/src/freetype/src/cache/ftcsbits.c
C | 421 lines | 254 code | 88 blank | 79 comment | 33 complexity | ea403d3fbbdfd75045c4322da125beb9 MD5 | raw file
1/***************************************************************************/ 2/* */ 3/* ftcsbits.c */ 4/* */ 5/* FreeType sbits manager (body). */ 6/* */ 7/* Copyright 2000-2001, 2002, 2003, 2004, 2005, 2006, 2009, 2010, 2011 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 { 164 FT_TRACE2(( "ftc_snode_load:" 165 " glyph too large for small bitmap cache\n")); 166 goto BadGlyph; 167 } 168 169 sbit->width = (FT_Byte)bitmap->width; 170 sbit->height = (FT_Byte)bitmap->rows; 171 sbit->pitch = (FT_Char)bitmap->pitch; 172 sbit->left = (FT_Char)slot->bitmap_left; 173 sbit->top = (FT_Char)slot->bitmap_top; 174 sbit->xadvance = (FT_Char)xadvance; 175 sbit->yadvance = (FT_Char)yadvance; 176 sbit->format = (FT_Byte)bitmap->pixel_mode; 177 sbit->max_grays = (FT_Byte)(bitmap->num_grays - 1); 178 179 /* copy the bitmap into a new buffer -- ignore error */ 180 error = ftc_sbit_copy_bitmap( sbit, bitmap, memory ); 181 182 /* now, compute size */ 183 if ( asize ) 184 *asize = FT_ABS( sbit->pitch ) * sbit->height; 185 186 } /* glyph loading successful */ 187 188 /* ignore the errors that might have occurred -- */ 189 /* we mark unloaded glyphs with `sbit.buffer == 0' */ 190 /* and `width == 255', `height == 0' */ 191 /* */ 192 if ( error && error != FTC_Err_Out_Of_Memory ) 193 { 194 BadGlyph: 195 sbit->width = 255; 196 sbit->height = 0; 197 sbit->buffer = NULL; 198 error = FTC_Err_Ok; 199 if ( asize ) 200 *asize = 0; 201 } 202 203 return error; 204 } 205 206 207 FT_LOCAL_DEF( FT_Error ) 208 FTC_SNode_New( FTC_SNode *psnode, 209 FTC_GQuery gquery, 210 FTC_Cache cache ) 211 { 212 FT_Memory memory = cache->memory; 213 FT_Error error; 214 FTC_SNode snode = NULL; 215 FT_UInt gindex = gquery->gindex; 216 FTC_Family family = gquery->family; 217 218 FTC_SFamilyClass clazz = FTC_CACHE__SFAMILY_CLASS( cache ); 219 FT_UInt total; 220 FT_UInt node_count; 221 222 223 total = clazz->family_get_count( family, cache->manager ); 224 if ( total == 0 || gindex >= total ) 225 { 226 error = FTC_Err_Invalid_Argument; 227 goto Exit; 228 } 229 230 if ( !FT_NEW( snode ) ) 231 { 232 FT_UInt count, start; 233 234 235 start = gindex - ( gindex % FTC_SBIT_ITEMS_PER_NODE ); 236 count = total - start; 237 if ( count > FTC_SBIT_ITEMS_PER_NODE ) 238 count = FTC_SBIT_ITEMS_PER_NODE; 239 240 FTC_GNode_Init( FTC_GNODE( snode ), start, family ); 241 242 snode->count = count; 243 for ( node_count = 0; node_count < count; node_count++ ) 244 { 245 snode->sbits[node_count].width = 255; 246 } 247 248 error = ftc_snode_load( snode, 249 cache->manager, 250 gindex, 251 NULL ); 252 if ( error ) 253 { 254 FTC_SNode_Free( snode, cache ); 255 snode = NULL; 256 } 257 } 258 259 Exit: 260 *psnode = snode; 261 return error; 262 } 263 264 265 FT_LOCAL_DEF( FT_Error ) 266 ftc_snode_new( FTC_Node *ftcpsnode, 267 FT_Pointer ftcgquery, 268 FTC_Cache cache ) 269 { 270 FTC_SNode *psnode = (FTC_SNode*)ftcpsnode; 271 FTC_GQuery gquery = (FTC_GQuery)ftcgquery; 272 273 274 return FTC_SNode_New( psnode, gquery, cache ); 275 } 276 277 278 FT_LOCAL_DEF( FT_Offset ) 279 ftc_snode_weight( FTC_Node ftcsnode, 280 FTC_Cache cache ) 281 { 282 FTC_SNode snode = (FTC_SNode)ftcsnode; 283 FT_UInt count = snode->count; 284 FTC_SBit sbit = snode->sbits; 285 FT_Int pitch; 286 FT_Offset size; 287 288 FT_UNUSED( cache ); 289 290 291 FT_ASSERT( snode->count <= FTC_SBIT_ITEMS_PER_NODE ); 292 293 /* the node itself */ 294 size = sizeof ( *snode ); 295 296 for ( ; count > 0; count--, sbit++ ) 297 { 298 if ( sbit->buffer ) 299 { 300 pitch = sbit->pitch; 301 if ( pitch < 0 ) 302 pitch = -pitch; 303 304 /* add the size of a given glyph image */ 305 size += pitch * sbit->height; 306 } 307 } 308 309 return size; 310 } 311 312 313#if 0 314 315 FT_LOCAL_DEF( FT_Offset ) 316 FTC_SNode_Weight( FTC_SNode snode ) 317 { 318 return ftc_snode_weight( FTC_NODE( snode ), NULL ); 319 } 320 321#endif /* 0 */ 322 323 324 FT_LOCAL_DEF( FT_Bool ) 325 ftc_snode_compare( FTC_Node ftcsnode, 326 FT_Pointer ftcgquery, 327 FTC_Cache cache, 328 FT_Bool* list_changed ) 329 { 330 FTC_SNode snode = (FTC_SNode)ftcsnode; 331 FTC_GQuery gquery = (FTC_GQuery)ftcgquery; 332 FTC_GNode gnode = FTC_GNODE( snode ); 333 FT_UInt gindex = gquery->gindex; 334 FT_Bool result; 335 336 337 if (list_changed) 338 *list_changed = FALSE; 339 result = FT_BOOL( gnode->family == gquery->family && 340 (FT_UInt)( gindex - gnode->gindex ) < snode->count ); 341 if ( result ) 342 { 343 /* check if we need to load the glyph bitmap now */ 344 FTC_SBit sbit = snode->sbits + ( gindex - gnode->gindex ); 345 346 347 /* 348 * The following code illustrates what to do when you want to 349 * perform operations that may fail within a lookup function. 350 * 351 * Here, we want to load a small bitmap on-demand; we thus 352 * need to call the `ftc_snode_load' function which may return 353 * a non-zero error code only when we are out of memory (OOM). 354 * 355 * The correct thing to do is to use @FTC_CACHE_TRYLOOP and 356 * @FTC_CACHE_TRYLOOP_END in order to implement a retry loop 357 * that is capable of flushing the cache incrementally when 358 * an OOM errors occur. 359 * 360 * However, we need to `lock' the node before this operation to 361 * prevent it from being flushed within the loop. 362 * 363 * When we exit the loop, we unlock the node, then check the `error' 364 * variable. If it is non-zero, this means that the cache was 365 * completely flushed and that no usable memory was found to load 366 * the bitmap. 367 * 368 * We then prefer to return a value of 0 (i.e., NO MATCH). This 369 * ensures that the caller will try to allocate a new node. 370 * This operation consequently _fail_ and the lookup function 371 * returns the appropriate OOM error code. 372 * 373 * Note that `buffer == NULL && width == 255' is a hack used to 374 * tag `unavailable' bitmaps in the array. We should never try 375 * to load these. 376 * 377 */ 378 379 if ( sbit->buffer == NULL && sbit->width == 255 ) 380 { 381 FT_ULong size; 382 FT_Error error; 383 384 385 ftcsnode->ref_count++; /* lock node to prevent flushing */ 386 /* in retry loop */ 387 388 FTC_CACHE_TRYLOOP( cache ) 389 { 390 error = ftc_snode_load( snode, cache->manager, gindex, &size ); 391 } 392 FTC_CACHE_TRYLOOP_END( list_changed ); 393 394 ftcsnode->ref_count--; /* unlock the node */ 395 396 if ( error ) 397 result = 0; 398 else 399 cache->manager->cur_weight += size; 400 } 401 } 402 403 return result; 404 } 405 406 407#ifdef FTC_INLINE 408 409 FT_LOCAL_DEF( FT_Bool ) 410 FTC_SNode_Compare( FTC_SNode snode, 411 FTC_GQuery gquery, 412 FTC_Cache cache, 413 FT_Bool* list_changed ) 414 { 415 return ftc_snode_compare( FTC_NODE( snode ), gquery, 416 cache, list_changed ); 417 } 418 419#endif 420 421/* END */