Differences between revisions 1 and 2
⇤ ← Revision 1 as of 2019-05-06 06:36:08 →
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Editor: Arkiny
Comment:
← Revision 2 as of 2019-05-06 06:44:29 → ⇥
Size: 0
Editor: Arkiny
Comment: 라이브러리 클래스와 이름이 비슷하여 문서 이름 바꿈
Deletions are marked like this. Additions are marked like this.
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= DKComputeShader 101 =

== 1. Get the ComputeCoommandQueue from the Device ==
for sure
{{{#!highlight C++
DKObject<DKGraphicsDevice> device = DKGraphicsDevice::SharedInstance();
DKObject<DKCommandQueue> computeQueue = device->CreateCommandQueue(DKCommandQueue::Compute);
}}}



== 2. Prepare the gpu resources ==

=== 1. Texture ===
Texture usage decription should has one of these flags.

{{{#!highlight C++
DKTexture::UsageStorage // Recommended
DKTexture::UsageShaderWrite // Could be deprecated soon
}}}

Texutre Decriptor Example
{{{#!highlight C++
DKTextureDescriptor texDesc = {};
texDesc.textureType = DKTexture::Type2D;
texDesc.pixelFormat = DKPixelFormat::BGRA8Unorm;
texDesc.width = w;
texDesc.height = h;
texDesc.depth = 1;
texDesc.mipmapLevels = 1;
texDesc.sampleCount = 1;
texDesc.arrayLength = 1;
texDesc.usage = DKTexture::UsageStorage // For Compute Shader
              | DKTexture::UsageSampled | DKTexture::UsageShaderRead; // For Fragment Shader
textureTarget = device->CreateTexture(texDesc);
}}}


=== 2. Shader ===
In DKGL2, we use same class for all type of shaders.


=== 1. LoadResourceData From the resource path ===
{{{#!highlight C++
DKObject<DKData> computeShaderData = resourcePool.LoadResourceData("shaders/ComputeShader.comp.spv");
}}}


=== 2. Create Function from data above step ===
{{{#!highlight C++
DKGraphicsDevice* device = queue->Device();
DKShader shader(shaderData);
DKObject<DKShaderModule> shaderModule = device->CreateShaderModule(&shader);
DKObject<DKShaderFunction> shaderFunc = shaderModule->CreateFunction(shaderModule->FunctionNames().Value(0));
}}}


== 3. Prepare Uniformbuffers and BindSet ==
TODO


== 4. Prepare the Pipeline ==
Ususally compute shader need only setting for compute function.
Set the shader function to the Pipeline Descriptor

{{{#!highlight C++
DKComputePipelineDescriptor computePipelineDescriptor;
computePipelineDescriptor.computeFunction = csFunction; // csFunction as DKShaderFunction
auto computePipeLine = device->CreateComputePipeline(computePipelineDescriptor);
}}}


== 5. CommandBuffer Encoding ==

{{{#!highlight C++
DKObject<DKCommandBuffer> computeCmdbuffer = computeQueue->CreateCommandBuffer();
DKObject<DKComputeCommandEncoder> computeEncoder = computeCmdbuffer->CreateComputeCommandEncoder();
if (computeEncoder)
{
    if (computebindSet)
    {
        computebindSet->SetTexture(0, texture);
        computebindSet->SetTexture(1, targetTex);
    }
    computeEncoder->SetComputePipelineState(computePipeLine);
    computeEncoder->SetResources(0, computebindSet);
    computeEncoder->Dispatch(width / 16, height / 16, 1);
    computeEncoder->EndEncoding();
}
}}}