public RwGlTypeFaceBufferData GetVboForString(string text)
{
var characterRects = new List <Rectanglei>();
var uvRects = new List <Rectanglei>();
int xOffset = 0;
for (int i = 0; i < text.Length; i++)
{
char c = text[i];
// Obtain character UV
//
if (!InternalCharacterMap.ContainsKey(c))
{
LoadGlyphToTextureCache(c);
}
Rectanglei uvRect = InternalCharacterMap[c];
if (uvRect.Width > 0 && uvRect.Height > 0)
{
characterRects.Add(new Rectanglei(xOffset, 0, uvRect.Width, uvRect.Height));
uvRects.Add(uvRect);
}
xOffset += 32; // Temporary until character metrics are implemented
}
// Expand Rectanglei objects into floats for VBOs and return them
//
return(new RwGlTypeFaceBufferData(
ExpandRectangleiList(characterRects),
ExpandRectangleiList(uvRects)
));
}
private void LoadGlyphToTextureCache(char c)
{
if (InternalCharacterMap.ContainsKey(c))
{
throw new InvalidOperationException("The glyph is already present in the texture cache.");
}
// Load and render the glyph into memory
//
uint glyphIndex = Face.GetCharIndex(c);
Face.LoadGlyph(glyphIndex, LoadFlags.Default, LoadTarget.Normal);
Face.Glyph.RenderGlyph(RenderMode.Normal);
FTBitmap glyphBitmap = Face.Glyph.Bitmap;
// If the bitmap is zero size, skip the texture cache and add a dummy UV map to the dictionary
//
if (glyphBitmap.Width == 0 || glyphBitmap.Rows == 0)
{
InternalCharacterMap.Add(c, new Rectanglei(0, 0, 0, 0));
return;
}
// Bind the glyph cache texture in GL
//
GL.BindTexture(TextureTarget.Texture2D, GlTextureId);
// Store x-offset for the next glyph to be loaded into
//
int charXOffset = InternalTextureWidth;
// Resize the glyph cache texture's height if needed
//
if (InternalTextureHeight < glyphBitmap.Rows)
{
InternalTextureHeight = glyphBitmap.Rows;
}
InternalTextureWidth += glyphBitmap.Width;
GL.TexImage2D(TextureTarget.Texture2D, 0, PixelInternalFormat.Rgb, InternalTextureWidth, InternalTextureHeight,
0, PixelFormat.Rgb, PixelType.UnsignedByte, IntPtr.Zero);
// Load the glyph bitmap into the texture
//
byte[] gBuffer = new byte[glyphBitmap.Width * glyphBitmap.Rows * 3];
for (int y = 0; y < glyphBitmap.Rows; y++)
{
for (int x = 0; x < glyphBitmap.Width; x++)
{
for (int i = 0; i < 3; i++)
{
gBuffer[(x + y * glyphBitmap.Width) * 3 + i] = glyphBitmap.BufferData[x + glyphBitmap.Width * y];
}
}
}
GL.TexSubImage2D(TextureTarget.Texture2D, 0, charXOffset, 0, glyphBitmap.Width, glyphBitmap.Rows,
PixelFormat.Rgb, PixelType.UnsignedByte, gBuffer);
// Confirm the texture coordinates in the dictionary
//
InternalCharacterMap.Add(c, new Rectanglei(charXOffset, 0, glyphBitmap.Width, glyphBitmap.Rows));
}