/*
* Vulkan Example - 3D texture loading (and generation using perlin noise) example
*
* Copyright (C) 2016 by Sascha Willems - www.saschawillems.de
*
* This code is licensed under the MIT license (MIT) (http://opensource.org/licenses/MIT)
*/

#include "vulkanexamplebase.h"

#define VERTEX_BUFFER_BIND_ID 0
#define ENABLE_VALIDATION false

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

// Translation of Ken Perlin's JAVA implementation (http://mrl.nyu.edu/~perlin/noise/)
template <typename T>
class PerlinNoise
{
private:
	uint32_t permutations[512];
	T fade(T t)
	{
		return t * t * t * (t * (t * (T)6 - (T)15) + (T)10);
	}
	T lerp(T t, T a, T b)
	{
		return a + t * (b - a);
	}
	T grad(int hash, T x, T y, T z)
	{
		// Convert LO 4 bits of hash code into 12 gradient directions
		int h = hash & 15;
		T u = h < 8 ? x : y;
		T v = h < 4 ? y : h == 12 || h == 14 ? x : z;
		return ((h & 1) == 0 ? u : -u) + ((h & 2) == 0 ? v : -v);
	}
public:
	PerlinNoise()
	{
		// Generate random lookup for permutations containing all numbers from 0..255
		std::vector<uint8_t> plookup;
		plookup.resize(256);
		std::iota(plookup.begin(), plookup.end(), 0);
		std::default_random_engine rndEngine(std::random_device{}());
		std::shuffle(plookup.begin(), plookup.end(), rndEngine);

		for (uint32_t i = 0; i < 256; i++)
		{
			permutations[i] = permutations[256 + i] = plookup[i];
		}
	}
	T noise(T x, T y, T z)
	{
		// Find unit cube that contains point
		int32_t X = (int32_t)floor(x) & 255;
		int32_t Y = (int32_t)floor(y) & 255;
		int32_t Z = (int32_t)floor(z) & 255;
		// Find relative x,y,z of point in cube
		x -= floor(x);
		y -= floor(y);
		z -= floor(z);

		// Compute fade curves for each of x,y,z
		T u = fade(x);
		T v = fade(y);
		T w = fade(z);

		// Hash coordinates of the 8 cube corners
		uint32_t A = permutations[X] + Y;
		uint32_t AA = permutations[A] + Z;
		uint32_t AB = permutations[A + 1] + Z;
		uint32_t B = permutations[X + 1] + Y;
		uint32_t BA = permutations[B] + Z;
		uint32_t BB = permutations[B + 1] + Z;

		// And add blended results for 8 corners of the cube;
		T res = lerp(w, lerp(v,
			lerp(u, grad(permutations[AA], x, y, z), grad(permutations[BA], x - 1, y, z)), lerp(u, grad(permutations[AB], x, y - 1, z), grad(permutations[BB], x - 1, y - 1, z))),
			lerp(v, lerp(u, grad(permutations[AA + 1], x, y, z - 1), grad(permutations[BA + 1], x - 1, y, z - 1)), lerp(u, grad(permutations[AB + 1], x, y - 1, z - 1), grad(permutations[BB + 1], x - 1, y - 1, z - 1))));
		return res;
	}
};

// Fractal noise generator based on perlin noise above
template <typename T>
class FractalNoise
{
private:
	PerlinNoise<float> perlinNoise;
	uint32_t octaves;
	T frequency;
	T amplitude;
	T persistence;
public:

	FractalNoise(const PerlinNoise<T> &perlinNoise)
	{
		this->perlinNoise = perlinNoise;
		octaves = 6;
		persistence = (T)0.5;
	}

	T noise(T x, T y, T z)
	{
		T sum = 0;
		T frequency = (T)1;
		T amplitude = (T)1;
		T max = (T)0;
		for (uint32_t i = 0; i < octaves; i++)
		{
			sum += perlinNoise.noise(x * frequency, y * frequency, z * frequency) * amplitude;
			max += amplitude;
			amplitude *= persistence;
			frequency *= (T)2;
		}

		sum = sum / max;
		return (sum + (T)1.0) / (T)2.0;
	}
};

class VulkanExample : public VulkanExampleBase
{
public:
	// Contains all Vulkan objects that are required to store and use a 3D texture
	struct Texture {
		VkSampler sampler = VK_NULL_HANDLE;
		VkImage image = VK_NULL_HANDLE;
		VkImageLayout imageLayout;
		VkDeviceMemory deviceMemory = VK_NULL_HANDLE;
		VkImageView view = VK_NULL_HANDLE;
		VkDescriptorImageInfo descriptor;
		VkFormat format;
		uint32_t width, height, depth;
		uint32_t mipLevels;
	} texture;

	struct {
		VkPipelineVertexInputStateCreateInfo inputState;
		std::vector<VkVertexInputBindingDescription> inputBinding;
		std::vector<VkVertexInputAttributeDescription> inputAttributes;
	} vertices;

	vks::Buffer vertexBuffer;
	vks::Buffer indexBuffer;
	uint32_t indexCount;

	vks::Buffer uniformBufferVS;

	struct UboVS {
		glm::mat4 projection;
		glm::mat4 modelView;
		glm::vec4 viewPos;
		float depth = 0.0f;
	} uboVS;

	struct {
		VkPipeline solid;
	} pipelines;

	VkPipelineLayout pipelineLayout;
	VkDescriptorSet descriptorSet;
	VkDescriptorSetLayout descriptorSetLayout;

	VulkanExample() : VulkanExampleBase(ENABLE_VALIDATION)
	{
		title = "3D textures";
		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);
		settings.overlay = true;
		srand((unsigned int)time(NULL));
	}

	~VulkanExample()
	{
		// Clean up used Vulkan resources
		// Note : Inherited destructor cleans up resources stored in base class

		destroyTextureImage(texture);

		vkDestroyPipeline(device, pipelines.solid, nullptr);

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

		vertexBuffer.destroy();
		indexBuffer.destroy();
		uniformBufferVS.destroy();
	}

	// Prepare all Vulkan resources for the 3D texture (including descriptors)
	// Does not fill the texture with data
	void prepareNoiseTexture(uint32_t width, uint32_t height, uint32_t depth)
	{
		// A 3D texture is described as width x height x depth
		texture.width = width;
		texture.height = height;
		texture.depth = depth;
		texture.mipLevels = 1;
		texture.format = VK_FORMAT_R8_UNORM;

		// Format support check
		// 3D texture support in Vulkan is mandatory (in contrast to OpenGL) so no need to check if it's supported
		VkFormatProperties formatProperties;
		vkGetPhysicalDeviceFormatProperties(physicalDevice, texture.format, &formatProperties);
		// Check if format supports transfer
		if (!(formatProperties.optimalTilingFeatures & VK_FORMAT_FEATURE_TRANSFER_DST_BIT))
		{
			std::cout << "Error: Device does not support flag TRANSFER_DST for selected texture format!" << std::endl;
			return;
		}
		// Check if GPU supports requested 3D texture dimensions
		uint32_t maxImageDimension3D(vulkanDevice->properties.limits.maxImageDimension3D);
		if (width > maxImageDimension3D || height > maxImageDimension3D || depth > maxImageDimension3D)
		{
			std::cout << "Error: Requested texture dimensions is greater than supported 3D texture dimension!" << std::endl;
			return;
		}

		// Create optimal tiled target image
		VkImageCreateInfo imageCreateInfo = vks::initializers::imageCreateInfo();
		imageCreateInfo.imageType = VK_IMAGE_TYPE_3D;
		imageCreateInfo.format = texture.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;
		imageCreateInfo.extent.width = texture.width;
		imageCreateInfo.extent.height = texture.height;
		imageCreateInfo.extent.depth = texture.depth;
		// Set initial layout of the image to undefined
		imageCreateInfo.initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
		imageCreateInfo.usage = VK_IMAGE_USAGE_TRANSFER_DST_BIT | VK_IMAGE_USAGE_SAMPLED_BIT;
		VK_CHECK_RESULT(vkCreateImage(device, &imageCreateInfo, nullptr, &texture.image));

		// Device local memory to back up 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));

		// Create 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_CLAMP_TO_EDGE;
		sampler.addressModeV = VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE;
		sampler.addressModeW = VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE;
		sampler.mipLodBias = 0.0f;
		sampler.compareOp = VK_COMPARE_OP_NEVER;
		sampler.minLod = 0.0f;
		sampler.maxLod = 0.0f;
		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.image = texture.image;
		view.viewType = VK_IMAGE_VIEW_TYPE_3D;
		view.format = texture.format;
		view.components = { VK_COMPONENT_SWIZZLE_R, VK_COMPONENT_SWIZZLE_G, VK_COMPONENT_SWIZZLE_B, VK_COMPONENT_SWIZZLE_A };
		view.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
		view.subresourceRange.baseMipLevel = 0;
		view.subresourceRange.baseArrayLayer = 0;
		view.subresourceRange.layerCount = 1;
		view.subresourceRange.levelCount = 1;
		VK_CHECK_RESULT(vkCreateImageView(device, &view, nullptr, &texture.view));

		// Fill image descriptor image info to be used descriptor set setup
		texture.descriptor.imageLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
		texture.descriptor.imageView = texture.view;
		texture.descriptor.sampler = texture.sampler;

		updateNoiseTexture();
	}

	// Generate randomized noise and upload it to the 3D texture using staging
	void updateNoiseTexture()
	{
		const uint32_t texMemSize = texture.width * texture.height * texture.depth;

		uint8_t *data = new uint8_t[texMemSize];
		memset(data, 0, texMemSize);

		// Generate perlin based noise
		std::cout << "Generating " << texture.width << " x " << texture.height << " x " << texture.depth << " noise texture..." << std::endl;

		auto tStart = std::chrono::high_resolution_clock::now();

		PerlinNoise<float> perlinNoise;
		FractalNoise<float> fractalNoise(perlinNoise);

		const float noiseScale = static_cast<float>(rand() % 10) + 4.0f;

#pragma omp parallel for
		for (int32_t z = 0; z < texture.depth; z++)
		{
			for (int32_t y = 0; y < texture.height; y++)
			{
				for (int32_t x = 0; x < texture.width; x++)
				{
					float nx = (float)x / (float)texture.width;
					float ny = (float)y / (float)texture.height;
					float nz = (float)z / (float)texture.depth;
#define FRACTAL
#ifdef FRACTAL
					float n = fractalNoise.noise(nx * noiseScale, ny * noiseScale, nz * noiseScale);
#else
					float n = 20.0 * perlinNoise.noise(nx, ny, nz);
#endif
					n = n - floor(n);

					data[x + y * texture.width + z * texture.width * texture.height] = static_cast<uint8_t>(floor(n * 255));
				}
			}
		}

		auto tEnd = std::chrono::high_resolution_clock::now();
		auto tDiff = std::chrono::duration<double, std::milli>(tEnd - tStart).count();

		std::cout << "Done in " << tDiff << "ms" << std::endl;

		// Create a host-visible staging buffer that contains the raw image data
		VkBuffer stagingBuffer;
		VkDeviceMemory stagingMemory;

		// Buffer object
		VkBufferCreateInfo bufferCreateInfo = vks::initializers::bufferCreateInfo();
		bufferCreateInfo.size = texMemSize;
		bufferCreateInfo.usage = VK_BUFFER_USAGE_TRANSFER_SRC_BIT;
		bufferCreateInfo.sharingMode = VK_SHARING_MODE_EXCLUSIVE;
		VK_CHECK_RESULT(vkCreateBuffer(device, &bufferCreateInfo, nullptr, &stagingBuffer));

		// Allocate host visible memory for data upload
		VkMemoryAllocateInfo memAllocInfo = vks::initializers::memoryAllocateInfo();
		VkMemoryRequirements memReqs = {};
		vkGetBufferMemoryRequirements(device, stagingBuffer, &memReqs);
		memAllocInfo.allocationSize = memReqs.size;
		memAllocInfo.memoryTypeIndex = vulkanDevice->getMemoryType(memReqs.memoryTypeBits, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT);
		VK_CHECK_RESULT(vkAllocateMemory(device, &memAllocInfo, nullptr, &stagingMemory));
		VK_CHECK_RESULT(vkBindBufferMemory(device, stagingBuffer, stagingMemory, 0));

		// Copy texture data into staging buffer
		uint8_t *mapped;
		VK_CHECK_RESULT(vkMapMemory(device, stagingMemory, 0, memReqs.size, 0, (void **)&mapped));
		memcpy(mapped, data, texMemSize);
		vkUnmapMemory(device, stagingMemory);

		VkCommandBuffer copyCmd = vulkanDevice->createCommandBuffer(VK_COMMAND_BUFFER_LEVEL_PRIMARY, true);

		// The sub resource range describes the regions of the image we will be transitioned
		VkImageSubresourceRange subresourceRange = {};
		subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
		subresourceRange.baseMipLevel = 0;
		subresourceRange.levelCount = 1;
		subresourceRange.layerCount = 1;

		// Optimal image will be used as destination for the copy, so we must transfer from our
		// initial undefined image layout to the transfer destination layout
		vks::tools::setImageLayout(
			copyCmd,
			texture.image,
			VK_IMAGE_LAYOUT_UNDEFINED,
			VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL,
			subresourceRange);

		// Copy 3D noise data to texture

		// Setup buffer copy regions
		VkBufferImageCopy bufferCopyRegion{};
		bufferCopyRegion.imageSubresource.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
		bufferCopyRegion.imageSubresource.mipLevel = 0;
		bufferCopyRegion.imageSubresource.baseArrayLayer = 0;
		bufferCopyRegion.imageSubresource.layerCount = 1;
		bufferCopyRegion.imageExtent.width = texture.width;
		bufferCopyRegion.imageExtent.height = texture.height;
		bufferCopyRegion.imageExtent.depth = texture.depth;

		vkCmdCopyBufferToImage(
			copyCmd,
			stagingBuffer,
			texture.image,
			VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL,
			1,
			&bufferCopyRegion);

		// Change texture image layout to shader read after all mip levels have been copied
		texture.imageLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
		vks::tools::setImageLayout(
			copyCmd,
			texture.image,
			VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL,
			texture.imageLayout,
			subresourceRange);

		vulkanDevice->flushCommandBuffer(copyCmd, queue, true);

		// Clean up staging resources
		delete[] data;
		vkFreeMemory(device, stagingMemory, nullptr);
		vkDestroyBuffer(device, stagingBuffer, nullptr);
	}

	// Free all Vulkan resources used a texture object
	void destroyTextureImage(Texture texture)
	{
		if (texture.view != VK_NULL_HANDLE)
			vkDestroyImageView(device, texture.view, nullptr);
		if (texture.image != VK_NULL_HANDLE)
			vkDestroyImage(device, texture.image, nullptr);
		if (texture.sampler != VK_NULL_HANDLE)
			vkDestroySampler(device, texture.sampler, nullptr);
		if (texture.deviceMemory != VK_NULL_HANDLE)
			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, NULL);
			vkCmdBindPipeline(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, pipelines.solid);

			VkDeviceSize offsets[1] = { 0 };
			vkCmdBindVertexBuffers(drawCmdBuffers[i], VERTEX_BUFFER_BIND_ID, 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]));
		}
	}

	void draw()
	{
		VulkanExampleBase::prepareFrame();

		// Command buffer to be submitted to the queue
		submitInfo.commandBufferCount = 1;
		submitInfo.pCommandBuffers = &drawCmdBuffers[currentBuffer];

		// Submit to queue
		VK_CHECK_RESULT(vkQueueSubmit(queue, 1, &submitInfo, VK_NULL_HANDLE));

		VulkanExampleBase::submitFrame();
	}

	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
		// For the sake of simplicity we won't stage the vertex data to the gpu memory
		// Vertex buffer
		VK_CHECK_RESULT(vulkanDevice->createBuffer(
			VK_BUFFER_USAGE_VERTEX_BUFFER_BIT,
			VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT,
			&vertexBuffer,
			vertices.size() * sizeof(Vertex),
			vertices.data()));
		// Index buffer
		VK_CHECK_RESULT(vulkanDevice->createBuffer(
			VK_BUFFER_USAGE_INDEX_BUFFER_BIT,
			VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT,
			&indexBuffer,
			indices.size() * sizeof(uint32_t),
			indices.data()));
	}

	void setupVertexDescriptions()
	{
		// Binding description
		vertices.inputBinding.resize(1);
		vertices.inputBinding[0] =
			vks::initializers::vertexInputBindingDescription(
				VERTEX_BUFFER_BIND_ID,
				sizeof(Vertex),
				VK_VERTEX_INPUT_RATE_VERTEX);

		// Attribute descriptions
		// Describes memory layout and shader positions
		vertices.inputAttributes.resize(3);
		// Location 0 : Position
		vertices.inputAttributes[0] =
			vks::initializers::vertexInputAttributeDescription(
				VERTEX_BUFFER_BIND_ID,
				0,
				VK_FORMAT_R32G32B32_SFLOAT,
				offsetof(Vertex, pos));
		// Location 1 : Texture coordinates
		vertices.inputAttributes[1] =
			vks::initializers::vertexInputAttributeDescription(
				VERTEX_BUFFER_BIND_ID,
				1,
				VK_FORMAT_R32G32_SFLOAT,
				offsetof(Vertex, uv));
		// Location 1 : Vertex normal
		vertices.inputAttributes[2] =
			vks::initializers::vertexInputAttributeDescription(
				VERTEX_BUFFER_BIND_ID,
				2,
				VK_FORMAT_R32G32B32_SFLOAT,
				offsetof(Vertex, normal));

		vertices.inputState = vks::initializers::pipelineVertexInputStateCreateInfo();
		vertices.inputState.vertexBindingDescriptionCount = static_cast<uint32_t>(vertices.inputBinding.size());
		vertices.inputState.pVertexBindingDescriptions = vertices.inputBinding.data();
		vertices.inputState.vertexAttributeDescriptionCount = static_cast<uint32_t>(vertices.inputAttributes.size());
		vertices.inputState.pVertexAttributeDescriptions = vertices.inputAttributes.data();
	}

	void setupDescriptorPool()
	{
		// Example uses one ubo and one image sampler
		std::vector<VkDescriptorPoolSize> poolSizes =
		{
			vks::initializers::descriptorPoolSize(VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 1),
			vks::initializers::descriptorPoolSize(VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 1)
		};

		VkDescriptorPoolCreateInfo descriptorPoolInfo =
			vks::initializers::descriptorPoolCreateInfo(
				static_cast<uint32_t>(poolSizes.size()),
				poolSizes.data(),
				2);

		VK_CHECK_RESULT(vkCreateDescriptorPool(device, &descriptorPoolInfo, nullptr, &descriptorPool));
	}

	void setupDescriptorSetLayout()
	{
		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.data(),
				static_cast<uint32_t>(setLayoutBindings.size()));

		VK_CHECK_RESULT(vkCreateDescriptorSetLayout(device, &descriptorLayout, nullptr, &descriptorSetLayout));

		VkPipelineLayoutCreateInfo pPipelineLayoutCreateInfo =
			vks::initializers::pipelineLayoutCreateInfo(
				&descriptorSetLayout,
				1);

		VK_CHECK_RESULT(vkCreatePipelineLayout(device, &pPipelineLayoutCreateInfo, nullptr, &pipelineLayout));
	}

	void setupDescriptorSet()
	{
		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,
				&uniformBufferVS.descriptor),
			// Binding 1 : Fragment shader texture sampler
			vks::initializers::writeDescriptorSet(
				descriptorSet,
				VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER,
				1,
				&texture.descriptor)
		};

		vkUpdateDescriptorSets(device, static_cast<uint32_t>(writeDescriptorSets.size()), writeDescriptorSets.data(), 0, NULL);
	}

	void preparePipelines()
	{
		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.data(),
				static_cast<uint32_t>(dynamicStateEnables.size()),
				0);

		// Load shaders
		std::array<VkPipelineShaderStageCreateInfo,2> shaderStages;

		shaderStages[0] = loadShader(getShadersPath() + "texture3d/texture3d.vert.spv", VK_SHADER_STAGE_VERTEX_BIT);
		shaderStages[1] = loadShader(getShadersPath() + "texture3d/texture3d.frag.spv", VK_SHADER_STAGE_FRAGMENT_BIT);

		VkGraphicsPipelineCreateInfo pipelineCreateInfo =
			vks::initializers::pipelineCreateInfo(
				pipelineLayout,
				renderPass,
				0);

		pipelineCreateInfo.pVertexInputState = &vertices.inputState;
		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, &pipelines.solid));
	}

	// 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,
			&uniformBufferVS,
			sizeof(uboVS),
			&uboVS));
		VK_CHECK_RESULT(uniformBufferVS.map());
		updateUniformBuffers();
	}

	void updateUniformBuffers(bool viewchanged = true)
	{
		if (viewchanged)
		{
			uboVS.projection = camera.matrices.perspective;
			uboVS.modelView = camera.matrices.view;
			uboVS.viewPos = camera.viewPos;
		}
		else
		{
			uboVS.depth += frameTimer * 0.15f;
			if (uboVS.depth > 1.0f)
				uboVS.depth = uboVS.depth - 1.0f;
		}
		memcpy(uniformBufferVS.mapped, &uboVS, sizeof(uboVS));
	}

	void prepare()
	{
		VulkanExampleBase::prepare();
		generateQuad();
		setupVertexDescriptions();
		prepareUniformBuffers();
		prepareNoiseTexture(128, 128, 128);
		setupDescriptorSetLayout();
		preparePipelines();
		setupDescriptorPool();
		setupDescriptorSet();
		buildCommandBuffers();
		prepared = true;
	}

	virtual void render()
	{
		if (!prepared)
			return;
		draw();
		if (!paused || camera.updated)
			updateUniformBuffers(camera.updated);
	}

	virtual void OnUpdateUIOverlay(vks::UIOverlay *overlay)
	{
		if (overlay->header("Settings")) {
			if (overlay->button("Generate new texture")) {
				updateNoiseTexture();
			}
		}
	}
};

VULKAN_EXAMPLE_MAIN()