#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__
