void RadixCreatePlan(FRadixPlan512* Plan, uint32 Slices)
{
Plan->Slices = Slices;
// Create 6 param sets for 512x512 transform
const uint32 thread_count = Plan->Slices * (512 * 512) / 8;
uint32 ostride = 512 * 512 / 8;
uint32 istride = ostride;
uint32 pstride = 512;
double phase_base = -TWO_PI / (512.0 * 512.0);
RadixSetPerFrameParams(Plan, 0, thread_count, ostride, istride, pstride, (float)phase_base);
for (int i = 1; i < FFT_PARAM_SETS; i++)
{
istride /= 8;
phase_base *= 8.0;
if (i == 3)
{
ostride /= 512;
pstride = 1;
}
RadixSetPerFrameParams(Plan, i, thread_count, ostride, istride, pstride, (float)phase_base);
}
// Temp buffers
uint32 BytesPerElement = sizeof(float) * 2;
uint32 NumElements = (512 * Plan->Slices) * 512;
Plan->pBuffer_Tmp = RHICreateStructuredBuffer(BytesPerElement, BytesPerElement * NumElements, NULL, (BUF_UnorderedAccess | BUF_ShaderResource));
Plan->pUAV_Tmp = RHICreateUnorderedAccessView(Plan->pBuffer_Tmp, false, false);
Plan->pSRV_Tmp = RHICreateShaderResourceView(Plan->pBuffer_Tmp);
}
void UVaOceanSimulatorComponent::CreateBufferAndUAV(FResourceArrayInterface* Data, uint32 byte_width, uint32 byte_stride,
FStructuredBufferRHIRef* ppBuffer, FUnorderedAccessViewRHIRef* ppUAV, FShaderResourceViewRHIRef* ppSRV)
{
*ppBuffer = RHICreateStructuredBuffer(byte_stride, Data->GetResourceDataSize(), Data, (BUF_UnorderedAccess | BUF_ShaderResource));
*ppUAV = RHICreateUnorderedAccessView(*ppBuffer, false, false);
*ppSRV = RHICreateShaderResourceView(*ppBuffer);
}
FComputeShaderUsageExample::FComputeShaderUsageExample(float SimulationSpeed, int32 SizeX, int32 SizeY, ERHIFeatureLevel::Type ShaderFeatureLevel)
{
FeatureLevel = ShaderFeatureLevel;
ConstantParameters.SimulationSpeed = SimulationSpeed;
VariableParameters = FComputeShaderVariableParameters();
bIsComputeShaderExecuting = false;
bIsUnloading = false;
bSave = false;
//There are only a few different texture formats we can use if we want to use the output texture as input in a pixel shader later
//I would have loved to go with the R8G8B8A8_UNORM approach, but unfortunately, it seems UE4 does not support this in an obvious way, which is why I chose the UINT format using packing instead :)
//There is some excellent information on this topic in the following links:
//http://www.gamedev.net/topic/605356-r8g8b8a8-texture-format-in-compute-shader/
//https://msdn.microsoft.com/en-us/library/ff728749(v=vs.85).aspx
FRHIResourceCreateInfo CreateInfo;
Texture = RHICreateTexture2D(SizeX, SizeY, PF_R32_UINT, 1, 1, TexCreate_ShaderResource | TexCreate_UAV, CreateInfo);
TextureUAV = RHICreateUnorderedAccessView(Texture);
}
FFluidSimulationShaderInstance::FFluidSimulationShaderInstance(int32 SizeX, int32 SizeY, int32 SizeZ, ERHIFeatureLevel::Type ShaderFeatureLevel)
{
FeatureLevel = ShaderFeatureLevel;
ConstantParameters = FFluidSimulationShaderConstantParameters();
VariableParameters = FFluidSimulationShaderVariableParameters();
bIsShaderExecuting = false;
bIsUnloading = false;
FRHIResourceCreateInfo CreateInfo;
PressureIn = RHICreateTexture3D(SizeX, SizeY, SizeZ, PF_R32_UINT, 1, TexCreate_ShaderResource | TexCreate_UAV, CreateInfo);
PressureOut = RHICreateTexture3D(SizeX, SizeY, SizeZ, PF_R32_UINT, 1, TexCreate_ShaderResource | TexCreate_UAV, CreateInfo);
Divergence = RHICreateTexture3D(SizeX, SizeY, SizeZ, PF_R32_UINT, 1, TexCreate_ShaderResource | TexCreate_UAV, CreateInfo);
VelocityIn = RHICreateTexture3D(SizeX, SizeY, SizeZ, PF_A32B32G32R32F, 1, TexCreate_ShaderResource | TexCreate_UAV, CreateInfo);
VelocityOut = RHICreateTexture3D(SizeX, SizeY, SizeZ, PF_A32B32G32R32F, 1, TexCreate_ShaderResource | TexCreate_UAV, CreateInfo);
DensityIn = RHICreateTexture3D(SizeX, SizeY, SizeZ, PF_A32B32G32R32F, 1, TexCreate_ShaderResource | TexCreate_UAV, CreateInfo);
DensityOut = RHICreateTexture3D(SizeX, SizeY, SizeZ, PF_A32B32G32R32F, 1, TexCreate_ShaderResource | TexCreate_UAV, CreateInfo);
TemperatureIn = RHICreateTexture3D(SizeX, SizeY, SizeZ, PF_R32_UINT, 1, TexCreate_ShaderResource | TexCreate_UAV, CreateInfo);
TemperatureOut = RHICreateTexture3D(SizeX, SizeY, SizeZ, PF_R32_UINT, 1, TexCreate_ShaderResource | TexCreate_UAV, CreateInfo);
Obstacle = RHICreateTexture3D(SizeX, SizeY, SizeZ, PF_R32_UINT, 1, TexCreate_ShaderResource | TexCreate_UAV, CreateInfo);
VorticityIn = RHICreateTexture3D(SizeX, SizeY, SizeZ, PF_A32B32G32R32F, 1, TexCreate_ShaderResource | TexCreate_UAV, CreateInfo);
VorticityOut = RHICreateTexture3D(SizeX, SizeY, SizeZ, PF_A32B32G32R32F, 1, TexCreate_ShaderResource | TexCreate_UAV, CreateInfo);
PressureInUAV = RHICreateUnorderedAccessView(PressureIn);
PressureOutUAV = RHICreateUnorderedAccessView(PressureOut);
DivergenceUAV = RHICreateUnorderedAccessView(Divergence);
VelocityInUAV = RHICreateUnorderedAccessView(VelocityIn);
VelocityOutUAV = RHICreateUnorderedAccessView(VelocityOut);
DensityInUAV = RHICreateUnorderedAccessView(DensityIn);
DensityOutUAV = RHICreateUnorderedAccessView(DensityOut);
TemperatureInUAV = RHICreateUnorderedAccessView(TemperatureIn);
TemperatureOutUAV = RHICreateUnorderedAccessView(TemperatureOut);
ObstacleUAV = RHICreateUnorderedAccessView(Obstacle);
VorticityInUAV = RHICreateUnorderedAccessView(VorticityIn);
VorticityOutUAV = RHICreateUnorderedAccessView(VorticityOut);
PressureInSRV = RHICreateShaderResourceView(PressureIn, 0);
PressureOutSRV = RHICreateShaderResourceView(PressureOut, 0);
DivergenceSRV = RHICreateShaderResourceView(Divergence, 0);
VelocityInSRV = RHICreateShaderResourceView(VelocityIn, 0);
VelocityOutSRV = RHICreateShaderResourceView(VelocityOut, 0);
DensityInSRV = RHICreateShaderResourceView(DensityIn, 0);
DensityOutSRV = RHICreateShaderResourceView(DensityOut, 0);
TemperatureInSRV = RHICreateShaderResourceView(TemperatureIn, 0);
TemperatureOutSRV = RHICreateShaderResourceView(TemperatureOut, 0);
ObstacleSRV = RHICreateShaderResourceView(Obstacle, 0);
VorticityInSRV = RHICreateShaderResourceView(VorticityIn, 0);
VorticityOutSRV = RHICreateShaderResourceView(VorticityOut, 0);
GEngine->FluidSimDensitySRV = RHICreateShaderResourceView(DensityIn, 0);
// Set up walls of simulation
ExecuteObstaclesShader();
}