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#include "FTGLTextureFont.h"
#include "FTTextureGlyph.h"
#ifdef FTGL_DEBUG
#include "mmgr.h"
#endif
using namespace std; // for memset
inline GLuint NextPowerOf2( GLuint in)
{
in -= 1;
in |= in >> 16;
in |= in >> 8;
in |= in >> 4;
in |= in >> 2;
in |= in >> 1;
return in + 1;
}
FTGLTextureFont::FTGLTextureFont()
: maxTextSize(0),
textureWidth(0),
textureHeight(0),
numTextures(0),
textMem(0),
glyphHeight(0),
glyphWidth(0),
padding(1),
remGlyphs(0),
xOffset(0),
yOffset(0)
{}
FTGLTextureFont::~FTGLTextureFont()
{
glDeleteTextures( numTextures, (const GLuint*)glTextureID);
}
FTGlyph* FTGLTextureFont::MakeGlyph( unsigned int g)
{
FT_Glyph* ftGlyph = face.Glyph( g, FT_LOAD_NO_HINTING);
if( ftGlyph)
{
// Estimate the glyph size size - global bbox
glyphHeight = ( charSize.Height());
glyphWidth = ( charSize.Width());
// Is there a current texture
if( numTextures == 0)
{
glTextureID[0] = CreateTexture();
xOffset = yOffset = padding;
++numTextures;
}
// will it fit in the current texture
if( xOffset > ( textureWidth - glyphWidth))
{
xOffset = padding;
yOffset += glyphHeight;
if( yOffset > ( textureHeight - glyphHeight))
{
// no - make a new texture
glTextureID[numTextures] = CreateTexture();
yOffset = padding;
++numTextures;
}
}
// yes - load the glyph
FTTextureGlyph* tempGlyph = new FTTextureGlyph( *ftGlyph, glTextureID[numTextures - 1],
xOffset, yOffset, textureWidth, textureHeight);
xOffset += tempGlyph->BBox().x2 - tempGlyph->BBox().x1 + padding;
--remGlyphs;
// FT_Done_Glyph( *ftGlyph );
return tempGlyph;
}
err = face.Error();
return NULL;
}
bool FTGLTextureFont::MakeGlyphList()
{
if( !maxTextSize)
glGetIntegerv( GL_MAX_TEXTURE_SIZE, (GLint*)&maxTextSize);
remGlyphs = numGlyphs;
FTFont::MakeGlyphList();
return !err; // FIXME what err?
}
void FTGLTextureFont::GetSize()
{
//work out the max width. Most likely maxTextSize
textureWidth = NextPowerOf2( (remGlyphs * glyphWidth) + padding * 2);
if( textureWidth > maxTextSize)
{
textureWidth = maxTextSize;
}
int h = static_cast<int>( (textureWidth - padding * 2) / glyphWidth);
textureHeight = NextPowerOf2( (( numGlyphs / h) + 1) * glyphHeight);
textureHeight = textureHeight > maxTextSize ? maxTextSize : textureHeight;
}
int FTGLTextureFont::CreateTexture()
{
// calc the size
GetSize();
// allocate some mem and clear it to black
int totalMem = textureWidth * textureHeight;
textMem = new unsigned char[totalMem]; // GL_ALPHA texture;
memset( textMem, 0, totalMem);
// Create the blank texture
int textID;
glGenTextures( 1, (GLuint*)&textID);
glPixelStorei( GL_UNPACK_ALIGNMENT, 1); //What does this do exactly?
glBindTexture( GL_TEXTURE_2D, textID);
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexImage2D( GL_TEXTURE_2D, 0, GL_ALPHA, textureWidth, textureHeight, 0, GL_ALPHA, GL_UNSIGNED_BYTE, textMem);
delete [] textMem;
return textID;
}
void FTGLTextureFont::render( const char* string)
{
glPushAttrib( GL_ENABLE_BIT | GL_HINT_BIT | GL_LINE_BIT | GL_PIXEL_MODE_BIT);
glEnable(GL_BLEND);
glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); // GL_ONE
FTFont::render( string);
glPopAttrib();
}
void FTGLTextureFont::render( const wchar_t* string)
{
glPushAttrib( GL_ENABLE_BIT | GL_HINT_BIT | GL_LINE_BIT | GL_PIXEL_MODE_BIT);
glEnable(GL_BLEND);
glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); // GL_ONE
FTFont::render( string);
glPopAttrib();
}