kc3-lang/ftgl/include/FTGLTextureFont.h

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• Hash : 789b1cf3
  Author :
  Date : 2001-11-04T04:33:30
  

  Changes to allow glyphs to be loaded on the fly... MakeGlyphList is no longer pure virtual. New function MakeGlyph is pure virtual Open now has a flag for pre-cache GlyphContainer builds a list of null pointers advance and render functions check if glyph has been loaded and loads it if it has'nt

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• include/FTGLTextureFont.h

• #ifndef		__FTGLTextureFont__
  #define		__FTGLTextureFont__
  
  #include "FTGL.h"
  #include "FTFont.h"
  
  class FTTextureGlyph;
  
  /**
   * FTGLTextureFont is a specialisation of the FTFont class for handling
   * Texture mapped fonts
   *
   * @see		FTFont
   */
  class  FTGL_EXPORT FTGLTextureFont : public FTFont
  {
  	public:
  		/**
  		 * Default Constructor
  		 */
  		FTGLTextureFont();
  		
  		/**
  		 * Destructor
  		 */
  		virtual ~FTGLTextureFont();
  		
  		/**
  		 * Get the total width of the texture that holds this font
  		 */
  		virtual GLsizei TextureWidth() const { return textureWidth;}
  		
  		/**
  		 * Get the total height of the texture that holds this font
  		 */
  		virtual GLsizei TextureHeight() const { return textureHeight;}
  		
  		/**
  		 * Renders a string of characters
  		 * 
  		 * @param string	'C' style string to be output.	 
  		 */
  		virtual void render( const char* string);
  		
  		/**
  		 * Renders a string of characters
  		 * 
  		 * @param string	wchar_t string to be output.	 
  		 */
  		virtual void render( const wchar_t* string);
  
  		
  	private:
  		virtual FTGlyph* MakeGlyph( unsigned int g){ return NULL;}
  				
  		/**
  		 * Constructs the internal glyph cache.
  		 *
  		 * This a list of glyphs processed for openGL rendering NOT
  		 * freetype glyphs
  		 */
  		bool MakeGlyphList();
  		
  		/**
  		 * Draw a series of glyphs into texture memory
  		 *
  		 * This function will start with glyph index glyphStart and draw each
  		 * glyph into the texture until it runs out of space in the current
  		 * texture. It will return the index of the last glyph it drew so
  		 * that if more textures are required, we know where to start from.
  		 *
  		 * @param glyphStart	The index of the first glyph to be drawn
  		 * @param textID		The index of the openGLtexture to draw glyphs into
  		 * @param textureWidth	The texture width
  		 * @param textureHeight	The texture height
  		 * @param textMem		A pointer to the texture memory.
  		 */
  		unsigned int FillGlyphs( unsigned int glyphStart, GLuint textID, GLsizei textureWidth, GLsizei textureHeight, unsigned char* textMem);
  
  		/**
  		 * Get the size of a block of memory required to layout the glyphs
  		 *
  		 * Calculates a width and height based on the glyph sizes and the
  		 * number of glyphs.
  		 */
  		void GetSize();
  
  		/**
  		 * Creates an OpenGL texture object.
  		 *
  		 * The format is GL_ALPHA and the params are
  		 * GL_TEXTURE_WRAP_S = GL_CLAMP
  		 * GL_TEXTURE_WRAP_T = GL_CLAMP
  		 * GL_TEXTURE_MAG_FILTER = GL_LINEAR
  		 * GL_TEXTURE_MIN_FILTER = GL_LINEAR
  		 * Note that mipmapping is NOT used
  		 * @param id		The index into an array of glTextureIDs.
  		 * @param width		The width of the texture in bytes
  		 * @param height	The number of rows of bytes.
  		 * @param data		A pointer to the texture data
  		 */
  		void CreateTexture( GLuint id, GLsizei width, GLsizei height, unsigned char* data);
  		
  		/**
  		 * The maximum texture dimension on this OpenGL implemetation
  		 */
  		GLsizei maxTextSize;
  		
  		/**
  		 * The minimum texture width required to hold the glyphs
  		 */
  		GLsizei textureWidth;
  		
  		/**
  		 * The minimum texture height required to hold the glyphs
  		 */
  		GLsizei textureHeight;
  		
  		/**
  		 * An array of texture ids
  		 */
  		unsigned long glTextureID[16];
  		
  		/**
  		 * The number of textures required to hold the glyphs
  		 */
  		int numTextures;
  
  		/**
  		 * The memeory where the textures are built before beiing transferred 
  		 * to OpenGL
  		 */
  		unsigned char* textMem;
  		
  		/**
  		 * The max height for glyphs in the current font
  		 */
  		int glyphHeight;
  
  		/**
  		 * The max width for glyphs in the current font
  		 */
  		int glyphWidth;
  
  		/**
  		 * A value to be added to the height and width to ensure that
  		 * glyphs don't overlap in the texture
  		 */
  		int padding;
  
  };
  
  
  #endif // __FTGLTextureFont__
  
  
  

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