kc3-lang/ftgl/src/FTCharmap.h

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• Hash : fbcf2a88
  Author :
  Date : 2008-05-01T18:33:44
  

  * Optimise FTFace::KernAdvance() so that kerning for font indices < 128 is precomputed during FTFace() instantiation to avoid calling FT_Get_Kerning() too often. Patch by Sean Morrison, taken from bzflag commit r14652, reworked for safety and performance by me.

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• src/FTCharmap.h

• /*
   * 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     __FTCharmap__
  #define     __FTCharmap__
  
  
  #include <ft2build.h>
  #include FT_FREETYPE_H
  #include FT_GLYPH_H
  
  #include "FTGL/ftgl.h"
  #include "FTCharToGlyphIndexMap.h"
  
  
  /**
   * FTCharmap takes care of specifying the encoding for a font and mapping
   * character codes to glyph indices.
   *
   * It doesn't preprocess all indices, only on an as needed basis. This may
   * seem like a performance penalty but it is quicker than using the 'raw'
   * freetype calls and will save significant amounts of memory when dealing
   * with unicode encoding
   *
   * @see "Freetype 2 Documentation"
   *
   */
  
  class FTFace;
  
  class FTCharmap
  {
      public:
          /**
           * Constructor
           */
          FTCharmap(FTFace* face);
  
          /**
           * Destructor
           */
          virtual ~FTCharmap();
  
          /**
           * Queries for the current character map code.
           *
           * @return  The current character map code.
           */
          FT_Encoding Encoding() const { return ftEncoding; }
  
          /**
           * Sets the character map for the face. If an error occurs the object is not modified.
           * Valid encodings as at Freetype 2.0.4
           *      ft_encoding_none
           *      ft_encoding_symbol
           *      ft_encoding_unicode
           *      ft_encoding_latin_2
           *      ft_encoding_sjis
           *      ft_encoding_gb2312
           *      ft_encoding_big5
           *      ft_encoding_wansung
           *      ft_encoding_johab
           *      ft_encoding_adobe_standard
           *      ft_encoding_adobe_expert
           *      ft_encoding_adobe_custom
           *      ft_encoding_apple_roman
           *
           * @param encoding  the Freetype encoding symbol. See above.
           * @return          <code>true</code> if charmap was valid and set
           *                  correctly.
           */
          bool CharMap(FT_Encoding encoding);
  
          /**
           * Get the FTGlyphContainer index of the input character.
           *
           * @param characterCode The character code of the requested glyph in
           *                      the current encoding eg apple roman.
           * @return      The FTGlyphContainer index for the character or zero
           *              if it wasn't found
           */
          unsigned int GlyphListIndex(const unsigned int characterCode);
  
          /**
           * Get the font glyph index of the input character.
           *
           * @param characterCode The character code of the requested glyph in
           *                      the current encoding eg apple roman.
           * @return      The glyph index for the character.
           */
          unsigned int FontIndex(const unsigned int characterCode);
  
          /**
           * Set the FTGlyphContainer index of the character code.
           *
           * @param characterCode  The character code of the requested glyph in
           *                       the current encoding eg apple roman.
           * @param containerIndex The index into the FTGlyphContainer of the
           *                       character code.
           */
          void InsertIndex(const unsigned int characterCode,
                           const unsigned int containerIndex);
  
          /**
           * Queries for errors.
           *
           * @return  The current error code. Zero means no error.
           */
          FT_Error Error() const { return err; }
  
      private:
          /**
           * Current character map code.
           */
          FT_Encoding ftEncoding;
  
          /**
           * The current Freetype face.
           */
          const FT_Face ftFace;
  
          /**
           * A structure that maps glyph indices to character codes
           *
           * < character code, face glyph index>
           */
          typedef FTCharToGlyphIndexMap CharacterMap;
          CharacterMap charMap;
  
          /**
           * Precomputed font indices.
           */
          static const unsigned int MAX_PRECOMPUTED = 128;
          unsigned int charIndexCache[MAX_PRECOMPUTED];
  
          /**
           * Current error code.
           */
          FT_Error err;
  };
  
  
  #endif  //  __FTCharmap__
  

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