本文整理汇总了C++中CommandContext::AllocateDynamicGPUVisibleDescriptor方法的典型用法代码示例。如果您正苦于以下问题：C++ CommandContext::AllocateDynamicGPUVisibleDescriptor方法的具体用法？C++ CommandContext::AllocateDynamicGPUVisibleDescriptor怎么用？C++ CommandContext::AllocateDynamicGPUVisibleDescriptor使用的例子？那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类CommandContext的用法示例。
在下文中一共展示了CommandContext::AllocateDynamicGPUVisibleDescriptor方法的1个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的C++代码示例。
示例1: GenerateMips
void GenerateMipsHelper::GenerateMips(RenderDeviceD3D12Impl *pRenderDeviceD3D12, TextureViewD3D12Impl *pTexView, CommandContext& Ctx)
{
auto &ComputeCtx = Ctx.AsComputeContext();
ComputeCtx.SetRootSignature(m_pGenerateMipsRS);
auto *pTexture = pTexView->GetTexture();
auto *pTexD3D12 = ValidatedCast<TextureD3D12Impl>( pTexture );
auto &TexDesc = pTexture->GetDesc();
auto *pSRV = pTexture->GetDefaultView(TEXTURE_VIEW_SHADER_RESOURCE);
auto *pSRVD3D12Impl = ValidatedCast<TextureViewD3D12Impl>(pSRV);
auto SRVDescriptorHandle = pSRVD3D12Impl->GetCPUDescriptorHandle();
Ctx.TransitionResource(pTexD3D12, D3D12_RESOURCE_STATE_UNORDERED_ACCESS);
auto *pd3d12Device = pRenderDeviceD3D12->GetD3D12Device();
for (uint32_t TopMip = 0; TopMip < TexDesc.MipLevels-1; )
{
uint32_t SrcWidth = TexDesc.Width >> TopMip;
uint32_t SrcHeight = TexDesc.Height >> TopMip;
uint32_t DstWidth = SrcWidth >> 1;
uint32_t DstHeight = SrcHeight >> 1;
// Determine if the first downsample is more than 2:1. This happens whenever
// the source width or height is odd.
uint32_t NonPowerOfTwo = (SrcWidth & 1) | (SrcHeight & 1) << 1;
if (TexDesc.Format == TEX_FORMAT_RGBA8_UNORM_SRGB)
ComputeCtx.SetPipelineState(m_pGenerateMipsGammaPSO[NonPowerOfTwo]);
else
ComputeCtx.SetPipelineState(m_pGenerateMipsLinearPSO[NonPowerOfTwo]);
// We can downsample up to four times, but if the ratio between levels is not
// exactly 2:1, we have to shift our blend weights, which gets complicated or
// expensive. Maybe we can update the code later to compute sample weights for
// each successive downsample. We use _BitScanForward to count number of zeros
// in the low bits. Zeros indicate we can divide by two without truncating.
uint32_t AdditionalMips;
_BitScanForward((unsigned long*)&AdditionalMips, DstWidth | DstHeight);
uint32_t NumMips = 1 + (AdditionalMips > 3 ? 3 : AdditionalMips);
if (TopMip + NumMips > TexDesc.MipLevels-1)
NumMips = TexDesc.MipLevels-1 - TopMip;
// These are clamped to 1 after computing additional mips because clamped
// dimensions should not limit us from downsampling multiple times. (E.g.
// 16x1 -> 8x1 -> 4x1 -> 2x1 -> 1x1.)
if (DstWidth == 0)
DstWidth = 1;
if (DstHeight == 0)
DstHeight = 1;
D3D12_DESCRIPTOR_HEAP_TYPE HeapType = D3D12_DESCRIPTOR_HEAP_TYPE_CBV_SRV_UAV;
auto DescriptorAlloc = Ctx.AllocateDynamicGPUVisibleDescriptor(HeapType, 5);
CommandContext::ShaderDescriptorHeaps Heaps(DescriptorAlloc.GetDescriptorHeap());
ComputeCtx.SetDescriptorHeaps(Heaps);
Ctx.GetCommandList()->SetComputeRootDescriptorTable(1, DescriptorAlloc.GetGpuHandle(0));
Ctx.GetCommandList()->SetComputeRootDescriptorTable(2, DescriptorAlloc.GetGpuHandle(1));
struct RootCBData
{
Uint32 SrcMipLevel; // Texture level of source mip
Uint32 NumMipLevels; // Number of OutMips to write: [1, 4]
float TexelSize[2]; // 1.0 / OutMip1.Dimensions
} CBData = {TopMip, NumMips, 1.0f / static_cast<float>(DstWidth), 1.0f / static_cast<float>(DstHeight)};
Ctx.GetCommandList()->SetComputeRoot32BitConstants(0, 4, &CBData, 0);
// TODO: Shouldn't we transition top mip to shader resource state?
D3D12_CPU_DESCRIPTOR_HANDLE DstDescriptorRange = DescriptorAlloc.GetCpuHandle();
UINT DstRangeSize = 1+NumMips;
D3D12_CPU_DESCRIPTOR_HANDLE SrcDescriptorRanges[5] = {};
SrcDescriptorRanges[0] = SRVDescriptorHandle;
UINT SrcRangeSizes[5] = {1,1,1,1,1};
for(Uint32 u=0; u < NumMips; ++u)
SrcDescriptorRanges[1+u] = pTexD3D12->GetUAVDescriptorHandle(TopMip+u+1, 0);
pd3d12Device->CopyDescriptors(1, &DstDescriptorRange, &DstRangeSize, 1+NumMips, SrcDescriptorRanges, SrcRangeSizes, D3D12_DESCRIPTOR_HEAP_TYPE_CBV_SRV_UAV);
ComputeCtx.Dispatch((DstWidth+7)/8, (DstHeight+7)/8);
Ctx.InsertUAVBarrier(*pTexD3D12, *pTexD3D12);
TopMip += NumMips;
}
}