Function CreateRTProgram

Chapter_14/src/Graphics.cpp:1192–1269

* Load and create the DXR Ray Generation program and global root signature. */

* Load and create the DXR Ray Generation program and global root signature.
*/
void CreateRTProgram(D3D12Global &d3d, DXRGlobal &dxr, D3D12ShaderCompilerInfo &shaderCompiler)
{
	// Load and compile the ray generation shader
	dxr.rtProgram = RtProgram(D3D12ShaderInfo(L"shaders\\PathTracer.hlsl", L"", L"lib_6_3"));
	D3DShaders::CompileShader(shaderCompiler, dxr.rtProgram);

	// Describe the global root signature
	D3D12_DESCRIPTOR_RANGE ranges[6];

	ranges[0].BaseShaderRegister = 0;
	ranges[0].NumDescriptors = UINT(DescriptorHeapConstants::CBTotal);
	ranges[0].RegisterSpace = 0;
	ranges[0].RangeType = D3D12_DESCRIPTOR_RANGE_TYPE_CBV;
	ranges[0].OffsetInDescriptorsFromTableStart = UINT(DescriptorHeapConstants::CBStart);

	ranges[1].BaseShaderRegister = 0;
	ranges[1].NumDescriptors = UINT(DescriptorHeapConstants::UAV0Total);
	ranges[1].RegisterSpace = 0;
	ranges[1].RangeType = D3D12_DESCRIPTOR_RANGE_TYPE_UAV;
	ranges[1].OffsetInDescriptorsFromTableStart = UINT(DescriptorHeapConstants::UAV0Start);

	ranges[2].BaseShaderRegister = 0;
	ranges[2].NumDescriptors = UINT(DescriptorHeapConstants::SRV0Total);
	ranges[2].RegisterSpace = 0;
	ranges[2].RangeType = D3D12_DESCRIPTOR_RANGE_TYPE_SRV;
	ranges[2].OffsetInDescriptorsFromTableStart = UINT(DescriptorHeapConstants::SRV0Start);

	ranges[3].BaseShaderRegister = 0;
	ranges[3].NumDescriptors = UINT(DescriptorHeapConstants::SRV1Total);
	ranges[3].RegisterSpace = 1;
	ranges[3].RangeType = D3D12_DESCRIPTOR_RANGE_TYPE_SRV;
	ranges[3].OffsetInDescriptorsFromTableStart = UINT(DescriptorHeapConstants::SRV1Start);

	ranges[4].BaseShaderRegister = 0;
	ranges[4].NumDescriptors = UINT(DescriptorHeapConstants::SRV2Total);
	ranges[4].RegisterSpace = 2;
	ranges[4].RangeType = D3D12_DESCRIPTOR_RANGE_TYPE_SRV;
	ranges[4].OffsetInDescriptorsFromTableStart = UINT(DescriptorHeapConstants::SRV2Start);

	ranges[5].BaseShaderRegister = 0;
	ranges[5].NumDescriptors = UINT(DescriptorHeapConstants::SRV3Total);
	ranges[5].RegisterSpace = 3;
	ranges[5].RangeType = D3D12_DESCRIPTOR_RANGE_TYPE_SRV;
	ranges[5].OffsetInDescriptorsFromTableStart = UINT(DescriptorHeapConstants::SRV3Start);

	D3D12_ROOT_PARAMETER param0 = {};
	param0.ParameterType = D3D12_ROOT_PARAMETER_TYPE_DESCRIPTOR_TABLE;
	param0.ShaderVisibility = D3D12_SHADER_VISIBILITY_ALL;
	param0.DescriptorTable.NumDescriptorRanges = _countof(ranges);
	param0.DescriptorTable.pDescriptorRanges = ranges;

	D3D12_ROOT_PARAMETER rootParams[1] = { param0 };

	D3D12_STATIC_SAMPLER_DESC staticSampler = {};
	staticSampler.Filter = D3D12_FILTER_MIN_MAG_MIP_LINEAR;
	staticSampler.AddressU = D3D12_TEXTURE_ADDRESS_MODE_WRAP;
	staticSampler.AddressV = D3D12_TEXTURE_ADDRESS_MODE_WRAP;
	staticSampler.AddressW = D3D12_TEXTURE_ADDRESS_MODE_WRAP;