buffer == NULL && sbit->width != 255 )
 368       {
 369         FT_ULong  size;
 370         FT_Error  error;
 371
 372
 373         ftcsnode->ref_count++;  /* lock node to prevent flushing */
 374                                 /* in retry loop                 */
 375
 376         FTC_CACHE_TRYLOOP( cache )
 377         {
 378           error = ftc_snode_load( snode, cache->manager, gindex, &size );
 379         }
 380         FTC_CACHE_TRYLOOP_END();
 381
 382         ftcsnode->ref_count--;  /* unlock the node */
 383
 384         if ( error )
 385           result = 0;
 386         else
 387           cache->manager->cur_weight += size;
 388       }
 389     }
 390
 391     return result;
 392   }
 393
 394
 395   FT_LOCAL_DEF( FT_Bool )
 396   FTC_SNode_Compare( FTC_SNode   snode,
 397                      FTC_GQuery  gquery,
 398                      FTC_Cache   cache )
 399   {
 400     return ftc_snode_compare( FTC_NODE( snode ), gquery, cache );
 401   }
 402
 403
 404 /* END */