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Diffstat (limited to 'src/ftgl/FTCharToGlyphIndexMap.h')
| -rw-r--r-- | src/ftgl/FTCharToGlyphIndexMap.h | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/src/ftgl/FTCharToGlyphIndexMap.h b/src/ftgl/FTCharToGlyphIndexMap.h new file mode 100644 index 0000000..3aa10a1 --- /dev/null +++ b/src/ftgl/FTCharToGlyphIndexMap.h @@ -0,0 +1,155 @@ +/* + * FTGL - OpenGL font library + * + * Copyright (c) 2001-2004 Henry Maddocks <ftgl@opengl.geek.nz> + * + * Permission is hereby granted, free of charge, to any person obtaining + * a copy of this software and associated documentation files (the + * "Software"), to deal in the Software without restriction, including + * without limitation the rights to use, copy, modify, merge, publish, + * distribute, sublicense, and/or sell copies of the Software, and to + * permit persons to whom the Software is furnished to do so, subject to + * the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. + * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY + * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, + * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE + * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. + */ + +#ifndef __FTCharToGlyphIndexMap__ +#define __FTCharToGlyphIndexMap__ + +#include <stdlib.h> + +#include "FTGL/ftgl.h" + +/** + * Provides a non-STL alternative to the STL map<unsigned long, unsigned long> + * which maps character codes to glyph indices inside FTCharmap. + * + * Implementation: + * - NumberOfBuckets buckets are considered. + * - Each bucket has BucketSize entries. + * - When the glyph index for the character code C has to be stored, the + * bucket this character belongs to is found using 'C div BucketSize'. + * If this bucket has not been allocated yet, do it now. + * The entry in the bucked is found using 'C mod BucketSize'. + * If it is set to IndexNotFound, then the glyph entry has not been set. + * - Try to mimic the calls made to the STL map API. + * + * Caveats: + * - The glyph index is now a signed long instead of unsigned long, so + * the special value IndexNotFound (= -1) can be used to specify that the + * glyph index has not been stored yet. + */ +class FTCharToGlyphIndexMap +{ + public: + + typedef unsigned long CharacterCode; + typedef signed long GlyphIndex; + + enum + { + NumberOfBuckets = 256, + BucketSize = 256, + IndexNotFound = -1 + }; + + FTCharToGlyphIndexMap() + { + this->Indices = 0; + } + + virtual ~FTCharToGlyphIndexMap() + { + if(this->Indices) + { + // Free all buckets + this->clear(); + + // Free main structure + delete [] this->Indices; + this->Indices = 0; + } + } + + void clear() + { + if(this->Indices) + { + for(int i = 0; i < FTCharToGlyphIndexMap::NumberOfBuckets; i++) + { + if(this->Indices[i]) + { + delete [] this->Indices[i]; + this->Indices[i] = 0; + } + } + } + } + + const GlyphIndex find(CharacterCode c) + { + if(!this->Indices) + { + return 0; + } + + // Find position of char code in buckets + div_t pos = div(c, FTCharToGlyphIndexMap::BucketSize); + + if(!this->Indices[pos.quot]) + { + return 0; + } + + const FTCharToGlyphIndexMap::GlyphIndex *ptr = &this->Indices[pos.quot][pos.rem]; + if(*ptr == FTCharToGlyphIndexMap::IndexNotFound) + { + return 0; + } + + return *ptr; + } + + void insert(CharacterCode c, GlyphIndex g) + { + if(!this->Indices) + { + this->Indices = new GlyphIndex* [FTCharToGlyphIndexMap::NumberOfBuckets]; + for(int i = 0; i < FTCharToGlyphIndexMap::NumberOfBuckets; i++) + { + this->Indices[i] = 0; + } + } + + // Find position of char code in buckets + div_t pos = div(c, FTCharToGlyphIndexMap::BucketSize); + + // Allocate bucket if does not exist yet + if(!this->Indices[pos.quot]) + { + this->Indices[pos.quot] = new GlyphIndex [FTCharToGlyphIndexMap::BucketSize]; + for(int i = 0; i < FTCharToGlyphIndexMap::BucketSize; i++) + { + this->Indices[pos.quot][i] = FTCharToGlyphIndexMap::IndexNotFound; + } + } + + this->Indices[pos.quot][pos.rem] = g; + } + + private: + GlyphIndex** Indices; +}; + + +#endif // __FTCharToGlyphIndexMap__ |