plumageRender/homework/homework1/homework1.cpp

/*
* Vulkan Example - glTF scene loading and rendering
*
* Copyright (C) 2020-2022 by Sascha Willems - www.saschawillems.de
*
* This code is licensed under the MIT license (MIT) (http://opensource.org/licenses/MIT)
*/

/*
 * Shows how to load and display a simple scene from a glTF file
 * Note that this isn't a complete glTF loader and only basic functions are shown here
 * This means no complex materials, no animations, no skins, etc.
 * For details on how glTF 2.0 works, see the official spec at https://github.com/KhronosGroup/glTF/tree/master/specification/2.0
 *
 * Other samples will load models using a dedicated model loader with more features (see base/VulkanglTFModel.hpp)
 *
 * If you are looking for a complete glTF implementation, check out https://github.com/SaschaWillems/Vulkan-glTF-PBR/
 */


#include "homework1.h"



	/*
		glTF loading functions

		The following functions take a glTF input model loaded via tinyglTF and convert all required data into our own structure
	*/

	void VulkanglTFModel::loadImages(tinygltf::Model& input)
	{
		images.resize(input.images.size());
		for (size_t i = 0; i < input.images.size(); i++) {
			tinygltf::Image& glTFImage = input.images[i];
			// Get the image data from the glTF loader
			unsigned char* buffer = nullptr;
			VkDeviceSize bufferSize = 0;
			bool deleteBuffer = false;
			// We convert RGB-only images to RGBA, as most devices don't support RGB-formats in Vulkan
			if (glTFImage.component == 3) {
				bufferSize = glTFImage.width * glTFImage.height * 4;
				buffer = new unsigned char[bufferSize];
				unsigned char* rgba = buffer;
				unsigned char* rgb = &glTFImage.image[0];
				for (size_t i = 0; i < glTFImage.width * glTFImage.height; ++i) {
					memcpy(rgba, rgb, sizeof(unsigned char) * 3);
					rgba += 4;
					rgb += 3;
				}
				deleteBuffer = true;
			}
			else {
				buffer = &glTFImage.image[0];
				bufferSize = glTFImage.image.size();
			}
			// Load texture from image buffer
			images[i].texture.fromBuffer(buffer, bufferSize, VK_FORMAT_R8G8B8A8_UNORM, glTFImage.width, glTFImage.height, vulkanDevice, copyQueue);
			if (deleteBuffer) {
				delete[] buffer;
			}
		}
	}

	void VulkanglTFModel::loadTextures(tinygltf::Model& input)
	{
		textures.resize(input.textures.size());
		for (size_t i = 0; i < input.textures.size(); i++) {
			textures[i].imageIndex = input.textures[i].source;
		}
	}

	void VulkanglTFModel::loadMaterials(tinygltf::Model& input)
	{
		materials.resize(input.materials.size());
		for (size_t i = 0; i < input.materials.size(); i++) {
			// We only read the most basic properties required for our sample
			tinygltf::Material glTFMaterial = input.materials[i];
			// Get the base color factor
			if (glTFMaterial.values.find("baseColorFactor") != glTFMaterial.values.end()) {
				materials[i].baseColorFactor = glm::make_vec4(glTFMaterial.values["baseColorFactor"].ColorFactor().data());
			}
			// Get base color texture index
			if (glTFMaterial.values.find("baseColorTexture") != glTFMaterial.values.end()) {
				materials[i].baseColorTextureIndex = glTFMaterial.values["baseColorTexture"].TextureIndex();
			}
			if (glTFMaterial.values.find("metallicRoughnessTexture") != glTFMaterial.values.end()) {
				materials[i].matalicRoughTextureIndex = glTFMaterial.values["metallicRoughnessTexture"].TextureIndex();
			}
			if (glTFMaterial.additionalValues.find("normalTexture") != glTFMaterial.additionalValues.end())
			{
				materials[i].normalMapTextureIndex = glTFMaterial.additionalValues["normalTexture"].TextureIndex();
			}
			if (glTFMaterial.emissiveTexture.index != -1)
			{
				materials[i].emissiveTextureIndex = glTFMaterial.emissiveTexture.index;
			}
			if (glTFMaterial.emissiveFactor.size() == 3)
			{
				materials[i].materialData.values.emissiveFactor = glm::make_vec3(glTFMaterial.emissiveFactor.data());
			}

			if (glTFMaterial.values.find("baseColorFactor") != glTFMaterial.values.end())
			{
				materials[i].materialData.values.baseColorFactor = glm::make_vec4(glTFMaterial.values["baseColorFactor"].ColorFactor().data());
			}
		}
	}
	
	
	//animation loader
	void VulkanglTFModel::loadAnimations(tinygltf::Model& input)
	{
		animations.resize(input.animations.size());

		for (size_t i = 0; i < input.animations.size(); i++)
		{
			tinygltf::Animation glTFAnimation = input.animations[i];
			animations[i].name = glTFAnimation.name;

			// Samplers
			animations[i].samplers.resize(glTFAnimation.samplers.size());
			for (size_t j = 0; j < glTFAnimation.samplers.size(); j++)
			{
				tinygltf::AnimationSampler glTFSampler = glTFAnimation.samplers[j];
				AnimationSampler& dstSampler = animations[i].samplers[j];
				dstSampler.interpolation = glTFSampler.interpolation;

				// Read sampler keyframe input time values
				{
					const tinygltf::Accessor& accessor = input.accessors[glTFSampler.input];
					const tinygltf::BufferView& bufferView = input.bufferViews[accessor.bufferView];
					const tinygltf::Buffer& buffer = input.buffers[bufferView.buffer];
					const void* dataPtr = &buffer.data[accessor.byteOffset + bufferView.byteOffset];
					const float* buf = static_cast<const float*>(dataPtr);
					for (size_t index = 0; index < accessor.count; index++)
					{
						dstSampler.inputs.push_back(buf[index]);
					}
					// Adjust animation's start and end times
					for (auto input : animations[i].samplers[j].inputs)
					{
						if (input < animations[i].start)
						{
							animations[i].start = input;
						};
						if (input > animations[i].end)
						{
							animations[i].end = input;
						}
					}
				}

				// Read sampler keyframe output translate/rotate/scale values
				{
					const tinygltf::Accessor& accessor = input.accessors[glTFSampler.output];
					const tinygltf::BufferView& bufferView = input.bufferViews[accessor.bufferView];
					const tinygltf::Buffer& buffer = input.buffers[bufferView.buffer];
					const void* dataPtr = &buffer.data[accessor.byteOffset + bufferView.byteOffset];
					switch (accessor.type)
					{
					case TINYGLTF_TYPE_VEC3: {
						const glm::vec3* buf = static_cast<const glm::vec3*>(dataPtr);
						for (size_t index = 0; index < accessor.count; index++)
						{
							dstSampler.outputsVec4.push_back(glm::vec4(buf[index], 0.0f));
						}
						break;
					}
					case TINYGLTF_TYPE_VEC4: {
						const glm::vec4* buf = static_cast<const glm::vec4*>(dataPtr);
						for (size_t index = 0; index < accessor.count; index++)
						{
							dstSampler.outputsVec4.push_back(buf[index]);
						}
						break;
					}
					default: {
						std::cout << "unknown type" << std::endl;
						break;
					}
					}
				}
			}

			// Channels
			animations[i].channels.resize(glTFAnimation.channels.size());
			for (size_t j = 0; j < glTFAnimation.channels.size(); j++)
			{
				tinygltf::AnimationChannel glTFChannel = glTFAnimation.channels[j];
				AnimationChannel& dstChannel = animations[i].channels[j];
				dstChannel.path = glTFChannel.target_path;
				dstChannel.samplerIndex = glTFChannel.sampler;
				dstChannel.node = nodeFromIndex(glTFChannel.target_node);
			}
		}

		
	}
	/*
	// load skins from glTF model
	void VulkanglTFModel::loadSkins(tinygltf::Model& input)
	{
		
		skins.resize(input.skins.size());
		if (skins.size() > 0)
		{
			for (size_t i = 0; i < input.skins.size(); i++)
				{
					tinygltf::Skin glTFSkin = input.skins[i];

					skins[i].name = glTFSkin.name;
					//follow the tree structure,find the root node of skeleton by index
					skins[i].skeletonRoot = nodeFromIndex(glTFSkin.skeleton);

					//join nodes
					for (int jointIndex : glTFSkin.joints)
						{
							Node* node = nodeFromIndex(jointIndex);
							if (node)
							{
								skins[i].joints.push_back(node);
							}
						}
					//get the inverse bind matrices
					if (glTFSkin.inverseBindMatrices > -1)
						{
							const tinygltf::Accessor& accessor = input.accessors[glTFSkin.inverseBindMatrices];
							const tinygltf::BufferView& bufferview = input.bufferViews[accessor.bufferView];
							const tinygltf::Buffer& buffer = input.buffers[bufferview.buffer];
							skins[i].inverseBindMatrices.resize(accessor.count);
							memcpy(skins[i].inverseBindMatrices.data(), &buffer.data[accessor.byteOffset + bufferview.byteOffset], accessor.count * sizeof(glm::mat4));

							//create a host visible shader buffer to store inverse bind matrices for this skin
							VK_CHECK_RESULT(
								vulkanDevice->createBuffer(
								VK_BUFFER_USAGE_STORAGE_BUFFER_BIT,
								VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT,
								&skins[i].ssbo,
								sizeof(glm::mat4) * skins[i].inverseBindMatrices.size(),
								skins[i].inverseBindMatrices.data()));
							VK_CHECK_RESULT(skins[i].ssbo.map());
						}
				}

		}
		


	}*/
	
	//glTF nodes loading helper function
	//rewrite node loader,simplify logic
	//Search node from parent to children by index
	VulkanglTFModel::Node* VulkanglTFModel::findNode(Node* parent, uint32_t index)
	{
		Node* nodeFound = nullptr;
		if (parent->index == index)
		{
			return parent;
		}
		for (auto& child : parent->children)
		{
			nodeFound = findNode(child, index);
			if (nodeFound)
			{
				break;
			}
		}
		return nodeFound;
	}	//iterate vector of nodes to check weather nodes exist or not
	VulkanglTFModel::Node* VulkanglTFModel::nodeFromIndex(uint32_t index)
	{
		Node* nodeFound = nullptr;
		for (auto& node : nodes)
		{
			nodeFound = findNode(node, index);
			if (nodeFound)
			{
				break;
			}
		}
		return nodeFound;
	}


	//node loader
	void VulkanglTFModel::loadNode(const tinygltf::Node& inputNode, const tinygltf::Model& input, VulkanglTFModel::Node* parent, uint32_t nodeIndex, std::vector<uint32_t>& indexBuffer, std::vector<VulkanglTFModel::Vertex>& vertexBuffer)
	{
		VulkanglTFModel::Node* node = new VulkanglTFModel::Node{};
		node->matrix = glm::mat4(1.0f);
		node->parent = parent;
		node->index = nodeIndex;

		// Get the local node matrix
		// It's either made up from translation, rotation, scale or a 4x4 matrix
		if (inputNode.translation.size() == 3) {
			node->matrix = glm::translate(node->matrix, glm::vec3(glm::make_vec3(inputNode.translation.data())));
		}
		if (inputNode.rotation.size() == 4) {
			glm::quat q = glm::make_quat(inputNode.rotation.data());
			node->matrix *= glm::mat4(q);
		}
		if (inputNode.scale.size() == 3) {
			node->matrix = glm::scale(node->matrix, glm::vec3(glm::make_vec3(inputNode.scale.data())));
		}
		if (inputNode.matrix.size() == 16) {
			node->matrix = glm::make_mat4x4(inputNode.matrix.data());
		};

		// Load node's children
		if (inputNode.children.size() > 0) {
			for (size_t i = 0; i < inputNode.children.size(); i++) {
				loadNode(input.nodes[inputNode.children[i]], input, node, inputNode.children[i], indexBuffer, vertexBuffer);
			}
		}

		// If the node contains mesh data, we load vertices and indices from the buffers
		// In glTF this is done via accessors and buffer views
		if (inputNode.mesh > -1) {
			const tinygltf::Mesh mesh = input.meshes[inputNode.mesh];
			// Iterate through all primitives of this node's mesh
			for (size_t i = 0; i < mesh.primitives.size(); i++) {
				const tinygltf::Primitive& glTFPrimitive = mesh.primitives[i];
				uint32_t firstIndex = static_cast<uint32_t>(indexBuffer.size());
				uint32_t vertexStart = static_cast<uint32_t>(vertexBuffer.size());
				uint32_t indexCount = 0;
				// Vertices
				{
					const float* positionBuffer = nullptr;
					const float* normalsBuffer = nullptr;
					const float* texCoordsBuffer = nullptr;
					const float* tangentsBuffer = nullptr;
					size_t vertexCount = 0;

					// Get buffer data for vertex positions
					if (glTFPrimitive.attributes.find("POSITION") != glTFPrimitive.attributes.end()) {
						const tinygltf::Accessor& accessor = input.accessors[glTFPrimitive.attributes.find("POSITION")->second];
						const tinygltf::BufferView& view = input.bufferViews[accessor.bufferView];
						positionBuffer = reinterpret_cast<const float*>(&(input.buffers[view.buffer].data[accessor.byteOffset + view.byteOffset]));
						vertexCount = accessor.count;
					}
					// Get buffer data for vertex normals
					if (glTFPrimitive.attributes.find("NORMAL") != glTFPrimitive.attributes.end()) {
						const tinygltf::Accessor& accessor = input.accessors[glTFPrimitive.attributes.find("NORMAL")->second];
						const tinygltf::BufferView& view = input.bufferViews[accessor.bufferView];
						normalsBuffer = reinterpret_cast<const float*>(&(input.buffers[view.buffer].data[accessor.byteOffset + view.byteOffset]));
					}
					// Get buffer data for vertex texture coordinates
					// glTF supports multiple sets, we only load the first one
					if (glTFPrimitive.attributes.find("TEXCOORD_0") != glTFPrimitive.attributes.end()) {
						const tinygltf::Accessor& accessor = input.accessors[glTFPrimitive.attributes.find("TEXCOORD_0")->second];
						const tinygltf::BufferView& view = input.bufferViews[accessor.bufferView];
						texCoordsBuffer = reinterpret_cast<const float*>(&(input.buffers[view.buffer].data[accessor.byteOffset + view.byteOffset]));
					}

					if (glTFPrimitive.attributes.find("TANGENT") != glTFPrimitive.attributes.end())
					{
						const tinygltf::Accessor& accessor = input.accessors[glTFPrimitive.attributes.find("TANGENT")->second];
						const tinygltf::BufferView& view = input.bufferViews[accessor.bufferView];
						tangentsBuffer = reinterpret_cast<const float*>(&(input.buffers[view.buffer].data[accessor.byteOffset + view.byteOffset]));
					}

					// Append data to model's vertex buffer
					for (size_t v = 0; v < vertexCount; v++) {
						Vertex vert{};
						vert.pos = glm::vec4(glm::make_vec3(&positionBuffer[v * 3]), 1.0f);
						vert.normal = glm::normalize(glm::vec3(normalsBuffer ? glm::make_vec3(&normalsBuffer[v * 3]) : glm::vec3(0.0f)));
						vert.uv = texCoordsBuffer ? glm::make_vec2(&texCoordsBuffer[v * 2]) : glm::vec3(0.0f);
						vert.tangent = tangentsBuffer ? glm::normalize(glm::make_vec3(&tangentsBuffer[v * 4])) : glm::vec3(0.0f);
						vert.color = glm::vec3(1.0f, 1.0f, nodeIndex);//Temp set index in color attribute
						vertexBuffer.push_back(vert);
					}
				}
				// Indices
				{
					const tinygltf::Accessor& accessor = input.accessors[glTFPrimitive.indices];
					const tinygltf::BufferView& bufferView = input.bufferViews[accessor.bufferView];
					const tinygltf::Buffer& buffer = input.buffers[bufferView.buffer];

					indexCount += static_cast<uint32_t>(accessor.count);

					// glTF supports different component types of indices
					switch (accessor.componentType) {
					case TINYGLTF_PARAMETER_TYPE_UNSIGNED_INT: {
						const uint32_t* buf = reinterpret_cast<const uint32_t*>(&buffer.data[accessor.byteOffset + bufferView.byteOffset]);
						for (size_t index = 0; index < accessor.count; index++) {
							indexBuffer.push_back(buf[index] + vertexStart);
						}
						break;
					}
					case TINYGLTF_PARAMETER_TYPE_UNSIGNED_SHORT: {
						const uint16_t* buf = reinterpret_cast<const uint16_t*>(&buffer.data[accessor.byteOffset + bufferView.byteOffset]);
						for (size_t index = 0; index < accessor.count; index++) {
							indexBuffer.push_back(buf[index] + vertexStart);
						}
						break;
					}
					case TINYGLTF_PARAMETER_TYPE_UNSIGNED_BYTE: {
						const uint8_t* buf = reinterpret_cast<const uint8_t*>(&buffer.data[accessor.byteOffset + bufferView.byteOffset]);
						for (size_t index = 0; index < accessor.count; index++) {
							indexBuffer.push_back(buf[index] + vertexStart);
						}
						break;
					}
					default:
						std::cerr << "Index component type " << accessor.componentType << " not supported!" << std::endl;
						return;
					}
				}
				Primitive primitive{};
				primitive.firstIndex = firstIndex;
				primitive.indexCount = indexCount;
				primitive.materialIndex = glTFPrimitive.material;
				node->mesh.primitives.push_back(primitive);
			}
		}

		if (parent) {
			parent->children.push_back(node);
		}
		else {
			nodes.push_back(node);
		}
	}


	/*
		vertex skinning functions
	*/
	glm::mat4 VulkanglTFModel::getNodeMatrix(VulkanglTFModel::Node* node)
	{
		glm::mat4 nodeMatrix = node->getLocalMatrix();
		VulkanglTFModel::Node* currentParent = node->parent;
		while (currentParent)
		{
			nodeMatrix = currentParent->getLocalMatrix() * nodeMatrix;
			currentParent = currentParent->parent;
		}
		return nodeMatrix;
	}
	
	void VulkanglTFModel::updateNodeMatrix(Node* node, std::vector<glm::mat4>& nodeMatrics)
	{
		if (node->skin <= -1)
		{
			nodeMatrics[node->index] = getNodeMatrix(node);
			for (auto& child : node->children)
			{
				updateNodeMatrix(child, nodeMatrics);
			}
		}
		
	}

	void VulkanglTFModel::updateJoints(VulkanglTFModel::Node* node)
	{
		if (node->skin > -1)
		{
			glm::mat4 inversTransform = glm::inverse(getNodeMatrix(node));
			Skin skin = skins[node->skin];
			size_t numJoints = (uint32_t)skin.joints.size();
			std::vector<glm::mat4> jointMatrices(numJoints);
			for (size_t i = 0; i < numJoints; i++)
			{
				jointMatrices[i] = getNodeMatrix(skin.joints[i]) * skin.inverseBindMatrices[i];
				jointMatrices[i] = inversTransform * jointMatrices[i];
			}
			skin.ssbo.copyTo(jointMatrices.data(), jointMatrices.size() * sizeof(glm::mat4));
		}
		for (auto& child : node->children)
		{
			updateJoints(child);
		}
	}

	void VulkanglTFModel::updateAnimation(float deltaTime,vks::Buffer buffer)
	{
		if (activeAnimation > static_cast<uint32_t>(animations.size()) - 1)
		{
			std::cout << "No animation with index " << activeAnimation << std::endl;
			return;
		}
		Animation& animation = animations[activeAnimation];
		animation.currentTime += deltaTime;
		if (animation.currentTime > animation.end)
		{
			animation.currentTime -= animation.end;
		}

		for (auto& channel : animation.channels)
		{
			AnimationSampler& sampler = animation.samplers[channel.samplerIndex];
			for (size_t i = 0; i < sampler.inputs.size() - 1; ++i)
			{
				if (sampler.interpolation != "LINEAR")
				{
					std::cout << "This sample only supports linear interpolations\n";
					continue;
				}

				// Get the input keyframe values for the current time stamp
				if ((animation.currentTime >= sampler.inputs[i]) && (animation.currentTime <= sampler.inputs[i + 1]))
				{
					float ratio = (animation.currentTime - sampler.inputs[i]) / (sampler.inputs[i + 1] - sampler.inputs[i]);
					if (channel.path == "translation")
					{
						channel.node->translation = glm::mix(sampler.outputsVec4[i], sampler.outputsVec4[i + 1], ratio);
						channel.node->bAnimateNode = true;
					}
					if (channel.path == "rotation")
					{
						glm::quat q1;
						q1.x = sampler.outputsVec4[i].x;
						q1.y = sampler.outputsVec4[i].y;
						q1.z = sampler.outputsVec4[i].z;
						q1.w = sampler.outputsVec4[i].w;

						glm::quat q2;
						q2.x = sampler.outputsVec4[i + 1].x;
						q2.y = sampler.outputsVec4[i + 1].y;
						q2.z = sampler.outputsVec4[i + 1].z;
						q2.w = sampler.outputsVec4[i + 1].w;

						channel.node->rotation = glm::normalize(glm::slerp(q1, q2, ratio));
						channel.node->bAnimateNode = true;
					}
					if (channel.path == "scale")
					{
						channel.node->scale = glm::mix(sampler.outputsVec4[i], sampler.outputsVec4[i + 1], ratio);
						channel.node->bAnimateNode = true;
					}
				}
			}
		}
		//if no skin in model , update node matrix to update animation stage
		std::vector<glm::mat4> nodeMatrics(nodeCount);
		for (auto& node : nodes)
		{
			//updateJoints(node);
			updateNodeMatrix(node, nodeMatrics);
		}
		buffer.copyTo(nodeMatrics.data(), nodeCount * sizeof(glm::mat4));

	}
	/*
		glTF rendering functions
	*/

	// Draw a single node including child nodes (if present)
	void VulkanglTFModel::drawNode(VkCommandBuffer commandBuffer, VkPipelineLayout pipelineLayout, VulkanglTFModel::Node node)
	{
		if (node.mesh.primitives.size() > 0) {
			// Pass the node's matrix via push constants
			// Traverse the node hierarchy to the top-most parent to get the final matrix of the current node
			glm::mat4 nodeMatrix = node.matrix;
			VulkanglTFModel::Node* currentParent = node.parent;
			while (currentParent) {
				nodeMatrix = currentParent->matrix * nodeMatrix;
				currentParent = currentParent->parent;
			}
			
			for (VulkanglTFModel::Primitive& primitive : node.mesh.primitives) {
				if (primitive.indexCount > 0) {
					// Get the texture index for this primitive
					if (textures.size() > 0)
					{
						VulkanglTFModel::Texture texture = textures[materials[primitive.materialIndex].baseColorTextureIndex];
						VulkanglTFModel::Texture normalMap = textures[materials[primitive.materialIndex].normalMapTextureIndex];
						VulkanglTFModel::Texture roughMetalMap = textures[materials[primitive.materialIndex].matalicRoughTextureIndex];

						if (materials[primitive.materialIndex].emissiveTextureIndex >= 0)
						{
							VulkanglTFModel::Texture emissiveMap = textures[materials[primitive.materialIndex].emissiveTextureIndex];
							vkCmdBindDescriptorSets(commandBuffer, VK_PIPELINE_BIND_POINT_GRAPHICS, pipelineLayout, 4, 1, &images[emissiveMap.imageIndex].descriptorSet, 0, nullptr);
						}

						// Bind the descriptor for the current primitive's texture
						vkCmdBindDescriptorSets(commandBuffer, VK_PIPELINE_BIND_POINT_GRAPHICS, pipelineLayout, 1, 1, &images[texture.imageIndex].descriptorSet, 0, nullptr);
						vkCmdBindDescriptorSets(commandBuffer, VK_PIPELINE_BIND_POINT_GRAPHICS, pipelineLayout, 2, 1, &images[normalMap.imageIndex].descriptorSet, 0, nullptr);
						vkCmdBindDescriptorSets(commandBuffer, VK_PIPELINE_BIND_POINT_GRAPHICS, pipelineLayout, 3, 1, &images[roughMetalMap.imageIndex].descriptorSet, 0, nullptr);
						vkCmdBindDescriptorSets(commandBuffer, VK_PIPELINE_BIND_POINT_GRAPHICS, pipelineLayout, 5, 1, &materials[primitive.materialIndex].materialData.descriptorSet, 0, nullptr);
					}
					vkCmdDrawIndexed(commandBuffer, primitive.indexCount, 1, primitive.firstIndex, 0, 0);
				}
			}
		}
		for (auto &child : node.children) {
			drawNode(commandBuffer, pipelineLayout, *child);
		}
	}

	// Draw the glTF scene starting at the top-level-nodes
	void VulkanglTFModel::draw(VkCommandBuffer commandBuffer, VkPipelineLayout pipelineLayout )
	{
		// All vertices and indices are stored in single buffers, so we only need to bind once
		VkDeviceSize offsets[1] = { 0 };
		vkCmdBindVertexBuffers(commandBuffer, 0, 1, &vertices.buffer, offsets);
		vkCmdBindIndexBuffer(commandBuffer, indices.buffer, 0, VK_INDEX_TYPE_UINT32);
		// Render all nodes at top-level
		for (auto& node : nodes) {
			drawNode(commandBuffer, pipelineLayout, *node);
		}
	}




VulkanExample::VulkanExample():
	VulkanExampleBase(ENABLE_VALIDATION)
	{
		title = "homework1";
		camera.type = Camera::CameraType::lookat;
		camera.flipY = true;
		camera.setPosition(glm::vec3(0.0f, -0.1f, -1.0f));
		camera.setRotation(glm::vec3(0.0f, 45.0f, 0.0f));
		camera.setPerspective(60.0f, (float)width / (float)height, 0.1f, 256.0f);
	}

void VulkanExample::setupFrameBuffer()
{
	VulkanExampleBase::setupFrameBuffer();
	if (pbrFrameBuffer.bCreate && (pbrFrameBuffer.fbo.width != width || pbrFrameBuffer.fbo.height != height))
	{
		pbrFrameBuffer.color.destroy(device);
		pbrFrameBuffer.depth.destroy(device);
		pbrFrameBuffer.fbo.destroy(device);
		vkDestroySampler(device, colorSampler, nullptr);
	}

	pbrFrameBuffer.fbo.setSize(width, height);
	VkFormat attachDepthFormat;
	VkBool32 validDepthFormat = vks::tools::getSupportedDepthFormat(physicalDevice, &attachDepthFormat);
	assert(validDepthFormat);

	VulkanExample::createAttachment(VK_FORMAT_R8G8B8A8_UNORM, VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT, &pbrFrameBuffer.color, width, height);
	VulkanExample::createAttachment(attachDepthFormat, VK_IMAGE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT, &pbrFrameBuffer.depth, width, height);


	std::array<VkAttachmentDescription, 2> attachs = {};
	for (uint32_t i = 0; i < static_cast<uint32_t>(attachs.size()); i++)
	{
		attachs[i].samples = VK_SAMPLE_COUNT_1_BIT;
		attachs[i].loadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
		attachs[i].storeOp = VK_ATTACHMENT_STORE_OP_STORE;
		attachs[i].stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE;
		attachs[i].stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
		attachs[i].initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
		attachs[i].finalLayout = 1 ? VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL : VK_IMAGE_LAYOUT_READ_ONLY_OPTIMAL;
	}
	attachs[0].format = pbrFrameBuffer.color.format;
	attachs[1].format = pbrFrameBuffer.depth.format;
	

	VkAttachmentReference colorRefference = {};
	colorRefference.attachment = 0;
	colorRefference.layout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;

	VkAttachmentReference depthRefference = {};
	colorRefference.attachment = 1;
	colorRefference.layout = VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL;

	VkSubpassDescription subpass = {};
	subpass.pipelineBindPoint = VK_PIPELINE_BIND_POINT_GRAPHICS;
	subpass.pColorAttachments = &colorRefference;
	subpass.colorAttachmentCount = 1;
	subpass.pDepthStencilAttachment = &depthRefference;

	std::array<VkSubpassDependency, 2> dependencies;
	//To test src 0
	dependencies[0].srcSubpass = VK_SUBPASS_EXTERNAL;
	dependencies[0].dstSubpass = 0;
	dependencies[0].srcStageMask = VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT;
	dependencies[0].dstStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
	dependencies[0].srcAccessMask = VK_ACCESS_SHADER_READ_BIT;
	dependencies[0].dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
	dependencies[0].dependencyFlags = VK_DEPENDENCY_BY_REGION_BIT;

	dependencies[1].srcSubpass = 0;
	dependencies[1].dstSubpass = VK_SUBPASS_EXTERNAL;
	dependencies[1].srcStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
	dependencies[1].dstStageMask = VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT;
	dependencies[1].srcAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
	dependencies[1].dstAccessMask = VK_ACCESS_SHADER_READ_BIT;
	dependencies[1].dependencyFlags = VK_DEPENDENCY_BY_REGION_BIT;

	VkRenderPassCreateInfo renderPassCI = {};
	renderPassCI.sType = VK_STRUCTURE_TYPE_RENDER_PASS_CREATE_INFO;
	renderPassCI.pAttachments = attachs.data();
	renderPassCI.attachmentCount = static_cast<uint32_t>(attachs.size());
	renderPassCI.pSubpasses = &subpass;
	renderPassCI.pDependencies = dependencies.data();
	renderPassCI.dependencyCount = 2;
	VK_CHECK_RESULT(vkCreateRenderPass(device, &renderPassCI, nullptr, &pbrFrameBuffer.fbo.renderPass));
	// FBO
	VkImageView attachments[2] = { pbrFrameBuffer.color.imageView,pbrFrameBuffer.depth.imageView };
	VkFramebufferCreateInfo frameBufferCreateInfo = vks::initializers::framebufferCreateInfo();
	frameBufferCreateInfo.renderPass = pbrFrameBuffer.fbo.renderPass;
	frameBufferCreateInfo.pAttachments = attachments;
	frameBufferCreateInfo.attachmentCount = 2;
	frameBufferCreateInfo.width = pbrFrameBuffer.fbo.width;
	frameBufferCreateInfo.height = pbrFrameBuffer.fbo.height;
	frameBufferCreateInfo.layers = 1;
	VK_CHECK_RESULT(vkCreateFramebuffer(device, &frameBufferCreateInfo, nullptr, &pbrFrameBuffer.fbo.frameBuffer));

	VkSamplerCreateInfo samplerCI = vks::initializers::samplerCreateInfo();
	samplerCI.magFilter = VK_FILTER_NEAREST;
	samplerCI.minFilter = VK_FILTER_NEAREST;
	samplerCI.mipmapMode = VK_SAMPLER_MIPMAP_MODE_LINEAR;
	samplerCI.addressModeU = VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE;
	samplerCI.addressModeV = VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE;
	samplerCI.addressModeW = VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE;

	samplerCI.minLod = 0.0f;
	samplerCI.maxLod = 1.0f;
	samplerCI.borderColor = VK_BORDER_COLOR_FLOAT_OPAQUE_WHITE;
	VK_CHECK_RESULT(vkCreateSampler(device, &samplerCI, nullptr, &colorSampler));
	if (tonemappingDescriptorSet != VK_NULL_HANDLE)
	{
		auto imageInfo = vks::initializers::descriptorImageInfo(colorSampler, pbrFrameBuffer.color.imageView, VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL);
		VkWriteDescriptorSet writeDescriptorSet = vks::initializers::writeDescriptorSet(tonemappingDescriptorSet, VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 0, &imageInfo);
		vkUpdateDescriptorSets(device, 1, &writeDescriptorSet, 0, nullptr);

	}
	pbrFrameBuffer.bCreate = true;
}

void VulkanExample::getEnabledFeatures()
{
	// Fill mode non solid is required for wireframe display
	if (deviceFeatures.fillModeNonSolid) {
		enabledFeatures.fillModeNonSolid = VK_TRUE;
	};
}

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

		VkClearValue clearValues[2];
		clearValues[0].color = defaultClearColor;
		clearValues[0].color = { { 0.25f, 0.25f, 0.25f, 1.0f } };
		clearValues[1].depthStencil = { 1.0f, 0 };

		VkRenderPassBeginInfo renderPassBeginInfo = vks::initializers::renderPassBeginInfo();
		renderPassBeginInfo.renderPass = pbrFrameBuffer.fbo.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;

		const VkViewport viewport = vks::initializers::viewport((float)width, (float)height, 0.0f, 1.0f);
		const VkRect2D scissor = vks::initializers::rect2D(width, height, 0, 0);

		for (int32_t i = 0; i < drawCmdBuffers.size(); ++i)
		{
			renderPassBeginInfo.framebuffer = pbrFrameBuffer.fbo.frameBuffer;
			VK_CHECK_RESULT(vkBeginCommandBuffer(drawCmdBuffers[i], &cmdBufInfo));
			vkCmdBeginRenderPass(drawCmdBuffers[i], &renderPassBeginInfo, VK_SUBPASS_CONTENTS_INLINE);
			vkCmdSetViewport(drawCmdBuffers[i], 0, 1, &viewport);
			vkCmdSetScissor(drawCmdBuffers[i], 0, 1, &scissor);
			// Bind scene matrices descriptor to set 0
			vkCmdBindDescriptorSets(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, pipelineLayouts.pbrLayout, 0, 1, &descriptorSet, 0, nullptr);
			vkCmdBindDescriptorSets(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, pipelineLayouts.pbrLayout, 6, 1, &skinDescriptorSet, 0, nullptr);
			vkCmdBindPipeline(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, wireframe ? wireframePipeline : solidPipeline);
			glTFModel.draw(drawCmdBuffers[i], pipelineLayouts.pbrLayout);
			vkCmdEndRenderPass(drawCmdBuffers[i]);

			{
				VkRenderPassBeginInfo renderPassBeginInfo = vks::initializers::renderPassBeginInfo();
				renderPassBeginInfo.renderPass = renderPass;
				renderPassBeginInfo.framebuffer = VulkanExampleBase::frameBuffers[i];
				renderPassBeginInfo.renderArea.extent.width = width;
				renderPassBeginInfo.renderArea.extent.height = height;
				renderPassBeginInfo.clearValueCount = 2;
				renderPassBeginInfo.pClearValues = clearValues;

				vkCmdBeginRenderPass(drawCmdBuffers[i], &renderPassBeginInfo, VK_SUBPASS_CONTENTS_INLINE);
				vkCmdSetViewport(drawCmdBuffers[i], 0, 1, &viewport);
				vkCmdSetScissor(drawCmdBuffers[i], 0, 1, &scissor);
				vkCmdBindDescriptorSets(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, pipelineLayouts.tonemappingLayout, 0, 1, &tonemappingDescriptorSet, 0, NULL);
				vkCmdBindPipeline(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, toneMappingPipeline);
				vkCmdDraw(drawCmdBuffers[i], 3, 1, 0, 0);
				drawUI(drawCmdBuffers[i]);
				vkCmdEndRenderPass(drawCmdBuffers[i]);
			}
			VK_CHECK_RESULT(vkEndCommandBuffer(drawCmdBuffers[i]));
		}
	}

	void VulkanExample::loadglTFFile(std::string filename, VulkanglTFModel& model, bool bSkyboxFlag)
	{
		tinygltf::Model glTFInput;
		tinygltf::TinyGLTF gltfContext;
		std::string error, warning;

		this->device = device;

#if defined(__ANDROID__)
		// On Android all assets are packed with the apk in a compressed form, so we need to open them using the asset manager
		// We let tinygltf handle this, by passing the asset manager of our app
		tinygltf::asset_manager = androidApp->activity->assetManager;
#endif
		bool fileLoaded = gltfContext.LoadASCIIFromFile(&glTFInput, &error, &warning, filename);

		// Pass some Vulkan resources required for setup and rendering to the glTF model loading class
		model.vulkanDevice = vulkanDevice;
		model.copyQueue = queue;

		std::vector<uint32_t> indexBuffer;
		std::vector<VulkanglTFModel::Vertex> vertexBuffer;

		if (fileLoaded) {
			model.nodeCount = static_cast<uint32_t>(glTFInput.nodes.size());
			model.loadImages(glTFInput);
			model.loadMaterials(glTFInput);
			model.loadTextures(glTFInput);
			const tinygltf::Scene& scene = glTFInput.scenes[0];
			for (size_t i = 0; i < scene.nodes.size(); i++) {
				const tinygltf::Node node = glTFInput.nodes[scene.nodes[i]];
				model.loadNode(node, glTFInput, nullptr, scene.nodes[i], indexBuffer, vertexBuffer);
			}
			model.loadAnimations(glTFInput);
		}
		else {
			vks::tools::exitFatal("Could not open the glTF file.\n\nThe file is part of the additional asset pack.\n\nRun \"download_assets.py\" in the repository root to download the latest version.", -1);
			return;
		}

		// Create and upload vertex and index buffer
		// We will be using one single vertex buffer and one single index buffer for the whole glTF scene
		// Primitives (of the glTF model) will then index into these using index offsets

		size_t vertexBufferSize = vertexBuffer.size() * sizeof(VulkanglTFModel::Vertex);
		size_t indexBufferSize = indexBuffer.size() * sizeof(uint32_t);
		model.indices.count = static_cast<uint32_t>(indexBuffer.size());

		// Create host visible staging buffers (source)
		VK_CHECK_RESULT(vulkanDevice->createBuffer(
			VK_BUFFER_USAGE_TRANSFER_SRC_BIT,
			VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT,
			vertexBufferSize,
			&vertexStaging.buffer,
			&vertexStaging.memory,
			vertexBuffer.data()));
		// Index data
		VK_CHECK_RESULT(vulkanDevice->createBuffer(
			VK_BUFFER_USAGE_TRANSFER_SRC_BIT,
			VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT,
			indexBufferSize,
			&indexStaging.buffer,
			&indexStaging.memory,
			indexBuffer.data()));

		// Create device local buffers (target)
		VK_CHECK_RESULT(vulkanDevice->createBuffer(
			VK_BUFFER_USAGE_VERTEX_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT,
			VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT,
			vertexBufferSize,
			&model.vertices.buffer,
			&model.vertices.memory));
		VK_CHECK_RESULT(vulkanDevice->createBuffer(
			VK_BUFFER_USAGE_INDEX_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT,
			VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT,
			indexBufferSize,
			&model.indices.buffer,
			&model.indices.memory));

		// Copy data from staging buffers (host) do device local buffer (gpu)
		VkCommandBuffer copyCmd = vulkanDevice->createCommandBuffer(VK_COMMAND_BUFFER_LEVEL_PRIMARY, true);
		VkBufferCopy copyRegion = {};

		copyRegion.size = vertexBufferSize;
		vkCmdCopyBuffer(
			copyCmd,
			vertexStaging.buffer,
			model.vertices.buffer,
			1,
			&copyRegion);

		copyRegion.size = indexBufferSize;
		vkCmdCopyBuffer(
			copyCmd,
			indexStaging.buffer,
			model.indices.buffer,
			1,
			&copyRegion);

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

		// Free staging resources
		vkDestroyBuffer(device, vertexStaging.buffer, nullptr);
		vkFreeMemory(device, vertexStaging.memory, nullptr);
		vkDestroyBuffer(device, indexStaging.buffer, nullptr);
		vkFreeMemory(device, indexStaging.memory, nullptr);
	}

	void VulkanExample::loadAssets()
	{
		loadglTFFile(getAssetPath() + "buster_drone/busterDrone.gltf",glTFModel);
		loadglTFFile(getAssetPath() + "models/cube.gltf", skyboxModel, true);
		ibltextures.skyboxCube.loadFromFile(getAssetPath() + "textures/hdr/pisa_cube.ktx", VK_FORMAT_R16G16B16A16_SFLOAT, vulkanDevice, queue);
		
	}

	void VulkanExample::setupDescriptors()
	{
		/*
			This sample uses separate descriptor sets (and layouts) for the matrices and materials (textures)
		*/

		std::vector<VkDescriptorPoolSize> poolSizes = {
		vks::initializers::descriptorPoolSize(VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 4),
		// One combined image sampler per material image/texture
		vks::initializers::descriptorPoolSize(VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, static_cast<uint32_t>(glTFModel.images.size())),
		// One ssbo per skin
		//vks::initializers::descriptorPoolSize(VK_DESCRIPTOR_TYPE_STORAGE_BUFFER, static_cast<uint32_t>(glTFModel.skins.size())),
		// sampler descriptor
		vks::initializers::descriptorPoolSize(VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER,4),
		//animation storage buffer
		vks::initializers::descriptorPoolSize(VK_DESCRIPTOR_TYPE_STORAGE_BUFFER,1)

		};
		// One set for matrices and one per model image/texture
		const uint32_t maxSetCount = static_cast<uint32_t>(glTFModel.images.size()) + 6;
		VkDescriptorPoolCreateInfo descriptorPoolInfo = vks::initializers::descriptorPoolCreateInfo(poolSizes, maxSetCount);
		VK_CHECK_RESULT(vkCreateDescriptorPool(device, &descriptorPoolInfo, nullptr, &descriptorPool));

		// Descriptor set layouts
		std::vector<VkDescriptorSetLayoutBinding> setLayoutBindings =
		{
			vks::initializers::descriptorSetLayoutBinding(VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, VK_SHADER_STAGE_VERTEX_BIT | VK_SHADER_STAGE_FRAGMENT_BIT, 0),
			vks::initializers::descriptorSetLayoutBinding(VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, VK_SHADER_STAGE_FRAGMENT_BIT, 1),
			vks::initializers::descriptorSetLayoutBinding(VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, VK_SHADER_STAGE_FRAGMENT_BIT, 2),
			vks::initializers::descriptorSetLayoutBinding(VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, VK_SHADER_STAGE_FRAGMENT_BIT, 3),
		};
		VkDescriptorSetLayoutCreateInfo descriptorSetLayoutCI = vks::initializers::descriptorSetLayoutCreateInfo(setLayoutBindings);
		VK_CHECK_RESULT(vkCreateDescriptorSetLayout(device, &descriptorSetLayoutCI, nullptr, &descriptorSetLayouts.matrices));

		VkDescriptorSetLayoutBinding materialBufferLayoutBinding = vks::initializers::descriptorSetLayoutBinding(VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, VK_SHADER_STAGE_FRAGMENT_BIT, 0);
		descriptorSetLayoutCI = vks::initializers::descriptorSetLayoutCreateInfo(&materialBufferLayoutBinding, 1);
		VK_CHECK_RESULT(vkCreateDescriptorSetLayout(device, &descriptorSetLayoutCI, nullptr, &descriptorSetLayouts.materialUniform));

		// Descriptor set layout for passing material textures
		VkDescriptorSetLayoutBinding setLayoutBinding = vks::initializers::descriptorSetLayoutBinding(VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, VK_SHADER_STAGE_FRAGMENT_BIT, 0);
		descriptorSetLayoutCI = vks::initializers::descriptorSetLayoutCreateInfo(&setLayoutBinding, 1);
		VK_CHECK_RESULT(vkCreateDescriptorSetLayout(device, &descriptorSetLayoutCI, nullptr, &descriptorSetLayouts.textures));

		setLayoutBinding = vks::initializers::descriptorSetLayoutBinding(VK_DESCRIPTOR_TYPE_STORAGE_BUFFER, VK_SHADER_STAGE_VERTEX_BIT, 0);
		VK_CHECK_RESULT(vkCreateDescriptorSetLayout(device, &descriptorSetLayoutCI, nullptr, &descriptorSetLayouts.ssbo));
		// Descriptor set layout for passing skin joint matrices
		
		//setLayoutBinding = vks::initializers::descriptorSetLayoutBinding(VK_DESCRIPTOR_TYPE_STORAGE_BUFFER, VK_SHADER_STAGE_VERTEX_BIT, 0);
		//VK_CHECK_RESULT(vkCreateDescriptorSetLayout(device, &descriptorSetLayoutCI, nullptr, &descriptorSetLayouts.jointMatrices));

		// The pipeline layout uses three sets:
		// Set 0 = Scene matrices (VS)
		// Set 1 = Joint matrices (VS)
		// Set 2 = Material texture (FS)
		std::array<VkDescriptorSetLayout, 7> setLayouts = {
			descriptorSetLayouts.matrices,
			//descriptorSetLayouts.jointMatrices,
			descriptorSetLayouts.textures,
			descriptorSetLayouts.textures,
			descriptorSetLayouts.textures,
			descriptorSetLayouts.textures,
			descriptorSetLayouts.materialUniform,
			descriptorSetLayouts.ssbo,
		};
		VkPipelineLayoutCreateInfo pipelineLayoutCI = vks::initializers::pipelineLayoutCreateInfo(setLayouts.data(), static_cast<uint32_t>(setLayouts.size()));
		VK_CHECK_RESULT(vkCreatePipelineLayout(device, &pipelineLayoutCI, nullptr, &pipelineLayouts.pbrLayout));
		// Descriptor set for scene matrices
		VkDescriptorSetAllocateInfo allocInfo = vks::initializers::descriptorSetAllocateInfo(descriptorPool, &descriptorSetLayouts.matrices, 1);
		VK_CHECK_RESULT(vkAllocateDescriptorSets(device, &allocInfo, &descriptorSet));
		std::vector<VkWriteDescriptorSet> writeDescriptorSets =
		{
			vks::initializers::writeDescriptorSet(descriptorSet,VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER,0,&shaderData.buffer.descriptor),
			vks::initializers::writeDescriptorSet(descriptorSet,VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER,1,&ibltextures.irradianceCube.descriptor),
			vks::initializers::writeDescriptorSet(descriptorSet,VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER,2,&ibltextures.lutBrdf.descriptor),
			vks::initializers::writeDescriptorSet(descriptorSet,VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER,3,&ibltextures.prefilteredCube.descriptor),
		};

		vkUpdateDescriptorSets(device, 4, writeDescriptorSets.data(), 0, nullptr);
		
		for (auto& material : glTFModel.materials)
		{
			const VkDescriptorSetAllocateInfo allocInfo = vks::initializers::descriptorSetAllocateInfo(descriptorPool, &descriptorSetLayouts.materialUniform, 1);
			VK_CHECK_RESULT(vkAllocateDescriptorSets(device, &allocInfo, &material.materialData.descriptorSet));
			VkWriteDescriptorSet writeDescriptorSet = vks::initializers::writeDescriptorSet(
				material.materialData.descriptorSet, VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 0, &material.materialData.buffer.descriptor);
			vkUpdateDescriptorSets(device, 1, &writeDescriptorSet, 0, nullptr);
		}

		// Descriptor sets for materials
		for (auto& image : glTFModel.images) {
			const VkDescriptorSetAllocateInfo allocInfo = vks::initializers::descriptorSetAllocateInfo(descriptorPool, &descriptorSetLayouts.textures, 1);
			VK_CHECK_RESULT(vkAllocateDescriptorSets(device, &allocInfo, &image.descriptorSet));
			VkWriteDescriptorSet writeDescriptorSet = vks::initializers::writeDescriptorSet(image.descriptorSet, VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 0, &image.texture.descriptor);
			vkUpdateDescriptorSets(device, 1, &writeDescriptorSet, 0, nullptr);
		}
		{
			const VkDescriptorSetAllocateInfo allocInfo = vks::initializers::descriptorSetAllocateInfo(descriptorPool, &descriptorSetLayouts.ssbo, 1);
			VK_CHECK_RESULT(vkAllocateDescriptorSets(device, &allocInfo, &skinDescriptorSet));
			VkWriteDescriptorSet writeDescriptorSet = vks::initializers::writeDescriptorSet(skinDescriptorSet, VK_DESCRIPTOR_TYPE_STORAGE_BUFFER, 0, &shaderData.skinSSBO.descriptor);
			vkUpdateDescriptorSets(device, 1, &writeDescriptorSet, 0, nullptr);
		}
	
	//Tone Mapping pipeline layout
		{
		auto pipelineLayoutCI = vks::initializers::pipelineLayoutCreateInfo(&descriptorSetLayouts.textures, 1);
		VK_CHECK_RESULT(vkCreatePipelineLayout(device, &pipelineLayoutCI, nullptr, &pipelineLayouts.tonemappingLayout));

		const VkDescriptorSetAllocateInfo allocInfo = vks::initializers::descriptorSetAllocateInfo(descriptorPool, &descriptorSetLayouts.textures, 1);
		VK_CHECK_RESULT(vkAllocateDescriptorSets(device, &allocInfo, &tonemappingDescriptorSet));

		auto imageInfo = vks::initializers::descriptorImageInfo(colorSampler, pbrFrameBuffer.color.imageView, VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL);
		VkWriteDescriptorSet writeDescriptorSet = vks::initializers::writeDescriptorSet(tonemappingDescriptorSet, VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 0, &imageInfo);
		vkUpdateDescriptorSets(device, 1, &writeDescriptorSet, 0, nullptr);
		}
		
	}

	void VulkanExample::preparePipelines()
	{
		VkPipelineInputAssemblyStateCreateInfo inputAssemblyStateCI = vks::initializers::pipelineInputAssemblyStateCreateInfo(VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST, 0, VK_FALSE);
		VkPipelineRasterizationStateCreateInfo rasterizationStateCI = vks::initializers::pipelineRasterizationStateCreateInfo(VK_POLYGON_MODE_FILL, VK_CULL_MODE_BACK_BIT, VK_FRONT_FACE_COUNTER_CLOCKWISE, 0);
		VkPipelineColorBlendAttachmentState blendAttachmentStateCI = vks::initializers::pipelineColorBlendAttachmentState(0xf, VK_FALSE);
		VkPipelineColorBlendStateCreateInfo colorBlendStateCI = vks::initializers::pipelineColorBlendStateCreateInfo(1, &blendAttachmentStateCI);
		VkPipelineDepthStencilStateCreateInfo depthStencilStateCI = vks::initializers::pipelineDepthStencilStateCreateInfo(VK_TRUE, VK_TRUE, VK_COMPARE_OP_LESS_OR_EQUAL);
		VkPipelineViewportStateCreateInfo viewportStateCI = vks::initializers::pipelineViewportStateCreateInfo(1, 1, 0);
		VkPipelineMultisampleStateCreateInfo multisampleStateCI = vks::initializers::pipelineMultisampleStateCreateInfo(VK_SAMPLE_COUNT_1_BIT, 0);
		const std::vector<VkDynamicState> dynamicStateEnables = { VK_DYNAMIC_STATE_VIEWPORT, VK_DYNAMIC_STATE_SCISSOR };
		VkPipelineDynamicStateCreateInfo dynamicStateCI = vks::initializers::pipelineDynamicStateCreateInfo(dynamicStateEnables.data(), static_cast<uint32_t>(dynamicStateEnables.size()), 0);
		// Vertex input bindings and attributes
		const std::vector<VkVertexInputBindingDescription> vertexInputBindings = {
			vks::initializers::vertexInputBindingDescription(0, sizeof(VulkanglTFModel::Vertex), VK_VERTEX_INPUT_RATE_VERTEX),
		};
		const std::vector<VkVertexInputAttributeDescription> vertexInputAttributes = {
			vks::initializers::vertexInputAttributeDescription(0, 0, VK_FORMAT_R32G32B32_SFLOAT, offsetof(VulkanglTFModel::Vertex, pos)),	// Location 0: Position
			vks::initializers::vertexInputAttributeDescription(0, 1, VK_FORMAT_R32G32B32_SFLOAT, offsetof(VulkanglTFModel::Vertex, normal)),// Location 1: Normal
			vks::initializers::vertexInputAttributeDescription(0, 2, VK_FORMAT_R32G32B32_SFLOAT, offsetof(VulkanglTFModel::Vertex, uv)),	// Location 2: Texture coordinates
			vks::initializers::vertexInputAttributeDescription(0, 3, VK_FORMAT_R32G32B32_SFLOAT, offsetof(VulkanglTFModel::Vertex, color)),	// Location 3: Color
			vks::initializers::vertexInputAttributeDescription(0, 4, VK_FORMAT_R32G32B32_SFLOAT, offsetof(VulkanglTFModel::Vertex, tangent)), // Location 4 : Tangent
		};
		VkPipelineVertexInputStateCreateInfo vertexInputStateCI = vks::initializers::pipelineVertexInputStateCreateInfo();
		vertexInputStateCI.vertexBindingDescriptionCount = static_cast<uint32_t>(vertexInputBindings.size());
		vertexInputStateCI.pVertexBindingDescriptions = vertexInputBindings.data();
		vertexInputStateCI.vertexAttributeDescriptionCount = static_cast<uint32_t>(vertexInputAttributes.size());
		vertexInputStateCI.pVertexAttributeDescriptions = vertexInputAttributes.data();

		std::array<VkPipelineShaderStageCreateInfo, 2> shaderStages = {
			loadShader(getHomeworkShadersPath() + "homework1/mesh.vert.spv", VK_SHADER_STAGE_VERTEX_BIT),
			loadShader(getHomeworkShadersPath() + "homework1/mesh.frag.spv", VK_SHADER_STAGE_FRAGMENT_BIT)
		};

		VkGraphicsPipelineCreateInfo pipelineCI = vks::initializers::pipelineCreateInfo(pipelineLayouts.pbrLayout, pbrFrameBuffer.fbo.renderPass, 0);
		pipelineCI.pVertexInputState = &vertexInputStateCI;
		pipelineCI.pInputAssemblyState = &inputAssemblyStateCI;
		pipelineCI.pRasterizationState = &rasterizationStateCI;
		pipelineCI.pColorBlendState = &colorBlendStateCI;
		pipelineCI.pMultisampleState = &multisampleStateCI;
		pipelineCI.pViewportState = &viewportStateCI;
		pipelineCI.pDepthStencilState = &depthStencilStateCI;
		pipelineCI.pDynamicState = &dynamicStateCI;
		pipelineCI.stageCount = static_cast<uint32_t>(shaderStages.size());
		pipelineCI.pStages = shaderStages.data();
		
		// Solid rendering pipeline
		VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCI, nullptr, &solidPipeline));

		// Wire frame rendering pipeline
		if (deviceFeatures.fillModeNonSolid) {
			rasterizationStateCI.polygonMode = VK_POLYGON_MODE_LINE;
			rasterizationStateCI.lineWidth = 1.0f;
			VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCI, nullptr, &wireframePipeline));
		}
		//Create Tone Mapping render pipeline
		prepareToneMappingPipeline();
	}

	void VulkanExample::prepareToneMappingPipeline()
	{
		if (toneMappingPipeline != VK_NULL_HANDLE)
		{
			vkDestroyPipeline(device, toneMappingPipeline, nullptr);
			toneMappingPipeline = VK_NULL_HANDLE;
		}
		VkPipelineInputAssemblyStateCreateInfo inputAssemblyStateCI = vks::initializers::pipelineInputAssemblyStateCreateInfo(VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST, 0, VK_FALSE);
		VkPipelineRasterizationStateCreateInfo rasterizationStateCI = vks::initializers::pipelineRasterizationStateCreateInfo(VK_POLYGON_MODE_FILL, VK_CULL_MODE_BACK_BIT, VK_FRONT_FACE_COUNTER_CLOCKWISE, 0);
		VkPipelineColorBlendAttachmentState blendAttachmentStateCI = vks::initializers::pipelineColorBlendAttachmentState(0xf, VK_FALSE);
		VkPipelineColorBlendStateCreateInfo colorBlendStateCI = vks::initializers::pipelineColorBlendStateCreateInfo(1, &blendAttachmentStateCI);
		VkPipelineDepthStencilStateCreateInfo depthStencilStateCI = vks::initializers::pipelineDepthStencilStateCreateInfo(VK_TRUE, VK_TRUE, VK_COMPARE_OP_LESS_OR_EQUAL);
		VkPipelineViewportStateCreateInfo viewportStateCI = vks::initializers::pipelineViewportStateCreateInfo(1, 1, 0);
		VkPipelineMultisampleStateCreateInfo multisampleStateCI = vks::initializers::pipelineMultisampleStateCreateInfo(VK_SAMPLE_COUNT_1_BIT, 0);
		const std::vector<VkDynamicState> dynamicStateEnables = { VK_DYNAMIC_STATE_VIEWPORT, VK_DYNAMIC_STATE_SCISSOR };
		VkPipelineDynamicStateCreateInfo dynamicStateCI = vks::initializers::pipelineDynamicStateCreateInfo(dynamicStateEnables.data(), static_cast<uint32_t>(dynamicStateEnables.size()), 0);
		VkPipelineVertexInputStateCreateInfo emptyInputState = vks::initializers::pipelineVertexInputStateCreateInfo();

		const std::string fragPath = ToneMapping ? "homework1/tonemapping_enable.frag.spv" : "homework1/tonemapping_disable.frag.spv";
		std::array<VkPipelineShaderStageCreateInfo, 2> shaderStages = {
			loadShader(getHomeworkShadersPath() + "homework1/genbrdflut.vert.spv", VK_SHADER_STAGE_VERTEX_BIT),
			loadShader(getHomeworkShadersPath() + fragPath, VK_SHADER_STAGE_FRAGMENT_BIT)
		};

		VkGraphicsPipelineCreateInfo pipelineCI = vks::initializers::pipelineCreateInfo(pipelineLayouts.tonemappingLayout, renderPass, 0);
		pipelineCI.pVertexInputState = &emptyInputState;
		pipelineCI.pInputAssemblyState = &inputAssemblyStateCI;
		pipelineCI.pRasterizationState = &rasterizationStateCI;
		pipelineCI.pColorBlendState = &colorBlendStateCI;
		pipelineCI.pMultisampleState = &multisampleStateCI;
		pipelineCI.pViewportState = &viewportStateCI;
		pipelineCI.pDepthStencilState = &depthStencilStateCI;
		pipelineCI.pDynamicState = &dynamicStateCI;
		pipelineCI.stageCount = static_cast<uint32_t>(shaderStages.size());
		pipelineCI.pStages = shaderStages.data();

		VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCI, nullptr, &toneMappingPipeline));
	}

	// Prepare and initialize uniform buffer containing shader uniforms
	void VulkanExample::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,
			&shaderData.buffer,
			sizeof(shaderData.values)));

		VK_CHECK_RESULT(vulkanDevice->createBuffer(
			VK_BUFFER_USAGE_STORAGE_BUFFER_BIT,
			VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT,
			&shaderData.skinSSBO,
			sizeof(glm::mat4) * glTFModel.nodeCount));
		// Map persistent
		VK_CHECK_RESULT(shaderData.buffer.map());
		VK_CHECK_RESULT(shaderData.skinSSBO.map());

		for (auto& material : glTFModel.materials)
		{
			VK_CHECK_RESULT(vulkanDevice->createBuffer(
				VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT,
				VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT,
				&material.materialData.buffer,
				sizeof(VulkanglTFModel::MaterialData::Values),
				&material.materialData.values
			));

		}

		
		
		updateUniformBuffers();
	}

	void VulkanExample::updateUniformBuffers()
	{
		shaderData.values.projection = camera.matrices.perspective;
		shaderData.values.model = camera.matrices.view;
		shaderData.values.viewPos = camera.viewPos;
		shaderData.values.bFlagSet.x = normalMapping;
		shaderData.values.bFlagSet.y = pbrEnabled;

		memcpy(shaderData.buffer.mapped, &shaderData.values, sizeof(shaderData.values));
	}

// --------- BRDF LUT precompute preparation ----------------
	void VulkanExample::generateIrradianceCubemap()
	{
		auto tStart = std::chrono::high_resolution_clock::now();

		constexpr VkFormat format = VK_FORMAT_R32G32B32A32_SFLOAT;
		constexpr int32_t dim = 64;
		const uint32_t numMips = static_cast<uint32_t>(floor(log2(dim))) + 1;

		VkImageCreateInfo imageCI = vks::initializers::imageCreateInfo();
		imageCI.imageType = VK_IMAGE_TYPE_2D;
		imageCI.format = format;
		imageCI.extent.width = dim;
		imageCI.extent.height = dim;
		imageCI.extent.depth = 1;
		imageCI.mipLevels = numMips;
		imageCI.arrayLayers = 6;
		imageCI.samples = VK_SAMPLE_COUNT_1_BIT;
		imageCI.tiling = VK_IMAGE_TILING_OPTIMAL;
		imageCI.usage = VK_IMAGE_USAGE_SAMPLED_BIT | VK_IMAGE_USAGE_TRANSFER_DST_BIT;
		imageCI.flags = VK_IMAGE_CREATE_CUBE_COMPATIBLE_BIT;
		VK_CHECK_RESULT(vkCreateImage(device, &imageCI, nullptr, &ibltextures.irradianceCube.image))

			// allocate memory for irradiance cube map
		VkMemoryAllocateInfo memAlloc = vks::initializers::memoryAllocateInfo();
		VkMemoryRequirements memReqs;
		vkGetImageMemoryRequirements(device, ibltextures.irradianceCube.image, &memReqs);
		memAlloc.allocationSize = memReqs.size;
		memAlloc.memoryTypeIndex = vulkanDevice->getMemoryType(memReqs.memoryTypeBits, VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT);
		VK_CHECK_RESULT(vkAllocateMemory(device, &memAlloc, nullptr, &ibltextures.irradianceCube.deviceMemory))
		VK_CHECK_RESULT(vkBindImageMemory(device, ibltextures.irradianceCube.image, ibltextures.irradianceCube.deviceMemory, 0))


		VkImageViewCreateInfo viewCI = vks::initializers::imageViewCreateInfo();
		viewCI.viewType = VK_IMAGE_VIEW_TYPE_CUBE;
		viewCI.format = format;
		viewCI.subresourceRange = {};
		viewCI.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
		viewCI.subresourceRange.levelCount = numMips;
		viewCI.subresourceRange.layerCount = 6;
		viewCI.image = ibltextures.irradianceCube.image;
		VK_CHECK_RESULT(vkCreateImageView(device, &viewCI, nullptr, &ibltextures.irradianceCube.view))

			// set up sampler and image view
		VkSamplerCreateInfo samplerCI = vks::initializers::samplerCreateInfo();
		samplerCI.magFilter = VK_FILTER_LINEAR;
		samplerCI.minFilter = VK_FILTER_LINEAR;
		samplerCI.mipmapMode = VK_SAMPLER_MIPMAP_MODE_LINEAR;
		samplerCI.addressModeU = VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE;
		samplerCI.addressModeV = VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE;
		samplerCI.addressModeW = VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE;
		samplerCI.minLod = 0.0f;
		samplerCI.maxLod = static_cast<float>(numMips);
		samplerCI.borderColor = VK_BORDER_COLOR_FLOAT_OPAQUE_WHITE;
		VK_CHECK_RESULT(vkCreateSampler(device, &samplerCI, nullptr, &ibltextures.irradianceCube.sampler))

		ibltextures.irradianceCube.descriptor.imageView = ibltextures.irradianceCube.view;
		ibltextures.irradianceCube.descriptor.sampler = ibltextures.irradianceCube.sampler;
		ibltextures.irradianceCube.descriptor.imageLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
		ibltextures.irradianceCube.device = vulkanDevice;


		//Setup Framebuffer and so on
		VkAttachmentDescription attachDescription = {};
		attachDescription.format = format;
		attachDescription.samples = VK_SAMPLE_COUNT_1_BIT;
		attachDescription.loadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
		attachDescription.storeOp = VK_ATTACHMENT_STORE_OP_STORE;
		attachDescription.stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE;
		attachDescription.stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
		attachDescription.initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
		attachDescription.finalLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;

		VkAttachmentReference colorReference = { 0, VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL };
		VkSubpassDescription subpassDescription = {};
		subpassDescription.pipelineBindPoint = VK_PIPELINE_BIND_POINT_GRAPHICS;
		subpassDescription.colorAttachmentCount = 1;
		subpassDescription.pColorAttachments = &colorReference;

		std::array<VkSubpassDependency, 2> dependencies;
		dependencies[0].srcSubpass = VK_SUBPASS_EXTERNAL;
		dependencies[0].dstSubpass = 0;
		dependencies[0].srcStageMask = VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT;
		dependencies[0].dstStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
		dependencies[0].srcAccessMask = VK_ACCESS_MEMORY_READ_BIT;
		dependencies[0].dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_READ_BIT | VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
		dependencies[0].dependencyFlags = VK_DEPENDENCY_BY_REGION_BIT;
		dependencies[1].srcSubpass = 0;
		dependencies[1].dstSubpass = VK_SUBPASS_EXTERNAL;
		dependencies[1].srcStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
		dependencies[1].dstStageMask = VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT;
		dependencies[1].srcAccessMask = VK_ACCESS_COLOR_ATTACHMENT_READ_BIT | VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
		dependencies[1].dstAccessMask = VK_ACCESS_MEMORY_READ_BIT;
		dependencies[1].dependencyFlags = VK_DEPENDENCY_BY_REGION_BIT;
		//set up render pass
		VkRenderPassCreateInfo renderPassCI = vks::initializers::renderPassCreateInfo();
		renderPassCI.attachmentCount = 1;
		renderPassCI.pAttachments = &attachDescription;
		renderPassCI.subpassCount = 1;
		renderPassCI.pSubpasses = &subpassDescription;
		renderPassCI.dependencyCount = 2;
		renderPassCI.pDependencies = dependencies.data();
		VkRenderPass renderpass;
		VK_CHECK_RESULT(vkCreateRenderPass(device, &renderPassCI, nullptr, &renderpass));

		// create offscreen image
		VkImageCreateInfo imageCreateInfo = vks::initializers::imageCreateInfo();
		imageCreateInfo.imageType = VK_IMAGE_TYPE_2D;
		imageCreateInfo.format = format;
		imageCreateInfo.extent.width = dim;
		imageCreateInfo.extent.height = dim;
		imageCreateInfo.extent.depth = 1;
		imageCreateInfo.mipLevels = 1;
		imageCreateInfo.arrayLayers = 1;
		imageCreateInfo.samples = VK_SAMPLE_COUNT_1_BIT;
		imageCreateInfo.tiling = VK_IMAGE_TILING_OPTIMAL;
		imageCreateInfo.initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
		imageCreateInfo.usage = VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT | VK_IMAGE_USAGE_TRANSFER_SRC_BIT;
		imageCreateInfo.sharingMode = VK_SHARING_MODE_EXCLUSIVE;
		VK_CHECK_RESULT(vkCreateImage(device, &imageCreateInfo, nullptr, &offscreen.image))

			// allocate memory
		VkMemoryAllocateInfo imageCIMemAlloc = vks::initializers::memoryAllocateInfo();
		VkMemoryRequirements imageCIMemReqs;
		vkGetImageMemoryRequirements(device, offscreen.image, &imageCIMemReqs);
		imageCIMemAlloc.allocationSize = imageCIMemReqs.size;
		imageCIMemAlloc.memoryTypeIndex = vulkanDevice->getMemoryType(imageCIMemReqs.memoryTypeBits, VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT);
		VK_CHECK_RESULT(vkAllocateMemory(device, &imageCIMemAlloc, nullptr, &offscreen.memory))
		VK_CHECK_RESULT(vkBindImageMemory(device, offscreen.image, offscreen.memory, 0))

			// create color image view
		VkImageViewCreateInfo colorImageView = vks::initializers::imageViewCreateInfo();
		colorImageView.viewType = VK_IMAGE_VIEW_TYPE_2D;
		colorImageView.format = format;
		colorImageView.flags = 0;
		colorImageView.subresourceRange = {};
		colorImageView.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
		colorImageView.subresourceRange.baseMipLevel = 0;
		colorImageView.subresourceRange.levelCount = 1;
		colorImageView.subresourceRange.baseArrayLayer = 0;
		colorImageView.subresourceRange.layerCount = 1;
		colorImageView.image = offscreen.image;
		VK_CHECK_RESULT(vkCreateImageView(device, &colorImageView, nullptr, &offscreen.view))

			// set up framebuffer for offscreen image
		VkFramebufferCreateInfo fbufCreateInfo = vks::initializers::framebufferCreateInfo();
		fbufCreateInfo.renderPass = renderpass;
		fbufCreateInfo.attachmentCount = 1;
		fbufCreateInfo.pAttachments = &offscreen.view;
		fbufCreateInfo.width = dim;
		fbufCreateInfo.height = dim;
		fbufCreateInfo.layers = 1;
		VK_CHECK_RESULT(vkCreateFramebuffer(device, &fbufCreateInfo, nullptr, &offscreen.framebuffer))

		VkCommandBuffer layoutCmd = vulkanDevice->createCommandBuffer(VK_COMMAND_BUFFER_LEVEL_PRIMARY, true);
		vks::tools::setImageLayout(
			layoutCmd,
			offscreen.image,
			VK_IMAGE_ASPECT_COLOR_BIT,
			VK_IMAGE_LAYOUT_UNDEFINED,
			VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL);
		vulkanDevice->flushCommandBuffer(layoutCmd, queue, true);

		// create descriptor set layout
		VkDescriptorSetLayout descriptorsetlayout;
		std::vector<VkDescriptorSetLayoutBinding> setLayoutBindings =
		{
			vks::initializers::descriptorSetLayoutBinding(VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, VK_SHADER_STAGE_FRAGMENT_BIT, 0),
		};
		VkDescriptorSetLayoutCreateInfo descriptorsetlayoutCI = vks::initializers::descriptorSetLayoutCreateInfo(setLayoutBindings);
		VK_CHECK_RESULT(vkCreateDescriptorSetLayout(device, &descriptorsetlayoutCI, nullptr, &descriptorsetlayout));
		// allocate pool
		std::vector<VkDescriptorPoolSize> poolSizes = { vks::initializers::descriptorPoolSize(VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 1) };
		VkDescriptorPoolCreateInfo descriptorPoolCI = vks::initializers::descriptorPoolCreateInfo(poolSizes, 2);
		VkDescriptorPool descriptorpool;
		VK_CHECK_RESULT(vkCreateDescriptorPool(device, &descriptorPoolCI, nullptr, &descriptorpool));
		//write to poos
		VkDescriptorSet descriptorset;
		VkDescriptorSetAllocateInfo allocInfo = vks::initializers::descriptorSetAllocateInfo(descriptorpool, &descriptorsetlayout, 1);
		VK_CHECK_RESULT(vkAllocateDescriptorSets(device, &allocInfo, &descriptorset));
		VkWriteDescriptorSet writeDescriptorSet = vks::initializers::writeDescriptorSet(descriptorset, VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 0, &ibltextures.skyboxCube.descriptor);
		vkUpdateDescriptorSets(device, 1, &writeDescriptorSet, 0, nullptr);
		// push matrix 
		VkPipelineLayout pipelinelayout;
		std::vector<VkPushConstantRange> pushConstantRanges =
		{
			vks::initializers::pushConstantRange(VK_SHADER_STAGE_VERTEX_BIT | VK_SHADER_STAGE_FRAGMENT_BIT, sizeof(IrradiancePushBlock), 0)
		};
		VkPipelineLayoutCreateInfo pipelineLayoutCI = vks::initializers::pipelineLayoutCreateInfo(&descriptorsetlayout, 1);
		pipelineLayoutCI.pushConstantRangeCount = 1;
		pipelineLayoutCI.pPushConstantRanges = pushConstantRanges.data();
		VK_CHECK_RESULT(vkCreatePipelineLayout(device, &pipelineLayoutCI, nullptr, &pipelinelayout));

		//Pipeline Setting
		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);
		VkPipelineColorBlendAttachmentState blendAttachmentState = vks::initializers::pipelineColorBlendAttachmentState(0xf, VK_FALSE);
		VkPipelineColorBlendStateCreateInfo colorBlendState = vks::initializers::pipelineColorBlendStateCreateInfo(1, &blendAttachmentState);
		VkPipelineDepthStencilStateCreateInfo depthStencilState = vks::initializers::pipelineDepthStencilStateCreateInfo(VK_FALSE, VK_FALSE, VK_COMPARE_OP_LESS_OR_EQUAL);
		VkPipelineViewportStateCreateInfo viewportState = vks::initializers::pipelineViewportStateCreateInfo(1, 1);
		VkPipelineMultisampleStateCreateInfo multisampleState = vks::initializers::pipelineMultisampleStateCreateInfo(VK_SAMPLE_COUNT_1_BIT);
		std::vector<VkDynamicState> dynamicStateEnables = { VK_DYNAMIC_STATE_VIEWPORT, VK_DYNAMIC_STATE_SCISSOR };
		VkPipelineDynamicStateCreateInfo dynamicState = vks::initializers::pipelineDynamicStateCreateInfo(dynamicStateEnables);
		std::array<VkPipelineShaderStageCreateInfo, 2> shaderStages;

		const std::vector<VkVertexInputBindingDescription> vertexInputBindings =
		{
			vks::initializers::vertexInputBindingDescription(0, sizeof(VulkanglTFModel::Vertex), VK_VERTEX_INPUT_RATE_VERTEX),
		};

		const std::vector<VkVertexInputAttributeDescription> vertexInputAttributes = {
			vks::initializers::vertexInputAttributeDescription(0, 0, VK_FORMAT_R32G32B32_SFLOAT, offsetof(VulkanglTFModel::Vertex, pos)),	// Location 0: Position
		};
		VkPipelineVertexInputStateCreateInfo vertexInputStateCI = vks::initializers::pipelineVertexInputStateCreateInfo();
		vertexInputStateCI.vertexBindingDescriptionCount = static_cast<uint32_t>(vertexInputBindings.size());
		vertexInputStateCI.pVertexBindingDescriptions = vertexInputBindings.data();
		vertexInputStateCI.vertexAttributeDescriptionCount = static_cast<uint32_t>(vertexInputAttributes.size());
		vertexInputStateCI.pVertexAttributeDescriptions = vertexInputAttributes.data();

		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 = 2;
		pipelineCI.pStages = shaderStages.data();
		pipelineCI.renderPass = renderpass;

		pipelineCI.pVertexInputState = &vertexInputStateCI;
		shaderStages[0] = loadShader(getHomeworkShadersPath() + "homework1/filtercube.vert.spv", VK_SHADER_STAGE_VERTEX_BIT);
		shaderStages[1] = loadShader(getHomeworkShadersPath() + "homework1/irradiancecube.frag.spv", VK_SHADER_STAGE_FRAGMENT_BIT);
		VkPipeline pipeline;
		VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCI, nullptr, &pipeline));

		// offscreen Render pass begin
		VkClearValue clearValues[1];
		clearValues[0].color = { { 0.0f, 0.0f, 0.2f, 0.0f } };
		VkRenderPassBeginInfo renderPassBeginInfo = vks::initializers::renderPassBeginInfo();
		renderPassBeginInfo.renderPass = renderpass;
		renderPassBeginInfo.framebuffer = offscreen.framebuffer;
		renderPassBeginInfo.renderArea.extent.width = dim;
		renderPassBeginInfo.renderArea.extent.height = dim;
		renderPassBeginInfo.clearValueCount = 1;
		renderPassBeginInfo.pClearValues = clearValues;

		//six face in cube map
		std::vector<glm::mat4> matrices = {
			// POSITIVE_X
			glm::rotate(glm::rotate(glm::mat4(1.0f), glm::radians(90.0f), glm::vec3(0.0f, 1.0f, 0.0f)), glm::radians(180.0f), glm::vec3(1.0f, 0.0f, 0.0f)),
			// NEGATIVE_X
			glm::rotate(glm::rotate(glm::mat4(1.0f), glm::radians(-90.0f), glm::vec3(0.0f, 1.0f, 0.0f)), glm::radians(180.0f), glm::vec3(1.0f, 0.0f, 0.0f)),
			// POSITIVE_Y
			glm::rotate(glm::mat4(1.0f), glm::radians(-90.0f), glm::vec3(1.0f, 0.0f, 0.0f)),
			// NEGATIVE_Y
			glm::rotate(glm::mat4(1.0f), glm::radians(90.0f), glm::vec3(1.0f, 0.0f, 0.0f)),
			// POSITIVE_Z
			glm::rotate(glm::mat4(1.0f), glm::radians(180.0f), glm::vec3(1.0f, 0.0f, 0.0f)),
			// NEGATIVE_Z
			glm::rotate(glm::mat4(1.0f), glm::radians(180.0f), glm::vec3(0.0f, 0.0f, 1.0f)),
		};
		VkCommandBuffer cmdBuf = vulkanDevice->createCommandBuffer(VK_COMMAND_BUFFER_LEVEL_PRIMARY, true);
		VkViewport viewport = vks::initializers::viewport((float)dim, (float)dim, 0.0f, 1.0f);
		VkRect2D scissor = vks::initializers::rect2D(dim, dim, 0, 0);

		vkCmdSetViewport(cmdBuf, 0, 1, &viewport);
		vkCmdSetScissor(cmdBuf, 0, 1, &scissor);

		VkImageSubresourceRange subresourceRange = {};
		subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
		subresourceRange.baseMipLevel = 0;
		subresourceRange.levelCount = numMips;
		subresourceRange.layerCount = 6;

		vks::tools::setImageLayout(
			cmdBuf,
			ibltextures.irradianceCube.image,
			VK_IMAGE_LAYOUT_UNDEFINED,
			VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL,
			subresourceRange);

		for (uint32_t m = 0; m < numMips; ++m)
		{
			for (uint32_t f = 0; f < 6; ++f)
			{
				viewport.width = static_cast<float>(dim * std::pow(0.5f, m));
				viewport.height = static_cast<float>(dim * std::pow(0.5f, m));
				vkCmdSetViewport(cmdBuf, 0, 1, &viewport);
				// Render scene from cube face's point of view
				vkCmdBeginRenderPass(cmdBuf, &renderPassBeginInfo, VK_SUBPASS_CONTENTS_INLINE);
				irradinacePushBlock.mvp = glm::perspective((float)(M_PI / 2.0), 1.0f, 0.1f, 512.0f) * matrices[f];
				vkCmdPushConstants(cmdBuf, pipelinelayout, VK_SHADER_STAGE_VERTEX_BIT | VK_SHADER_STAGE_FRAGMENT_BIT, 0, sizeof(IrradiancePushBlock), &irradinacePushBlock);

				vkCmdBindPipeline(cmdBuf, VK_PIPELINE_BIND_POINT_GRAPHICS, pipeline);
				vkCmdBindDescriptorSets(cmdBuf, VK_PIPELINE_BIND_POINT_GRAPHICS, pipelinelayout, 0, 1, &descriptorset, 0, NULL);
				skyboxModel.draw(cmdBuf, pipelinelayout);
				vkCmdEndRenderPass(cmdBuf);

				vks::tools::setImageLayout(
					cmdBuf,
					offscreen.image,
					VK_IMAGE_ASPECT_COLOR_BIT,
					VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL,
					VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL);

				VkImageCopy copyRegion = {};
				copyRegion.srcSubresource.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
				copyRegion.srcSubresource.layerCount = 1;
				copyRegion.srcSubresource.mipLevel = 0;
				copyRegion.srcSubresource.baseArrayLayer = 0;

				copyRegion.dstSubresource.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
				copyRegion.dstSubresource.layerCount = 1;
				copyRegion.dstSubresource.mipLevel = m;
				copyRegion.dstSubresource.baseArrayLayer = f;

				copyRegion.extent.width = static_cast<uint32_t>(viewport.width);
				copyRegion.extent.height = static_cast<uint32_t>(viewport.height);
				copyRegion.extent.depth = 1;

				vkCmdCopyImage(
					cmdBuf,
					offscreen.image,
					VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL,
					ibltextures.irradianceCube.image,
					VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL,
					1,
					&copyRegion);
				vks::tools::setImageLayout(cmdBuf,
					offscreen.image,
					VK_IMAGE_ASPECT_COLOR_BIT,
					VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL,
					VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL
				);
			}
		}

		vks::tools::setImageLayout(cmdBuf,
			ibltextures.irradianceCube.image,
			VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL,
			VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL,
			subresourceRange);
		vulkanDevice->flushCommandBuffer(cmdBuf, queue);

		vkDestroyRenderPass(device, renderpass, nullptr);
		vkDestroyFramebuffer(device, offscreen.framebuffer, nullptr);
		vkFreeMemory(device, offscreen.memory, nullptr);
		vkDestroyImageView(device, offscreen.view, nullptr);
		vkDestroyImage(device, offscreen.image, nullptr);
		vkDestroyDescriptorPool(device, descriptorpool, nullptr);
		vkDestroyDescriptorSetLayout(device, descriptorsetlayout, nullptr);
		vkDestroyPipeline(device, pipeline, nullptr);
		vkDestroyPipelineLayout(device, pipelinelayout, nullptr);

		auto tEnd = std::chrono::high_resolution_clock::now();
		auto tDiff = std::chrono::duration<double, std::milli>(tEnd - tStart).count();
		std::cout << "Generating irradiance cube with " << numMips << " mip levels took " << tDiff << " ms" << std::endl;

	}


	void VulkanExample::generatePrefilteredCubemap()
	{
		auto tStart = std::chrono::high_resolution_clock::now();

		constexpr VkFormat format = VK_FORMAT_R32G32B32A32_SFLOAT;
		constexpr int32_t dim = 512;
		const uint32_t numMips = static_cast<uint32_t>(floor(log2(dim))) + 1;

		VkImageCreateInfo imageCI = vks::initializers::imageCreateInfo();
		imageCI.imageType = VK_IMAGE_TYPE_2D;
		imageCI.format = format;
		imageCI.extent.width = dim;
		imageCI.extent.height = dim;
		imageCI.extent.depth = 1;
		imageCI.mipLevels = numMips;
		imageCI.arrayLayers = 6;
		imageCI.samples = VK_SAMPLE_COUNT_1_BIT;
		imageCI.tiling = VK_IMAGE_TILING_OPTIMAL;
		imageCI.usage = VK_IMAGE_USAGE_SAMPLED_BIT | VK_IMAGE_USAGE_TRANSFER_DST_BIT;
		imageCI.flags = VK_IMAGE_CREATE_CUBE_COMPATIBLE_BIT;

		VK_CHECK_RESULT(vkCreateImage(device, &imageCI, nullptr, &ibltextures.prefilteredCube.image));
		VkMemoryAllocateInfo memAlloc = vks::initializers::memoryAllocateInfo();
		VkMemoryRequirements memReqs;
		vkGetImageMemoryRequirements(device, ibltextures.prefilteredCube.image, &memReqs);
		memAlloc.allocationSize = memReqs.size;
		memAlloc.memoryTypeIndex = vulkanDevice->getMemoryType(memReqs.memoryTypeBits, VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT);
		VK_CHECK_RESULT(vkAllocateMemory(device, &memAlloc, nullptr, &ibltextures.prefilteredCube.deviceMemory));
		VK_CHECK_RESULT(vkBindImageMemory(device, ibltextures.prefilteredCube.image, ibltextures.prefilteredCube.deviceMemory, 0));

		// Image view
		VkImageViewCreateInfo viewCI = vks::initializers::imageViewCreateInfo();
		viewCI.viewType = VK_IMAGE_VIEW_TYPE_CUBE;
		viewCI.format = format;
		viewCI.subresourceRange = {};
		viewCI.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
		viewCI.subresourceRange.levelCount = numMips;
		viewCI.subresourceRange.layerCount = 6;
		viewCI.image = ibltextures.prefilteredCube.image;
		VK_CHECK_RESULT(vkCreateImageView(device, &viewCI, nullptr, &ibltextures.prefilteredCube.view));

		// Sampler
		VkSamplerCreateInfo samplerCI = vks::initializers::samplerCreateInfo();
		samplerCI.magFilter = VK_FILTER_LINEAR;
		samplerCI.minFilter = VK_FILTER_LINEAR;
		samplerCI.mipmapMode = VK_SAMPLER_MIPMAP_MODE_LINEAR;
		samplerCI.addressModeU = VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE;
		samplerCI.addressModeV = VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE;
		samplerCI.addressModeW = VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE;
		samplerCI.minLod = 0.0f;
		samplerCI.maxLod = static_cast<float>(numMips);
		samplerCI.borderColor = VK_BORDER_COLOR_FLOAT_OPAQUE_WHITE;
		VK_CHECK_RESULT(vkCreateSampler(device, &samplerCI, nullptr, &ibltextures.prefilteredCube.sampler));

		ibltextures.prefilteredCube.descriptor.imageView = ibltextures.prefilteredCube.view;
		ibltextures.prefilteredCube.descriptor.sampler = ibltextures.prefilteredCube.sampler;
		ibltextures.prefilteredCube.descriptor.imageLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
		ibltextures.prefilteredCube.device = vulkanDevice;

		// FB, Att, RP, Pipe, etc.
		VkAttachmentDescription attDesc = {};
		// Color attachment
		attDesc.format = format;
		attDesc.samples = VK_SAMPLE_COUNT_1_BIT;
		attDesc.loadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
		attDesc.storeOp = VK_ATTACHMENT_STORE_OP_STORE;
		attDesc.stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE;
		attDesc.stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
		attDesc.initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
		attDesc.finalLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
		VkAttachmentReference colorReference = { 0, VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL };

		VkSubpassDescription subpassDescription = {};
		subpassDescription.pipelineBindPoint = VK_PIPELINE_BIND_POINT_GRAPHICS;
		subpassDescription.colorAttachmentCount = 1;
		subpassDescription.pColorAttachments = &colorReference;

		// Use subpass dependencies for layout transitions
		std::array<VkSubpassDependency, 2> dependencies;
		dependencies[0].srcSubpass = VK_SUBPASS_EXTERNAL;
		dependencies[0].dstSubpass = 0;
		dependencies[0].srcStageMask = VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT;
		dependencies[0].dstStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
		dependencies[0].srcAccessMask = VK_ACCESS_MEMORY_READ_BIT;
		dependencies[0].dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_READ_BIT | VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
		dependencies[0].dependencyFlags = VK_DEPENDENCY_BY_REGION_BIT;
		dependencies[1].srcSubpass = 0;
		dependencies[1].dstSubpass = VK_SUBPASS_EXTERNAL;
		dependencies[1].srcStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
		dependencies[1].dstStageMask = VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT;
		dependencies[1].srcAccessMask = VK_ACCESS_COLOR_ATTACHMENT_READ_BIT | VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
		dependencies[1].dstAccessMask = VK_ACCESS_MEMORY_READ_BIT;
		dependencies[1].dependencyFlags = VK_DEPENDENCY_BY_REGION_BIT;

		// Renderpass
		VkRenderPassCreateInfo renderPassCI = vks::initializers::renderPassCreateInfo();
		renderPassCI.attachmentCount = 1;
		renderPassCI.pAttachments = &attDesc;
		renderPassCI.subpassCount = 1;
		renderPassCI.pSubpasses = &subpassDescription;
		renderPassCI.dependencyCount = 2;
		renderPassCI.pDependencies = dependencies.data();
		VkRenderPass renderpass;
		VK_CHECK_RESULT(vkCreateRenderPass(device, &renderPassCI, nullptr, &renderpass));

		//framebuffer
		{
			// Color attachment
			VkImageCreateInfo imageCreateInfo = vks::initializers::imageCreateInfo();
			imageCreateInfo.imageType = VK_IMAGE_TYPE_2D;
			imageCreateInfo.format = format;
			imageCreateInfo.extent.width = dim;
			imageCreateInfo.extent.height = dim;
			imageCreateInfo.extent.depth = 1;
			imageCreateInfo.mipLevels = 1;
			imageCreateInfo.arrayLayers = 1;
			imageCreateInfo.samples = VK_SAMPLE_COUNT_1_BIT;
			imageCreateInfo.tiling = VK_IMAGE_TILING_OPTIMAL;
			imageCreateInfo.initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
			imageCreateInfo.usage = VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT | VK_IMAGE_USAGE_TRANSFER_SRC_BIT;
			imageCreateInfo.sharingMode = VK_SHARING_MODE_EXCLUSIVE;
			VK_CHECK_RESULT(vkCreateImage(device, &imageCreateInfo, nullptr, &offscreen.image));

			VkMemoryAllocateInfo memAlloc = vks::initializers::memoryAllocateInfo();
			VkMemoryRequirements memReqs;
			vkGetImageMemoryRequirements(device, offscreen.image, &memReqs);
			memAlloc.allocationSize = memReqs.size;
			memAlloc.memoryTypeIndex = vulkanDevice->getMemoryType(memReqs.memoryTypeBits, VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT);
			VK_CHECK_RESULT(vkAllocateMemory(device, &memAlloc, nullptr, &offscreen.memory));
			VK_CHECK_RESULT(vkBindImageMemory(device, offscreen.image, offscreen.memory, 0));

			VkImageViewCreateInfo colorImageView = vks::initializers::imageViewCreateInfo();
			colorImageView.viewType = VK_IMAGE_VIEW_TYPE_2D;
			colorImageView.format = format;
			colorImageView.flags = 0;
			colorImageView.subresourceRange = {};
			colorImageView.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
			colorImageView.subresourceRange.baseMipLevel = 0;
			colorImageView.subresourceRange.levelCount = 1;
			colorImageView.subresourceRange.baseArrayLayer = 0;
			colorImageView.subresourceRange.layerCount = 1;
			colorImageView.image = offscreen.image;
			VK_CHECK_RESULT(vkCreateImageView(device, &colorImageView, nullptr, &offscreen.view));

			VkFramebufferCreateInfo fbufCreateInfo = vks::initializers::framebufferCreateInfo();
			fbufCreateInfo.renderPass = renderpass;
			fbufCreateInfo.attachmentCount = 1;
			fbufCreateInfo.pAttachments = &offscreen.view;
			fbufCreateInfo.width = dim;
			fbufCreateInfo.height = dim;
			fbufCreateInfo.layers = 1;
			VK_CHECK_RESULT(vkCreateFramebuffer(device, &fbufCreateInfo, nullptr, &offscreen.framebuffer));

			VkCommandBuffer layoutCmd = vulkanDevice->createCommandBuffer(VK_COMMAND_BUFFER_LEVEL_PRIMARY, true);
			vks::tools::setImageLayout(
				layoutCmd,
				offscreen.image,
				VK_IMAGE_ASPECT_COLOR_BIT,
				VK_IMAGE_LAYOUT_UNDEFINED,
				VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL);
			vulkanDevice->flushCommandBuffer(layoutCmd, queue, true);
		}

		// Descriptors
		VkDescriptorSetLayout descriptorsetlayout;
		std::vector<VkDescriptorSetLayoutBinding> setLayoutBindings = {
			vks::initializers::descriptorSetLayoutBinding(VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, VK_SHADER_STAGE_FRAGMENT_BIT, 0),
		};
		VkDescriptorSetLayoutCreateInfo descriptorsetlayoutCI = vks::initializers::descriptorSetLayoutCreateInfo(setLayoutBindings);
		VK_CHECK_RESULT(vkCreateDescriptorSetLayout(device, &descriptorsetlayoutCI, nullptr, &descriptorsetlayout));

		// Descriptor Pool
		std::vector<VkDescriptorPoolSize> poolSizes = { vks::initializers::descriptorPoolSize(VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 1) };
		VkDescriptorPoolCreateInfo descriptorPoolCI = vks::initializers::descriptorPoolCreateInfo(poolSizes, 2);
		VkDescriptorPool descriptorpool;
		VK_CHECK_RESULT(vkCreateDescriptorPool(device, &descriptorPoolCI, nullptr, &descriptorpool));

		VkDescriptorSet descriptorset;
		VkDescriptorSetAllocateInfo allocInfo = vks::initializers::descriptorSetAllocateInfo(descriptorpool, &descriptorsetlayout, 1);
		VK_CHECK_RESULT(vkAllocateDescriptorSets(device, &allocInfo, &descriptorset));
		VkWriteDescriptorSet writeDescriptorSet = vks::initializers::writeDescriptorSet(descriptorset, VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 0, &ibltextures.skyboxCube.descriptor);
		vkUpdateDescriptorSets(device, 1, &writeDescriptorSet, 0, nullptr);


		std::vector<VkPushConstantRange> pushConstantRanges = {
			vks::initializers::pushConstantRange(VK_SHADER_STAGE_VERTEX_BIT | VK_SHADER_STAGE_FRAGMENT_BIT, sizeof(PrefilterPushBlock), 0),
		};
		VkPipelineLayoutCreateInfo pipelineLayoutCI = vks::initializers::pipelineLayoutCreateInfo(&descriptorsetlayout, 1);
		pipelineLayoutCI.pushConstantRangeCount = 1;
		pipelineLayoutCI.pPushConstantRanges = pushConstantRanges.data();
		VkPipelineLayout pipelinelayout;
		VK_CHECK_RESULT(vkCreatePipelineLayout(device, &pipelineLayoutCI, nullptr, &pipelinelayout));

		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);
		VkPipelineColorBlendAttachmentState blendAttachmentState = vks::initializers::pipelineColorBlendAttachmentState(0xf, VK_FALSE);
		VkPipelineColorBlendStateCreateInfo colorBlendState = vks::initializers::pipelineColorBlendStateCreateInfo(1, &blendAttachmentState);
		VkPipelineDepthStencilStateCreateInfo depthStencilState = vks::initializers::pipelineDepthStencilStateCreateInfo(VK_FALSE, VK_FALSE, VK_COMPARE_OP_LESS_OR_EQUAL);
		VkPipelineViewportStateCreateInfo viewportState = vks::initializers::pipelineViewportStateCreateInfo(1, 1);
		VkPipelineMultisampleStateCreateInfo multisampleState = vks::initializers::pipelineMultisampleStateCreateInfo(VK_SAMPLE_COUNT_1_BIT);
		std::vector<VkDynamicState> dynamicStateEnables = { VK_DYNAMIC_STATE_VIEWPORT, VK_DYNAMIC_STATE_SCISSOR };
		VkPipelineDynamicStateCreateInfo dynamicState = vks::initializers::pipelineDynamicStateCreateInfo(dynamicStateEnables);
		std::array<VkPipelineShaderStageCreateInfo, 2> shaderStages;

		const std::vector<VkVertexInputBindingDescription> vertexInputBindings =
		{
			vks::initializers::vertexInputBindingDescription(0, sizeof(VulkanglTFModel::Vertex), VK_VERTEX_INPUT_RATE_VERTEX),
		};

		const std::vector<VkVertexInputAttributeDescription> vertexInputAttributes = {
			vks::initializers::vertexInputAttributeDescription(0, 0, VK_FORMAT_R32G32B32_SFLOAT, offsetof(VulkanglTFModel::Vertex, pos)),	// Location 0: Position
		};
		VkPipelineVertexInputStateCreateInfo vertexInputStateCI = vks::initializers::pipelineVertexInputStateCreateInfo();
		vertexInputStateCI.vertexBindingDescriptionCount = static_cast<uint32_t>(vertexInputBindings.size());
		vertexInputStateCI.pVertexBindingDescriptions = vertexInputBindings.data();
		vertexInputStateCI.vertexAttributeDescriptionCount = static_cast<uint32_t>(vertexInputAttributes.size());
		vertexInputStateCI.pVertexAttributeDescriptions = vertexInputAttributes.data();

		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 = 2;
		pipelineCI.pStages = shaderStages.data();
		pipelineCI.renderPass = renderpass;
		pipelineCI.pVertexInputState = &vertexInputStateCI;

		shaderStages[0] = loadShader(getHomeworkShadersPath() + "homework1/filtercube.vert.spv", VK_SHADER_STAGE_VERTEX_BIT);
		shaderStages[1] = loadShader(getHomeworkShadersPath() + "homework1/prefilterenvmap.frag.spv", VK_SHADER_STAGE_FRAGMENT_BIT);

		VkPipeline pipeline;
		VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCI, nullptr, &pipeline));

		//Render & build cmd
		VkClearValue clearValues[1];
		clearValues[0].color = { { 0.0f, 0.0f, 0.2f, 0.0f } };

		VkRenderPassBeginInfo renderPassBeginInfo = vks::initializers::renderPassBeginInfo();
		// Reuse render pass from example pass
		renderPassBeginInfo.renderPass = renderpass;
		renderPassBeginInfo.framebuffer = offscreen.framebuffer;
		renderPassBeginInfo.renderArea.extent.width = dim;
		renderPassBeginInfo.renderArea.extent.height = dim;
		renderPassBeginInfo.clearValueCount = 1;
		renderPassBeginInfo.pClearValues = clearValues;

		std::vector<glm::mat4> matrices = {
			// POSITIVE_X
			glm::rotate(glm::rotate(glm::mat4(1.0f), glm::radians(90.0f), glm::vec3(0.0f, 1.0f, 0.0f)), glm::radians(180.0f), glm::vec3(1.0f, 0.0f, 0.0f)),
			// NEGATIVE_X
			glm::rotate(glm::rotate(glm::mat4(1.0f), glm::radians(-90.0f), glm::vec3(0.0f, 1.0f, 0.0f)), glm::radians(180.0f), glm::vec3(1.0f, 0.0f, 0.0f)),
			// POSITIVE_Y
			glm::rotate(glm::mat4(1.0f), glm::radians(-90.0f), glm::vec3(1.0f, 0.0f, 0.0f)),
			// NEGATIVE_Y
			glm::rotate(glm::mat4(1.0f), glm::radians(90.0f), glm::vec3(1.0f, 0.0f, 0.0f)),
			// POSITIVE_Z
			glm::rotate(glm::mat4(1.0f), glm::radians(180.0f), glm::vec3(1.0f, 0.0f, 0.0f)),
			// NEGATIVE_Z
			glm::rotate(glm::mat4(1.0f), glm::radians(180.0f), glm::vec3(0.0f, 0.0f, 1.0f)),
		};
		VkCommandBuffer cmdBuf = vulkanDevice->createCommandBuffer(VK_COMMAND_BUFFER_LEVEL_PRIMARY, true);

		VkViewport viewport = vks::initializers::viewport((float)dim, (float)dim, 0.0f, 1.0f);
		VkRect2D scissor = vks::initializers::rect2D(dim, dim, 0, 0);

		vkCmdSetViewport(cmdBuf, 0, 1, &viewport);
		vkCmdSetScissor(cmdBuf, 0, 1, &scissor);

		VkImageSubresourceRange subresourceRange = {};
		subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
		subresourceRange.baseMipLevel = 0;
		subresourceRange.levelCount = numMips;
		subresourceRange.layerCount = 6;

		vks::tools::setImageLayout(
			cmdBuf,
			ibltextures.prefilteredCube.image,
			VK_IMAGE_LAYOUT_UNDEFINED,
			VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL,
			subresourceRange);

		for (uint32_t m = 0; m < numMips; ++m)
		{
			//mip level according to roughness
			prefilterPushBlock.roughness = float(m) / float(numMips - 1);
			for (uint32_t f = 0; f < 6; ++f)
			{
				viewport.width = static_cast<float>(dim * std::pow(0.5f, m));
				viewport.height = static_cast<float>(dim * std::pow(0.5f, m));
				vkCmdSetViewport(cmdBuf, 0, 1, &viewport);
				// Render scene from cube face's point of view
				vkCmdBeginRenderPass(cmdBuf, &renderPassBeginInfo, VK_SUBPASS_CONTENTS_INLINE);

				// Update shader push constant block
				prefilterPushBlock.mvp = glm::perspective((float)(M_PI / 2.0), 1.0f, 0.1f, 512.0f) * matrices[f];

				vkCmdPushConstants(cmdBuf, pipelinelayout, VK_SHADER_STAGE_VERTEX_BIT | VK_SHADER_STAGE_FRAGMENT_BIT, 0, sizeof(PrefilterPushBlock), &prefilterPushBlock);
				vkCmdBindPipeline(cmdBuf, VK_PIPELINE_BIND_POINT_GRAPHICS, pipeline);
				vkCmdBindDescriptorSets(cmdBuf, VK_PIPELINE_BIND_POINT_GRAPHICS, pipelinelayout, 0, 1, &descriptorset, 0, nullptr);
				skyboxModel.draw(cmdBuf, pipelinelayout);
				vkCmdEndRenderPass(cmdBuf);

				vks::tools::setImageLayout(
					cmdBuf,
					offscreen.image,
					VK_IMAGE_ASPECT_COLOR_BIT,
					VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL,
					VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL);

				VkImageCopy copyRegion{};
				copyRegion.srcSubresource.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
				copyRegion.srcSubresource.baseArrayLayer = 0;
				copyRegion.srcSubresource.mipLevel = 0;
				copyRegion.srcSubresource.layerCount = 1;
				copyRegion.srcOffset = { 0, 0, 0 };

				copyRegion.dstSubresource.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
				copyRegion.dstSubresource.baseArrayLayer = f;
				copyRegion.dstSubresource.mipLevel = m;
				copyRegion.dstSubresource.layerCount = 1;
				copyRegion.dstOffset = { 0, 0, 0 };

				copyRegion.extent.width = static_cast<uint32_t>(viewport.width);
				copyRegion.extent.height = static_cast<uint32_t>(viewport.height);
				copyRegion.extent.depth = 1;

				vkCmdCopyImage(
					cmdBuf,
					offscreen.image,
					VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL,
					ibltextures.prefilteredCube.image,
					VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL,
					1,
					&copyRegion);

				//Reset frame buffer image layout
				vks::tools::setImageLayout(
					cmdBuf,
					offscreen.image,
					VK_IMAGE_ASPECT_COLOR_BIT,
					VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL,
					VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL);
			}
		}

		//Set format shader read
		vks::tools::setImageLayout(
			cmdBuf,
			ibltextures.prefilteredCube.image,
			VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL,
			VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL,
			subresourceRange);

		vulkanDevice->flushCommandBuffer(cmdBuf, queue);

		vkDestroyRenderPass(device, renderpass, nullptr);
		vkDestroyFramebuffer(device, offscreen.framebuffer, nullptr);
		vkFreeMemory(device, offscreen.memory, nullptr);
		vkDestroyImageView(device, offscreen.view, nullptr);
		vkDestroyImage(device, offscreen.image, nullptr);
		vkDestroyDescriptorPool(device, descriptorpool, nullptr);
		vkDestroyDescriptorSetLayout(device, descriptorsetlayout, nullptr);
		vkDestroyPipeline(device, pipeline, nullptr);
		vkDestroyPipelineLayout(device, pipelinelayout, nullptr);

		auto tEnd = std::chrono::high_resolution_clock::now();
		auto tDiff = std::chrono::duration<double, std::milli>(tEnd - tStart).count();
		std::cout << "Generating pre-filtered enivornment cube with " << numMips << " mip levels took " << tDiff << " ms" << std::endl;
	}

	void VulkanExample::generateBRDFLUT()
	{
		auto tStart = std::chrono::high_resolution_clock::now();

		constexpr VkFormat format = VK_FORMAT_R16G16_SFLOAT;
		constexpr int32_t dim = 512;

		// Image
		VkImageCreateInfo imageCI = vks::initializers::imageCreateInfo();
		imageCI.imageType = VK_IMAGE_TYPE_2D;
		imageCI.format = format;
		imageCI.extent.width = dim;
		imageCI.extent.height = dim;
		imageCI.extent.depth = 1;
		imageCI.mipLevels = 1;
		imageCI.arrayLayers = 1;
		imageCI.samples = VK_SAMPLE_COUNT_1_BIT;
		imageCI.tiling = VK_IMAGE_TILING_OPTIMAL;
		imageCI.usage = VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT | VK_IMAGE_USAGE_SAMPLED_BIT;
		VK_CHECK_RESULT(vkCreateImage(device, &imageCI, nullptr, &ibltextures.lutBrdf.image));
		VkMemoryAllocateInfo memAlloc = vks::initializers::memoryAllocateInfo();
		VkMemoryRequirements memReqs;
		vkGetImageMemoryRequirements(device, ibltextures.lutBrdf.image, &memReqs);
		memAlloc.allocationSize = memReqs.size;
		memAlloc.memoryTypeIndex = vulkanDevice->getMemoryType(memReqs.memoryTypeBits, VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT);
		VK_CHECK_RESULT(vkAllocateMemory(device, &memAlloc, nullptr, &ibltextures.lutBrdf.deviceMemory));
		VK_CHECK_RESULT(vkBindImageMemory(device, ibltextures.lutBrdf.image, ibltextures.lutBrdf.deviceMemory, 0));

		// Image view
		VkImageViewCreateInfo viewCI = vks::initializers::imageViewCreateInfo();
		viewCI.viewType = VK_IMAGE_VIEW_TYPE_2D;
		viewCI.format = format;
		viewCI.subresourceRange = {};
		viewCI.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
		viewCI.subresourceRange.levelCount = 1;
		viewCI.subresourceRange.layerCount = 1;
		viewCI.image = ibltextures.lutBrdf.image;
		VK_CHECK_RESULT(vkCreateImageView(device, &viewCI, nullptr, &ibltextures.lutBrdf.view));

		// Sampler
		VkSamplerCreateInfo samplerCI = vks::initializers::samplerCreateInfo();
		samplerCI.magFilter = VK_FILTER_LINEAR;
		samplerCI.minFilter = VK_FILTER_LINEAR;
		samplerCI.mipmapMode = VK_SAMPLER_MIPMAP_MODE_LINEAR;
		samplerCI.addressModeU = VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE;
		samplerCI.addressModeV = VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE;
		samplerCI.addressModeW = VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE;
		samplerCI.minLod = 0.0f;
		samplerCI.maxLod = 1.0f;
		samplerCI.borderColor = VK_BORDER_COLOR_FLOAT_OPAQUE_WHITE;
		VK_CHECK_RESULT(vkCreateSampler(device, &samplerCI, nullptr, &ibltextures.lutBrdf.sampler));

		ibltextures.lutBrdf.descriptor.imageView = ibltextures.lutBrdf.view;
		ibltextures.lutBrdf.descriptor.sampler = ibltextures.lutBrdf.sampler;
		ibltextures.lutBrdf.descriptor.imageLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
		ibltextures.lutBrdf.device = vulkanDevice;

		// FB, Att, RP, Pipe, etc.
		VkAttachmentDescription attDesc = {};
		// Color attachment
		attDesc.format = format;
		attDesc.samples = VK_SAMPLE_COUNT_1_BIT;
		attDesc.loadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
		attDesc.storeOp = VK_ATTACHMENT_STORE_OP_STORE;
		attDesc.stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE;
		attDesc.stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
		attDesc.initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
		attDesc.finalLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
		VkAttachmentReference colorReference = { 0, VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL };

		VkSubpassDescription subpassDescription = {};
		subpassDescription.pipelineBindPoint = VK_PIPELINE_BIND_POINT_GRAPHICS;
		subpassDescription.colorAttachmentCount = 1;
		subpassDescription.pColorAttachments = &colorReference;

		// Use subpass dependencies for layout transitions
		std::array<VkSubpassDependency, 2> dependencies;
		dependencies[0].srcSubpass = VK_SUBPASS_EXTERNAL;
		dependencies[0].dstSubpass = 0;
		dependencies[0].srcStageMask = VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT;
		dependencies[0].dstStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
		dependencies[0].srcAccessMask = VK_ACCESS_MEMORY_READ_BIT;
		dependencies[0].dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_READ_BIT | VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
		dependencies[0].dependencyFlags = VK_DEPENDENCY_BY_REGION_BIT;
		dependencies[1].srcSubpass = 0;
		dependencies[1].dstSubpass = VK_SUBPASS_EXTERNAL;
		dependencies[1].srcStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
		dependencies[1].dstStageMask = VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT;
		dependencies[1].srcAccessMask = VK_ACCESS_COLOR_ATTACHMENT_READ_BIT | VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
		dependencies[1].dstAccessMask = VK_ACCESS_MEMORY_READ_BIT;
		dependencies[1].dependencyFlags = VK_DEPENDENCY_BY_REGION_BIT;

		// Create the actual renderpass
		VkRenderPassCreateInfo renderPassCI = vks::initializers::renderPassCreateInfo();
		renderPassCI.attachmentCount = 1;
		renderPassCI.pAttachments = &attDesc;
		renderPassCI.subpassCount = 1;
		renderPassCI.pSubpasses = &subpassDescription;
		renderPassCI.dependencyCount = 2;
		renderPassCI.pDependencies = dependencies.data();

		VkRenderPass renderpass;
		VK_CHECK_RESULT(vkCreateRenderPass(device, &renderPassCI, nullptr, &renderpass));

		VkFramebufferCreateInfo framebufferCI = vks::initializers::framebufferCreateInfo();
		framebufferCI.renderPass = renderpass;
		framebufferCI.attachmentCount = 1;
		framebufferCI.pAttachments = &ibltextures.lutBrdf.view;
		framebufferCI.width = dim;
		framebufferCI.height = dim;
		framebufferCI.layers = 1;

		VkFramebuffer framebuffer;
		VK_CHECK_RESULT(vkCreateFramebuffer(device, &framebufferCI, nullptr, &framebuffer));

		// Descriptors
		VkDescriptorSetLayout descriptorsetlayout;
		std::vector<VkDescriptorSetLayoutBinding> setLayoutBindings = {};
		VkDescriptorSetLayoutCreateInfo descriptorsetlayoutCI = vks::initializers::descriptorSetLayoutCreateInfo(setLayoutBindings);
		VK_CHECK_RESULT(vkCreateDescriptorSetLayout(device, &descriptorsetlayoutCI, nullptr, &descriptorsetlayout));

		// Descriptor Pool
		std::vector<VkDescriptorPoolSize> poolSizes = { vks::initializers::descriptorPoolSize(VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 1) };
		VkDescriptorPoolCreateInfo descriptorPoolCI = vks::initializers::descriptorPoolCreateInfo(poolSizes, 2);
		VkDescriptorPool descriptorpool;
		VK_CHECK_RESULT(vkCreateDescriptorPool(device, &descriptorPoolCI, nullptr, &descriptorpool));

		// Descriptor sets
		VkDescriptorSet descriptorset;
		VkDescriptorSetAllocateInfo allocInfo = vks::initializers::descriptorSetAllocateInfo(descriptorpool, &descriptorsetlayout, 1);
		VK_CHECK_RESULT(vkAllocateDescriptorSets(device, &allocInfo, &descriptorset));

		// Pipeline layout
		VkPipelineLayout pipelinelayout;
		VkPipelineLayoutCreateInfo pipelineLayoutCI = vks::initializers::pipelineLayoutCreateInfo(&descriptorsetlayout, 1);
		VK_CHECK_RESULT(vkCreatePipelineLayout(device, &pipelineLayoutCI, 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);
		VkPipelineColorBlendAttachmentState blendAttachmentState = vks::initializers::pipelineColorBlendAttachmentState(0xf, VK_FALSE);
		VkPipelineColorBlendStateCreateInfo colorBlendState = vks::initializers::pipelineColorBlendStateCreateInfo(1, &blendAttachmentState);
		VkPipelineDepthStencilStateCreateInfo depthStencilState = vks::initializers::pipelineDepthStencilStateCreateInfo(VK_FALSE, VK_FALSE, VK_COMPARE_OP_LESS_OR_EQUAL);
		VkPipelineViewportStateCreateInfo viewportState = vks::initializers::pipelineViewportStateCreateInfo(1, 1);
		VkPipelineMultisampleStateCreateInfo multisampleState = vks::initializers::pipelineMultisampleStateCreateInfo(VK_SAMPLE_COUNT_1_BIT);
		std::vector<VkDynamicState> dynamicStateEnables = { VK_DYNAMIC_STATE_VIEWPORT, VK_DYNAMIC_STATE_SCISSOR };
		VkPipelineDynamicStateCreateInfo dynamicState = vks::initializers::pipelineDynamicStateCreateInfo(dynamicStateEnables);
		VkPipelineVertexInputStateCreateInfo emptyInputState = vks::initializers::pipelineVertexInputStateCreateInfo();
		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 = 2;
		pipelineCI.pStages = shaderStages.data();
		pipelineCI.pVertexInputState = &emptyInputState;

		// Look-up-table (from BRDF) pipeline
		shaderStages[0] = loadShader(getHomeworkShadersPath() + "homework1/genbrdflut.vert.spv", VK_SHADER_STAGE_VERTEX_BIT);
		shaderStages[1] = loadShader(getHomeworkShadersPath() + "homework1/genbrdflut.frag.spv", VK_SHADER_STAGE_FRAGMENT_BIT);
		VkPipeline pipeline;
		VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCI, nullptr, &pipeline));

		// Render
		VkClearValue clearValues[1];
		clearValues[0].color = { { 0.0f, 0.0f, 0.0f, 1.0f } };

		VkRenderPassBeginInfo renderPassBeginInfo = vks::initializers::renderPassBeginInfo();
		renderPassBeginInfo.renderPass = renderpass;
		renderPassBeginInfo.renderArea.extent.width = dim;
		renderPassBeginInfo.renderArea.extent.height = dim;
		renderPassBeginInfo.clearValueCount = 1;
		renderPassBeginInfo.pClearValues = clearValues;
		renderPassBeginInfo.framebuffer = framebuffer;

		VkCommandBuffer cmdBuf = vulkanDevice->createCommandBuffer(VK_COMMAND_BUFFER_LEVEL_PRIMARY, true);
		vkCmdBeginRenderPass(cmdBuf, &renderPassBeginInfo, VK_SUBPASS_CONTENTS_INLINE);
		VkViewport viewport = vks::initializers::viewport((float)dim, (float)dim, 0.0f, 1.0f);
		VkRect2D scissor = vks::initializers::rect2D(dim, dim, 0, 0);
		vkCmdSetViewport(cmdBuf, 0, 1, &viewport);
		vkCmdSetScissor(cmdBuf, 0, 1, &scissor);
		vkCmdBindPipeline(cmdBuf, VK_PIPELINE_BIND_POINT_GRAPHICS, pipeline);
		vkCmdDraw(cmdBuf, 3, 1, 0, 0);
		vkCmdEndRenderPass(cmdBuf);
		vulkanDevice->flushCommandBuffer(cmdBuf, queue);

		vkQueueWaitIdle(queue);

		vkDestroyPipeline(device, pipeline, nullptr);
		vkDestroyPipelineLayout(device, pipelinelayout, nullptr);
		vkDestroyRenderPass(device, renderpass, nullptr);
		vkDestroyFramebuffer(device, framebuffer, nullptr);
		vkDestroyDescriptorSetLayout(device, descriptorsetlayout, nullptr);
		vkDestroyDescriptorPool(device, descriptorpool, nullptr);

		auto tEnd = std::chrono::high_resolution_clock::now();
		auto tDiff = std::chrono::duration<double, std::milli>(tEnd - tStart).count();
		std::cout << "Generating BRDF LUT took " << tDiff << " ms" << std::endl;
}

//-------------------------- pbr precompute start ----------------------------------

#pragma region pbr render pass setting

	void VulkanExample::createAttachment(VkFormat format, VkImageUsageFlagBits usage, VulkanExample::FrameBufferAttachment* attachment, uint32_t width, uint32_t height)
	{
		VkImageAspectFlags aspectMask = 0;
		VkImageUsageFlags imageUsage = VK_IMAGE_USAGE_TRANSFER_SRC_BIT;
		attachment->format = format;
		if (usage & VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT)
		{
			aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
			imageUsage |= VK_IMAGE_USAGE_SAMPLED_BIT;
		}
		if (usage & VK_IMAGE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT)
		{
			aspectMask = VK_IMAGE_ASPECT_DEPTH_BIT;
			if (format >= VK_FORMAT_D16_UNORM_S8_UINT)
				aspectMask |= VK_IMAGE_ASPECT_STENCIL_BIT;
		}

		assert(aspectMask > 0);

		VkImageCreateInfo image = vks::initializers::imageCreateInfo();
		image.imageType = VK_IMAGE_TYPE_2D;
		image.format = format;
		image.extent.width = width;
		image.extent.height = height;
		image.extent.depth = 1;
		image.mipLevels = 1;
		image.arrayLayers = 1;
		image.samples = VK_SAMPLE_COUNT_1_BIT;
		image.tiling = VK_IMAGE_TILING_OPTIMAL;
		image.usage = imageUsage | usage;

		VkMemoryAllocateInfo memAlloc = vks::initializers::memoryAllocateInfo();
		VkMemoryRequirements memReqs;

		VK_CHECK_RESULT(vkCreateImage(device, &image, nullptr, &attachment->image));
		vkGetImageMemoryRequirements(device, attachment->image, &memReqs);
		memAlloc.allocationSize = memReqs.size;
		memAlloc.memoryTypeIndex = vulkanDevice->getMemoryType(memReqs.memoryTypeBits, VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT);
		VK_CHECK_RESULT(vkAllocateMemory(device, &memAlloc, nullptr, &attachment->deviceMemory));
		VK_CHECK_RESULT(vkBindImageMemory(device, attachment->image, attachment->deviceMemory, 0));

		VkImageViewCreateInfo imageView = vks::initializers::imageViewCreateInfo();
		imageView.viewType = VK_IMAGE_VIEW_TYPE_2D;
		imageView.format = format;
		imageView.subresourceRange = {};
		imageView.subresourceRange.aspectMask = aspectMask;
		imageView.subresourceRange.baseMipLevel = 0;
		imageView.subresourceRange.levelCount = 1;
		imageView.subresourceRange.baseArrayLayer = 0;
		imageView.subresourceRange.layerCount = 1;
		imageView.image = attachment->image;
		VK_CHECK_RESULT(vkCreateImageView(device, &imageView, nullptr, &attachment->imageView));
	}
	

#pragma endregion
		
// ----------------------- pbr precompute end ---------------------------------------	



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

	void VulkanExample::render()
	{
		renderFrame();
		if (camera.updated) {
			updateUniformBuffers();
		}
		if (!paused)
		{
			glTFModel.updateAnimation(frameTimer,shaderData.skinSSBO);
		}
	}

	void VulkanExample::viewChanged()
	{
		updateUniformBuffers();
	}

	void VulkanExample::OnUpdateUIOverlay(vks::UIOverlay *overlay)
	{
		if (overlay->header("Settings")) {
			if (overlay->checkBox("Wireframe", &wireframe)) {
				buildCommandBuffers();
			}
		}
		if (overlay->header("Animation"))
		{
			overlay->checkBox("pause", &paused);
		}
	}


VULKAN_EXAMPLE_MAIN()