public FontSystem(IFontLoader fontLoader, ITexture2DCreator textureCreator, int width, int height, int blurAmount = 0, int strokeAmount = 0, bool premultiplyAlpha = true)
{
if (fontLoader == null)
{
throw new ArgumentNullException(nameof(fontLoader));
}
if (textureCreator == null)
{
throw new ArgumentNullException(nameof(textureCreator));
}
_fontLoader = fontLoader;
_textureCreator = textureCreator;
if (width <= 0)
{
throw new ArgumentOutOfRangeException(nameof(width));
}
if (height <= 0)
{
throw new ArgumentOutOfRangeException(nameof(height));
}
if (blurAmount < 0 || blurAmount > 20)
{
throw new ArgumentOutOfRangeException(nameof(blurAmount));
}
if (strokeAmount < 0 || strokeAmount > 20)
{
throw new ArgumentOutOfRangeException(nameof(strokeAmount));
}
if (strokeAmount != 0 && blurAmount != 0)
{
throw new ArgumentException("Cannot have both blur and stroke.");
}
BlurAmount = blurAmount;
StrokeAmount = strokeAmount;
PremultiplyAlpha = premultiplyAlpha;
_size = new Point(width, height);
}
public FontSystem(ITexture2DCreator textureCreator, int width, int height, int blurAmount = 0, int strokeAmount = 0, bool premultiplyAlpha = true) :
this(StbTrueTypeSharpFontLoader.Instance, textureCreator, width, height, blurAmount, strokeAmount, premultiplyAlpha)
{
}
public void RenderGlyph(ITexture2DCreator textureCreator, FontGlyph glyph, int blurAmount, int strokeAmount, bool premultiplyAlpha)
{
var pad = Math.Max(FontGlyph.PadFromBlur(blurAmount), FontGlyph.PadFromBlur(strokeAmount));
// Render glyph to byte buffer
var bufferSize = glyph.Bounds.Width * glyph.Bounds.Height;
var buffer = _byteBuffer;
if ((buffer == null) || (buffer.Length < bufferSize))
{
buffer = new byte[bufferSize];
_byteBuffer = buffer;
}
Array.Clear(buffer, 0, bufferSize);
var colorBuffer = _colorBuffer;
if ((colorBuffer == null) || (colorBuffer.Length < bufferSize * 4))
{
colorBuffer = new byte[bufferSize * 4];
_colorBuffer = colorBuffer;
}
glyph.Font.RasterizeGlyphBitmap(glyph.Id,
glyph.Size,
buffer,
pad + pad * glyph.Bounds.Width,
glyph.Bounds.Width - pad * 2,
glyph.Bounds.Height - pad * 2,
glyph.Bounds.Width);
if (strokeAmount > 0)
{
var width = glyph.Bounds.Width;
var top = width * strokeAmount;
var bottom = (glyph.Bounds.Height - strokeAmount) * glyph.Bounds.Width;
var right = glyph.Bounds.Width - strokeAmount;
var left = strokeAmount;
byte d;
for (var i = 0; i < bufferSize; ++i)
{
var ci = i * 4;
var col = buffer[i];
var black = 0;
if (col == 255)
{
colorBuffer[ci] = colorBuffer[ci + 1] = colorBuffer[ci + 2] = colorBuffer[ci + 3] = 255;
continue;
}
if (i >= top)
{
black = buffer[i - top];
}
if (i < bottom)
{
d = buffer[i + top];
black = ((255 - d) * black + 255 * d) / 255;
}
if (i % width >= left)
{
d = buffer[i - strokeAmount];
black = ((255 - d) * black + 255 * d) / 255;
}
if (i % width < right)
{
d = buffer[i + strokeAmount];
black = ((255 - d) * black + 255 * d) / 255;
}
if (black == 0)
{
if (col == 0)
{
colorBuffer[ci] = colorBuffer[ci + 1] = colorBuffer[ci + 2] = colorBuffer[ci + 3] = 0; //black transparency to suit stroke
continue;
}
if (premultiplyAlpha)
{
colorBuffer[ci] = colorBuffer[ci + 1] = colorBuffer[ci + 2] = colorBuffer[ci + 3] = col;
}
else
{
colorBuffer[ci] = colorBuffer[ci + 1] = colorBuffer[ci + 2] = 255;
colorBuffer[ci + 3] = col;
}
}
else
{
if (col == 0)
{
colorBuffer[ci] = colorBuffer[ci + 1] = colorBuffer[ci + 2] = 0;
colorBuffer[ci + 3] = (byte)black;
continue;
}
if (premultiplyAlpha)
{
var alpha = ((255 - col) * black + 255 * col) / 255;
colorBuffer[ci] = colorBuffer[ci + 1] = colorBuffer[ci + 2] = (byte)((alpha * col) / 255);
colorBuffer[ci + 3] = (byte)alpha;
}
else
{
colorBuffer[ci] = colorBuffer[ci + 1] = colorBuffer[ci + 2] = col;
colorBuffer[ci + 3] = (byte)(((255 - col) * black + 255 * col) / 255);
}
}
}
}
else
{
if (blurAmount > 0)
{
fixed(byte *bdst = &buffer[0])
{
Blur(bdst, glyph.Bounds.Width, glyph.Bounds.Height, glyph.Bounds.Width, blurAmount);
}
}
for (var i = 0; i < bufferSize; ++i)
{
var ci = i * 4;
var c = buffer[i];
if (premultiplyAlpha)
{
colorBuffer[ci] = colorBuffer[ci + 1] = colorBuffer[ci + 2] = colorBuffer[ci + 3] = c;
}
else
{
colorBuffer[ci] = colorBuffer[ci + 1] = colorBuffer[ci + 2] = 255;
colorBuffer[ci + 3] = c;
}
}
}
// Write to texture
if (Texture == null)
{
Texture = textureCreator.Create(Width, Height);
}
Texture.SetData(glyph.Bounds, colorBuffer);
}
