Hash :
4cd99a38
Author :
Date :
2001-07-30T02:24:24
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#include "gl.h"
#include "FTGLTextureFont.h"
#include "FTGlyphContainer.h"
#include "FTGL.h"
#include "FTTextureGlyph.h"
typedef unsigned long UInt32; // a mac thing?
inline UInt32 NextPowerOf2( UInt32 in)
{
in -= 1;
in |= in >> 16;
in |= in >> 8;
in |= in >> 4;
in |= in >> 2;
in |= in >> 1;
return in + 1;
}
FTGLTextureFont::FTGLTextureFont()
: glTextureID(0),
textMem(0),
padding(15)
{
// glGetIntegerv( GL_MAX_TEXTURE_SIZE, &maxTextSize);
// glGenTextures( 1, &glTextureID);
}
FTGLTextureFont::~FTGLTextureFont()
{
glDeleteTextures( 1, &glTextureID);
delete [] textMem;
}
bool FTGLTextureFont::MakeGlyphList()
{
FT_Face* ftFace = face.Face();
CreateTexture();
int currentTextX = padding;
int currentTextY = padding + padding;
float currTextU = (float)padding / (float)textureSize;
float currTextV = (float)padding / (float)textureSize;
float Uinc = (float)glyphWidth / (float)textureSize;
float Vinc = (float)glyphHeight / (float)textureSize;
int currGlyph = 0;
int glyphIndex;
for( int n = 0; n <= numGlyphs; ++n)
{
glyphIndex = FT_Get_Char_Index( *ftFace, n);
err = FT_Load_Glyph( *ftFace, glyphIndex, FT_LOAD_DEFAULT);
if( err)
{ }
FT_Glyph ftGlyph;
err = FT_Get_Glyph( (*ftFace)->glyph, &ftGlyph);
if( err)
{}
unsigned char* data = textMem + ( ( currentTextY * textureSize) + currentTextX);
currTextU = (float)currentTextX / (float)textureSize;
tempGlyph = new FTTextureGlyph( ftGlyph, glyphIndex, data, textureSize, currTextU, currTextV);
glyphList->Add( tempGlyph);
currentTextX += glyphWidth;
if( currentTextX > ( textureSize - glyphWidth))
{
currentTextY += glyphHeight;
currentTextX = padding;
currTextV = (float)currentTextY / (float)textureSize;
}
}
glPixelStorei(GL_UNPACK_ALIGNMENT, 1); //What does this do exactly?
glBindTexture( GL_TEXTURE_2D, glTextureID);
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexImage2D( GL_TEXTURE_2D, 0, GL_ALPHA, textureSize, textureSize, 0, GL_ALPHA, GL_UNSIGNED_BYTE, textMem);
}
bool FTGLTextureFont::CreateTexture()
{
glGetIntegerv( GL_MAX_TEXTURE_SIZE, &maxTextSize);
glGenTextures( 1, &glTextureID);
// calc the area required for this font
glyphHeight = ( charSize.Height()) + padding;
glyphWidth = ( charSize.Width()) + padding;
// calc the smallest texture size to fit the glyphs
//FIXME
// x * y
// o = --------
// x + y
// int x = glyphWidth * numGlyphs;
// int y = glyphHeight * numGlyphs;
// int o = ( x * y) / ( x + y);
// textureSize = NextPowerOf2( o);
textureSize = 1024;
horizGlyphs = static_cast<int>( textureSize / glyphWidth);
vertGlyphs = static_cast<int>(( numGlyphs / horizGlyphs) + 1);
// build the texture.
textMem = new unsigned char[ textureSize * textureSize]; // GL_ALPHA texture;
//FIXME
for( int i = 0; i < ( textureSize * textureSize); ++i)
textMem[i] = 0;
}
bool FTGLTextureFont::render( const char* string)
{
char* c = string;
FT_Vector kernAdvance;
pen.x = 0; pen.y = 0;
glBindTexture( GL_TEXTURE_2D, glTextureID);
glBegin( GL_QUADS);
while( *c)
{
kernAdvance = glyphList->render( *c, *(c + 1), pen);
pen.x += kernAdvance.x;
pen.y += kernAdvance.y;
++c;
}
glEnd();
}