From d573f9e9073e155e368a12e25d62a9215e891223 Mon Sep 17 00:00:00 2001
From: Magnus Norddahl <dpjudas@users.noreply.github.com>
Date: Mon, 1 Nov 2021 02:20:57 +0100
Subject: [PATCH] Create the pipeline

---
 src/lightmap/gpuraytracer.cpp | 43 +++++++++++++++++++++++++++++++++--
 src/lightmap/gpuraytracer.h   |  8 +++++++
 2 files changed, 49 insertions(+), 2 deletions(-)

diff --git a/src/lightmap/gpuraytracer.cpp b/src/lightmap/gpuraytracer.cpp
index e13c802..df93ca0 100644
--- a/src/lightmap/gpuraytracer.cpp
+++ b/src/lightmap/gpuraytracer.cpp
@@ -84,6 +84,9 @@ void GPURaytracer::Raytrace(LevelMesh* level)
 	printf("Creating shaders\n");
 	CreateShaders();
 
+	printf("Creating pipeline\n");
+	CreatePipeline();
+
 	cmdbuffer->end();
 
 #if 0
@@ -325,12 +328,12 @@ void GPURaytracer::CreateVertexAndIndexBuffers()
 	size_t indexoffset = vertexoffset + vertexbuffersize;
 
 	BufferBuilder vbuilder;
-	vbuilder.setUsage(VK_BUFFER_USAGE_VERTEX_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT | VK_BUFFER_USAGE_SHADER_DEVICE_ADDRESS_BIT | VK_BUFFER_USAGE_ACCELERATION_STRUCTURE_BUILD_INPUT_READ_ONLY_BIT_KHR);
+	vbuilder.setUsage(VK_BUFFER_USAGE_VERTEX_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT | VK_BUFFER_USAGE_SHADER_DEVICE_ADDRESS_BIT | VK_BUFFER_USAGE_ACCELERATION_STRUCTURE_BUILD_INPUT_READ_ONLY_BIT_KHR | VK_BUFFER_USAGE_STORAGE_BUFFER_BIT);
 	vbuilder.setSize(vertexbuffersize);
 	vertexBuffer = vbuilder.create(device.get());
 
 	BufferBuilder ibuilder;
-	ibuilder.setUsage(VK_BUFFER_USAGE_INDEX_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT | VK_BUFFER_USAGE_SHADER_DEVICE_ADDRESS_BIT | VK_BUFFER_USAGE_ACCELERATION_STRUCTURE_BUILD_INPUT_READ_ONLY_BIT_KHR);
+	ibuilder.setUsage(VK_BUFFER_USAGE_INDEX_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT | VK_BUFFER_USAGE_SHADER_DEVICE_ADDRESS_BIT | VK_BUFFER_USAGE_ACCELERATION_STRUCTURE_BUILD_INPUT_READ_ONLY_BIT_KHR | VK_BUFFER_USAGE_STORAGE_BUFFER_BIT);
 	ibuilder.setSize(indexbuffersize);
 	indexBuffer = ibuilder.create(device.get());
 
@@ -611,3 +614,39 @@ void GPURaytracer::CreateShaders()
 		shaderClosestHit = builder.create(device.get());
 	}
 }
+
+void GPURaytracer::CreatePipeline()
+{
+	DescriptorSetLayoutBuilder setbuilder;
+	setbuilder.addBinding(0, VK_DESCRIPTOR_TYPE_ACCELERATION_STRUCTURE_KHR, 1, VK_SHADER_STAGE_RAYGEN_BIT_KHR);
+	setbuilder.addBinding(1, VK_DESCRIPTOR_TYPE_STORAGE_IMAGE, 1, VK_SHADER_STAGE_RAYGEN_BIT_KHR);
+	setbuilder.addBinding(2, VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 1, VK_SHADER_STAGE_RAYGEN_BIT_KHR);
+	descriptorSetLayout = setbuilder.create(device.get());
+
+	PipelineLayoutBuilder layoutbuilder;
+	layoutbuilder.addSetLayout(descriptorSetLayout.get());
+	pipelineLayout = layoutbuilder.create(device.get());
+
+	RayTracingPipelineBuilder builder;
+	builder.setLayout(pipelineLayout.get());
+	builder.setMaxPipelineRayRecursionDepth(1);
+	builder.addShader(VK_SHADER_STAGE_RAYGEN_BIT_KHR, shaderRayGen.get());
+	builder.addShader(VK_SHADER_STAGE_CLOSEST_HIT_BIT_KHR, shaderClosestHit.get());
+	builder.addShader(VK_SHADER_STAGE_MISS_BIT_KHR, shaderMiss.get());
+	pipeline = builder.create(device.get());
+
+	BufferBuilder bufbuilder;
+	bufbuilder.setUsage(VK_BUFFER_USAGE_SHADER_BINDING_TABLE_BIT_KHR | VK_BUFFER_USAGE_TRANSFER_DST_BIT);
+	bufbuilder.setSize(pipeline->shaderGroupHandles.size());
+	shaderBindingTable = bufbuilder.create(device.get());
+
+	BufferBuilder tbuilder;
+	tbuilder.setUsage(VK_BUFFER_USAGE_TRANSFER_SRC_BIT, VMA_MEMORY_USAGE_CPU_ONLY);
+	tbuilder.setSize(pipeline->shaderGroupHandles.size());
+	sbtTransferBuffer = tbuilder.create(device.get());
+	auto data = sbtTransferBuffer->Map(0, pipeline->shaderGroupHandles.size());
+	memcpy(data, pipeline->shaderGroupHandles.data(), pipeline->shaderGroupHandles.size());
+	sbtTransferBuffer->Unmap();
+
+	cmdbuffer->copyBuffer(sbtTransferBuffer.get(), shaderBindingTable.get());
+}
diff --git a/src/lightmap/gpuraytracer.h b/src/lightmap/gpuraytracer.h
index dad952c..a6b3f4a 100644
--- a/src/lightmap/gpuraytracer.h
+++ b/src/lightmap/gpuraytracer.h
@@ -19,6 +19,7 @@ private:
 	void CreateBottomLevelAccelerationStructure();
 	void CreateTopLevelAccelerationStructure();
 	void CreateShaders();
+	void CreatePipeline();
 
 	void RaytraceProbeSample(LightProbeSample* probe);
 	void RaytraceSurfaceSample(Surface* surface, int x, int y);
@@ -55,6 +56,13 @@ private:
 	std::unique_ptr<VulkanShader> shaderMiss;
 	std::unique_ptr<VulkanShader> shaderClosestHit;
 
+	std::unique_ptr<VulkanDescriptorSetLayout> descriptorSetLayout;
+
+	std::unique_ptr<VulkanPipelineLayout> pipelineLayout;
+	std::unique_ptr<VulkanPipeline> pipeline;
+	std::unique_ptr<VulkanBuffer> shaderBindingTable;
+	std::unique_ptr<VulkanBuffer> sbtTransferBuffer;
+
 	std::unique_ptr<VulkanCommandPool> cmdpool;
 	std::unique_ptr<VulkanCommandBuffer> cmdbuffer;
 };