/// <summary>
/// Makes bloom effect using specified input texture.
/// </summary>
/// <param name="texture">Texture to apply effect on.</param>
/// <returns>Texture with applied effect.</returns>
public ShaderResourceView MakeBloomEffect(RenderTarget texture)
{
Viewport viewport = graphicsDevice.ImmediateContext.Rasterizer.GetViewports()[0];
DataBox data = graphicsDevice.ImmediateContext.MapSubresource(constantBuffer, MapMode.WriteDiscard, MapFlags.None);
data.Data.Write<Vector4>(new Vector4(viewport.Width, viewport.Height, 0, 0));
data.Data.Write<Vector4>(Settings.BloomSettings);
graphicsDevice.ImmediateContext.UnmapSubresource(constantBuffer, 0);
// DownSample4x to RT0
Dispatch("DownSample4x", 4, renderTargets[0], texture);
// DownSample4x to RT1
Dispatch("DownSample4x", 16, renderTargets[1], renderTargets[0]);
// BrightPass to RT2
Dispatch("BrightPass", 16, renderTargets[2], renderTargets[1]);
// BlurV to RT1
Dispatch("BlurV", 16, renderTargets[1], renderTargets[2]);
// BlurH to RT2
Dispatch("BlurH", 16, renderTargets[2], renderTargets[1]);
// BlurV to RT1
Dispatch("BlurV", 16, renderTargets[1], renderTargets[2]);
// BlurH to RT2
Dispatch("BlurH", 16, renderTargets[2], renderTargets[1]);
// UpSample4x to RT0
Dispatch("UpSample4x", 4, renderTargets[0], renderTargets[2]);
// UpSample4xCombine RT0 and texture to RT3
Dispatch("UpSample4xCombine", 1, renderTargets[3], texture, renderTargets[0]);
return renderTargets[3].GetShaderResourceView();
}
/// <summary>
/// Sets specified shader program and performs computations.
/// </summary>
/// <param name="shader">Name of shader program.</param>
/// <param name="outputScale">Screen space scale factor.</param>
/// <param name="output">Output render target.</param>
/// <param name="input">Input render targets.</param>
private void Dispatch(string shader, int outputScale, RenderTarget output, params RenderTarget[] input)
{
Viewport viewport = graphicsDevice.ImmediateContext.Rasterizer.GetViewports()[0];
graphicsDevice.ImmediateContext.ComputeShader.Set(effects[shader]);
graphicsDevice.ImmediateContext.ComputeShader.SetConstantBuffer(constantBuffer, 0);
for (int i = 0; i < input.Length; i++)
graphicsDevice.ImmediateContext.ComputeShader.SetShaderResource(input[i].GetShaderResourceView(), i);
graphicsDevice.ImmediateContext.ComputeShader.SetUnorderedAccessView(output.GetUnorderedAccessView(), 0);
graphicsDevice.ImmediateContext.Dispatch((int)Math.Ceiling(viewport.Width / (32 * outputScale)), (int)Math.Ceiling(viewport.Height / (32 * outputScale)), 1);
graphicsDevice.ImmediateContext.ComputeShader.SetUnorderedAccessView(null, 0);
}