procedural-3d-engine/triangle/triangle.cpp

/*
* Vulkan Example - Basic indexed triangle rendering
*
* Note :
*	This is a "pedal to the metal" example to show off how to get Vulkan up an displaying something
*	Contrary to the other examples, this one won't make use of helper functions or initializers
*	Except in a few cases (swap chain setup e.g.)
*
* Copyright (C) 2016 by Sascha Willems - www.saschawillems.de
*
* This code is licensed under the MIT license (MIT) (http://opensource.org/licenses/MIT)
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <vector>
#include <exception>

#define GLM_FORCE_RADIANS
#define GLM_FORCE_DEPTH_ZERO_TO_ONE
#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>

#include <vulkan/vulkan.h>
#include "vulkanexamplebase.h"

#define VERTEX_BUFFER_BIND_ID 0
// Set to "true" to enable Vulkan's validation layers
// See vulkandebug.cpp for details
#define ENABLE_VALIDATION false
// Set to "true" to use staging buffers for uploading
// vertex and index data to device local memory
// See "prepareVertices" for details on what's staging
// and on why to use it
#define USE_STAGING true

class VulkanExample : public VulkanExampleBase
{
public:
	struct {
		VkBuffer buf;
		VkDeviceMemory mem;
		VkPipelineVertexInputStateCreateInfo inputState;
		std::vector<VkVertexInputBindingDescription> bindingDescriptions;
		std::vector<VkVertexInputAttributeDescription> attributeDescriptions;
	} vertices;

	struct {
		int count;
		VkBuffer buf;
		VkDeviceMemory mem;
	} indices;

	struct {
		VkBuffer buffer;
		VkDeviceMemory memory;
		VkDescriptorBufferInfo descriptor;
	}  uniformDataVS;

	// For simplicity we use the same uniform block layout as in the shader:
	//
	//	layout(set = 0, binding = 0) uniform UBO
	//	{
	//		mat4 projectionMatrix;
	//		mat4 modelMatrix;
	//		mat4 viewMatrix;
	//	} ubo;
	//
	// This way we can just memcopy the ubo data to the ubo
	// Note that you should be using data types that align with the GPU
	// in order to avoid manual padding
	struct {
		glm::mat4 projectionMatrix;
		glm::mat4 modelMatrix;
		glm::mat4 viewMatrix;
	} uboVS;

	// The pipeline (state objects) is a static store for the 3D pipeline states (including shaders)
	// Other than OpenGL this makes you setup the render states up-front
	// If different render states are required you need to setup multiple pipelines
	// and switch between them
	// Note that there are a few dynamic states (scissor, viewport, line width) that
	// can be set from a command buffer and does not have to be part of the pipeline
	// This basic example only uses one pipeline
	VkPipeline pipeline;

	// The pipeline layout defines the resource binding slots to be used with a pipeline
	// This includes bindings for buffes (ubos, ssbos), images and sampler
	// A pipeline layout can be used for multiple pipeline (state objects) as long as 
	// their shaders use the same binding layout
	VkPipelineLayout pipelineLayout;
	
	// The descriptor set stores the resources bound to the binding points in a shader
	// It connects the binding points of the different shaders with the buffers and images
	// used for those bindings
	VkDescriptorSet descriptorSet;

	// The descriptor set layout describes the shader binding points without referencing
	// the actual buffers. 
	// Like the pipeline layout it's pretty much a blueprint and can be used with
	// different descriptor sets as long as the binding points (and shaders) match
	VkDescriptorSetLayout descriptorSetLayout;

	// Synchronization semaphores
	// Semaphores are used to synchronize dependencies between command buffers
	// We use them to ensure that we e.g. don't present to the swap chain
	// until all rendering has completed
	struct {
		VkSemaphore presentComplete;
		VkSemaphore renderComplete;
	} semaphores;

	VulkanExample() : VulkanExampleBase(ENABLE_VALIDATION)
	{
		width = 1280;
		height = 720;
		zoom = -2.5f;
		title = "Vulkan Example - Basic indexed triangle";
		// Values not set here are initialized in the base class constructor
	}

	~VulkanExample()
	{
		// Clean up used Vulkan resources 
		// Note : Inherited destructor cleans up resources stored in base class
		vkDestroyPipeline(device, pipeline, nullptr);

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

		vkDestroyBuffer(device, vertices.buf, nullptr);
		vkFreeMemory(device, vertices.mem, nullptr);

		vkDestroyBuffer(device, indices.buf, nullptr);
		vkFreeMemory(device, indices.mem, nullptr);

		vkDestroySemaphore(device, semaphores.presentComplete, nullptr);
		vkDestroySemaphore(device, semaphores.renderComplete, nullptr);

		vkDestroyBuffer(device, uniformDataVS.buffer, nullptr);
		vkFreeMemory(device, uniformDataVS.memory, nullptr);
	}

	// This function is used to request a device memory type that supports all the property flags we request (e.g. device local, host visibile)
	// Upon success it will return the index of the memory type that fits our requestes memory properties
	// This is necessary as implementations can offer an arbitrary number of memory types with different
	// memory properties. 
	// You can check http://vulkan.gpuinfo.org/ for details on different memory configurations
	uint32_t getMemoryTypeIndex(uint32_t typeBits, VkMemoryPropertyFlags properties)
	{
		// Iterate over all memory types available for the device used in this example
		for (uint32_t i = 0; i < deviceMemoryProperties.memoryTypeCount; i++)
		{
			if ((typeBits & 1) == 1)
			{
				if ((deviceMemoryProperties.memoryTypes[i].propertyFlags & properties) == properties)
				{						
					return i;
				}
			}
			typeBits >>= 1;
		}

		throw "Could not find a suitable memory type!";
	}

	// We are going to use several temporary command buffers for setup stuff
	// like submitting barriers for layout translations of buffer copies
	// This function will allocate a single (primary) command buffer from the 
	// examples' command buffer pool and if begin is set to true it will
	// also start the buffer so we can directly put commands into it
	VkCommandBuffer getCommandBuffer(bool begin)
	{
		VkCommandBuffer cmdBuffer;

		VkCommandBufferAllocateInfo cmdBufAllocateInfo = {};
		cmdBufAllocateInfo.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_ALLOCATE_INFO;
		cmdBufAllocateInfo.commandPool = cmdPool;
		cmdBufAllocateInfo.level = VK_COMMAND_BUFFER_LEVEL_PRIMARY;
		cmdBufAllocateInfo.commandBufferCount = 1;
	
		VK_CHECK_RESULT(vkAllocateCommandBuffers(device, &cmdBufAllocateInfo, &cmdBuffer));

		// If requested, also start the new command buffer
		if (begin)
		{
			VkCommandBufferBeginInfo cmdBufInfo = vkTools::initializers::commandBufferBeginInfo();
			VK_CHECK_RESULT(vkBeginCommandBuffer(cmdBuffer, &cmdBufInfo));
		}

		return cmdBuffer;
	}

	// This will end the command buffer and submit it to the examples' queue
	// Then waits for the queue to become idle so our submission is finished
	// and then deletes the command buffer
	// For use with setup command buffers created by getCommandBuffer
	void flushCommandBuffer(VkCommandBuffer commandBuffer)
	{
		assert(commandBuffer != VK_NULL_HANDLE);

		VK_CHECK_RESULT(vkEndCommandBuffer(commandBuffer));

		VkSubmitInfo submitInfo = {};
		submitInfo.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
		submitInfo.commandBufferCount = 1;
		submitInfo.pCommandBuffers = &commandBuffer;

		VK_CHECK_RESULT(vkQueueSubmit(queue, 1, &submitInfo, VK_NULL_HANDLE));
		VK_CHECK_RESULT(vkQueueWaitIdle(queue));

		vkFreeCommandBuffers(device, cmdPool, 1, &commandBuffer);
	}

	// Build separate command buffers for every framebuffer image
	// Unlike in OpenGL all rendering commands are recorded once
	// into command buffers that are then resubmitted to the queue
	void buildCommandBuffers()
	{
		VkCommandBufferBeginInfo cmdBufInfo = {};
		cmdBufInfo.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;
		cmdBufInfo.pNext = NULL;

		// Set clear values for all framebuffer attachments with loadOp set to clear
		// We use two attachments (color and depth) that are cleared at the 
		// start of the subpass and as such we need to set clear values for both
		VkClearValue clearValues[2];
		clearValues[0].color = defaultClearColor;
		clearValues[1].depthStencil = { 1.0f, 0 };

		VkRenderPassBeginInfo renderPassBeginInfo = {};
		renderPassBeginInfo.sType = VK_STRUCTURE_TYPE_RENDER_PASS_BEGIN_INFO;
		renderPassBeginInfo.pNext = NULL;
		renderPassBeginInfo.renderPass = renderPass;
		renderPassBeginInfo.renderArea.offset.x = 0;
		renderPassBeginInfo.renderArea.offset.y = 0;
		renderPassBeginInfo.renderArea.extent.width = width;
		renderPassBeginInfo.renderArea.extent.height = height;
		renderPassBeginInfo.clearValueCount = 2;
		renderPassBeginInfo.pClearValues = clearValues;
	
		for (int32_t i = 0; i < drawCmdBuffers.size(); ++i)
		{
			// Set target frame buffer
			renderPassBeginInfo.framebuffer = frameBuffers[i];

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

			// Start the first sub pass specified in our default render pass setup by the base class
			// This will clear the color and depth attachment
			vkCmdBeginRenderPass(drawCmdBuffers[i], &renderPassBeginInfo, VK_SUBPASS_CONTENTS_INLINE);

			// Update dynamic viewport state
			VkViewport viewport = {};
			viewport.height = (float)height;
			viewport.width = (float)width;
			viewport.minDepth = (float) 0.0f;
			viewport.maxDepth = (float) 1.0f;
			vkCmdSetViewport(drawCmdBuffers[i], 0, 1, &viewport);

			// Update dynamic scissor state
			VkRect2D scissor = {};
			scissor.extent.width = width;
			scissor.extent.height = height;
			scissor.offset.x = 0;
			scissor.offset.y = 0;
			vkCmdSetScissor(drawCmdBuffers[i], 0, 1, &scissor);

			// Bind descriptor sets describing shader binding points
			vkCmdBindDescriptorSets(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, pipelineLayout, 0, 1, &descriptorSet, 0, NULL);

			// Bind the rendering pipeline
			// The pipeline (state object) contains all states of the rendering pipeline
			// So once we bind a pipeline all states that were set upon creation of that
			// pipeline will be set
			vkCmdBindPipeline(drawCmdBuffers[i], VK_PIPELINE_BIND_POINT_GRAPHICS, pipeline);

			// Bind triangle vertex buffer (contains position and colors)
			VkDeviceSize offsets[1] = { 0 };
			vkCmdBindVertexBuffers(drawCmdBuffers[i], VERTEX_BUFFER_BIND_ID, 1, &vertices.buf, offsets);

			// Bind triangle index buffer
			vkCmdBindIndexBuffer(drawCmdBuffers[i], indices.buf, 0, VK_INDEX_TYPE_UINT32);

			// Draw indexed triangle
			vkCmdDrawIndexed(drawCmdBuffers[i], indices.count, 1, 0, 0, 1);

			vkCmdEndRenderPass(drawCmdBuffers[i]);

			// Add a present memory barrier to the end of the command buffer
			// This will transform the frame buffer color attachment to a
			// new layout for presenting it to the windowing system integration 
			VkImageMemoryBarrier prePresentBarrier = {};
			prePresentBarrier.sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
			prePresentBarrier.pNext = NULL;
			prePresentBarrier.srcAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
			prePresentBarrier.dstAccessMask = VK_ACCESS_MEMORY_READ_BIT;
			prePresentBarrier.oldLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
			prePresentBarrier.newLayout = VK_IMAGE_LAYOUT_PRESENT_SRC_KHR;
			prePresentBarrier.srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
			prePresentBarrier.dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
			prePresentBarrier.subresourceRange = { VK_IMAGE_ASPECT_COLOR_BIT, 0, 1, 0, 1 };			
			prePresentBarrier.image = swapChain.buffers[i].image;

			VkImageMemoryBarrier *pMemoryBarrier = &prePresentBarrier;
			vkCmdPipelineBarrier(
				drawCmdBuffers[i], 
				VK_PIPELINE_STAGE_ALL_COMMANDS_BIT,
				VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT,
				VK_FLAGS_NONE,
				0, nullptr,
				0, nullptr,
				1, &prePresentBarrier);

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

		// Build command buffers for the post present image barrier for each swap chain image
		// Note: The command Buffers are allocated in the base class

		for (uint32_t i = 0; i < swapChain.imageCount; i++)
		{
			// Insert a post present image barrier to transform the image back to a
			// color attachment that our render pass can write to
			// We always use undefined image layout as the source as it doesn't actually matter
			// what is done with the previous image contents
			VkImageMemoryBarrier postPresentBarrier = vkTools::initializers::imageMemoryBarrier();
			postPresentBarrier.srcAccessMask = 0;
			postPresentBarrier.dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
			postPresentBarrier.oldLayout = VK_IMAGE_LAYOUT_UNDEFINED;
			postPresentBarrier.newLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
			postPresentBarrier.srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
			postPresentBarrier.dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
			postPresentBarrier.subresourceRange = { VK_IMAGE_ASPECT_COLOR_BIT, 0, 1, 0, 1 };
			postPresentBarrier.image = swapChain.buffers[i].image;

			// Use dedicated command buffer from example base class for submitting the post present barrier
			VkCommandBufferBeginInfo cmdBufInfo = {};
			cmdBufInfo.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;

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

			// Put post present barrier into command buffer
			vkCmdPipelineBarrier(
				postPresentCmdBuffers[i],
				VK_PIPELINE_STAGE_ALL_COMMANDS_BIT,
				VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT,
				VK_FLAGS_NONE,
				0, nullptr,
				0, nullptr,
				1, &postPresentBarrier);

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

	void draw()
	{
		// Get next image in the swap chain (back/front buffer)
		VK_CHECK_RESULT(swapChain.acquireNextImage(semaphores.presentComplete, &currentBuffer));

		// Submit the post present image barrier to transform the image back to a color attachment
		// that can be used to write to by our render pass
		VkSubmitInfo submitInfo = {};
		submitInfo.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
		submitInfo.commandBufferCount = 1;
		submitInfo.pCommandBuffers = &postPresentCmdBuffers[currentBuffer];

		VK_CHECK_RESULT(vkQueueSubmit(queue, 1, &submitInfo, VK_NULL_HANDLE));
		
		// Make sure that the image barrier command submitted to the queue 
		// has finished executing
		VK_CHECK_RESULT(vkQueueWaitIdle(queue));

		// The submit infor strcuture contains a list of
		// command buffers and semaphores to be submitted to a queue
		// If you want to submit multiple command buffers, pass an array
		VkPipelineStageFlags pipelineStages = VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT;
		submitInfo.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
		submitInfo.pWaitDstStageMask = &pipelineStages;
		// The wait semaphore ensures that the image is presented 
		// before we start submitting command buffers agein
		submitInfo.waitSemaphoreCount = 1;
		submitInfo.pWaitSemaphores = &semaphores.presentComplete;
		// Submit the currently active command buffer
		submitInfo.commandBufferCount = 1;
		submitInfo.pCommandBuffers = &drawCmdBuffers[currentBuffer];
		// The signal semaphore is used during queue presentation
		// to ensure that the image is not rendered before all
		// commands have been submitted
		submitInfo.signalSemaphoreCount = 1;
		submitInfo.pSignalSemaphores = &semaphores.renderComplete;

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

		// Present the current buffer to the swap chain
		// We pass the signal semaphore from the submit info
		// to ensure that the image is not rendered until
		// all commands have been submitted
		VK_CHECK_RESULT(swapChain.queuePresent(queue, currentBuffer, semaphores.renderComplete));
	}

	// Create synchronzation semaphores
	void prepareSemaphore()
	{
		VkSemaphoreCreateInfo semaphoreCreateInfo = {};
		semaphoreCreateInfo.sType = VK_STRUCTURE_TYPE_SEMAPHORE_CREATE_INFO;
		semaphoreCreateInfo.pNext = NULL;

		// This semaphore ensures that the image is complete
		// before starting to submit again
		VK_CHECK_RESULT(vkCreateSemaphore(device, &semaphoreCreateInfo, nullptr, &semaphores.presentComplete));

		// This semaphore ensures that all commands submitted
		// have been finished before submitting the image to the queue
		VK_CHECK_RESULT(vkCreateSemaphore(device, &semaphoreCreateInfo, nullptr, &semaphores.renderComplete));
	}

	// Setups vertex and index buffers for an indexed triangle,
	// uploads them to the VRAM and sets binding points and attribute
	// descriptions to match locations inside the shaders
	void prepareVertices(bool useStagingBuffers)
	{
		struct Vertex {
			float pos[3];
			float col[3];
		};

		// Setup vertices
		std::vector<Vertex> vertexBuffer = {
			{ {  1.0f,  1.0f, 0.0f }, { 1.0f, 0.0f, 0.0f } },
			{ { -1.0f,  1.0f, 0.0f }, { 0.0f, 1.0f, 0.0f } },
			{ {  0.0f, -1.0f, 0.0f }, { 0.0f, 0.0f, 1.0f } }
		};
		uint32_t vertexBufferSize = static_cast<uint32_t>(vertexBuffer.size()) * sizeof(Vertex);

		// Setup indices
		std::vector<uint32_t> indexBuffer = { 0, 1, 2 };
		indices.count = static_cast<uint32_t>(indexBuffer.size());
		uint32_t indexBufferSize = indices.count * sizeof(uint32_t);

		VkMemoryAllocateInfo memAlloc = {};
		memAlloc.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO;
		VkMemoryRequirements memReqs;

		void *data;

		if (useStagingBuffers)
		{
			// Static data like vertex and index buffer should be stored on the device memory 
			// for optimal (and fastest) access by the GPU
			//
			// To achieve this we use so-called "staging buffers" :
			// - Create a buffer that's visible to the host (and can be mapped)
			// - Copy the data to this buffer
			// - Create another buffer that's local on the device (VRAM) with the same size
			// - Copy the data from the host to the device using a command buffer
			// - Delete the host visible (staging) buffer
			// - Use the device local buffers for rendering

			struct StagingBuffer {
				VkDeviceMemory memory;
				VkBuffer buffer;
			};

			struct {
				StagingBuffer vertices;
				StagingBuffer indices;
			} stagingBuffers;

			// Vertex buffer
			VkBufferCreateInfo vertexBufferInfo = {};
			vertexBufferInfo.sType = VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO;
			vertexBufferInfo.size = vertexBufferSize;
			// Buffer is used as the copy source
			vertexBufferInfo.usage = VK_BUFFER_USAGE_TRANSFER_SRC_BIT;
			// Create a host-visible buffer to copy the vertex data to (staging buffer)
			VK_CHECK_RESULT(vkCreateBuffer(device, &vertexBufferInfo, nullptr, &stagingBuffers.vertices.buffer));
			vkGetBufferMemoryRequirements(device, stagingBuffers.vertices.buffer, &memReqs);
			memAlloc.allocationSize = memReqs.size;
			// Request a host visible memory type that can be used to copy our data do
			// Also request it to be coherent, so that writes are visible to the GPU right after unmapping the buffer
			memAlloc.memoryTypeIndex = getMemoryTypeIndex(memReqs.memoryTypeBits, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT);
			VK_CHECK_RESULT(vkAllocateMemory(device, &memAlloc, nullptr, &stagingBuffers.vertices.memory));
			// Map and copy
			VK_CHECK_RESULT(vkMapMemory(device, stagingBuffers.vertices.memory, 0, memAlloc.allocationSize, 0, &data));
			memcpy(data, vertexBuffer.data(), vertexBufferSize);
			vkUnmapMemory(device, stagingBuffers.vertices.memory);
			VK_CHECK_RESULT(vkBindBufferMemory(device, stagingBuffers.vertices.buffer, stagingBuffers.vertices.memory, 0));

			// Create the destination buffer with device only visibility
			// Buffer will be used as a vertex buffer and is the copy destination
			vertexBufferInfo.usage = VK_BUFFER_USAGE_VERTEX_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT;
			VK_CHECK_RESULT(vkCreateBuffer(device, &vertexBufferInfo, nullptr, &vertices.buf));
			vkGetBufferMemoryRequirements(device, vertices.buf, &memReqs);
			memAlloc.allocationSize = memReqs.size;
			memAlloc.memoryTypeIndex = getMemoryTypeIndex(memReqs.memoryTypeBits, VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT);
			VK_CHECK_RESULT(vkAllocateMemory(device, &memAlloc, nullptr, &vertices.mem));
			VK_CHECK_RESULT(vkBindBufferMemory(device, vertices.buf, vertices.mem, 0));

			// Index buffer
			VkBufferCreateInfo indexbufferInfo = {};
			indexbufferInfo.sType = VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO;
			indexbufferInfo.size = indexBufferSize;
			indexbufferInfo.usage = VK_BUFFER_USAGE_TRANSFER_SRC_BIT;
			// Copy index data to a buffer visible to the host (staging buffer)
			VK_CHECK_RESULT(vkCreateBuffer(device, &indexbufferInfo, nullptr, &stagingBuffers.indices.buffer));
			vkGetBufferMemoryRequirements(device, stagingBuffers.indices.buffer, &memReqs);
			memAlloc.allocationSize = memReqs.size;
			memAlloc.memoryTypeIndex = getMemoryTypeIndex(memReqs.memoryTypeBits, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT);
			VK_CHECK_RESULT(vkAllocateMemory(device, &memAlloc, nullptr, &stagingBuffers.indices.memory));
			VK_CHECK_RESULT(vkMapMemory(device, stagingBuffers.indices.memory, 0, indexBufferSize, 0, &data));
			memcpy(data, indexBuffer.data(), indexBufferSize);
			vkUnmapMemory(device, stagingBuffers.indices.memory);
			VK_CHECK_RESULT(vkBindBufferMemory(device, stagingBuffers.indices.buffer, stagingBuffers.indices.memory, 0));

			// Create destination buffer with device only visibility
			indexbufferInfo.usage = VK_BUFFER_USAGE_INDEX_BUFFER_BIT | VK_BUFFER_USAGE_TRANSFER_DST_BIT;
			VK_CHECK_RESULT(vkCreateBuffer(device, &indexbufferInfo, nullptr, &indices.buf));
			vkGetBufferMemoryRequirements(device, indices.buf, &memReqs);
			memAlloc.allocationSize = memReqs.size;
			memAlloc.memoryTypeIndex = getMemoryTypeIndex(memReqs.memoryTypeBits, VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT);
			VK_CHECK_RESULT(vkAllocateMemory(device, &memAlloc, nullptr, &indices.mem));
			VK_CHECK_RESULT(vkBindBufferMemory(device, indices.buf, indices.mem, 0));

			VkCommandBufferBeginInfo cmdBufferBeginInfo = {};
			cmdBufferBeginInfo.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;
			cmdBufferBeginInfo.pNext = NULL;

			// Buffer copies have to be submitted to a queue, so we need a command buffer for them
			// Note that some devices offer a dedicated transfer queue (with only the transfer bit set)
			// If you do lots of copies (especially at runtime) it's advised to use such a queu instead
			// of a generalized graphics queue (that also supports transfers)
			VkCommandBuffer copyCmd = getCommandBuffer(true);

			// Put buffer region copies into command buffer
			// Note that the staging buffer must not be deleted before the copies have been submitted and executed

			VkBufferCopy copyRegion = {};

			// Vertex buffer
			copyRegion.size = vertexBufferSize;
			vkCmdCopyBuffer(
				copyCmd,
				stagingBuffers.vertices.buffer,
				vertices.buf,
				1,
				&copyRegion);
			// Index buffer
			copyRegion.size = indexBufferSize;
			vkCmdCopyBuffer(
				copyCmd,
				stagingBuffers.indices.buffer,
				indices.buf,
				1,
				&copyRegion);

			flushCommandBuffer(copyCmd);

			// Destroy staging buffers
			vkDestroyBuffer(device, stagingBuffers.vertices.buffer, nullptr);
			vkFreeMemory(device, stagingBuffers.vertices.memory, nullptr);
			vkDestroyBuffer(device, stagingBuffers.indices.buffer, nullptr);
			vkFreeMemory(device, stagingBuffers.indices.memory, nullptr);
		}
		else
		{
			// Don't use staging
			// Create host-visible buffers only and use these for rendering
			// This is not advised for real world applications and will
			// result in lower performances at least on devices that
			// separate between host visible and device local memory

			// Vertex buffer
			VkBufferCreateInfo vertexBufferInfo = {};
			vertexBufferInfo.sType = VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO;
			vertexBufferInfo.size = vertexBufferSize;
			vertexBufferInfo.usage = VK_BUFFER_USAGE_VERTEX_BUFFER_BIT;

			// Copy vertex data to a buffer visible to the host
			VK_CHECK_RESULT(vkCreateBuffer(device, &vertexBufferInfo, nullptr, &vertices.buf));
			vkGetBufferMemoryRequirements(device, vertices.buf, &memReqs);
			memAlloc.allocationSize = memReqs.size;
			memAlloc.memoryTypeIndex = getMemoryTypeIndex(memReqs.memoryTypeBits, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT);
			VK_CHECK_RESULT(vkAllocateMemory(device, &memAlloc, nullptr, &vertices.mem));
			VK_CHECK_RESULT(vkMapMemory(device, vertices.mem, 0, memAlloc.allocationSize, 0, &data));
			memcpy(data, vertexBuffer.data(), vertexBufferSize);
			vkUnmapMemory(device, vertices.mem);
			VK_CHECK_RESULT(vkBindBufferMemory(device, vertices.buf, vertices.mem, 0));

			// Index buffer
			VkBufferCreateInfo indexbufferInfo = {};
			indexbufferInfo.sType = VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO;
			indexbufferInfo.size = indexBufferSize;
			indexbufferInfo.usage = VK_BUFFER_USAGE_INDEX_BUFFER_BIT;

			// Copy index data to a buffer visible to the host
			VK_CHECK_RESULT(vkCreateBuffer(device, &indexbufferInfo, nullptr, &indices.buf));
			vkGetBufferMemoryRequirements(device, indices.buf, &memReqs);
			memAlloc.allocationSize = memReqs.size;
			memAlloc.memoryTypeIndex = getMemoryTypeIndex(memReqs.memoryTypeBits, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT);
			VK_CHECK_RESULT(vkAllocateMemory(device, &memAlloc, nullptr, &indices.mem));
			VK_CHECK_RESULT(vkMapMemory(device, indices.mem, 0, indexBufferSize, 0, &data));
			memcpy(data, indexBuffer.data(), indexBufferSize);
			vkUnmapMemory(device, indices.mem);
			VK_CHECK_RESULT(vkBindBufferMemory(device, indices.buf, indices.mem, 0));
		}

		// Binding description
		vertices.bindingDescriptions.resize(1);
		vertices.bindingDescriptions[0].binding = VERTEX_BUFFER_BIND_ID;
		vertices.bindingDescriptions[0].stride = sizeof(Vertex);
		vertices.bindingDescriptions[0].inputRate = VK_VERTEX_INPUT_RATE_VERTEX;

		// Attribute descriptions
		// Describes memory layout and shader attribute locations
		vertices.attributeDescriptions.resize(2);
		// Location 0 : Position
		vertices.attributeDescriptions[0].binding = VERTEX_BUFFER_BIND_ID;
		vertices.attributeDescriptions[0].location = 0;
		vertices.attributeDescriptions[0].format = VK_FORMAT_R32G32B32_SFLOAT;
		vertices.attributeDescriptions[0].offset = 0;
		// Location 1 : Color
		vertices.attributeDescriptions[1].binding = VERTEX_BUFFER_BIND_ID;
		vertices.attributeDescriptions[1].location = 1;
		vertices.attributeDescriptions[1].format = VK_FORMAT_R32G32B32_SFLOAT;
		vertices.attributeDescriptions[1].offset = sizeof(float) * 3;

		// Assign to vertex input state
		vertices.inputState.sType = VK_STRUCTURE_TYPE_PIPELINE_VERTEX_INPUT_STATE_CREATE_INFO;
		vertices.inputState.pNext = NULL;
		vertices.inputState.flags = VK_FLAGS_NONE;
		vertices.inputState.vertexBindingDescriptionCount = static_cast<uint32_t>(vertices.bindingDescriptions.size());
		vertices.inputState.pVertexBindingDescriptions = vertices.bindingDescriptions.data();
		vertices.inputState.vertexAttributeDescriptionCount = static_cast<uint32_t>(vertices.attributeDescriptions.size());
		vertices.inputState.pVertexAttributeDescriptions = vertices.attributeDescriptions.data();
	}

	void setupDescriptorPool()
	{
		// We need to tell the API the number of max. requested descriptors per type
		VkDescriptorPoolSize typeCounts[1];
		// This example only uses one descriptor type (uniform buffer) and only
		// requests one descriptor of this type
		typeCounts[0].type = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
		typeCounts[0].descriptorCount = 1;
		// For additional types you need to add new entries in the type count list
		// E.g. for two combined image samplers :
		// typeCounts[1].type = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
		// typeCounts[1].descriptorCount = 2;

		// Create the global descriptor pool
		// All descriptors used in this example are allocated from this pool
		VkDescriptorPoolCreateInfo descriptorPoolInfo = {};
		descriptorPoolInfo.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_POOL_CREATE_INFO;
		descriptorPoolInfo.pNext = NULL;
		descriptorPoolInfo.poolSizeCount = 1;
		descriptorPoolInfo.pPoolSizes = typeCounts;
		// Set the max. number of sets that can be requested
		// Requesting descriptors beyond maxSets will result in an error
		descriptorPoolInfo.maxSets = 1;

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

	void setupDescriptorSetLayout()
	{
		// Setup layout of descriptors used in this example
		// Basically connects the different shader stages to descriptors
		// for binding uniform buffers, image samplers, etc.
		// So every shader binding should map to one descriptor set layout
		// binding

		// Binding 0 : Uniform buffer (Vertex shader)
		VkDescriptorSetLayoutBinding layoutBinding = {};
		layoutBinding.descriptorType = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
		layoutBinding.descriptorCount = 1;
		layoutBinding.stageFlags = VK_SHADER_STAGE_VERTEX_BIT;
		layoutBinding.pImmutableSamplers = NULL;

		VkDescriptorSetLayoutCreateInfo descriptorLayout = {};
		descriptorLayout.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_CREATE_INFO;
		descriptorLayout.pNext = NULL;
		descriptorLayout.bindingCount = 1;
		descriptorLayout.pBindings = &layoutBinding;

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

		// Create the pipeline layout that is used to generate the rendering pipelines that
		// are based on this descriptor set layout
		// In a more complex scenario you would have different pipeline layouts for different
		// descriptor set layouts that could be reused
		VkPipelineLayoutCreateInfo pPipelineLayoutCreateInfo = {};
		pPipelineLayoutCreateInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_LAYOUT_CREATE_INFO;
		pPipelineLayoutCreateInfo.pNext = NULL;
		pPipelineLayoutCreateInfo.setLayoutCount = 1;
		pPipelineLayoutCreateInfo.pSetLayouts = &descriptorSetLayout;

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

	void setupDescriptorSet()
	{
		// Allocate a new descriptor set from the global descriptor pool
		VkDescriptorSetAllocateInfo allocInfo = {};
		allocInfo.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_ALLOCATE_INFO;
		allocInfo.descriptorPool = descriptorPool;
		allocInfo.descriptorSetCount = 1;
		allocInfo.pSetLayouts = &descriptorSetLayout;

		VK_CHECK_RESULT(vkAllocateDescriptorSets(device, &allocInfo, &descriptorSet));

		// Update the descriptor set determining the shader binding points
		// For every binding point used in a shader there needs to be one
		// descriptor set matching that binding point

		VkWriteDescriptorSet writeDescriptorSet = {};

		// Binding 0 : Uniform buffer
		writeDescriptorSet.sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
		writeDescriptorSet.dstSet = descriptorSet;
		writeDescriptorSet.descriptorCount = 1;
		writeDescriptorSet.descriptorType = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
		writeDescriptorSet.pBufferInfo = &uniformDataVS.descriptor;
		// Binds this uniform buffer to binding point 0
		writeDescriptorSet.dstBinding = 0;

		vkUpdateDescriptorSets(device, 1, &writeDescriptorSet, 0, NULL);
	}

	// Create the depth (and stencil) buffer attachments used by our framebuffers
	// Note : Override of virtual function in the base class and called from within VulkanExampleBase::prepare
	void setupDepthStencil()
	{
		// Create an optimal image used as the depth stencil attachment
		VkImageCreateInfo image = {};
		image.sType = VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO;
		image.imageType = VK_IMAGE_TYPE_2D;
		image.format = depthFormat;
		// Use example's height and width
		image.extent = { width, height, 1 };
		image.mipLevels = 1;
		image.arrayLayers = 1;
		image.samples = VK_SAMPLE_COUNT_1_BIT;
		image.tiling = VK_IMAGE_TILING_OPTIMAL;
		image.usage = VK_IMAGE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT | VK_IMAGE_USAGE_TRANSFER_SRC_BIT;
		image.initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
		VK_CHECK_RESULT(vkCreateImage(device, &image, nullptr, &depthStencil.image));

		// Allocate memory for the image (device local) and bind it to our image
		VkMemoryAllocateInfo memAlloc = {};
		memAlloc.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO;
		VkMemoryRequirements memReqs;
		vkGetImageMemoryRequirements(device, depthStencil.image, &memReqs);
		memAlloc.allocationSize = memReqs.size;
		memAlloc.memoryTypeIndex = getMemoryTypeIndex(memReqs.memoryTypeBits, VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT);
		VK_CHECK_RESULT(vkAllocateMemory(device, &memAlloc, nullptr, &depthStencil.mem));
		VK_CHECK_RESULT(vkBindImageMemory(device, depthStencil.image, depthStencil.mem, 0));

		// We need to do an initial layout transition before we can use this image as the depth (and stencil) attachment
		// Note that this may be ignored by implementations that don't care about image layout
		// transitions, but it's crucial for those that do

		VkCommandBuffer layoutCmd = getCommandBuffer(true);

		VkImageMemoryBarrier imageMemoryBarrier = {};
		imageMemoryBarrier.sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
		imageMemoryBarrier.srcAccessMask = VK_FLAGS_NONE;
		imageMemoryBarrier.dstAccessMask = VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_WRITE_BIT;
		// Transform layout from undefined (initial) to depth/stencil attachment (usage)
		imageMemoryBarrier.oldLayout = VK_IMAGE_LAYOUT_UNDEFINED;
		imageMemoryBarrier.newLayout = VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL;
		imageMemoryBarrier.srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
		imageMemoryBarrier.dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
		imageMemoryBarrier.subresourceRange = { VK_IMAGE_ASPECT_DEPTH_BIT | VK_IMAGE_ASPECT_STENCIL_BIT, 0, 1, 0, 1 };
		imageMemoryBarrier.image = depthStencil.image;

		vkCmdPipelineBarrier(
			layoutCmd,
			VK_PIPELINE_STAGE_ALL_COMMANDS_BIT,
			VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT,
			VK_FLAGS_NONE,
			0, nullptr,
			0, nullptr,
			1, &imageMemoryBarrier);

		flushCommandBuffer(layoutCmd);

		// Create a view for ourt depth stencil image
		// In Vulkan we can't access the images directly, but rather through views
		// that describe a sub resource range
		// So you can actually have multiple views for a single image if required
		VkImageViewCreateInfo depthStencilView = {};
		depthStencilView.sType = VK_STRUCTURE_TYPE_IMAGE_VIEW_CREATE_INFO;
		depthStencilView.viewType = VK_IMAGE_VIEW_TYPE_2D;
		depthStencilView.format = depthFormat;
		depthStencilView.subresourceRange = {};
		depthStencilView.subresourceRange.aspectMask = VK_IMAGE_ASPECT_DEPTH_BIT | VK_IMAGE_ASPECT_STENCIL_BIT;
		depthStencilView.subresourceRange.baseMipLevel = 0;
		depthStencilView.subresourceRange.levelCount = 1;
		depthStencilView.subresourceRange.baseArrayLayer = 0;
		depthStencilView.subresourceRange.layerCount = 1;
		depthStencilView.image = depthStencil.image;
		VK_CHECK_RESULT(vkCreateImageView(device, &depthStencilView, nullptr, &depthStencil.view));
	}

	// Create a frame buffer for each swap chain image
	// Note : Override of virtual function in the base class and called from within VulkanExampleBase::prepare
	void setupFrameBuffer()
	{
		// Create a frame buffers for every image in our swapchain
		frameBuffers.resize(swapChain.imageCount);
		for (size_t i = 0; i < frameBuffers.size(); i++)
		{
			std::array<VkImageView, 2> attachments;
			// Color attachment is the view of the swapchain image
			attachments[0] = swapChain.buffers[i].view;
			// Depth/Stencil attachment is the same for all frame buffers
			attachments[1] = depthStencil.view;

			VkFramebufferCreateInfo frameBufferCreateInfo = {};
			frameBufferCreateInfo.sType = VK_STRUCTURE_TYPE_FRAMEBUFFER_CREATE_INFO;
			// All frame buffers use the same renderpass setu<74> 
			frameBufferCreateInfo.renderPass = renderPass;
			frameBufferCreateInfo.attachmentCount = static_cast<uint32_t>(attachments.size());
			frameBufferCreateInfo.pAttachments = attachments.data();
			frameBufferCreateInfo.width = width;
			frameBufferCreateInfo.height = height;
			frameBufferCreateInfo.layers = 1;
			// Create the framebuffer
			VK_CHECK_RESULT(vkCreateFramebuffer(device, &frameBufferCreateInfo, nullptr, &frameBuffers[i]));
		}
	}

	// Render pass setup for this example
	// Note : Override of virtual function in the base class and called from within VulkanExampleBase::prepare
	void setupRenderPass()
	{
		// Render passes are a new concept in Vulkan
		// They describe the attachments used during rendering
		// and may contain multiple subpasses with attachment
		// dependencies 
		// This allows the driver to know up-front how the
		// rendering will look like and is a good opportunity to
		// optimize, especially on tile-based renderers (with multiple subpasses)

		// This example will use a single render pass with
		// one subpass, which is the minimum setup

		// Two attachments
		// Basic setup with a color and a depth attachments
		std::array<VkAttachmentDescription, 2> attachments = {};

		// Color attachment
		attachments[0].format = colorformat;
		// We don't use multi sampling
		// Multi sampling requires a setup with resolve attachments
		// See the multisampling example for more details
		attachments[0].samples = VK_SAMPLE_COUNT_1_BIT;
		// loadOp describes what happens with the attachment content at the beginning of the subpass
		// We want the color buffer to be cleared
		attachments[0].loadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
		// storeOp describes what happens with the attachment content after the subpass is finished
		// As we want to display the color attachment after rendering is done we have to store it
		attachments[0].storeOp = VK_ATTACHMENT_STORE_OP_STORE;
		// We don't use stencil and DONT_CARE allows the driver to discard the result 
		attachments[0].stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE;
		attachments[0].stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
		// Set the initial image layout for the color atttachment
		attachments[0].initialLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
		attachments[0].finalLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;

		// Depth attachment
		attachments[1].format = depthFormat;
		attachments[1].samples = VK_SAMPLE_COUNT_1_BIT;
		// Clear depth at the beginnging of the subpass
		attachments[1].loadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
		// We don't need the contents of the depth buffer after the sub pass
		// anymore, so let the driver discard it
		attachments[1].storeOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
		// Don't care for stencil 
		attachments[1].stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE;
		attachments[1].stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
		// Set the initial image layout for the depth attachment
		attachments[1].initialLayout = VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL;
		attachments[1].finalLayout = VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL;

		// Setup references to our attachments for the sub pass
		VkAttachmentReference colorReference = {};
		colorReference.attachment = 0;
		colorReference.layout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;

		VkAttachmentReference depthReference = {};
		depthReference.attachment = 1;
		depthReference.layout = VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL;

		// Setup a single subpass that references our color and depth attachments
		VkSubpassDescription subpass = {};
		subpass.pipelineBindPoint = VK_PIPELINE_BIND_POINT_GRAPHICS;
		// Input attachments can be used to sample from contents of attachments 
		// written to by previous sub passes in a setup with multiple sub passes
		// This example doesn't make use of this
		subpass.inputAttachmentCount = 0;
		subpass.pInputAttachments = nullptr;
		// Preserved attachments can be used to loop (and preserve) attachments
		// through a sub pass that does not actually use them
		// This example doesn't make use of this
		subpass.preserveAttachmentCount = 0;
		subpass.pPreserveAttachments = nullptr;
		// Resoluve attachments are resolved at the end of a sub pass and can be
		// used for e.g. multi sampling
		// This example doesn't make use of this
		subpass.pResolveAttachments = nullptr;
		// Reference to the color attachment
		subpass.colorAttachmentCount = 1;
		subpass.pColorAttachments = &colorReference;
		// Reference to the depth attachment
		subpass.pDepthStencilAttachment = &depthReference;

		// Setup the render pass
		VkRenderPassCreateInfo renderPassInfo = {};
		renderPassInfo.sType = VK_STRUCTURE_TYPE_RENDER_PASS_CREATE_INFO;
		// Set attachments used in our renderpass
		renderPassInfo.attachmentCount = static_cast<uint32_t>(attachments.size());
		renderPassInfo.pAttachments = attachments.data();
		// We only use one subpass
		renderPassInfo.subpassCount = 1;
		renderPassInfo.pSubpasses = &subpass;
		// As we only use one subpass we don't have any subpass dependencies
		renderPassInfo.dependencyCount = 0;
		renderPassInfo.pDependencies = nullptr;

		// Create the renderpass
		VK_CHECK_RESULT(vkCreateRenderPass(device, &renderPassInfo, nullptr, &renderPass));
	}

	void preparePipelines()
	{
		// Create our rendering pipeline used in this example
		// Vulkan uses the concept of rendering pipelines to encapsulate
		// fixed states
		// This replaces OpenGL's huge (and cumbersome) state machine
		// A pipeline is then stored and hashed on the GPU making
		// pipeline changes much faster than having to set dozens of 
		// states
		// In a real world application you'd have dozens of pipelines
		// for every shader set used in a scene
		// Note that there are a few states that are not stored with
		// the pipeline. These are called dynamic states and the 
		// pipeline only stores that they are used with this pipeline,
		// but not their states

		VkGraphicsPipelineCreateInfo pipelineCreateInfo = {};

		pipelineCreateInfo.sType = VK_STRUCTURE_TYPE_GRAPHICS_PIPELINE_CREATE_INFO;
		// The layout used for this pipeline
		pipelineCreateInfo.layout = pipelineLayout;
		// Renderpass this pipeline is attached to
		pipelineCreateInfo.renderPass = renderPass;

		// Vertex input state
		// Describes the topoloy used with this pipeline
		VkPipelineInputAssemblyStateCreateInfo inputAssemblyState = {};
		inputAssemblyState.sType = VK_STRUCTURE_TYPE_PIPELINE_INPUT_ASSEMBLY_STATE_CREATE_INFO;
		// This pipeline renders vertex data as triangle lists
		inputAssemblyState.topology = VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST;

		// Rasterization state
		VkPipelineRasterizationStateCreateInfo rasterizationState = {};
		rasterizationState.sType = VK_STRUCTURE_TYPE_PIPELINE_RASTERIZATION_STATE_CREATE_INFO;
		// Solid polygon mode
		rasterizationState.polygonMode = VK_POLYGON_MODE_FILL;
		// No culling
		rasterizationState.cullMode = VK_CULL_MODE_NONE;
		rasterizationState.frontFace = VK_FRONT_FACE_COUNTER_CLOCKWISE;
		rasterizationState.depthClampEnable = VK_FALSE;
		rasterizationState.rasterizerDiscardEnable = VK_FALSE;
		rasterizationState.depthBiasEnable = VK_FALSE;
		rasterizationState.lineWidth = 1.0f;

		// Color blend state
		// Describes blend modes and color masks
		VkPipelineColorBlendStateCreateInfo colorBlendState = {};
		colorBlendState.sType = VK_STRUCTURE_TYPE_PIPELINE_COLOR_BLEND_STATE_CREATE_INFO;
		// One blend attachment state
		// Blending is not used in this example
		VkPipelineColorBlendAttachmentState blendAttachmentState[1] = {};
		blendAttachmentState[0].colorWriteMask = 0xf;
		blendAttachmentState[0].blendEnable = VK_FALSE;
		colorBlendState.attachmentCount = 1;
		colorBlendState.pAttachments = blendAttachmentState;

		// Viewport state
		VkPipelineViewportStateCreateInfo viewportState = {};
		viewportState.sType = VK_STRUCTURE_TYPE_PIPELINE_VIEWPORT_STATE_CREATE_INFO;
		// One viewport
		viewportState.viewportCount = 1;
		// One scissor rectangle
		viewportState.scissorCount = 1;

		// Enable dynamic states
		// Describes the dynamic states to be used with this pipeline
		// Dynamic states can be set even after the pipeline has been created
		// So there is no need to create new pipelines just for changing
		// a viewport's dimensions or a scissor box
		VkPipelineDynamicStateCreateInfo dynamicState = {};
		// The dynamic state properties themselves are stored in the command buffer
		std::vector<VkDynamicState> dynamicStateEnables;
		dynamicStateEnables.push_back(VK_DYNAMIC_STATE_VIEWPORT);
		dynamicStateEnables.push_back(VK_DYNAMIC_STATE_SCISSOR);
		dynamicState.sType = VK_STRUCTURE_TYPE_PIPELINE_DYNAMIC_STATE_CREATE_INFO;
		dynamicState.pDynamicStates = dynamicStateEnables.data();
		dynamicState.dynamicStateCount = static_cast<uint32_t>(dynamicStateEnables.size());

		// Depth and stencil state
		// Describes depth and stenctil test and compare ops
		VkPipelineDepthStencilStateCreateInfo depthStencilState = {};
		// Basic depth compare setup with depth writes and depth test enabled
		// No stencil used 
		depthStencilState.sType = VK_STRUCTURE_TYPE_PIPELINE_DEPTH_STENCIL_STATE_CREATE_INFO;
		depthStencilState.depthTestEnable = VK_TRUE;
		depthStencilState.depthWriteEnable = VK_TRUE;
		depthStencilState.depthCompareOp = VK_COMPARE_OP_LESS_OR_EQUAL;
		depthStencilState.depthBoundsTestEnable = VK_FALSE;
		depthStencilState.back.failOp = VK_STENCIL_OP_KEEP;
		depthStencilState.back.passOp = VK_STENCIL_OP_KEEP;
		depthStencilState.back.compareOp = VK_COMPARE_OP_ALWAYS;
		depthStencilState.stencilTestEnable = VK_FALSE;
		depthStencilState.front = depthStencilState.back;

		// Multi sampling state
		VkPipelineMultisampleStateCreateInfo multisampleState = {};
		multisampleState.sType = VK_STRUCTURE_TYPE_PIPELINE_MULTISAMPLE_STATE_CREATE_INFO;
		multisampleState.pSampleMask = NULL;
		// No multi sampling used in this example
		multisampleState.rasterizationSamples = VK_SAMPLE_COUNT_1_BIT;

		// Load shaders
		// Shaders are loaded from the SPIR-V format, which can be generated from glsl
		std::array<VkPipelineShaderStageCreateInfo,2> shaderStages;
		shaderStages[0] = loadShader(getAssetPath() + "shaders/triangle.vert.spv", VK_SHADER_STAGE_VERTEX_BIT);
		shaderStages[1] = loadShader(getAssetPath() + "shaders/triangle.frag.spv", VK_SHADER_STAGE_FRAGMENT_BIT);

		// Assign states
		// Assign pipeline state create information
		pipelineCreateInfo.stageCount = static_cast<uint32_t>(shaderStages.size());
		pipelineCreateInfo.pStages = shaderStages.data();
		pipelineCreateInfo.pVertexInputState = &vertices.inputState;
		pipelineCreateInfo.pInputAssemblyState = &inputAssemblyState;
		pipelineCreateInfo.pRasterizationState = &rasterizationState;
		pipelineCreateInfo.pColorBlendState = &colorBlendState;
		pipelineCreateInfo.pMultisampleState = &multisampleState;
		pipelineCreateInfo.pViewportState = &viewportState;
		pipelineCreateInfo.pDepthStencilState = &depthStencilState;
		pipelineCreateInfo.renderPass = renderPass;
		pipelineCreateInfo.pDynamicState = &dynamicState;

		// Create rendering pipeline
		VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCreateInfo, nullptr, &pipeline));
	}

	void prepareUniformBuffers()
	{
		// Prepare and initialize a uniform buffer block containing shader uniforms
		// In Vulkan there are no more single uniforms like in GL
		// All shader uniforms are passed as uniform buffer blocks 
		VkMemoryRequirements memReqs;

		// Vertex shader uniform buffer block
		VkBufferCreateInfo bufferInfo = {};
		VkMemoryAllocateInfo allocInfo = {};
		allocInfo.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO;
		allocInfo.pNext = NULL;
		allocInfo.allocationSize = 0;
		allocInfo.memoryTypeIndex = 0;

		bufferInfo.sType = VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO;
		bufferInfo.size = sizeof(uboVS);
		bufferInfo.usage = VK_BUFFER_USAGE_UNIFORM_BUFFER_BIT;

		// Create a new buffer
		VK_CHECK_RESULT(vkCreateBuffer(device, &bufferInfo, nullptr, &uniformDataVS.buffer));
		// Get memory requirements including size, alignment and memory type 
		vkGetBufferMemoryRequirements(device, uniformDataVS.buffer, &memReqs);
		allocInfo.allocationSize = memReqs.size;
		// Get the memory type index that supports host visibile memory access
		// Most implementations offer multiple memory tpyes and selecting the 
		// correct one to allocate memory from is important
		// We also want the buffer to be host coherent so we don't have to flush 
		// after every update. 
		// Note that this may affect performance so you might not want to do this 
		// in a real world application that updates buffers on a regular base
		allocInfo.memoryTypeIndex = getMemoryTypeIndex(memReqs.memoryTypeBits, VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT | VK_MEMORY_PROPERTY_HOST_COHERENT_BIT);
		// Allocate memory for the uniform buffer
		VK_CHECK_RESULT(vkAllocateMemory(device, &allocInfo, nullptr, &(uniformDataVS.memory)));
		// Bind memory to buffer
		VK_CHECK_RESULT(vkBindBufferMemory(device, uniformDataVS.buffer, uniformDataVS.memory, 0));
		
		// Store information in the uniform's descriptor
		uniformDataVS.descriptor.buffer = uniformDataVS.buffer;
		uniformDataVS.descriptor.offset = 0;
		uniformDataVS.descriptor.range = sizeof(uboVS);

		updateUniformBuffers();
	}

	void updateUniformBuffers()
	{
		// Update matrices
		uboVS.projectionMatrix = glm::perspective(glm::radians(60.0f), (float)width / (float)height, 0.1f, 256.0f);

		uboVS.viewMatrix = glm::translate(glm::mat4(), glm::vec3(0.0f, 0.0f, zoom));

		uboVS.modelMatrix = glm::mat4();
		uboVS.modelMatrix = glm::rotate(uboVS.modelMatrix, glm::radians(rotation.x), glm::vec3(1.0f, 0.0f, 0.0f));
		uboVS.modelMatrix = glm::rotate(uboVS.modelMatrix, glm::radians(rotation.y), glm::vec3(0.0f, 1.0f, 0.0f));
		uboVS.modelMatrix = glm::rotate(uboVS.modelMatrix, glm::radians(rotation.z), glm::vec3(0.0f, 0.0f, 1.0f));

		// Map uniform buffer and update it
		uint8_t *pData;
		VK_CHECK_RESULT(vkMapMemory(device, uniformDataVS.memory, 0, sizeof(uboVS), 0, (void **)&pData));
		memcpy(pData, &uboVS, sizeof(uboVS));
		vkUnmapMemory(device, uniformDataVS.memory);
	}

	void prepare()
	{
		VulkanExampleBase::prepare();
		prepareSemaphore();
		prepareVertices(USE_STAGING);
		prepareUniformBuffers();
		setupDescriptorSetLayout();
		preparePipelines();
		setupDescriptorPool();
		setupDescriptorSet();
		buildCommandBuffers();
		prepared = true;
	}

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

	virtual void viewChanged()
	{
		// This function is called by the base example class 
		// each time the view is changed by user input
		updateUniformBuffers();
	}
};

VulkanExample *vulkanExample;

#if defined(_WIN32)
LRESULT CALLBACK WndProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
	if (vulkanExample != NULL)
	{
		vulkanExample->handleMessages(hWnd, uMsg, wParam, lParam);
	}
	return (DefWindowProc(hWnd, uMsg, wParam, lParam));
}
#elif defined(__linux__) && !defined(__ANDROID__)
static void handleEvent(const xcb_generic_event_t *event)
{
	if (vulkanExample != NULL)
	{
		vulkanExample->handleEvent(event);
	}
}
#endif

// Main entry point
#if defined(_WIN32)
// Windows entry point
int APIENTRY WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR pCmdLine, int nCmdShow)
#elif defined(__ANDROID__)
// Android entry point
void android_main(android_app* state)
#elif defined(__linux__)
// Linux entry point
int main(const int argc, const char *argv[])
#endif
{
#if defined(__ANDROID__)
	// Removing this may cause the compiler to omit the main entry point 
	// which would make the application crash at start
	app_dummy();
#endif
	vulkanExample = new VulkanExample();
#if defined(_WIN32)
	vulkanExample->setupWindow(hInstance, WndProc);
#elif defined(__ANDROID__)
	// Attach vulkan example to global android application state
	state->userData = vulkanExample;
	state->onAppCmd = VulkanExample::handleAppCommand;
	state->onInputEvent = VulkanExample::handleAppInput;
	vulkanExample->androidApp = state;
#elif defined(__linux__)
	vulkanExample->setupWindow();
#endif
#if !defined(__ANDROID__)
	vulkanExample->initSwapchain();
	vulkanExample->prepare();
#endif
	vulkanExample->renderLoop();
	delete(vulkanExample);
#if !defined(__ANDROID__)
	return 0;
#endif
}