protected override ITextureFilter CreateFilter(ITextureFilter input)
{
if (Renderer.InputFormat.IsRgb())
{
return(input);
}
int bits = Renderer.InputFormat.GetBitDepth();
if (bits > MaxBitDepth)
{
return(input);
}
float[] consts =
{
(1 << bits) - 1,
Power
};
var Downscale = new Shader(FromFile("Downscale.hlsl"))
{
Transform = s => new TextureSize(s.Width / 2, s.Height / 2),
Arguments = consts
};
var DownscaleLuma = new Shader(FromFile("DownscaleLuma.hlsl"))
{
SizeIndex = 1,
Arguments = consts
};
DownscaleLuma["iteration"] = 0;
var Deband = new Shader(FromFile("Deband.hlsl", compilerOptions: PreserveDetail ? "PRESERVE_DETAIL=1" : ""))
{
Arguments = consts,
LinearSampling = false,
SizeIndex = 1
};
var pyramid = new Stack <ITextureFilter>();
var composition = input as ICompositionFilter;
if (composition != null)
{
pyramid.Push(composition.Luma);
pyramid.Push(DownscaleLuma.ApplyTo(composition.Luma, composition.Chroma));
}
else
{
pyramid.Push(input.ConvertToYuv());
}
// Build gaussian pyramid
while (pyramid.Peek().Size().Width >= 2 &&
pyramid.Peek().Size().Height >= 2)
{
Downscale["iteration"] = pyramid.Count - 1;
pyramid.Push(Downscale.ApplyTo(pyramid.Peek()));
}
// Process pyramid
ITextureFilter chroma = null;
ITextureFilter result = pyramid.Peek();
while (pyramid.Count > 1)
{
if (composition != null && pyramid.Count == 2)
{
chroma = result;
Deband.Format = TextureFormat.Unorm16_R;
}
result = Deband.ApplyTo(pyramid.Pop(), pyramid.Peek(), result);
}
if (composition != null)
{
return(result.ComposeWith(chroma, copyParametersFrom: composition));
}
else
{
return(result.ConvertToRgb());
}
}