kmx git

#include    <string>

#include    "FTGLTextureFont.h"
#include    "FTTextureGlyph.h"


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(3),
    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 = static_cast<int>( charSize.Height());
        glyphWidth = static_cast<int>( 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);
        
        // FIXME ceiling
        xOffset += static_cast<int>( tempGlyph->BBox().upperX - tempGlyph->BBox().lowerX + padding);
        
        --remGlyphs;
        return tempGlyph;
    }
    
    err = face.Error();
    return NULL;
}


bool FTGLTextureFont::MakeGlyphList()
{
    if( !maxTextSize)
        glGetIntegerv( GL_MAX_TEXTURE_SIZE, (GLint*)&maxTextSize);

    remGlyphs = numGlyphs = face.GlyphCount();

    return FTFont::MakeGlyphList();
}


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);
    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_COLOR_BUFFER_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_COLOR_BUFFER_BIT);
    
    glEnable(GL_BLEND);
    glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); // GL_ONE
    
    FTFont::render( string);
    
    glPopAttrib();
}
kc3-lang/ftgl/src/FTGLTextureFont.cpp

Commit

src/FTGLTextureFont.cpp
