internal AmbientOcclusionTechnique(
GBufferTechnique gbufferTechnique,
ShaderProgram postVertProg, ShaderProgram aoFragProg, ShaderProgram boxBlurFragProg,
RenderScene scene,
Logger logger = null)
{
if (gbufferTechnique == null)
{
throw new NullReferenceException(nameof(gbufferTechnique));
}
if (postVertProg == null)
{
throw new ArgumentNullException(nameof(postVertProg));
}
if (aoFragProg == null)
{
throw new ArgumentNullException(nameof(aoFragProg));
}
if (boxBlurFragProg == null)
{
throw new ArgumentNullException(nameof(boxBlurFragProg));
}
if (scene == null)
{
throw new NullReferenceException(nameof(scene));
}
this.gbufferTechnique = gbufferTechnique;
this.scene = scene;
this.logger = logger;
//Create renderer for rendering the ao texture
renderer = new Renderer(scene, logger);
renderer.AddSpecialization(scene.SwapchainCount);
renderer.AddSpecialization(sampleKernelSize);
renderer.AddSpecialization(sampleRadius);
renderer.AddSpecialization(sampleBias);
swapchainIndexPushDataBinding = renderer.AddPushData <int>();
targetSizePushBinding = renderer.AddPushData <Int2>();
//Create random for generating the kernel and noise (using a arbitrary fixed seed)
IRandom random = new ShiftRandom(seed: 1234);
//Create the sample kernel
Span <Float4> sampleKernel = stackalloc Float4[sampleKernelSize];
GenerateSampleKernel(random, sampleKernel);
sampleKernelBuffer = DeviceBuffer.UploadData <Float4>(
sampleKernel, scene, BufferUsages.UniformBuffer);
//Create the rotation noise texture
Float4Texture rotationNoiseTexture = TextureUtils.CreateRandomFloatTexture(
random, min: (-1f, -1f, 0f, 0f), max: (1f, 1f, 0f, 0f), size: (noiseSize, noiseSize));
rotationNoiseSampler = new DeviceSampler(scene.LogicalDevice,
texture: DeviceTexture.UploadTexture(rotationNoiseTexture, scene),
repeat: true,
pointFilter: true);
//Add full-screen object for drawing the composition
renderObject = new AttributelessObject(scene, vertexCount: 3, new TextureInfo[0]);
renderer.AddObject(renderObject, postVertProg, aoFragProg, debugName: "fullscreen");
//Create a BlurTechnique for blurring the ao texture (to hide the ao sample pattern)
blurTechnique = new BoxBlurTechnique(
postVertProg,
boxBlurFragProg,
blurSampleRange,
sampleScale: 1f,
scene,
logger);
}