private static void AddPadding(RenderGlyph renderGlyph, int padding)
{
if (padding == 0)
{
return;
}
int width = Math.Max(0, renderGlyph.Bitmap.Width + padding * 2);
int height = Math.Max(0, renderGlyph.Bitmap.Height + padding * 2);
BBitmap result = new BBitmap(width, height);
result.Draw(renderGlyph.Bitmap, padding, padding);
renderGlyph.Info.XOffset += padding;
renderGlyph.Info.YOffset = height;
renderGlyph.Bitmap = result;
}
private static void GenerateSignedDistanceField(RenderGlyph renderGlyph, int spread)
{
if (spread == 0)
{
return;
}
int width = renderGlyph.Bitmap.Width;
int height = renderGlyph.Bitmap.Height;
int bufferLength = renderGlyph.Bitmap.Buffer.Length;
uint[] input = renderGlyph.Bitmap.Buffer;
uint[] output = new uint[renderGlyph.Bitmap.Buffer.Length];
for (int x = 0; x < width; x++)
{
for (int y = 0; y < height; y++)
{
uint color = input[x + y * width];
bool inside = (color >> 24 & 0xff) != 0;
int distanceSquared = int.MaxValue;
for (int dx = -spread; dx <= spread; dx++)
{
for (int dy = -spread; dy <= spread; dy++)
{
int sx = x + dx;
int sy = y + dy;
if (dx == 0 || dy == 0 || sx < 0 || sx >= width || sy < 0 || sy >= height)
{
continue;
}
uint compareColor = input[sx + sy * width];
bool compareInside = (compareColor >> 24 & 0xff) != 0;
if (compareInside ^ inside)
{
int compareDistanceSquared = dx * dx + dy * dy;
if (compareDistanceSquared < distanceSquared)
{
distanceSquared = compareDistanceSquared;
}
}
}
}
float distance = inside ? 0 : (float)Math.Sqrt(distanceSquared);
distance = MathHelper.Clamp(distance, 0, spread);
byte alpha = (byte)(255 - (distance / spread) * 255);
output[x + y * width] = (uint)((alpha << 24) | 0xffffff);
}
}
Array.Copy(output, input, output.Length);
}
