private static void CopyGlyphToTexture(FontRenderer.Glyph glyph, DynamicTexture texture, IntVector2 position)
{
var srcPixels = glyph.Pixels;
if (srcPixels == null)
{
return; // Invisible glyph
}
int si;
Color4 color = Color4.Black;
var dstPixels = texture.GetPixels();
int bytesPerPixel = glyph.RgbIntensity ? 3 : 1;
for (int i = 0; i < glyph.Height; i++)
{
// Sometimes glyph.VerticalOffset could be negative for symbols with diacritics and this results the symbols
// get overlapped or run out of the texture bounds. We shift the glyph down and increase the current line
// height to fix the issue. Also we store the shift amount in FontChar.VerticalOffset property.
int verticalOffsetCorrection = -Math.Min(0, glyph.VerticalOffset);
var di = (position.Y + glyph.VerticalOffset + i + verticalOffsetCorrection) * texture.ImageSize.Width + position.X;
for (int j = 0; j < glyph.Width; j++)
{
si = i * glyph.Pitch + j * bytesPerPixel;
if (glyph.RgbIntensity)
{
color.A = 255;
color.R = srcPixels[si];
color.G = srcPixels[si + 1];
color.B = srcPixels[si + 2];
}
else
{
color = Color4.White;
color.A = srcPixels[si];
}
dstPixels[di++] = color;
}
}
texture.Invalidated = true;
}