/*
* Vulkan Example - Using different pipelines in a single renderpass
* 
* This sample shows how to setup multiple graphics pipelines and how to use them for drawing objects with differring visuals
*
* Copyright (C) 2016-2023 by Sascha Willems - www.saschawillems.de
*
* This code is licensed under the MIT license (MIT) (http://opensource.org/licenses/MIT)
*/

#include "vulkanexamplebase.h"
#include "VulkanglTFModel.h"

class VulkanExample: public VulkanExampleBase
{
public:
	vkglTF::Model scene;

	struct UniformData {
		glm::mat4 projection;
		glm::mat4 modelView;
		glm::vec4 lightPos{ 0.0f, 2.0f, 1.0f, 0.0f };
	} uniformData;
	vks::Buffer uniformBuffer;

	VkPipelineLayout pipelineLayout{ VK_NULL_HANDLE };
	VkDescriptorSet descriptorSet{ VK_NULL_HANDLE };
	VkDescriptorSetLayout descriptorSetLayout{ VK_NULL_HANDLE };

	struct {
		VkPipeline phong{ VK_NULL_HANDLE };
		VkPipeline wireframe{ VK_NULL_HANDLE };
		VkPipeline toon{ VK_NULL_HANDLE };
	} pipelines;

	VulkanExample() : VulkanExampleBase()
	{
		title = "Pipeline state objects";
		camera.type = Camera::CameraType::lookat;
		camera.setPosition(glm::vec3(0.0f, 0.0f, -10.5f));
		camera.setRotation(glm::vec3(-25.0f, 15.0f, 0.0f));
		camera.setRotationSpeed(0.5f);
		camera.setPerspective(60.0f, (float)(width / 3.0f) / (float)height, 0.1f, 256.0f);
	}

	~VulkanExample()
	{
		if (device) {
			vkDestroyPipeline(device, pipelines.phong, nullptr);
			if (enabledFeatures.fillModeNonSolid)
			{
				vkDestroyPipeline(device, pipelines.wireframe, nullptr);
			}
			vkDestroyPipeline(device, pipelines.toon, nullptr);

			vkDestroyPipelineLayout(device, pipelineLayout, nullptr);
			vkDestroyDescriptorSetLayout(device, descriptorSetLayout, nullptr);

			uniformBuffer.destroy();
		}
	}

	// Enable physical device features required for this example
	virtual void getEnabledFeatures()
	{
		// Fill mode non solid is required for wireframe display
		if (deviceFeatures.fillModeNonSolid) {
			enabledFeatures.fillModeNonSolid = VK_TRUE;
		};

		// Wide lines must be present for line width > 1.0f
		if (deviceFeatures.wideLines) {
			enabledFeatures.wideLines = VK_TRUE;
		}
	}

	void buildCommandBuffers()
	{
		VkCommandBufferBeginInfo cmdBufInfo = vks::initializers::commandBufferBeginInfo();

		VkClearValue clearValues[2];
		clearValues[0].color = defaultClearColor;
		clearValues[1].depthStencil = { 1.0f, 0 };

		VkRenderPassBeginInfo renderPassBeginInfo = vks::initializers::renderPassBeginInfo();
		renderPassBeginInfo.renderPass = renderPass;
		renderPassBeginInfo.renderArea.offset.x = 0;
		renderPassBeginInfo.renderArea.offset.y = 0;
		renderPassBeginInfo.renderArea.extent.width = width;
		renderPassBeginInfo.renderArea.extent.height = height;
		renderPassBeginInfo.clearValueCount = 2;
		renderPassBeginInfo.pClearValues = clearValues;

		for (int32_t i = 0; i < drawCmdBuffers.size(); ++i)
		{
			renderPassBeginInfo.framebuffer = frameBuffers[i];

			VK_CHECK_RESULT(vkBeginCommandBuffer(drawCmdBuffers[i], &cmdBufInfo));

			vkCmdBeginRenderPass(drawCmdBuffers[i], &renderPassBeginInfo, VK_SUBPASS_CONTENTS_INLINE);

			VkViewport viewport = vks::initializers::viewport((float)width, (float)height, 0.0f, 1.0f);
			vkCmdSetViewport(drawCmdBuffers[i], 0, 1, &viewport);

			VkRect2D scissor = vks::initializers::rect2D(width, height,	0, 0);
			vkCmdSetScissor(drawCmdBuffers[i], 0, 1, &scissor);

			vkCmdBindDescriptorSets(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, pipelineLayout, 0, 1, &descriptorSet, 0, NULL);
			scene.bindBuffers(drawCmdBuffers[i]);

			// Left : Render the scene using the solid colored pipeline with phong shading
			viewport.width = (float)width / 3.0f;
			vkCmdSetViewport(drawCmdBuffers[i], 0, 1, &viewport);
			vkCmdBindPipeline(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, pipelines.phong);
			vkCmdSetLineWidth(drawCmdBuffers[i], 1.0f);
			scene.draw(drawCmdBuffers[i]);

			// Center : Render the scene using a toon style pipeline
			viewport.x = (float)width / 3.0f;
			vkCmdSetViewport(drawCmdBuffers[i], 0, 1, &viewport);
			vkCmdBindPipeline(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, pipelines.toon);
			// Line width > 1.0f only if wide lines feature is supported
			if (enabledFeatures.wideLines) {
				vkCmdSetLineWidth(drawCmdBuffers[i], 2.0f);
			}
			scene.draw(drawCmdBuffers[i]);

			// Right : Render the scene as wireframe (if that feature is supported by the implementation)
			if (enabledFeatures.fillModeNonSolid) {
				viewport.x = (float)width / 3.0f + (float)width / 3.0f;
				vkCmdSetViewport(drawCmdBuffers[i], 0, 1, &viewport);
				vkCmdBindPipeline(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, pipelines.wireframe);
				scene.draw(drawCmdBuffers[i]);
			}

			drawUI(drawCmdBuffers[i]);

			vkCmdEndRenderPass(drawCmdBuffers[i]);

			VK_CHECK_RESULT(vkEndCommandBuffer(drawCmdBuffers[i]));
		}
	}

	void loadAssets()
	{
		const uint32_t glTFLoadingFlags = vkglTF::FileLoadingFlags::PreTransformVertices | vkglTF::FileLoadingFlags::PreMultiplyVertexColors | vkglTF::FileLoadingFlags::FlipY;
		scene.loadFromFile(getAssetPath() + "models/treasure_smooth.gltf", vulkanDevice, queue, glTFLoadingFlags);
	}

	void setupDescriptors()
	{
		// Pool
		std::vector<VkDescriptorPoolSize> poolSizes = {
			vks::initializers::descriptorPoolSize(VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 1)
		};
		VkDescriptorPoolCreateInfo descriptorPoolInfo = vks::initializers::descriptorPoolCreateInfo(poolSizes, 2);
		VK_CHECK_RESULT(vkCreateDescriptorPool(device, &descriptorPoolInfo, nullptr, &descriptorPool));

		// Layout
		std::vector<VkDescriptorSetLayoutBinding> setLayoutBindings = {
			// Binding 0 : Vertex shader uniform buffer
			vks::initializers::descriptorSetLayoutBinding(VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, VK_SHADER_STAGE_VERTEX_BIT, 0)
		};
		VkDescriptorSetLayoutCreateInfo descriptorLayout = vks::initializers::descriptorSetLayoutCreateInfo(setLayoutBindings);
		VK_CHECK_RESULT(vkCreateDescriptorSetLayout(device, &descriptorLayout, nullptr, &descriptorSetLayout));

		// Set
		VkDescriptorSetAllocateInfo allocInfo = vks::initializers::descriptorSetAllocateInfo(descriptorPool, &descriptorSetLayout, 1);
		VK_CHECK_RESULT(vkAllocateDescriptorSets(device, &allocInfo, &descriptorSet));

		std::vector<VkWriteDescriptorSet> writeDescriptorSets = {
			// Binding 0 : Vertex shader uniform buffer
			vks::initializers::writeDescriptorSet(descriptorSet, VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 0, &uniformBuffer.descriptor)
		};
		vkUpdateDescriptorSets(device, static_cast<uint32_t>(writeDescriptorSets.size()), writeDescriptorSets.data(), 0, nullptr);
	}

	void preparePipelines()
	{
		// Layout
		VkPipelineLayoutCreateInfo pipelineLayoutCreateInfo = vks::initializers::pipelineLayoutCreateInfo(&descriptorSetLayout, 1);
		VK_CHECK_RESULT(vkCreatePipelineLayout(device, &pipelineLayoutCreateInfo, nullptr, &pipelineLayout));

		// Pipelines
		
		// Most state is shared between all pipelines
		VkPipelineInputAssemblyStateCreateInfo inputAssemblyState = vks::initializers::pipelineInputAssemblyStateCreateInfo(VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST, 0, VK_FALSE);
		VkPipelineRasterizationStateCreateInfo rasterizationState = vks::initializers::pipelineRasterizationStateCreateInfo(VK_POLYGON_MODE_FILL, VK_CULL_MODE_BACK_BIT, VK_FRONT_FACE_COUNTER_CLOCKWISE, 0);
		VkPipelineColorBlendAttachmentState blendAttachmentState = vks::initializers::pipelineColorBlendAttachmentState(0xf, VK_FALSE);
		VkPipelineColorBlendStateCreateInfo colorBlendState = vks::initializers::pipelineColorBlendStateCreateInfo(1, &blendAttachmentState);
		VkPipelineDepthStencilStateCreateInfo depthStencilState = vks::initializers::pipelineDepthStencilStateCreateInfo(VK_TRUE, VK_TRUE, VK_COMPARE_OP_LESS_OR_EQUAL);
		VkPipelineViewportStateCreateInfo viewportState = vks::initializers::pipelineViewportStateCreateInfo(1, 1, 0);
		VkPipelineMultisampleStateCreateInfo multisampleState = vks::initializers::pipelineMultisampleStateCreateInfo(VK_SAMPLE_COUNT_1_BIT);
		std::vector<VkDynamicState> dynamicStateEnables = { VK_DYNAMIC_STATE_VIEWPORT, VK_DYNAMIC_STATE_SCISSOR, VK_DYNAMIC_STATE_LINE_WIDTH, };
		VkPipelineDynamicStateCreateInfo dynamicState = vks::initializers::pipelineDynamicStateCreateInfo(dynamicStateEnables);
		std::array<VkPipelineShaderStageCreateInfo, 2> shaderStages;

		VkGraphicsPipelineCreateInfo pipelineCI = vks::initializers::pipelineCreateInfo(pipelineLayout, renderPass);
		pipelineCI.pInputAssemblyState = &inputAssemblyState;
		pipelineCI.pRasterizationState = &rasterizationState;
		pipelineCI.pColorBlendState = &colorBlendState;
		pipelineCI.pMultisampleState = &multisampleState;
		pipelineCI.pViewportState = &viewportState;
		pipelineCI.pDepthStencilState = &depthStencilState;
		pipelineCI.pDynamicState = &dynamicState;
		pipelineCI.stageCount = static_cast<uint32_t>(shaderStages.size());
		pipelineCI.pStages = shaderStages.data();
		pipelineCI.pVertexInputState  = vkglTF::Vertex::getPipelineVertexInputState({vkglTF::VertexComponent::Position, vkglTF::VertexComponent::Normal, vkglTF::VertexComponent::Color});

		// Create the different pipelines used in this sample

		// We are using this pipeline as the base for the other pipelines (derivatives)
		// Pipeline derivatives can be used for pipelines that share most of their state
		// Depending on the implementation this may result in better performance for pipeline
		// switching and faster creation time
		pipelineCI.flags = VK_PIPELINE_CREATE_ALLOW_DERIVATIVES_BIT;

		// Textured pipeline
		// Phong shading pipeline
		shaderStages[0] = loadShader(getShadersPath() + "pipelines/phong.vert.spv", VK_SHADER_STAGE_VERTEX_BIT);
		shaderStages[1] = loadShader(getShadersPath() + "pipelines/phong.frag.spv", VK_SHADER_STAGE_FRAGMENT_BIT);
		VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCI, nullptr, &pipelines.phong));

		// All pipelines created after the base pipeline will be derivatives
		pipelineCI.flags = VK_PIPELINE_CREATE_DERIVATIVE_BIT;
		// Base pipeline will be our first created pipeline
		pipelineCI.basePipelineHandle = pipelines.phong;
		// It's only allowed to either use a handle or index for the base pipeline
		// As we use the handle, we must set the index to -1 (see section 9.5 of the specification)
		pipelineCI.basePipelineIndex = -1;

		// Toon shading pipeline
		shaderStages[0] = loadShader(getShadersPath() + "pipelines/toon.vert.spv", VK_SHADER_STAGE_VERTEX_BIT);
		shaderStages[1] = loadShader(getShadersPath() + "pipelines/toon.frag.spv", VK_SHADER_STAGE_FRAGMENT_BIT);
		VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCI, nullptr, &pipelines.toon));

		// Pipeline for wire frame rendering
		// Non solid rendering is not a mandatory Vulkan feature
		if (enabledFeatures.fillModeNonSolid) {
			rasterizationState.polygonMode = VK_POLYGON_MODE_LINE;
			shaderStages[0] = loadShader(getShadersPath() + "pipelines/wireframe.vert.spv", VK_SHADER_STAGE_VERTEX_BIT);
			shaderStages[1] = loadShader(getShadersPath() + "pipelines/wireframe.frag.spv", VK_SHADER_STAGE_FRAGMENT_BIT);
			VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCI, nullptr, &pipelines.wireframe));
		}
	}

	// Prepare and initialize uniform buffer containing shader uniforms
	void prepareUniformBuffers()
	{
		// Create the vertex shader uniform buffer block
		VK_CHECK_RESULT(vulkanDevice->createBuffer(VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT, &uniformBuffer, sizeof(UniformData)));
		// Map persistent
		VK_CHECK_RESULT(uniformBuffer.map());
	}

	void updateUniformBuffers()
	{
		// Override the base sample camera setup, since we use three viewports
		camera.setPerspective(60.0f, (float)(width / 3.0f) / (float)height, 0.1f, 256.0f);
		uniformData.projection = camera.matrices.perspective;
		uniformData.modelView = camera.matrices.view;
		memcpy(uniformBuffer.mapped, &uniformData, sizeof(UniformData));
	}

	void prepare()
	{
		VulkanExampleBase::prepare();
		loadAssets();
		prepareUniformBuffers();
		setupDescriptors();
		preparePipelines();
		buildCommandBuffers();
		prepared = true;
	}

	void draw()
	{
		VulkanExampleBase::prepareFrame();
		submitInfo.commandBufferCount = 1;
		submitInfo.pCommandBuffers = &drawCmdBuffers[currentBuffer];
		VK_CHECK_RESULT(vkQueueSubmit(queue, 1, &submitInfo, VK_NULL_HANDLE));
		VulkanExampleBase::submitFrame();
	}

	virtual void render()
	{
		if (!prepared)
			return;
		updateUniformBuffers();
		draw();
	}

	virtual void OnUpdateUIOverlay(vks::UIOverlay *overlay)
	{
		if (!enabledFeatures.fillModeNonSolid) {
			if (overlay->header("Info")) {
				overlay->text("Non solid fill modes not supported!");
			}
		}
	}
};

VULKAN_EXAMPLE_MAIN()