public void Draw(RenderDrawContext context, float sigmaRatio, Texture inputTexture, Texture outputTexture)
{
// Check if we need to regenerate offsetsWeights
if (offsetsWeights == null || this.sigmaRatio != sigmaRatio)
{
offsetsWeights = GaussianUtil.Calculate1D(Radius, sigmaRatio);
// Update parameters
blurH.Parameters.Set(GaussianBlurShaderKeys.OffsetsWeights, offsetsWeights);
blurV.Parameters.Set(GaussianBlurShaderKeys.OffsetsWeights, offsetsWeights);
this.sigmaRatio = sigmaRatio;
}
// Get a temporary texture for the intermediate pass
// This texture will be allocated only in the scope of this draw and returned to the pool at the exit of this method
var desc = inputTexture.Description;
desc.MultisampleCount = MultisampleCount.None; // TODO we should have a method to get a non-multisampled RT
var outputTextureH = gaussianBlur.NewScopedRenderTarget2D(desc);
// Horizontal pass
blurH.SetInput(inputTexture);
blurH.SetOutput(outputTextureH);
blurH.Draw(context, nameGaussianBlurH);
// Vertical pass
blurV.SetInput(outputTextureH);
blurV.SetOutput(outputTexture);
blurV.Draw(context, nameGaussianBlurV);
}
public GaussianBlurShader(GaussianBlur gaussianBlur, int radius)
{
Radius = radius;
this.gaussianBlur = gaussianBlur;
// Craete ImageEffectShader
blurH = gaussianBlur.ToLoadAndUnload(new ImageEffectShader("GaussianBlurEffect", true));
blurV = gaussianBlur.ToLoadAndUnload(new ImageEffectShader("GaussianBlurEffect", true));
blurH.Initialize(gaussianBlur.Context);
blurV.Initialize(gaussianBlur.Context);
// Setup Horizontal parameters
blurH.Parameters.Set(GaussianBlurKeys.VerticalBlur, false);
blurV.Parameters.Set(GaussianBlurKeys.VerticalBlur, true);
var size = radius * 2 + 1;
nameGaussianBlurH = string.Format("GaussianBlurH{0}x{0}", size);
nameGaussianBlurV = string.Format("GaussianBlurV{0}x{0}", size);
// TODO: cache if necessary
offsetsWeights = GaussianUtil.Calculate1D(this.Radius, gaussianBlur.SigmaRatio);
// Update permutation parameters
blurH.Parameters.Set(GaussianBlurKeys.Count, offsetsWeights.Length);
blurV.Parameters.Set(GaussianBlurKeys.Count, offsetsWeights.Length);
blurH.EffectInstance.UpdateEffect(gaussianBlur.Context.GraphicsDevice);
blurV.EffectInstance.UpdateEffect(gaussianBlur.Context.GraphicsDevice);
// Update parameters
blurH.Parameters.Set(GaussianBlurShaderKeys.OffsetsWeights, offsetsWeights);
blurV.Parameters.Set(GaussianBlurShaderKeys.OffsetsWeights, offsetsWeights);
}
