/*
* Vulkan Example - Host image copy using VK_EXT_host_image_copy
* 
* This sample shows how to use host image copies to directly upload an image to the devic without having to use staging
* 
* Work-in-progress
*
* Copyright (C) 2024 by Sascha Willems - www.saschawillems.de
*
* This code is licensed under the MIT license (MIT) (http://opensource.org/licenses/MIT)
*/

#include "vulkanexamplebase.h"
#include <ktx.h>
#include <ktxvulkan.h>

class VulkanExample : public VulkanExampleBase
{
public:
	// Pointers for functions added by the host image copy extension;
	PFN_vkCopyMemoryToImageEXT vkCopyMemoryToImageEXT{ nullptr };
	PFN_vkTransitionImageLayoutEXT vkTransitionImageLayoutEXT{ nullptr };

	VkPhysicalDeviceHostImageCopyFeaturesEXT enabledPhysicalDeviceHostImageCopyFeaturesEXT{};

	// Vertex layout for this example
	struct Vertex {
		float pos[3];
		float uv[2];
		float normal[3];
	};

	// Contains all Vulkan objects that are required to store and use a texture
	// Note that this repository contains a texture class (VulkanTexture.hpp) that encapsulates texture loading functionality in a class that is used in subsequent demos
	struct Texture {
		VkSampler sampler{ VK_NULL_HANDLE };
		VkImage image{ VK_NULL_HANDLE };
		VkDeviceMemory deviceMemory{ VK_NULL_HANDLE };
		VkImageView view{ VK_NULL_HANDLE };
		uint32_t width{ 0 };
		uint32_t height{ 0 };
		uint32_t mipLevels{ 0 };
	} texture;

	vks::Buffer vertexBuffer;
	vks::Buffer indexBuffer;
	uint32_t indexCount{ 0 };

	struct UniformData {
		glm::mat4 projection;
		glm::mat4 modelView;
		glm::vec4 viewPos;
		// This is used to change the bias for the level-of-detail (mips) in the fragment shader
		float lodBias = 0.0f;
	} uniformData;
	vks::Buffer uniformBuffer;

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

	VulkanExample() : VulkanExampleBase()
	{
		title = "Host image copy";
		camera.type = Camera::CameraType::lookat;
		camera.setPosition(glm::vec3(0.0f, 0.0f, -2.5f));
		camera.setRotation(glm::vec3(0.0f, 15.0f, 0.0f));
		camera.setPerspective(60.0f, (float)width / (float)height, 0.1f, 256.0f);

		// Enable required extensions
		enabledInstanceExtensions.push_back(VK_KHR_GET_PHYSICAL_DEVICE_PROPERTIES_2_EXTENSION_NAME);
		enabledDeviceExtensions.push_back(VK_KHR_FORMAT_FEATURE_FLAGS_2_EXTENSION_NAME);
		enabledDeviceExtensions.push_back(VK_KHR_COPY_COMMANDS_2_EXTENSION_NAME);
		enabledDeviceExtensions.push_back(VK_EXT_HOST_IMAGE_COPY_EXTENSION_NAME);

		// Enable host image copy feature
		enabledPhysicalDeviceHostImageCopyFeaturesEXT.sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_HOST_IMAGE_COPY_FEATURES_EXT;
		enabledPhysicalDeviceHostImageCopyFeaturesEXT.hostImageCopy = VK_TRUE;
		deviceCreatepNextChain = &enabledPhysicalDeviceHostImageCopyFeaturesEXT;
	}

	~VulkanExample()
	{
		if (device) {
			destroyTextureImage(texture);
			vkDestroyPipeline(device, pipeline, nullptr);
			vkDestroyPipelineLayout(device, pipelineLayout, nullptr);
			vkDestroyDescriptorSetLayout(device, descriptorSetLayout, nullptr);
			vertexBuffer.destroy();
			indexBuffer.destroy();
			uniformBuffer.destroy();
		}
	}

	// Enable physical device features required for this example
	virtual void getEnabledFeatures()
	{
		// Enable anisotropic filtering if supported
		if (deviceFeatures.samplerAnisotropy) {
			enabledFeatures.samplerAnisotropy = VK_TRUE;
		};
	}

	/*
		Upload texture image data to the GPU

		Vulkan offers two types of image tiling (memory layout):

		Linear tiled images:
			These are stored as is and can be copied directly to. But due to the linear nature they're not a good match for GPUs and format and feature support is very limited.
			It's not advised to use linear tiled images for anything else than copying from host to GPU if buffer copies are not an option.
			Linear tiling is thus only implemented for learning purposes, one should always prefer optimal tiled image.

		Optimal tiled images:
			These are stored in an implementation specific layout matching the capability of the hardware. They usually support more formats and features and are much faster.
			Optimal tiled images are stored on the device and not accessible by the host. So they can't be written directly to (like liner tiled images) and always require
			some sort of data copy, either from a buffer or	a linear tiled image.

		In Short: Always use optimal tiled images for rendering.
	*/
	void loadTexture()
	{
		// We use the Khronos texture format (https://www.khronos.org/opengles/sdk/tools/KTX/file_format_spec/)
		std::string filename = getAssetPath() + "textures/metalplate01_rgba.ktx";
		// Texture data contains 4 channels (RGBA) with unnormalized 8-bit values, this is the most commonly supported format
		VkFormat format = VK_FORMAT_R8G8B8A8_UNORM;

		ktxResult result;
		ktxTexture* ktxTexture;

#if defined(__ANDROID__)
		// Textures are stored inside the apk on Android (compressed)
		// So they need to be loaded via the asset manager
		AAsset* asset = AAssetManager_open(androidApp->activity->assetManager, filename.c_str(), AASSET_MODE_STREAMING);
		if (!asset) {
			vks::tools::exitFatal("Could not load texture from " + filename + "\n\nMake sure the assets submodule has been checked out and is up-to-date.", -1);
		}
		size_t size = AAsset_getLength(asset);
		assert(size > 0);

		ktx_uint8_t *textureData = new ktx_uint8_t[size];
		AAsset_read(asset, textureData, size);
		AAsset_close(asset);
		result = ktxTexture_CreateFromMemory(textureData, size, KTX_TEXTURE_CREATE_LOAD_IMAGE_DATA_BIT, &ktxTexture);
		delete[] textureData;
#else
		if (!vks::tools::fileExists(filename)) {
			vks::tools::exitFatal("Could not load texture from " + filename + "\n\nMake sure the assets submodule has been checked out and is up-to-date.", -1);
		}
		result = ktxTexture_CreateFromNamedFile(filename.c_str(), KTX_TEXTURE_CREATE_LOAD_IMAGE_DATA_BIT, &ktxTexture);
#endif
		assert(result == KTX_SUCCESS);

		// Get properties required for using and upload texture data from the ktx texture object
		texture.width = ktxTexture->baseWidth;
		texture.height = ktxTexture->baseHeight;
		texture.mipLevels = ktxTexture->numLevels;
		ktx_uint8_t *ktxTextureData = ktxTexture_GetData(ktxTexture);
		ktx_size_t ktxTextureSize = ktxTexture_GetSize(ktxTexture);

		// Copy data to an optimal tiled image using a direct 

		// Create optimal tiled target image on the device
		VkImageCreateInfo imageCreateInfo = vks::initializers::imageCreateInfo();
		imageCreateInfo.imageType = VK_IMAGE_TYPE_2D;
		imageCreateInfo.format = format;
		imageCreateInfo.mipLevels = texture.mipLevels;
		imageCreateInfo.arrayLayers = 1;
		imageCreateInfo.samples = VK_SAMPLE_COUNT_1_BIT;
		imageCreateInfo.tiling = VK_IMAGE_TILING_OPTIMAL;
		imageCreateInfo.sharingMode = VK_SHARING_MODE_EXCLUSIVE;
		// Set initial layout of the image to undefined
		imageCreateInfo.initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
		imageCreateInfo.extent = { texture.width, texture.height, 1 };
		// @todo: commtn
		imageCreateInfo.usage = VK_IMAGE_USAGE_SAMPLED_BIT | VK_IMAGE_USAGE_HOST_TRANSFER_BIT_EXT;
		VK_CHECK_RESULT(vkCreateImage(device, &imageCreateInfo, nullptr, &texture.image));

		VkMemoryAllocateInfo memAllocInfo = vks::initializers::memoryAllocateInfo();
		VkMemoryRequirements memReqs = {};
		vkGetImageMemoryRequirements(device, texture.image, &memReqs);
		memAllocInfo.allocationSize = memReqs.size;
		memAllocInfo.memoryTypeIndex = vulkanDevice->getMemoryType(memReqs.memoryTypeBits, VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT);
		VK_CHECK_RESULT(vkAllocateMemory(device, &memAllocInfo, nullptr, &texture.deviceMemory));
		VK_CHECK_RESULT(vkBindImageMemory(device, texture.image, texture.deviceMemory, 0));

		// @todo: comment
		std::vector<VkMemoryToImageCopyEXT> memoryToImageCopies{};
		for (uint32_t i = 0; i < texture.mipLevels; i++) {
			ktx_size_t offset;
			KTX_error_code ret = ktxTexture_GetImageOffset(ktxTexture, i, 0, 0, &offset);
			assert(ret == KTX_SUCCESS);
			// Setup a buffer image copy structure for the current mip level
			VkMemoryToImageCopyEXT memoryToImageCopy = {};
			memoryToImageCopy.sType = VK_STRUCTURE_TYPE_MEMORY_TO_IMAGE_COPY_EXT;
			memoryToImageCopy.imageSubresource.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
			memoryToImageCopy.imageSubresource.mipLevel = i;
			memoryToImageCopy.imageSubresource.baseArrayLayer = 0;
			memoryToImageCopy.imageSubresource.layerCount = 1;
			memoryToImageCopy.imageExtent.width = ktxTexture->baseWidth >> i;
			memoryToImageCopy.imageExtent.height = ktxTexture->baseHeight >> i;
			memoryToImageCopy.imageExtent.depth = 1;
			memoryToImageCopy.pHostPointer = ktxTextureData + offset;

			memoryToImageCopies.push_back(memoryToImageCopy);
		}

		VkImageSubresourceRange subresourceRange{};
		subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
		subresourceRange.baseMipLevel = 0;
		subresourceRange.levelCount = texture.mipLevels;
		subresourceRange.layerCount = 1;

		VkHostImageLayoutTransitionInfoEXT hostImageLayoutTransitionInfo{};
		hostImageLayoutTransitionInfo.sType = VK_STRUCTURE_TYPE_HOST_IMAGE_LAYOUT_TRANSITION_INFO_EXT;
		hostImageLayoutTransitionInfo.image = texture.image;
		hostImageLayoutTransitionInfo.oldLayout = VK_IMAGE_LAYOUT_UNDEFINED;
		hostImageLayoutTransitionInfo.newLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
		hostImageLayoutTransitionInfo.subresourceRange = subresourceRange;

		vkTransitionImageLayoutEXT(device, 1, &hostImageLayoutTransitionInfo);

		VkCopyMemoryToImageInfoEXT copyMemoryInfo{};
		copyMemoryInfo.sType = VK_STRUCTURE_TYPE_COPY_MEMORY_TO_IMAGE_INFO_EXT;
		copyMemoryInfo.dstImage = texture.image;
		copyMemoryInfo.dstImageLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
		copyMemoryInfo.regionCount = static_cast<uint32_t>(memoryToImageCopies.size());
		copyMemoryInfo.pRegions = memoryToImageCopies.data();

		vkCopyMemoryToImageEXT(device, &copyMemoryInfo);

		ktxTexture_Destroy(ktxTexture);

		// Create a texture sampler
		VkSamplerCreateInfo sampler = vks::initializers::samplerCreateInfo();
		sampler.magFilter = VK_FILTER_LINEAR;
		sampler.minFilter = VK_FILTER_LINEAR;
		sampler.mipmapMode = VK_SAMPLER_MIPMAP_MODE_LINEAR;
		sampler.addressModeU = VK_SAMPLER_ADDRESS_MODE_REPEAT;
		sampler.addressModeV = VK_SAMPLER_ADDRESS_MODE_REPEAT;
		sampler.addressModeW = VK_SAMPLER_ADDRESS_MODE_REPEAT;
		sampler.mipLodBias = 0.0f;
		sampler.compareOp = VK_COMPARE_OP_NEVER;
		sampler.minLod = 0.0f;
		sampler.maxLod = (float)texture.mipLevels;
		if (vulkanDevice->features.samplerAnisotropy) {
			sampler.maxAnisotropy = vulkanDevice->properties.limits.maxSamplerAnisotropy;
			sampler.anisotropyEnable = VK_TRUE;
		} else {
			sampler.maxAnisotropy = 1.0;
			sampler.anisotropyEnable = VK_FALSE;
		}
		sampler.borderColor = VK_BORDER_COLOR_FLOAT_OPAQUE_WHITE;
		VK_CHECK_RESULT(vkCreateSampler(device, &sampler, nullptr, &texture.sampler));

		// Create image view
		VkImageViewCreateInfo view = vks::initializers::imageViewCreateInfo();
		view.viewType = VK_IMAGE_VIEW_TYPE_2D;
		view.format = format;
		view.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
		view.subresourceRange.baseMipLevel = 0;
		view.subresourceRange.baseArrayLayer = 0;
		view.subresourceRange.layerCount = 1;
		view.subresourceRange.levelCount = texture.mipLevels;
		view.image = texture.image;
		VK_CHECK_RESULT(vkCreateImageView(device, &view, nullptr, &texture.view));
	}

	// Free all Vulkan resources used by a texture object
	void destroyTextureImage(Texture texture)
	{
		vkDestroyImageView(device, texture.view, nullptr);
		vkDestroyImage(device, texture.image, nullptr);
		vkDestroySampler(device, texture.sampler, nullptr);
		vkFreeMemory(device, texture.deviceMemory, nullptr);
	}

	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)
		{
			// Set target frame buffer
			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, nullptr);
			vkCmdBindPipeline(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, pipeline);

			VkDeviceSize offsets[1] = { 0 };
			vkCmdBindVertexBuffers(drawCmdBuffers[i], 0, 1, &vertexBuffer.buffer, offsets);
			vkCmdBindIndexBuffer(drawCmdBuffers[i], indexBuffer.buffer, 0, VK_INDEX_TYPE_UINT32);

			vkCmdDrawIndexed(drawCmdBuffers[i], indexCount, 1, 0, 0, 0);

			drawUI(drawCmdBuffers[i]);

			vkCmdEndRenderPass(drawCmdBuffers[i]);

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

	// Creates a vertex and index buffer for a quad made of two triangles
	// This is used to display the texture on
	void generateQuad()
	{
		// Setup vertices for a single uv-mapped quad made from two triangles
		std::vector<Vertex> vertices =
		{
			{ {  1.0f,  1.0f, 0.0f }, { 1.0f, 1.0f },{ 0.0f, 0.0f, 1.0f } },
			{ { -1.0f,  1.0f, 0.0f }, { 0.0f, 1.0f },{ 0.0f, 0.0f, 1.0f } },
			{ { -1.0f, -1.0f, 0.0f }, { 0.0f, 0.0f },{ 0.0f, 0.0f, 1.0f } },
			{ {  1.0f, -1.0f, 0.0f }, { 1.0f, 0.0f },{ 0.0f, 0.0f, 1.0f } }
		};

		// Setup indices
		std::vector<uint32_t> indices = { 0,1,2, 2,3,0 };
		indexCount = static_cast<uint32_t>(indices.size());

		// Create buffers and upload data to the GPU
		struct StagingBuffers {
			vks::Buffer vertices;
			vks::Buffer indices;
		} stagingBuffers;

		// Host visible source buffers (staging)
		VK_CHECK_RESULT(vulkanDevice->createBuffer(VK_BUFFER_USAGE_TRANSFER_SRC_BIT, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT, &stagingBuffers.vertices, vertices.size() * sizeof(Vertex), vertices.data()));
		VK_CHECK_RESULT(vulkanDevice->createBuffer(VK_BUFFER_USAGE_TRANSFER_SRC_BIT, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT, &stagingBuffers.indices, indices.size() * sizeof(uint32_t), indices.data()));

		// Device local destination buffers
		VK_CHECK_RESULT(vulkanDevice->createBuffer(VK_BUFFER_USAGE_VERTEX_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT, VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT, &vertexBuffer, vertices.size() * sizeof(Vertex)));
		VK_CHECK_RESULT(vulkanDevice->createBuffer(VK_BUFFER_USAGE_INDEX_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT, VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT, &indexBuffer, indices.size() * sizeof(uint32_t)));

		// Copy from host do device
		vulkanDevice->copyBuffer(&stagingBuffers.vertices, &vertexBuffer, queue);
		vulkanDevice->copyBuffer(&stagingBuffers.indices, &indexBuffer, queue);

		// Clean up
		stagingBuffers.vertices.destroy();
		stagingBuffers.indices.destroy();
	}

	void setupDescriptors()
	{
		// Pool
		std::vector<VkDescriptorPoolSize> poolSizes = {
			vks::initializers::descriptorPoolSize(VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 1),
			// The sample uses a combined image + sampler descriptor to sample the texture in the fragment shader
			vks::initializers::descriptorPoolSize(VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 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),
			// Binding 1 : Fragment shader image sampler
			vks::initializers::descriptorSetLayoutBinding(VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, VK_SHADER_STAGE_FRAGMENT_BIT, 1)
		};
		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));

		// Setup a descriptor image info for the current texture to be used as a combined image sampler
		VkDescriptorImageInfo textureDescriptor;
		textureDescriptor.imageView = texture.view;
		textureDescriptor.sampler = texture.sampler;
		textureDescriptor.imageLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;

		std::vector<VkWriteDescriptorSet> writeDescriptorSets = {
			// Binding 0 : Vertex shader uniform buffer
			vks::initializers::writeDescriptorSet(descriptorSet, VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 0, &uniformBuffer.descriptor),
			// Binding 1 : Fragment shader texture sampler
			//	Fragment shader: layout (binding = 1) uniform sampler2D samplerColor;
			vks::initializers::writeDescriptorSet(descriptorSet,
				VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER,		// The descriptor set will use a combined image sampler (as opposed to splitting image and sampler)
				1,												// Shader binding point 1
				&textureDescriptor)								// Pointer to the descriptor image for our texture
		};
		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));

		// Pipeline
		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_NONE, 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, 0);
		std::vector<VkDynamicState> dynamicStateEnables = { VK_DYNAMIC_STATE_VIEWPORT, VK_DYNAMIC_STATE_SCISSOR };
		VkPipelineDynamicStateCreateInfo dynamicState = vks::initializers::pipelineDynamicStateCreateInfo(dynamicStateEnables);
		std::array<VkPipelineShaderStageCreateInfo,2> shaderStages;

		// Shaders
		shaderStages[0] = loadShader(getShadersPath() + "texture/texture.vert.spv", VK_SHADER_STAGE_VERTEX_BIT);
		shaderStages[1] = loadShader(getShadersPath() + "texture/texture.frag.spv", VK_SHADER_STAGE_FRAGMENT_BIT);

		// Vertex input state
		std::vector<VkVertexInputBindingDescription> vertexInputBindings = {
			vks::initializers::vertexInputBindingDescription(0, sizeof(Vertex), VK_VERTEX_INPUT_RATE_VERTEX)
		};
		std::vector<VkVertexInputAttributeDescription> vertexInputAttributes = {
			vks::initializers::vertexInputAttributeDescription(0, 0, VK_FORMAT_R32G32B32_SFLOAT, offsetof(Vertex, pos)),
			vks::initializers::vertexInputAttributeDescription(0, 1, VK_FORMAT_R32G32_SFLOAT, offsetof(Vertex, uv)),
			vks::initializers::vertexInputAttributeDescription(0, 2, VK_FORMAT_R32G32B32_SFLOAT, offsetof(Vertex, normal)),
		};
		VkPipelineVertexInputStateCreateInfo vertexInputState = vks::initializers::pipelineVertexInputStateCreateInfo();
		vertexInputState.vertexBindingDescriptionCount = static_cast<uint32_t>(vertexInputBindings.size());
		vertexInputState.pVertexBindingDescriptions = vertexInputBindings.data();
		vertexInputState.vertexAttributeDescriptionCount = static_cast<uint32_t>(vertexInputAttributes.size());
		vertexInputState.pVertexAttributeDescriptions = vertexInputAttributes.data();

		VkGraphicsPipelineCreateInfo pipelineCreateInfo = vks::initializers::pipelineCreateInfo(pipelineLayout, renderPass, 0);
		pipelineCreateInfo.pVertexInputState = &vertexInputState;
		pipelineCreateInfo.pInputAssemblyState = &inputAssemblyState;
		pipelineCreateInfo.pRasterizationState = &rasterizationState;
		pipelineCreateInfo.pColorBlendState = &colorBlendState;
		pipelineCreateInfo.pMultisampleState = &multisampleState;
		pipelineCreateInfo.pViewportState = &viewportState;
		pipelineCreateInfo.pDepthStencilState = &depthStencilState;
		pipelineCreateInfo.pDynamicState = &dynamicState;
		pipelineCreateInfo.stageCount = static_cast<uint32_t>(shaderStages.size());
		pipelineCreateInfo.pStages = shaderStages.data();
		VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCreateInfo, nullptr, &pipeline));
	}

	// Prepare and initialize uniform buffer containing shader uniforms
	void prepareUniformBuffers()
	{
		// 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), &uniformData));
		VK_CHECK_RESULT(uniformBuffer.map());
	}

	void updateUniformBuffers()
	{
		uniformData.projection = camera.matrices.perspective;
		uniformData.modelView = camera.matrices.view;
		uniformData.viewPos = camera.viewPos;
		memcpy(uniformBuffer.mapped, &uniformData, sizeof(uniformData));
	}

	void prepare()
	{
		VulkanExampleBase::prepare();

		// Get the function pointers required host image copies
		vkCopyMemoryToImageEXT = reinterpret_cast<PFN_vkCopyMemoryToImageEXT>(vkGetDeviceProcAddr(device, "vkCopyMemoryToImageEXT"));
		vkTransitionImageLayoutEXT = reinterpret_cast<PFN_vkTransitionImageLayoutEXT>(vkGetDeviceProcAddr(device, "vkTransitionImageLayoutEXT"));

		loadTexture();
		generateQuad();
		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 (overlay->header("Settings")) {
			if (overlay->sliderFloat("LOD bias", &uniformData.lodBias, 0.0f, (float)texture.mipLevels)) {
				updateUniformBuffers();
			}
		}
	}
};

VULKAN_EXAMPLE_MAIN()