Method RenderDynamicExposure

trinity/PostProcess/Tr2PostProcessRenderer.cpp:1182–1241

Tr2GpuResourcePool::Buffer Tr2PostProcessRenderer::RenderDynamicExposure( const Tr2TextureAL& source, Tr2GpuResourcePool& gpuResourcePool, Tr2RenderContext& renderContext, Tr2PPDynamicExposureEffect* dynamicExposure )
{
	GPU_REGION( renderContext, "Exposure" );

	uint32_t tilesX = source.GetWidth() / HISTOGRAM_TILE_SIZE_X + 1;
	uint32_t tilesY = source.GetHeight() / HISTOGRAM_TILE_SIZE_Y + 1;

	uint32_t localHistogramCount = tilesX * tilesY * 16;

	auto localHistograms = gpuResourcePool.GetTempBuffer(
		"LocalHistograms",
		Tr2BufferDescriptionAL( Tr2RenderContextEnum::PIXEL_FORMAT_R32G32B32A32_UINT, localHistogramCount, Tr2GpuUsage::SHADER_RESOURCE | Tr2GpuUsage::UNORDERED_ACCESS, Tr2CpuUsage::NONE ) );


	auto histogram = gpuResourcePool.GetTempBuffer(
		"Histogram",
		Tr2BufferDescriptionAL( Tr2RenderContextEnum::PIXEL_FORMAT_R32_UINT, 65, Tr2GpuUsage::SHADER_RESOURCE | Tr2GpuUsage::UNORDERED_ACCESS, Tr2CpuUsage::NONE ) );


	// we also need to update the tonemapping buffer
	m_dynamicExposureCreateHistogramShader->SetParameter( MEMOIZED_STRING( "ScreenTilesX" ), float( tilesX ) );
	TEMP_PARAM( m_dynamicExposureCreateHistogramShader, "BlitOriginal", source );
	TEMP_PARAM( m_dynamicExposureCreateHistogramShader, "LocalHistograms", localHistograms );
	m_dynamicExposureMergeHistogramShader->SetParameter( MEMOIZED_STRING( "ScreenTilesX" ), float( tilesX ) );
	m_dynamicExposureMergeHistogramShader->SetParameter( MEMOIZED_STRING( "ScreenTilesY" ), float( tilesY ) );
	TEMP_PARAM( m_dynamicExposureMergeHistogramShader, "LocalHistograms", localHistograms );
	TEMP_PARAM( m_dynamicExposureMergeHistogramShader, "Histogram", histogram );

	uint32_t m_uintValue[4] = { 0, 0, 0, 0 };
	// Clear local histograms
	renderContext.ClearUav( localHistograms, m_uintValue );

	// Clear histograms
	renderContext.ClearUav( histogram, m_uintValue );

	// Create histograms
	m_dynamicExposureCreateHistogramShader->SetParameter( MEMOIZED_STRING( "MinLuminance" ), log( dynamicExposure->m_minLuminance ) );
	m_dynamicExposureCreateHistogramShader->SetParameter( MEMOIZED_STRING( "MaxLuminance" ), log( dynamicExposure->m_maxLuminance ) );
	m_dynamicExposureCreateHistogramShader->SetParameter( MEMOIZED_STRING( "MinBrightness" ), dynamicExposure->m_minBrightness );
	m_dynamicExposureCreateHistogramShader->SetParameter( MEMOIZED_STRING( "MaxBrightness" ), dynamicExposure->m_maxBrightness );
	Tr2Renderer::RunComputeShader( m_dynamicExposureCreateHistogramShader, tilesX, tilesY, 1, renderContext );

	// Merge histogram
	uint32_t mergeHistogramXDim = tilesX * tilesY / NUM_TILES_PER_THREAD_GROUP + 1;
	Tr2Renderer::RunComputeShader( m_dynamicExposureMergeHistogramShader, mergeHistogramXDim, 1, 1, renderContext );

	// Measure histogram
	m_dynamicExposureMeasureExposureShader->SetParameter( MEMOIZED_STRING( "MinLuminance" ), log( dynamicExposure->m_minLuminance ) );
	m_dynamicExposureMeasureExposureShader->SetParameter( MEMOIZED_STRING( "MaxLuminance" ), log( dynamicExposure->m_maxLuminance ) );
	m_dynamicExposureMeasureExposureShader->SetParameter( MEMOIZED_STRING( "MinBrightness" ), dynamicExposure->m_minBrightness );
	m_dynamicExposureMeasureExposureShader->SetParameter( MEMOIZED_STRING( "MaxBrightness" ), dynamicExposure->m_maxBrightness );
	m_dynamicExposureMeasureExposureShader->SetParameter( MEMOIZED_STRING( "IncreaseSpeed" ), dynamicExposure->m_increaseSpeed );
	m_dynamicExposureMeasureExposureShader->SetParameter( MEMOIZED_STRING( "DecreaseSpeed" ), dynamicExposure->m_decreaseSpeed );
	m_dynamicExposureMeasureExposureShader->SetParameter( MEMOIZED_STRING( "MinExposure" ), dynamicExposure->m_minExposure );
	m_dynamicExposureMeasureExposureShader->SetParameter( MEMOIZED_STRING( "MaxExposure" ), dynamicExposure->m_maxExposure );
	TEMP_PARAM( m_dynamicExposureMeasureExposureShader, "Histogram", histogram );
	TEMP_PARAM( m_dynamicExposureMeasureExposureShader, "Exposure", GetExposureBuffer( gpuResourcePool ) );
	Tr2Renderer::RunComputeShader( m_dynamicExposureMeasureExposureShader, 1, 1, 1, renderContext );