int sample_main(int argc, char *argv[]) {
    VkResult U_ASSERT_ONLY res;
    struct sample_info info = {};
    char sample_title[] = "Secondary command buffers";
    const bool depthPresent = true;

    process_command_line_args(info, argc, argv);
    init_global_layer_properties(info);
    init_instance_extension_names(info);
    init_device_extension_names(info);
    init_instance(info, sample_title);
    init_enumerate_device(info);
    init_window_size(info, 500, 500);
    init_connection(info);
    init_window(info);
    init_swapchain_extension(info);
    init_device(info);
    init_command_pool(info);
    init_command_buffer(info);
    execute_begin_command_buffer(info);
    init_device_queue(info);
    init_swap_chain(info);
    init_depth_buffer(info);
    init_uniform_buffer(info);
    init_descriptor_and_pipeline_layouts(info, true);
    init_renderpass(info, depthPresent, true, VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL);
    init_shaders(info, vertShaderText, fragShaderText);
    init_framebuffers(info, depthPresent);
    init_vertex_buffer(info, g_vb_texture_Data, sizeof(g_vb_texture_Data), sizeof(g_vb_texture_Data[0]), true);
    init_pipeline_cache(info);
    init_pipeline(info, depthPresent);

    // we have to set up a couple of things by hand, but this
    // isn't any different to other examples

    // get two different textures
    init_texture(info, "green.ppm");
    VkDescriptorImageInfo greenTex = info.texture_data.image_info;

    init_texture(info, "lunarg.ppm");
    VkDescriptorImageInfo lunargTex = info.texture_data.image_info;

    // create two identical descriptor sets, each with a different texture but
    // identical UBOa
    VkDescriptorPoolSize pool_size[2];
    pool_size[0].type = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
    pool_size[0].descriptorCount = 2;
    pool_size[1].type = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
    pool_size[1].descriptorCount = 2;

    VkDescriptorPoolCreateInfo descriptor_pool = {};
    descriptor_pool.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_POOL_CREATE_INFO;
    descriptor_pool.pNext = NULL;
    descriptor_pool.flags = 0;
    descriptor_pool.maxSets = 2;
    descriptor_pool.poolSizeCount = 2;
    descriptor_pool.pPoolSizes = pool_size;

    res = vkCreateDescriptorPool(info.device, &descriptor_pool, NULL, &info.desc_pool);
    assert(res == VK_SUCCESS);

    VkDescriptorSetLayout layouts[] = {info.desc_layout[0], info.desc_layout[0]};

    VkDescriptorSetAllocateInfo alloc_info[1];
    alloc_info[0].sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_ALLOCATE_INFO;
    alloc_info[0].pNext = NULL;
    alloc_info[0].descriptorPool = info.desc_pool;
    alloc_info[0].descriptorSetCount = 2;
    alloc_info[0].pSetLayouts = layouts;

    info.desc_set.resize(2);
    res = vkAllocateDescriptorSets(info.device, alloc_info, info.desc_set.data());
    assert(res == VK_SUCCESS);

    VkWriteDescriptorSet writes[2];

    writes[0].sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
    writes[0].pNext = NULL;
    writes[0].dstSet = info.desc_set[0];
    writes[0].descriptorCount = 1;
    writes[0].descriptorType = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
    writes[0].pBufferInfo = &info.uniform_data.buffer_info;
    writes[0].dstArrayElement = 0;
    writes[0].dstBinding = 0;

    writes[1].sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
    writes[1].pNext = NULL;
    writes[1].dstSet = info.desc_set[0];
    writes[1].dstBinding = 1;
    writes[1].descriptorCount = 1;
    writes[1].descriptorType = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
    writes[1].pImageInfo = &greenTex;
    writes[1].dstArrayElement = 0;

    vkUpdateDescriptorSets(info.device, 2, writes, 0, NULL);

    writes[0].dstSet = writes[1].dstSet = info.desc_set[1];
    writes[1].pImageInfo = &lunargTex;

    vkUpdateDescriptorSets(info.device, 2, writes, 0, NULL);

    /* VULKAN_KEY_START */

    // create four secondary command buffers, for each quadrant of the screen

    VkCommandBufferAllocateInfo cmdalloc = {};
    cmdalloc.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_ALLOCATE_INFO;
    cmdalloc.pNext = NULL;
    cmdalloc.commandPool = info.cmd_pool;
    cmdalloc.level = VK_COMMAND_BUFFER_LEVEL_SECONDARY;
    cmdalloc.commandBufferCount = 4;

    VkCommandBuffer secondary_cmds[4];

    res = vkAllocateCommandBuffers(info.device, &cmdalloc, secondary_cmds);
    assert(res == VK_SUCCESS);

    VkClearValue clear_values[2];
    clear_values[0].color.float32[0] = 0.2f;
    clear_values[0].color.float32[1] = 0.2f;
    clear_values[0].color.float32[2] = 0.2f;
    clear_values[0].color.float32[3] = 0.2f;
    clear_values[1].depthStencil.depth = 1.0f;
    clear_values[1].depthStencil.stencil = 0;

    VkSemaphore imageAcquiredSemaphore;
    VkSemaphoreCreateInfo imageAcquiredSemaphoreCreateInfo;
    imageAcquiredSemaphoreCreateInfo.sType = VK_STRUCTURE_TYPE_SEMAPHORE_CREATE_INFO;
    imageAcquiredSemaphoreCreateInfo.pNext = NULL;
    imageAcquiredSemaphoreCreateInfo.flags = 0;

    res = vkCreateSemaphore(info.device, &imageAcquiredSemaphoreCreateInfo, NULL, &imageAcquiredSemaphore);
    assert(res == VK_SUCCESS);

    // Get the index of the next available swapchain image:
    res = vkAcquireNextImageKHR(info.device, info.swap_chain, UINT64_MAX, imageAcquiredSemaphore, VK_NULL_HANDLE,
                                &info.current_buffer);
    // TODO: Deal with the VK_SUBOPTIMAL_KHR and VK_ERROR_OUT_OF_DATE_KHR
    // return codes
    assert(res == VK_SUCCESS);

    set_image_layout(info, info.buffers[info.current_buffer].image, VK_IMAGE_ASPECT_COLOR_BIT, VK_IMAGE_LAYOUT_UNDEFINED,
                     VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL, VK_PIPELINE_STAGE_TOP_OF_PIPE_BIT,
                     VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT);

    const VkDeviceSize offsets[1] = {0};

    VkViewport viewport;
    viewport.height = 200.0f;
    viewport.width = 200.0f;
    viewport.minDepth = (float)0.0f;
    viewport.maxDepth = (float)1.0f;
    viewport.x = 0;
    viewport.y = 0;

    VkRect2D scissor;
    scissor.extent.width = info.width;
    scissor.extent.height = info.height;
    scissor.offset.x = 0;
    scissor.offset.y = 0;

    // now we record four separate command buffers, one for each quadrant of the
    // screen
    VkCommandBufferInheritanceInfo cmd_buf_inheritance_info = {};
    cmd_buf_inheritance_info.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_INHERITANCE_INFO, cmd_buf_inheritance_info.pNext = NULL;
    cmd_buf_inheritance_info.renderPass = info.render_pass;
    cmd_buf_inheritance_info.subpass = 0;
    cmd_buf_inheritance_info.framebuffer = info.framebuffers[info.current_buffer];
    cmd_buf_inheritance_info.occlusionQueryEnable = VK_FALSE;
    cmd_buf_inheritance_info.queryFlags = 0;
    cmd_buf_inheritance_info.pipelineStatistics = 0;

    VkCommandBufferBeginInfo secondary_begin = {};
    secondary_begin.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;
    secondary_begin.pNext = NULL;
    secondary_begin.flags = VK_COMMAND_BUFFER_USAGE_ONE_TIME_SUBMIT_BIT | VK_COMMAND_BUFFER_USAGE_RENDER_PASS_CONTINUE_BIT;
    secondary_begin.pInheritanceInfo = &cmd_buf_inheritance_info;

    for (int i = 0; i < 4; i++) {
        vkBeginCommandBuffer(secondary_cmds[i], &secondary_begin);

        vkCmdBindPipeline(secondary_cmds[i], VK_PIPELINE_BIND_POINT_GRAPHICS, info.pipeline);
        vkCmdBindDescriptorSets(secondary_cmds[i], VK_PIPELINE_BIND_POINT_GRAPHICS, info.pipeline_layout, 0, 1,
                                &info.desc_set[i == 0 || i == 3], 0, NULL);

        vkCmdBindVertexBuffers(secondary_cmds[i], 0, 1, &info.vertex_buffer.buf, offsets);

        viewport.x = 25.0f + 250.0f * (i % 2);
        viewport.y = 25.0f + 250.0f * (i / 2);
        vkCmdSetViewport(secondary_cmds[i], 0, NUM_VIEWPORTS, &viewport);

        vkCmdSetScissor(secondary_cmds[i], 0, NUM_SCISSORS, &scissor);

        vkCmdDraw(secondary_cmds[i], 12 * 3, 1, 0, 0);

        vkEndCommandBuffer(secondary_cmds[i]);
    }

    VkRenderPassBeginInfo rp_begin;
    rp_begin.sType = VK_STRUCTURE_TYPE_RENDER_PASS_BEGIN_INFO;
    rp_begin.pNext = NULL;
    rp_begin.renderPass = info.render_pass;
    rp_begin.framebuffer = info.framebuffers[info.current_buffer];
    rp_begin.renderArea.offset.x = 0;
    rp_begin.renderArea.offset.y = 0;
    rp_begin.renderArea.extent.width = info.width;
    rp_begin.renderArea.extent.height = info.height;
    rp_begin.clearValueCount = 2;
    rp_begin.pClearValues = clear_values;

    // specifying VK_SUBPASS_CONTENTS_SECONDARY_COMMAND_BUFFERS means this
    // render pass may
    // ONLY call vkCmdExecuteCommands
    vkCmdBeginRenderPass(info.cmd, &rp_begin, VK_SUBPASS_CONTENTS_SECONDARY_COMMAND_BUFFERS);

    vkCmdExecuteCommands(info.cmd, 4, secondary_cmds);

    vkCmdEndRenderPass(info.cmd);

    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.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
    prePresentBarrier.subresourceRange.baseMipLevel = 0;
    prePresentBarrier.subresourceRange.levelCount = 1;
    prePresentBarrier.subresourceRange.baseArrayLayer = 0;
    prePresentBarrier.subresourceRange.layerCount = 1;
    prePresentBarrier.image = info.buffers[info.current_buffer].image;
    vkCmdPipelineBarrier(info.cmd, VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT, VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT, 0, 0, NULL,
                         0, NULL, 1, &prePresentBarrier);

    res = vkEndCommandBuffer(info.cmd);
    assert(res == VK_SUCCESS);

    const VkCommandBuffer cmd_bufs[] = {info.cmd};
    VkFenceCreateInfo fenceInfo;
    VkFence drawFence;
    fenceInfo.sType = VK_STRUCTURE_TYPE_FENCE_CREATE_INFO;
    fenceInfo.pNext = NULL;
    fenceInfo.flags = 0;
    vkCreateFence(info.device, &fenceInfo, NULL, &drawFence);

    VkPipelineStageFlags pipe_stage_flags = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
    VkSubmitInfo submit_info[1] = {};
    submit_info[0].pNext = NULL;
    submit_info[0].sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
    submit_info[0].waitSemaphoreCount = 1;
    submit_info[0].pWaitSemaphores = &imageAcquiredSemaphore;
    submit_info[0].pWaitDstStageMask = &pipe_stage_flags;
    submit_info[0].commandBufferCount = 1;
    submit_info[0].pCommandBuffers = cmd_bufs;
    submit_info[0].signalSemaphoreCount = 0;
    submit_info[0].pSignalSemaphores = NULL;

    /* Queue the command buffer for execution */
    res = vkQueueSubmit(info.graphics_queue, 1, submit_info, drawFence);
    assert(res == VK_SUCCESS);

    /* Now present the image in the window */

    VkPresentInfoKHR present;
    present.sType = VK_STRUCTURE_TYPE_PRESENT_INFO_KHR;
    present.pNext = NULL;
    present.swapchainCount = 1;
    present.pSwapchains = &info.swap_chain;
    present.pImageIndices = &info.current_buffer;
    present.pWaitSemaphores = NULL;
    present.waitSemaphoreCount = 0;
    present.pResults = NULL;

    /* Make sure command buffer is finished before presenting */
    do {
        res = vkWaitForFences(info.device, 1, &drawFence, VK_TRUE, FENCE_TIMEOUT);
    } while (res == VK_TIMEOUT);

    assert(res == VK_SUCCESS);
    res = vkQueuePresentKHR(info.present_queue, &present);
    assert(res == VK_SUCCESS);

    wait_seconds(1);
    if (info.save_images) write_ppm(info, "secondary_command_buffer");

    vkFreeCommandBuffers(info.device, info.cmd_pool, 4, secondary_cmds);

    /* VULKAN_KEY_END */

    vkDestroyFence(info.device, drawFence, NULL);
    vkDestroySemaphore(info.device, imageAcquiredSemaphore, NULL);
    destroy_pipeline(info);
    destroy_pipeline_cache(info);
    destroy_textures(info);
    destroy_descriptor_pool(info);
    destroy_vertex_buffer(info);
    destroy_framebuffers(info);
    destroy_shaders(info);
    destroy_renderpass(info);
    destroy_descriptor_and_pipeline_layouts(info);
    destroy_uniform_buffer(info);
    destroy_depth_buffer(info);
    destroy_swap_chain(info);
    destroy_command_buffer(info);
    destroy_command_pool(info);
    destroy_device(info);
    destroy_window(info);
    destroy_instance(info);
    return 0;
}
int sample_main(int argc, char *argv[]) {
    VkResult U_ASSERT_ONLY res;
    bool U_ASSERT_ONLY pass;
    struct sample_info info = {};
    char sample_title[] = "Input Attachment Sample";
    const bool depthPresent = false;
    const bool vertexPresent = false;

    process_command_line_args(info, argc, argv);
    init_global_layer_properties(info);
    init_instance_extension_names(info);
    init_device_extension_names(info);
    init_instance(info, sample_title);
    init_enumerate_device(info);

    VkFormatProperties props;
    vkGetPhysicalDeviceFormatProperties(info.gpus[0], VK_FORMAT_R8G8B8A8_UNORM, &props);
    if (!(props.optimalTilingFeatures & VK_FORMAT_FEATURE_COLOR_ATTACHMENT_BIT)) {
        std::cout << "VK_FORMAT_R8G8B8A8_UNORM format unsupported for input "
                     "attachment\n";
        exit(-1);
    }

    init_window_size(info, 500, 500);
    init_connection(info);
    init_window(info);
    init_swapchain_extension(info);
    init_device(info);
    init_command_pool(info);
    init_command_buffer(info);
    execute_begin_command_buffer(info);
    init_device_queue(info);
    init_swap_chain(info);

    /* VULKAN_KEY_START */

    // Create a framebuffer with 2 attachments, one the color attachment
    // the shaders render into, and the other an input attachment which
    // will be cleared to yellow, and then used by the shaders to color
    // the drawn triangle. Final result should be a yellow triangle

    // Create the image that will be used as the input attachment
    // The image for the color attachment is the presentable image already
    // created in init_swapchain()
    VkImageCreateInfo image_create_info = {};
    image_create_info.sType = VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO;
    image_create_info.pNext = NULL;
    image_create_info.imageType = VK_IMAGE_TYPE_2D;
    image_create_info.format = info.format;
    image_create_info.extent.width = info.width;
    image_create_info.extent.height = info.height;
    image_create_info.extent.depth = 1;
    image_create_info.mipLevels = 1;
    image_create_info.arrayLayers = 1;
    image_create_info.samples = NUM_SAMPLES;
    image_create_info.tiling = VK_IMAGE_TILING_OPTIMAL;
    image_create_info.initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
    image_create_info.usage = VK_IMAGE_USAGE_INPUT_ATTACHMENT_BIT | VK_IMAGE_USAGE_TRANSFER_DST_BIT;
    image_create_info.queueFamilyIndexCount = 0;
    image_create_info.pQueueFamilyIndices = NULL;
    image_create_info.sharingMode = VK_SHARING_MODE_EXCLUSIVE;
    image_create_info.flags = 0;

    VkMemoryAllocateInfo mem_alloc = {};
    mem_alloc.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO;
    mem_alloc.pNext = NULL;
    mem_alloc.allocationSize = 0;
    mem_alloc.memoryTypeIndex = 0;

    VkImage input_image;
    VkDeviceMemory input_memory;

    res = vkCreateImage(info.device, &image_create_info, NULL, &input_image);
    assert(res == VK_SUCCESS);

    VkMemoryRequirements mem_reqs;
    vkGetImageMemoryRequirements(info.device, input_image, &mem_reqs);

    mem_alloc.allocationSize = mem_reqs.size;

    pass = memory_type_from_properties(info, mem_reqs.memoryTypeBits, 0, &mem_alloc.memoryTypeIndex);
    assert(pass);

    res = vkAllocateMemory(info.device, &mem_alloc, NULL, &input_memory);
    assert(res == VK_SUCCESS);

    res = vkBindImageMemory(info.device, input_image, input_memory, 0);
    assert(res == VK_SUCCESS);

    // Set the image layout to TRANSFER_DST_OPTIMAL to be ready for clear
    set_image_layout(info, input_image, VK_IMAGE_ASPECT_COLOR_BIT, VK_IMAGE_LAYOUT_UNDEFINED, VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL,
                     VK_PIPELINE_STAGE_TOP_OF_PIPE_BIT, VK_PIPELINE_STAGE_TRANSFER_BIT);

    VkImageSubresourceRange srRange = {};
    srRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
    srRange.baseMipLevel = 0;
    srRange.levelCount = VK_REMAINING_MIP_LEVELS;
    srRange.baseArrayLayer = 0;
    srRange.layerCount = VK_REMAINING_ARRAY_LAYERS;

    VkClearColorValue clear_color;
    clear_color.float32[0] = 1.0f;
    clear_color.float32[1] = 1.0f;
    clear_color.float32[2] = 0.0f;
    clear_color.float32[3] = 0.0f;
    // Clear the input attachment image to yellow
    vkCmdClearColorImage(info.cmd, input_image, VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL, &clear_color, 1, &srRange);

    // Set the image layout to SHADER_READONLY_OPTIMAL for use by the shaders
    set_image_layout(info, input_image, VK_IMAGE_ASPECT_COLOR_BIT, VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL,
                     VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL, VK_PIPELINE_STAGE_TRANSFER_BIT,
                     VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT);

    VkImageViewCreateInfo view_info = {};
    view_info.sType = VK_STRUCTURE_TYPE_IMAGE_VIEW_CREATE_INFO;
    view_info.pNext = NULL;
    view_info.image = VK_NULL_HANDLE;
    view_info.viewType = VK_IMAGE_VIEW_TYPE_2D;
    view_info.format = info.format;
    view_info.components.r = VK_COMPONENT_SWIZZLE_R;
    view_info.components.g = VK_COMPONENT_SWIZZLE_G;
    view_info.components.b = VK_COMPONENT_SWIZZLE_B;
    view_info.components.a = VK_COMPONENT_SWIZZLE_A;
    view_info.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
    view_info.subresourceRange.baseMipLevel = 0;
    view_info.subresourceRange.levelCount = 1;
    view_info.subresourceRange.baseArrayLayer = 0;
    view_info.subresourceRange.layerCount = 1;

    VkImageView input_attachment_view;
    view_info.image = input_image;
    res = vkCreateImageView(info.device, &view_info, NULL, &input_attachment_view);
    assert(res == VK_SUCCESS);

    VkDescriptorImageInfo input_image_info = {};
    input_image_info.imageLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
    input_image_info.imageView = input_attachment_view;
    input_image_info.sampler = VK_NULL_HANDLE;

    VkDescriptorSetLayoutBinding layout_bindings[1];
    layout_bindings[0].binding = 0;
    layout_bindings[0].descriptorType = VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT;
    layout_bindings[0].descriptorCount = 1;
    layout_bindings[0].stageFlags = VK_SHADER_STAGE_FRAGMENT_BIT;
    layout_bindings[0].pImmutableSamplers = NULL;

    VkDescriptorSetLayoutCreateInfo descriptor_layout = {};
    descriptor_layout.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_CREATE_INFO;
    descriptor_layout.pNext = NULL;
    descriptor_layout.bindingCount = 1;
    descriptor_layout.pBindings = layout_bindings;

    info.desc_layout.resize(NUM_DESCRIPTOR_SETS);
    res = vkCreateDescriptorSetLayout(info.device, &descriptor_layout, NULL, info.desc_layout.data());
    assert(res == VK_SUCCESS);

    VkPipelineLayoutCreateInfo pPipelineLayoutCreateInfo = {};
    pPipelineLayoutCreateInfo.sType = VK_STRUCTURE_TYPE_PIPELINE_LAYOUT_CREATE_INFO;
    pPipelineLayoutCreateInfo.pNext = NULL;
    pPipelineLayoutCreateInfo.pushConstantRangeCount = 0;
    pPipelineLayoutCreateInfo.pPushConstantRanges = NULL;
    pPipelineLayoutCreateInfo.setLayoutCount = NUM_DESCRIPTOR_SETS;
    pPipelineLayoutCreateInfo.pSetLayouts = info.desc_layout.data();

    res = vkCreatePipelineLayout(info.device, &pPipelineLayoutCreateInfo, NULL, &info.pipeline_layout);
    assert(res == VK_SUCCESS);

    // First attachment is the color attachment - clear at the beginning of the
    // renderpass and transition layout to PRESENT_SRC_KHR at the end of
    // renderpass
    VkAttachmentDescription attachments[2];
    attachments[0].format = info.format;
    attachments[0].samples = VK_SAMPLE_COUNT_1_BIT;
    attachments[0].loadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
    attachments[0].storeOp = VK_ATTACHMENT_STORE_OP_STORE;
    attachments[0].stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE;
    attachments[0].stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
    attachments[0].initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
    attachments[0].finalLayout = VK_IMAGE_LAYOUT_PRESENT_SRC_KHR;
    attachments[0].flags = 0;

    // Second attachment is input attachment.  Once cleared it should have
    // width*height yellow pixels.  Doing a subpassLoad in the fragment shader
    // should give the shader the color at the fragments x,y location
    // from the input attachment
    attachments[1].format = info.format;
    attachments[1].samples = VK_SAMPLE_COUNT_1_BIT;
    attachments[1].loadOp = VK_ATTACHMENT_LOAD_OP_LOAD;
    attachments[1].storeOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
    attachments[1].stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE;
    attachments[1].stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
    attachments[1].initialLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
    attachments[1].finalLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
    attachments[1].flags = 0;

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

    VkAttachmentReference input_reference = {};
    input_reference.attachment = 1;
    input_reference.layout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;

    VkSubpassDescription subpass = {};
    subpass.pipelineBindPoint = VK_PIPELINE_BIND_POINT_GRAPHICS;
    subpass.flags = 0;
    subpass.inputAttachmentCount = 1;
    subpass.pInputAttachments = &input_reference;
    subpass.colorAttachmentCount = 1;
    subpass.pColorAttachments = &color_reference;
    subpass.pResolveAttachments = NULL;
    subpass.pDepthStencilAttachment = NULL;
    subpass.preserveAttachmentCount = 0;
    subpass.pPreserveAttachments = NULL;

    VkRenderPassCreateInfo rp_info = {};
    rp_info.sType = VK_STRUCTURE_TYPE_RENDER_PASS_CREATE_INFO;
    rp_info.pNext = NULL;
    rp_info.attachmentCount = 2;
    rp_info.pAttachments = attachments;
    rp_info.subpassCount = 1;
    rp_info.pSubpasses = &subpass;
    rp_info.dependencyCount = 0;
    rp_info.pDependencies = NULL;

    res = vkCreateRenderPass(info.device, &rp_info, NULL, &info.render_pass);
    assert(!res);

    init_shaders(info, vertShaderText, fragShaderText);

    VkImageView fb_attachments[2];
    fb_attachments[1] = input_attachment_view;

    VkFramebufferCreateInfo fbc_info = {};
    fbc_info.sType = VK_STRUCTURE_TYPE_FRAMEBUFFER_CREATE_INFO;
    fbc_info.pNext = NULL;
    fbc_info.renderPass = info.render_pass;
    fbc_info.attachmentCount = 2;
    fbc_info.pAttachments = fb_attachments;
    fbc_info.width = info.width;
    fbc_info.height = info.height;
    fbc_info.layers = 1;

    uint32_t i;

    info.framebuffers = (VkFramebuffer *)malloc(info.swapchainImageCount * sizeof(VkFramebuffer));

    for (i = 0; i < info.swapchainImageCount; i++) {
        fb_attachments[0] = info.buffers[i].view;
        res = vkCreateFramebuffer(info.device, &fbc_info, NULL, &info.framebuffers[i]);
        assert(res == VK_SUCCESS);
    }

    VkDescriptorPoolSize type_count[1];
    type_count[0].type = VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT;
    type_count[0].descriptorCount = 1;

    VkDescriptorPoolCreateInfo descriptor_pool = {};
    descriptor_pool.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_POOL_CREATE_INFO;
    descriptor_pool.pNext = NULL;
    descriptor_pool.maxSets = 1;
    descriptor_pool.poolSizeCount = 1;
    descriptor_pool.pPoolSizes = type_count;

    res = vkCreateDescriptorPool(info.device, &descriptor_pool, NULL, &info.desc_pool);
    assert(res == VK_SUCCESS);

    VkDescriptorSetAllocateInfo desc_alloc_info[1];
    desc_alloc_info[0].sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_ALLOCATE_INFO;
    desc_alloc_info[0].pNext = NULL;
    desc_alloc_info[0].descriptorPool = info.desc_pool;
    desc_alloc_info[0].descriptorSetCount = 1;
    desc_alloc_info[0].pSetLayouts = info.desc_layout.data();

    info.desc_set.resize(1);
    res = vkAllocateDescriptorSets(info.device, desc_alloc_info, info.desc_set.data());
    assert(res == VK_SUCCESS);

    VkWriteDescriptorSet writes[1];

    // Write descriptor set with one write describing input attachment
    writes[0] = {};
    writes[0].sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
    writes[0].dstSet = info.desc_set[0];
    writes[0].dstBinding = 0;
    writes[0].descriptorCount = 1;
    writes[0].descriptorType = VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT;
    writes[0].pImageInfo = &input_image_info;
    writes[0].pBufferInfo = nullptr;
    writes[0].pTexelBufferView = nullptr;
    writes[0].dstArrayElement = 0;

    vkUpdateDescriptorSets(info.device, 1, writes, 0, NULL);

    init_pipeline_cache(info);
    init_pipeline(info, depthPresent, vertexPresent);

    // Color attachment clear to gray
    VkClearValue clear_values;
    clear_values.color.float32[0] = 0.2f;
    clear_values.color.float32[1] = 0.2f;
    clear_values.color.float32[2] = 0.2f;
    clear_values.color.float32[3] = 0.2f;

    VkSemaphoreCreateInfo imageAcquiredSemaphoreCreateInfo;
    imageAcquiredSemaphoreCreateInfo.sType = VK_STRUCTURE_TYPE_SEMAPHORE_CREATE_INFO;
    imageAcquiredSemaphoreCreateInfo.pNext = NULL;
    imageAcquiredSemaphoreCreateInfo.flags = 0;

    res = vkCreateSemaphore(info.device, &imageAcquiredSemaphoreCreateInfo, NULL, &info.imageAcquiredSemaphore);
    assert(res == VK_SUCCESS);

    // Get the index of the next available swapchain image:
    res = vkAcquireNextImageKHR(info.device, info.swap_chain, UINT64_MAX, info.imageAcquiredSemaphore, VK_NULL_HANDLE,
                                &info.current_buffer);
    // TODO: Deal with the VK_SUBOPTIMAL_KHR and VK_ERROR_OUT_OF_DATE_KHR
    // return codes
    assert(res == VK_SUCCESS);

    VkRenderPassBeginInfo rp_begin;
    rp_begin.sType = VK_STRUCTURE_TYPE_RENDER_PASS_BEGIN_INFO;
    rp_begin.pNext = NULL;
    rp_begin.renderPass = info.render_pass;
    rp_begin.framebuffer = info.framebuffers[info.current_buffer];
    rp_begin.renderArea.offset.x = 0;
    rp_begin.renderArea.offset.y = 0;
    rp_begin.renderArea.extent.width = info.width;
    rp_begin.renderArea.extent.height = info.height;
    rp_begin.clearValueCount = 1;
    rp_begin.pClearValues = &clear_values;

    vkCmdBeginRenderPass(info.cmd, &rp_begin, VK_SUBPASS_CONTENTS_INLINE);

    vkCmdBindPipeline(info.cmd, VK_PIPELINE_BIND_POINT_GRAPHICS, info.pipeline);

    vkCmdBindDescriptorSets(info.cmd, VK_PIPELINE_BIND_POINT_GRAPHICS, info.pipeline_layout, 0, NUM_DESCRIPTOR_SETS,
                            info.desc_set.data(), 0, NULL);

    init_viewports(info);
    init_scissors(info);

    vkCmdDraw(info.cmd, 3, 1, 0, 0);

    vkCmdEndRenderPass(info.cmd);
    res = vkEndCommandBuffer(info.cmd);
    assert(res == VK_SUCCESS);

    /* VULKAN_KEY_END */

    const VkCommandBuffer cmd_bufs[] = {info.cmd};

    VkFenceCreateInfo fenceInfo;
    VkFence drawFence;
    fenceInfo.sType = VK_STRUCTURE_TYPE_FENCE_CREATE_INFO;
    fenceInfo.pNext = NULL;
    fenceInfo.flags = 0;
    vkCreateFence(info.device, &fenceInfo, NULL, &drawFence);

    execute_queue_cmdbuf(info, cmd_bufs, drawFence);

    do {
        res = vkWaitForFences(info.device, 1, &drawFence, VK_TRUE, FENCE_TIMEOUT);
    } while (res == VK_TIMEOUT);
    assert(res == VK_SUCCESS);
    vkDestroyFence(info.device, drawFence, NULL);

    execute_present_image(info);

    wait_seconds(1);

    if (info.save_images) write_ppm(info, "input_attachment");

    vkDestroySemaphore(info.device, info.imageAcquiredSemaphore, NULL);
    vkDestroyImageView(info.device, input_attachment_view, NULL);
    vkDestroyImage(info.device, input_image, NULL);
    vkFreeMemory(info.device, input_memory, NULL);
    destroy_pipeline(info);
    destroy_pipeline_cache(info);
    destroy_descriptor_pool(info);
    destroy_framebuffers(info);
    destroy_shaders(info);
    destroy_renderpass(info);
    destroy_descriptor_and_pipeline_layouts(info);
    destroy_swap_chain(info);
    destroy_command_buffer(info);
    destroy_command_pool(info);
    destroy_device(info);
    destroy_window(info);
    destroy_instance(info);
    return 0;
}
int main(int argc, char *argv[]) {
    VkResult U_ASSERT_ONLY res;
    struct sample_info info = {};
    char sample_title[] = "Swapchain Initialization Sample";

    /*
     * Set up swapchain:
     * - Get supported uses for all queues
     * - Try to find a queue that supports both graphics and present
     * - If no queue supports both, find a present queue and make sure we have a
     *   graphics queue
     * - Get a list of supported formats and use the first one
     * - Get surface properties and present modes and use them to create a swap
     *   chain
     * - Create swap chain buffers
     * - For each buffer, create a color attachment view and set its layout to
     *   color attachment
     */

    init_global_layer_properties(info);
    init_instance_extension_names(info);
    init_device_extension_names(info);
    init_instance(info, sample_title);
    init_enumerate_device(info);
    init_connection(info);
    init_window_size(info, 50, 50);
    init_window(info);

/* VULKAN_KEY_START */
// Construct the surface description:
#ifdef _WIN32
    VkWin32SurfaceCreateInfoKHR createInfo = {};
    createInfo.sType = VK_STRUCTURE_TYPE_WIN32_SURFACE_CREATE_INFO_KHR;
    createInfo.pNext = NULL;
    createInfo.hinstance = info.connection;
    createInfo.hwnd = info.window;
    res = vkCreateWin32SurfaceKHR(info.inst, &createInfo, NULL, &info.surface);
#else  // _WIN32
    VkXcbSurfaceCreateInfoKHR createInfo = {};
    createInfo.sType = VK_STRUCTURE_TYPE_XCB_SURFACE_CREATE_INFO_KHR;
    createInfo.pNext = NULL;
    createInfo.connection = info.connection;
    createInfo.window = info.window;
    res = vkCreateXcbSurfaceKHR(info.inst, &createInfo, NULL, &info.surface);
#endif // _WIN32
    assert(res == VK_SUCCESS);

    // Iterate over each queue to learn whether it supports presenting:
    VkBool32 *supportsPresent =
        (VkBool32 *)malloc(info.queue_count * sizeof(VkBool32));
    for (uint32_t i = 0; i < info.queue_count; i++) {
        vkGetPhysicalDeviceSurfaceSupportKHR(info.gpus[0], i, info.surface,
                                             &supportsPresent[i]);
    }

    // Search for a graphics queue and a present queue in the array of queue
    // families, try to find one that supports both
    uint32_t graphicsQueueNodeIndex = UINT32_MAX;
    for (uint32_t i = 0; i < info.queue_count; i++) {
        if ((info.queue_props[i].queueFlags & VK_QUEUE_GRAPHICS_BIT) != 0) {
            if (supportsPresent[i] == VK_TRUE) {
                graphicsQueueNodeIndex = i;
                break;
            }
        }
    }
    free(supportsPresent);

    // Generate error if could not find a queue that supports both a graphics
    // and present
    if (graphicsQueueNodeIndex == UINT32_MAX) {
        std::cout << "Could not find a queue that supports both graphics and "
                     "present\n";
        exit(-1);
    }

    info.graphics_queue_family_index = graphicsQueueNodeIndex;

    init_device(info);

    // Get the list of VkFormats that are supported:
    uint32_t formatCount;
    res = vkGetPhysicalDeviceSurfaceFormatsKHR(info.gpus[0], info.surface,
                                               &formatCount, NULL);
    assert(res == VK_SUCCESS);
    VkSurfaceFormatKHR *surfFormats =
        (VkSurfaceFormatKHR *)malloc(formatCount * sizeof(VkSurfaceFormatKHR));
    res = vkGetPhysicalDeviceSurfaceFormatsKHR(info.gpus[0], info.surface,
                                               &formatCount, surfFormats);
    assert(res == VK_SUCCESS);
    // If the format list includes just one entry of VK_FORMAT_UNDEFINED,
    // the surface has no preferred format.  Otherwise, at least one
    // supported format will be returned.
    if (formatCount == 1 && surfFormats[0].format == VK_FORMAT_UNDEFINED) {
        info.format = VK_FORMAT_B8G8R8A8_UNORM;
    } else {
        assert(formatCount >= 1);
        info.format = surfFormats[0].format;
    }

    VkSurfaceCapabilitiesKHR surfCapabilities;

    res = vkGetPhysicalDeviceSurfaceCapabilitiesKHR(info.gpus[0], info.surface,
                                                    &surfCapabilities);
    assert(res == VK_SUCCESS);

    uint32_t presentModeCount;
    res = vkGetPhysicalDeviceSurfacePresentModesKHR(info.gpus[0], info.surface,
                                                    &presentModeCount, NULL);
    assert(res == VK_SUCCESS);
    VkPresentModeKHR *presentModes =
        (VkPresentModeKHR *)malloc(presentModeCount * sizeof(VkPresentModeKHR));

    res = vkGetPhysicalDeviceSurfacePresentModesKHR(
        info.gpus[0], info.surface, &presentModeCount, presentModes);
    assert(res == VK_SUCCESS);

    VkExtent2D swapChainExtent;
    // width and height are either both -1, or both not -1.
    if (surfCapabilities.currentExtent.width == (uint32_t)-1) {
        // If the surface size is undefined, the size is set to
        // the size of the images requested.
        swapChainExtent.width = info.width;
        swapChainExtent.height = info.height;
    } else {
        // If the surface size is defined, the swap chain size must match
        swapChainExtent = surfCapabilities.currentExtent;
    }

    // If mailbox mode is available, use it, as is the lowest-latency non-
    // tearing mode.  If not, try IMMEDIATE which will usually be available,
    // and is fastest (though it tears).  If not, fall back to FIFO which is
    // always available.
    VkPresentModeKHR swapchainPresentMode = VK_PRESENT_MODE_FIFO_KHR;
    for (size_t i = 0; i < presentModeCount; i++) {
        if (presentModes[i] == VK_PRESENT_MODE_MAILBOX_KHR) {
            swapchainPresentMode = VK_PRESENT_MODE_MAILBOX_KHR;
            break;
        }
        if ((swapchainPresentMode != VK_PRESENT_MODE_MAILBOX_KHR) &&
            (presentModes[i] == VK_PRESENT_MODE_IMMEDIATE_KHR)) {
            swapchainPresentMode = VK_PRESENT_MODE_IMMEDIATE_KHR;
        }
    }

    // Determine the number of VkImage's to use in the swap chain (we desire to
    // own only 1 image at a time, besides the images being displayed and
    // queued for display):
    uint32_t desiredNumberOfSwapChainImages =
        surfCapabilities.minImageCount + 1;
    if ((surfCapabilities.maxImageCount > 0) &&
        (desiredNumberOfSwapChainImages > surfCapabilities.maxImageCount)) {
        // Application must settle for fewer images than desired:
        desiredNumberOfSwapChainImages = surfCapabilities.maxImageCount;
    }

    VkSurfaceTransformFlagBitsKHR preTransform;
    if (surfCapabilities.supportedTransforms &
        VK_SURFACE_TRANSFORM_IDENTITY_BIT_KHR) {
        preTransform = VK_SURFACE_TRANSFORM_IDENTITY_BIT_KHR;
    } else {
        preTransform = surfCapabilities.currentTransform;
    }

    VkSwapchainCreateInfoKHR swap_chain = {};
    swap_chain.sType = VK_STRUCTURE_TYPE_SWAPCHAIN_CREATE_INFO_KHR;
    swap_chain.pNext = NULL;
    swap_chain.surface = info.surface;
    swap_chain.minImageCount = desiredNumberOfSwapChainImages;
    swap_chain.imageFormat = info.format;
    swap_chain.imageExtent.width = swapChainExtent.width;
    swap_chain.imageExtent.height = swapChainExtent.height;
    swap_chain.preTransform = preTransform;
    swap_chain.compositeAlpha = VK_COMPOSITE_ALPHA_OPAQUE_BIT_KHR;
    swap_chain.imageArrayLayers = 1;
    swap_chain.presentMode = swapchainPresentMode;
    swap_chain.oldSwapchain = NULL;
    swap_chain.clipped = true;
    swap_chain.imageColorSpace = VK_COLORSPACE_SRGB_NONLINEAR_KHR;
    swap_chain.imageUsage = VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT;
    swap_chain.imageSharingMode = VK_SHARING_MODE_EXCLUSIVE;
    swap_chain.queueFamilyIndexCount = 0;
    swap_chain.pQueueFamilyIndices = NULL;

    res =
        vkCreateSwapchainKHR(info.device, &swap_chain, NULL, &info.swap_chain);
    assert(res == VK_SUCCESS);

    res = vkGetSwapchainImagesKHR(info.device, info.swap_chain,
                                  &info.swapchainImageCount, NULL);
    assert(res == VK_SUCCESS);

    VkImage *swapchainImages =
        (VkImage *)malloc(info.swapchainImageCount * sizeof(VkImage));
    assert(swapchainImages);
    res = vkGetSwapchainImagesKHR(info.device, info.swap_chain,
                                  &info.swapchainImageCount, swapchainImages);
    assert(res == VK_SUCCESS);

    info.buffers.resize(info.swapchainImageCount);

    // Going to need a command buffer to send the memory barriers in
    // set_image_layout but we couldn't have created one before we knew
    // what our graphics_queue_family_index is, but now that we have it,
    // create the command buffer

    init_command_pool(info);
    init_command_buffer(info);
    execute_begin_command_buffer(info);
    vkGetDeviceQueue(info.device, info.graphics_queue_family_index, 0,
                     &info.queue);

    for (uint32_t i = 0; i < info.swapchainImageCount; i++) {
        VkImageViewCreateInfo color_image_view = {};
        color_image_view.sType = VK_STRUCTURE_TYPE_IMAGE_VIEW_CREATE_INFO;
        color_image_view.pNext = NULL;
        color_image_view.format = info.format;
        color_image_view.components.r = VK_COMPONENT_SWIZZLE_R;
        color_image_view.components.g = VK_COMPONENT_SWIZZLE_G;
        color_image_view.components.b = VK_COMPONENT_SWIZZLE_B;
        color_image_view.components.a = VK_COMPONENT_SWIZZLE_A;
        color_image_view.subresourceRange.aspectMask =
            VK_IMAGE_ASPECT_COLOR_BIT;
        color_image_view.subresourceRange.baseMipLevel = 0;
        color_image_view.subresourceRange.levelCount = 1;
        color_image_view.subresourceRange.baseArrayLayer = 0;
        color_image_view.subresourceRange.layerCount = 1;
        color_image_view.viewType = VK_IMAGE_VIEW_TYPE_2D;
        color_image_view.flags = 0;

        info.buffers[i].image = swapchainImages[i];

        set_image_layout(info, info.buffers[i].image, VK_IMAGE_ASPECT_COLOR_BIT,
                         VK_IMAGE_LAYOUT_UNDEFINED,
                         VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL);

        color_image_view.image = info.buffers[i].image;

        res = vkCreateImageView(info.device, &color_image_view, NULL,
                                &info.buffers[i].view);
        assert(res == VK_SUCCESS);
    }
    free(swapchainImages);
    execute_end_command_buffer(info);
    execute_queue_command_buffer(info);
    /* VULKAN_KEY_END */

    /* Clean Up */
    VkCommandBuffer cmd_bufs[1] = {info.cmd};
    vkFreeCommandBuffers(info.device, info.cmd_pool, 1, cmd_bufs);
    vkDestroyCommandPool(info.device, info.cmd_pool, NULL);
    for (uint32_t i = 0; i < info.swapchainImageCount; i++) {
        vkDestroyImageView(info.device, info.buffers[i].view, NULL);
    }
    vkDestroySwapchainKHR(info.device, info.swap_chain, NULL);
    destroy_device(info);
    destroy_window(info);
    destroy_instance(info);

    return 0;
}
int sample_main(int argc, char *argv[]) {
    VkResult U_ASSERT_ONLY res;
    struct sample_info info = {};
    char sample_title[] = "Draw Textured Cube";
    const bool depthPresent = true;

    process_command_line_args(info, argc, argv);
    init_global_layer_properties(info);
    init_instance_extension_names(info);
    init_device_extension_names(info);
    init_instance(info, sample_title);
    init_enumerate_device(info);
    init_window_size(info, 500, 500);
    init_connection(info);
    init_window(info);
    init_swapchain_extension(info);
    init_device(info);
    init_command_pool(info);
    init_command_buffer(info);
    execute_begin_command_buffer(info);
    init_device_queue(info);
    init_swap_chain(info);
    init_depth_buffer(info);
    init_texture(info);
    init_uniform_buffer(info);
    init_descriptor_and_pipeline_layouts(info, true);
    init_renderpass(info, depthPresent);
    init_shaders(info, vertShaderText, fragShaderText);
    init_framebuffers(info, depthPresent);
    init_vertex_buffer(info, g_vb_texture_Data, sizeof(g_vb_texture_Data),
                       sizeof(g_vb_texture_Data[0]), true);
    init_descriptor_pool(info, true);
    init_descriptor_set(info, true);
    init_pipeline_cache(info);
    init_pipeline(info, depthPresent);

    /* VULKAN_KEY_START */

    VkClearValue clear_values[2];
    clear_values[0].color.float32[0] = 0.2f;
    clear_values[0].color.float32[1] = 0.2f;
    clear_values[0].color.float32[2] = 0.2f;
    clear_values[0].color.float32[3] = 0.2f;
    clear_values[1].depthStencil.depth = 1.0f;
    clear_values[1].depthStencil.stencil = 0;

    VkSemaphore presentCompleteSemaphore;
    VkSemaphoreCreateInfo presentCompleteSemaphoreCreateInfo;
    presentCompleteSemaphoreCreateInfo.sType =
        VK_STRUCTURE_TYPE_SEMAPHORE_CREATE_INFO;
    presentCompleteSemaphoreCreateInfo.pNext = NULL;
    presentCompleteSemaphoreCreateInfo.flags = 0;

    res = vkCreateSemaphore(info.device, &presentCompleteSemaphoreCreateInfo,
                            NULL, &presentCompleteSemaphore);
    assert(res == VK_SUCCESS);

    // Get the index of the next available swapchain image:
    res = vkAcquireNextImageKHR(info.device, info.swap_chain, UINT64_MAX,
                                presentCompleteSemaphore, VK_NULL_HANDLE,
                                &info.current_buffer);
    // TODO: Deal with the VK_SUBOPTIMAL_KHR and VK_ERROR_OUT_OF_DATE_KHR
    // return codes
    assert(res == VK_SUCCESS);

    set_image_layout(info, info.buffers[info.current_buffer].image,
                     VK_IMAGE_ASPECT_COLOR_BIT, VK_IMAGE_LAYOUT_UNDEFINED,
                     VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL);

    VkRenderPassBeginInfo rp_begin;
    rp_begin.sType = VK_STRUCTURE_TYPE_RENDER_PASS_BEGIN_INFO;
    rp_begin.pNext = NULL;
    rp_begin.renderPass = info.render_pass;
    rp_begin.framebuffer = info.framebuffers[info.current_buffer];
    rp_begin.renderArea.offset.x = 0;
    rp_begin.renderArea.offset.y = 0;
    rp_begin.renderArea.extent.width = info.width;
    rp_begin.renderArea.extent.height = info.height;
    rp_begin.clearValueCount = 2;
    rp_begin.pClearValues = clear_values;

    vkCmdBeginRenderPass(info.cmd, &rp_begin, VK_SUBPASS_CONTENTS_INLINE);

    vkCmdBindPipeline(info.cmd, VK_PIPELINE_BIND_POINT_GRAPHICS, info.pipeline);
    vkCmdBindDescriptorSets(info.cmd, VK_PIPELINE_BIND_POINT_GRAPHICS,
                            info.pipeline_layout, 0, NUM_DESCRIPTOR_SETS,
                            info.desc_set.data(), 0, NULL);

    const VkDeviceSize offsets[1] = {0};
    vkCmdBindVertexBuffers(info.cmd, 0, 1, &info.vertex_buffer.buf, offsets);

    init_viewports(info);
    init_scissors(info);

    vkCmdDraw(info.cmd, 12 * 3, 1, 0, 0);
    vkCmdEndRenderPass(info.cmd);

    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.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
    prePresentBarrier.subresourceRange.baseMipLevel = 0;
    prePresentBarrier.subresourceRange.levelCount = 1;
    prePresentBarrier.subresourceRange.baseArrayLayer = 0;
    prePresentBarrier.subresourceRange.layerCount = 1;
    prePresentBarrier.image = info.buffers[info.current_buffer].image;
    vkCmdPipelineBarrier(info.cmd, VK_PIPELINE_STAGE_ALL_COMMANDS_BIT,
                         VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT, 0, 0, NULL, 0,
                         NULL, 1, &prePresentBarrier);

    res = vkEndCommandBuffer(info.cmd);
    assert(res == VK_SUCCESS);

    const VkCommandBuffer cmd_bufs[] = {info.cmd};
    VkFenceCreateInfo fenceInfo;
    VkFence drawFence;
    fenceInfo.sType = VK_STRUCTURE_TYPE_FENCE_CREATE_INFO;
    fenceInfo.pNext = NULL;
    fenceInfo.flags = 0;
    vkCreateFence(info.device, &fenceInfo, NULL, &drawFence);

    VkPipelineStageFlags pipe_stage_flags =
        VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT;
    VkSubmitInfo submit_info[1] = {};
    submit_info[0].pNext = NULL;
    submit_info[0].sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
    submit_info[0].waitSemaphoreCount = 1;
    submit_info[0].pWaitSemaphores = &presentCompleteSemaphore;
    submit_info[0].pWaitDstStageMask = &pipe_stage_flags;
    submit_info[0].commandBufferCount = 1;
    submit_info[0].pCommandBuffers = cmd_bufs;
    submit_info[0].signalSemaphoreCount = 0;
    submit_info[0].pSignalSemaphores = NULL;

    /* Queue the command buffer for execution */
    res = vkQueueSubmit(info.queue, 1, submit_info, drawFence);
    assert(res == VK_SUCCESS);

    /* Now present the image in the window */

    VkPresentInfoKHR present;
    present.sType = VK_STRUCTURE_TYPE_PRESENT_INFO_KHR;
    present.pNext = NULL;
    present.swapchainCount = 1;
    present.pSwapchains = &info.swap_chain;
    present.pImageIndices = &info.current_buffer;
    present.pWaitSemaphores = NULL;
    present.waitSemaphoreCount = 0;
    present.pResults = NULL;

    /* Make sure command buffer is finished before presenting */
    do {
        res =
            vkWaitForFences(info.device, 1, &drawFence, VK_TRUE, FENCE_TIMEOUT);
    } while (res == VK_TIMEOUT);
    assert(res == VK_SUCCESS);
    res = vkQueuePresentKHR(info.queue, &present);
    assert(res == VK_SUCCESS);

    wait_seconds(1);
    /* VULKAN_KEY_END */
    if (info.save_images)
        write_ppm(info, "drawtexturedcube");

    vkDestroyFence(info.device, drawFence, NULL);
    vkDestroySemaphore(info.device, presentCompleteSemaphore, NULL);
    destroy_pipeline(info);
    destroy_pipeline_cache(info);
    destroy_textures(info);
    destroy_descriptor_pool(info);
    destroy_vertex_buffer(info);
    destroy_framebuffers(info);
    destroy_shaders(info);
    destroy_renderpass(info);
    destroy_descriptor_and_pipeline_layouts(info);
    destroy_uniform_buffer(info);
    destroy_depth_buffer(info);
    destroy_swap_chain(info);
    destroy_command_buffer(info);
    destroy_command_pool(info);
    destroy_device(info);
    destroy_window(info);
    destroy_instance(info);
    return 0;
}
int sample_main(int argc, char *argv[]) {
    VkResult U_ASSERT_ONLY res;
    struct sample_info info = {};
    char sample_title[] = "Copy/Blit Image";
    VkImageCreateInfo image_info;
    VkImage bltSrcImage;
    VkImage bltDstImage;
    VkMemoryRequirements memReq;
    VkMemoryAllocateInfo memAllocInfo;
    VkDeviceMemory dmem;
    unsigned char *pImgMem;

    process_command_line_args(info, argc, argv);
    init_global_layer_properties(info);
    init_instance_extension_names(info);
    init_device_extension_names(info);
    init_instance(info, sample_title);
    init_enumerate_device(info);
    init_window_size(info, 640, 640);
    init_connection(info);
    init_window(info);
    init_swapchain_extension(info);

    VkSurfaceCapabilitiesKHR surfCapabilities;
    res = vkGetPhysicalDeviceSurfaceCapabilitiesKHR(info.gpus[0], info.surface,
                                                    &surfCapabilities);
    if (!(surfCapabilities.supportedUsageFlags & VK_IMAGE_USAGE_TRANSFER_DST_BIT)) {
        std::cout << "Surface cannot be destination of blit - abort \n";
        exit(-1);
    }

    init_device(info);
    init_command_pool(info);
    init_command_buffer(info);
    execute_begin_command_buffer(info);
    init_device_queue(info);
    init_swap_chain(info,  VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT |
                           VK_IMAGE_USAGE_TRANSFER_DST_BIT);

    /* VULKAN_KEY_START */

    VkFormatProperties formatProps;
    vkGetPhysicalDeviceFormatProperties(info.gpus[0], info.format,
                                        &formatProps);
    assert(
        (formatProps.linearTilingFeatures & VK_FORMAT_FEATURE_BLIT_SRC_BIT) &&
        "Format cannot be used as transfer source");

    VkSemaphore presentCompleteSemaphore;
    VkSemaphoreCreateInfo presentCompleteSemaphoreCreateInfo;
    presentCompleteSemaphoreCreateInfo.sType =
        VK_STRUCTURE_TYPE_SEMAPHORE_CREATE_INFO;
    presentCompleteSemaphoreCreateInfo.pNext = NULL;
    presentCompleteSemaphoreCreateInfo.flags = VK_FENCE_CREATE_SIGNALED_BIT;

    res = vkCreateSemaphore(info.device, &presentCompleteSemaphoreCreateInfo,
                            NULL, &presentCompleteSemaphore);
    assert(res == VK_SUCCESS);

    // Get the index of the next available swapchain image:
    res = vkAcquireNextImageKHR(info.device, info.swap_chain, UINT64_MAX,
                                presentCompleteSemaphore, VK_NULL_HANDLE,
                                &info.current_buffer);
    // TODO: Deal with the VK_SUBOPTIMAL_KHR and VK_ERROR_OUT_OF_DATE_KHR
    // return codes
    assert(res == VK_SUCCESS);

    // Create an image, map it, and write some values to the image

    image_info.sType = VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO;
    image_info.pNext = NULL;
    image_info.imageType = VK_IMAGE_TYPE_2D;
    image_info.format = info.format;
    image_info.extent.width = info.width;
    image_info.extent.height = info.height;
    image_info.extent.depth = 1;
    image_info.mipLevels = 1;
    image_info.arrayLayers = 1;
    image_info.samples = NUM_SAMPLES;
    image_info.queueFamilyIndexCount = 0;
    image_info.pQueueFamilyIndices = NULL;
    image_info.sharingMode = VK_SHARING_MODE_EXCLUSIVE;
    image_info.usage = VK_IMAGE_USAGE_TRANSFER_SRC_BIT;
    image_info.flags = 0;
    image_info.tiling = VK_IMAGE_TILING_LINEAR;
    image_info.initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
    res = vkCreateImage(info.device, &image_info, NULL, &bltSrcImage);

    memAllocInfo.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO;
    memAllocInfo.pNext = NULL;

    vkGetImageMemoryRequirements(info.device, bltSrcImage, &memReq);
    bool pass = memory_type_from_properties(info, memReq.memoryTypeBits,
                                            VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT,
                                            &memAllocInfo.memoryTypeIndex);
    assert(pass);
    memAllocInfo.allocationSize = memReq.size;
    res = vkAllocateMemory(info.device, &memAllocInfo, NULL, &dmem);
    res = vkBindImageMemory(info.device, bltSrcImage, dmem, 0);
    set_image_layout(info, bltSrcImage, VK_IMAGE_ASPECT_COLOR_BIT,
                     VK_IMAGE_LAYOUT_UNDEFINED, VK_IMAGE_LAYOUT_GENERAL);

    res = vkEndCommandBuffer(info.cmd);
    assert(res == VK_SUCCESS);

    VkFence cmdFence;
    init_fence(info, cmdFence);
    VkPipelineStageFlags pipe_stage_flags =
        VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT;
    VkSubmitInfo submit_info = {};
    submit_info.pNext = NULL;
    submit_info.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
    submit_info.waitSemaphoreCount = 1;
    submit_info.pWaitSemaphores = &presentCompleteSemaphore;
    submit_info.pWaitDstStageMask = &pipe_stage_flags;
    submit_info.commandBufferCount = 1;
    submit_info.pCommandBuffers = &info.cmd;
    submit_info.signalSemaphoreCount = 0;
    submit_info.pSignalSemaphores = NULL;

    /* Queue the command buffer for execution */
    res = vkQueueSubmit(info.queue, 1, &submit_info, cmdFence);
    assert(res == VK_SUCCESS);

    /* Make sure command buffer is finished before mapping */
    do {
        res =
            vkWaitForFences(info.device, 1, &cmdFence, VK_TRUE, FENCE_TIMEOUT);
    } while (res == VK_TIMEOUT);
    assert(res == VK_SUCCESS);
    vkDestroyFence(info.device, cmdFence, NULL);

    res = vkMapMemory(info.device, dmem, 0, memReq.size, 0, (void **)&pImgMem);
    // Checkerboard of 8x8 pixel squares
    for (int row = 0; row < info.height; row++) {
        for (int col = 0; col < info.width; col++) {
            unsigned char rgb = (((row & 0x8) == 0) ^ ((col & 0x8) == 0)) * 255;
            pImgMem[0] = rgb;
            pImgMem[1] = rgb;
            pImgMem[2] = rgb;
            pImgMem[3] = 255;
            pImgMem += 4;
        }
    }

    // Flush the mapped memory and then unmap it  Assume it isn't coherent since
    // we didn't really confirm
    VkMappedMemoryRange memRange;
    memRange.sType = VK_STRUCTURE_TYPE_MAPPED_MEMORY_RANGE;
    memRange.pNext = NULL;
    memRange.memory = dmem;
    memRange.offset = 0;
    memRange.size = memReq.size;
    res = vkFlushMappedMemoryRanges(info.device, 1, &memRange);

    vkUnmapMemory(info.device, dmem);

    vkResetCommandBuffer(info.cmd, 0);
    execute_begin_command_buffer(info);
    set_image_layout(info, bltSrcImage, VK_IMAGE_ASPECT_COLOR_BIT,
                     VK_IMAGE_LAYOUT_GENERAL,
                     VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL);

    bltDstImage = info.buffers[info.current_buffer].image;
    // init_swap_chain will create the images as color attachment optimal
    // but we want transfer dst optimal
    set_image_layout(info, bltDstImage, VK_IMAGE_ASPECT_COLOR_BIT,
                     VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL,
                     VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL);

    // Do a 32x32 blit to all of the dst image - should get big squares
    VkImageBlit region;
    region.srcSubresource.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
    region.srcSubresource.mipLevel = 0;
    region.srcSubresource.baseArrayLayer = 0;
    region.srcSubresource.layerCount = 1;
    region.srcOffsets[0].x = 0;
    region.srcOffsets[0].y = 0;
    region.srcOffsets[0].z = 0;
    region.srcOffsets[1].x = 32;
    region.srcOffsets[1].y = 32;
    region.srcOffsets[1].z = 1;
    region.dstSubresource.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
    region.dstSubresource.mipLevel = 0;
    region.dstSubresource.baseArrayLayer = 0;
    region.dstSubresource.layerCount = 1;
    region.dstOffsets[0].x = 0;
    region.dstOffsets[0].y = 0;
    region.dstOffsets[0].z = 0;
    region.dstOffsets[1].x = info.width;
    region.dstOffsets[1].y = info.height;
    region.dstOffsets[1].z = 1;

    vkCmdBlitImage(info.cmd, bltSrcImage, VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL,
                   bltDstImage, VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL, 1,
                   &region, VK_FILTER_LINEAR);

    // Do a image copy to part of the dst image - checks should stay small
    VkImageCopy cregion;
    cregion.srcSubresource.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
    cregion.srcSubresource.mipLevel = 0;
    cregion.srcSubresource.baseArrayLayer = 0;
    cregion.srcSubresource.layerCount = 1;
    cregion.srcOffset.x = 0;
    cregion.srcOffset.y = 0;
    cregion.srcOffset.z = 0;
    cregion.dstSubresource.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
    cregion.dstSubresource.mipLevel = 0;
    cregion.dstSubresource.baseArrayLayer = 0;
    cregion.dstSubresource.layerCount = 1;
    cregion.dstOffset.x = 256;
    cregion.dstOffset.y = 256;
    cregion.dstOffset.z = 0;
    cregion.extent.width = 128;
    cregion.extent.height = 128;
    cregion.extent.depth = 1;

    vkCmdCopyImage(info.cmd, bltSrcImage, VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL,
                   bltDstImage, VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL, 1,
                   &cregion);

    VkImageMemoryBarrier prePresentBarrier = {};
    prePresentBarrier.sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
    prePresentBarrier.pNext = NULL;
    prePresentBarrier.srcAccessMask = VK_ACCESS_TRANSFER_WRITE_BIT;
    prePresentBarrier.dstAccessMask = VK_ACCESS_MEMORY_READ_BIT;
    prePresentBarrier.oldLayout = VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL;
    prePresentBarrier.newLayout = VK_IMAGE_LAYOUT_PRESENT_SRC_KHR;
    prePresentBarrier.srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
    prePresentBarrier.dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
    prePresentBarrier.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
    prePresentBarrier.subresourceRange.baseMipLevel = 0;
    prePresentBarrier.subresourceRange.levelCount = 1;
    prePresentBarrier.subresourceRange.baseArrayLayer = 0;
    prePresentBarrier.subresourceRange.layerCount = 1;
    prePresentBarrier.image = info.buffers[info.current_buffer].image;
    vkCmdPipelineBarrier(info.cmd, VK_PIPELINE_STAGE_ALL_COMMANDS_BIT,
                         VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT, 0, 0, NULL, 0,
                         NULL, 1, &prePresentBarrier);

    res = vkEndCommandBuffer(info.cmd);
    VkFenceCreateInfo fenceInfo;
    VkFence drawFence;
    fenceInfo.sType = VK_STRUCTURE_TYPE_FENCE_CREATE_INFO;
    fenceInfo.pNext = NULL;
    fenceInfo.flags = 0;
    vkCreateFence(info.device, &fenceInfo, NULL, &drawFence);

    submit_info.pNext = NULL;
    submit_info.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
    submit_info.waitSemaphoreCount = 0;
    submit_info.pWaitSemaphores = NULL;
    submit_info.pWaitDstStageMask = NULL;
    submit_info.commandBufferCount = 1;
    submit_info.pCommandBuffers = &info.cmd;
    submit_info.signalSemaphoreCount = 0;
    submit_info.pSignalSemaphores = NULL;

    /* Queue the command buffer for execution */
    res = vkQueueSubmit(info.queue, 1, &submit_info, drawFence);
    assert(res == VK_SUCCESS);

    res = vkQueueWaitIdle(info.queue);
    assert(res == VK_SUCCESS);

    /* Now present the image in the window */

    VkPresentInfoKHR present;
    present.sType = VK_STRUCTURE_TYPE_PRESENT_INFO_KHR;
    present.pNext = NULL;
    present.swapchainCount = 1;
    present.pSwapchains = &info.swap_chain;
    present.pImageIndices = &info.current_buffer;
    present.pWaitSemaphores = NULL;
    present.waitSemaphoreCount = 0;
    present.pResults = NULL;

    /* Make sure command buffer is finished before presenting */
    do {
        res =
            vkWaitForFences(info.device, 1, &drawFence, VK_TRUE, FENCE_TIMEOUT);
    } while (res == VK_TIMEOUT);
    assert(res == VK_SUCCESS);
    res = vkQueuePresentKHR(info.queue, &present);
    assert(res == VK_SUCCESS);

    wait_seconds(1);
    /* VULKAN_KEY_END */
    if (info.save_images)
        write_ppm(info, "copyblitimage");

    vkDestroySemaphore(info.device, presentCompleteSemaphore, NULL);
    vkDestroyFence(info.device, drawFence, NULL);
    vkDestroyImage(info.device, bltSrcImage, NULL);
    vkFreeMemory(info.device, dmem, NULL);
    destroy_swap_chain(info);
    destroy_command_buffer(info);
    destroy_command_pool(info);
    destroy_device(info);
    destroy_window(info);
    destroy_instance(info);
    return 0;
}
int sample_main(int argc, char *argv[]) {
    VkResult U_ASSERT_ONLY res;
    bool U_ASSERT_ONLY pass;
    struct sample_info info = {};
    char sample_title[] = "Texture Initialization Sample";

    init_global_layer_properties(info);
    init_instance_extension_names(info);
    init_device_extension_names(info);
    init_instance(info, sample_title);
    init_enumerate_device(info);
    init_connection(info);
    init_window_size(info, 50, 50);
    init_window(info);
    init_swapchain_extension(info);
    init_device(info);
    init_command_pool(info);
    init_command_buffer(info);
    execute_begin_command_buffer(info);
    init_device_queue(info);

    /* VULKAN_KEY_START */
    /*
     * Set up textures:
     * - Create a linear tiled image
     * - Map it and write the texture data into it
     * - If linear images cannot be used as textures, create an optimally
     *       tiled image and blit from the linearly tiled image to the optimally
     *       tiled image
     * -
     * -
     * -
     */

    struct texture_object texObj;
    std::string filename = get_base_data_dir();
    filename.append("lunarg.ppm");
    if (!read_ppm(filename.c_str(), texObj.tex_width, texObj.tex_height, 0,
                  NULL)) {
        std::cout << "Could not read texture file lunarg.ppm\n";
        exit(-1);
    }

    VkFormatProperties formatProps;
    vkGetPhysicalDeviceFormatProperties(info.gpus[0], VK_FORMAT_R8G8B8A8_UNORM,
                                        &formatProps);

    /* See if we can use a linear tiled image for a texture, if not, we will
     * need a staging image for the texture data */
    bool needStaging = (!(formatProps.linearTilingFeatures &
                          VK_FORMAT_FEATURE_SAMPLED_IMAGE_BIT))
                           ? true
                           : false;

    VkImageCreateInfo image_create_info = {};
    image_create_info.sType = VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO;
    image_create_info.pNext = NULL;
    image_create_info.imageType = VK_IMAGE_TYPE_2D;
    image_create_info.format = VK_FORMAT_R8G8B8A8_UNORM;
    image_create_info.extent.width = texObj.tex_width;
    image_create_info.extent.height = texObj.tex_height;
    image_create_info.extent.depth = 1;
    image_create_info.mipLevels = 1;
    image_create_info.arrayLayers = 1;
    image_create_info.samples = NUM_SAMPLES;
    image_create_info.tiling = VK_IMAGE_TILING_LINEAR;
    image_create_info.initialLayout = VK_IMAGE_LAYOUT_PREINITIALIZED;
    image_create_info.usage = needStaging ? VK_IMAGE_USAGE_TRANSFER_SRC_BIT
                                          : VK_IMAGE_USAGE_SAMPLED_BIT;
    image_create_info.queueFamilyIndexCount = 0;
    image_create_info.pQueueFamilyIndices = NULL;
    image_create_info.sharingMode = VK_SHARING_MODE_EXCLUSIVE;
    image_create_info.flags = 0;

    VkMemoryAllocateInfo mem_alloc = {};
    mem_alloc.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO;
    mem_alloc.pNext = NULL;
    mem_alloc.allocationSize = 0;
    mem_alloc.memoryTypeIndex = 0;

    VkImage mappableImage;
    VkDeviceMemory mappableMemory;

    VkMemoryRequirements mem_reqs;

    /* Create a mappable image.  It will be the texture if linear images are ok
     * to be textures or it will be the staging image if they are not.
     */
    res = vkCreateImage(info.device, &image_create_info, NULL, &mappableImage);
    assert(res == VK_SUCCESS);

    vkGetImageMemoryRequirements(info.device, mappableImage, &mem_reqs);

    mem_alloc.allocationSize = mem_reqs.size;

    /* Find the memory type that is host mappable */
    pass = memory_type_from_properties(info, mem_reqs.memoryTypeBits,
                                       VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT,
                                       &mem_alloc.memoryTypeIndex);
    assert(pass);

    /* allocate memory */
    res = vkAllocateMemory(info.device, &mem_alloc, NULL, &(mappableMemory));
    assert(res == VK_SUCCESS);

    /* bind memory */
    res = vkBindImageMemory(info.device, mappableImage, mappableMemory, 0);
    assert(res == VK_SUCCESS);

    VkImageSubresource subres = {};
    subres.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
    subres.mipLevel = 0;
    subres.arrayLayer = 0;

    VkSubresourceLayout layout;
    void *data;

    /* Get the subresource layout so we know what the row pitch is */
    vkGetImageSubresourceLayout(info.device, mappableImage, &subres, &layout);

    res = vkMapMemory(info.device, mappableMemory, 0, mem_reqs.size, 0, &data);
    assert(res == VK_SUCCESS);

    /* Read the ppm file into the mappable image's memory */
    if (!read_ppm(filename.c_str(), texObj.tex_width, texObj.tex_height,
                  layout.rowPitch, (unsigned char *)data)) {
        std::cout << "Could not load texture file lunarg.ppm\n";
        exit(-1);
    }

    vkUnmapMemory(info.device, mappableMemory);

    if (!needStaging) {
        /* If we can use the linear tiled image as a texture, just do it */
        texObj.image = mappableImage;
        texObj.mem = mappableMemory;
        texObj.imageLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
        set_image_layout(info, texObj.image, VK_IMAGE_ASPECT_COLOR_BIT,
                         VK_IMAGE_LAYOUT_PREINITIALIZED, texObj.imageLayout);
    } else {
        /* The mappable image cannot be our texture, so create an optimally
         * tiled image and blit to it */
        image_create_info.tiling = VK_IMAGE_TILING_OPTIMAL;
        image_create_info.usage =
            VK_IMAGE_USAGE_TRANSFER_DST_BIT | VK_IMAGE_USAGE_SAMPLED_BIT;
        image_create_info.initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;

        res =
            vkCreateImage(info.device, &image_create_info, NULL, &texObj.image);
        assert(res == VK_SUCCESS);

        vkGetImageMemoryRequirements(info.device, texObj.image, &mem_reqs);

        mem_alloc.allocationSize = mem_reqs.size;

        /* Find memory type - don't specify any mapping requirements */
        pass = memory_type_from_properties(info, mem_reqs.memoryTypeBits, 0,
                                           &mem_alloc.memoryTypeIndex);
        assert(pass);

        /* allocate memory */
        res = vkAllocateMemory(info.device, &mem_alloc, NULL, &texObj.mem);
        assert(res == VK_SUCCESS);

        /* bind memory */
        res = vkBindImageMemory(info.device, texObj.image, texObj.mem, 0);
        assert(res == VK_SUCCESS);

        /* Since we're going to blit from the mappable image, set its layout to
         * SOURCE_OPTIMAL */
        /* Side effect is that this will create info.cmd */
        set_image_layout(info, mappableImage, VK_IMAGE_ASPECT_COLOR_BIT,
                         VK_IMAGE_LAYOUT_PREINITIALIZED,
                         VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL);

        /* Since we're going to blit to the texture image, set its layout to
         * DESTINATION_OPTIMAL */
        set_image_layout(info, texObj.image, VK_IMAGE_ASPECT_COLOR_BIT,
                         VK_IMAGE_LAYOUT_UNDEFINED,
                         VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL);

        VkImageCopy copy_region;
        copy_region.srcSubresource.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
        copy_region.srcSubresource.mipLevel = 0;
        copy_region.srcSubresource.baseArrayLayer = 0;
        copy_region.srcSubresource.layerCount = 1;
        copy_region.srcOffset.x = 0;
        copy_region.srcOffset.y = 0;
        copy_region.srcOffset.z = 0;
        copy_region.dstSubresource.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
        copy_region.dstSubresource.mipLevel = 0;
        copy_region.dstSubresource.baseArrayLayer = 0;
        copy_region.dstSubresource.layerCount = 1;
        copy_region.dstOffset.x = 0;
        copy_region.dstOffset.y = 0;
        copy_region.dstOffset.z = 0;
        copy_region.extent.width = texObj.tex_width;
        copy_region.extent.height = texObj.tex_height;
        copy_region.extent.depth = 1;

        /* Put the copy command into the command buffer */
        vkCmdCopyImage(info.cmd, mappableImage,
                       VK_IMAGE_LAYOUT_TRANSFER_SRC_OPTIMAL, texObj.image,
                       VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL, 1, &copy_region);

        /* Set the layout for the texture image from DESTINATION_OPTIMAL to
         * SHADER_READ_ONLY */
        texObj.imageLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
        set_image_layout(info, texObj.image, VK_IMAGE_ASPECT_COLOR_BIT,
                         VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL,
                         texObj.imageLayout);
    }
    execute_end_command_buffer(info);
    execute_queue_command_buffer(info);

    VkSamplerCreateInfo samplerCreateInfo = {};
    samplerCreateInfo.sType = VK_STRUCTURE_TYPE_SAMPLER_CREATE_INFO;
    samplerCreateInfo.magFilter = VK_FILTER_NEAREST;
    samplerCreateInfo.minFilter = VK_FILTER_NEAREST;
    samplerCreateInfo.mipmapMode = VK_SAMPLER_MIPMAP_MODE_NEAREST;
    samplerCreateInfo.addressModeU = VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE;
    samplerCreateInfo.addressModeV = VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE;
    samplerCreateInfo.addressModeW = VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE;
    samplerCreateInfo.mipLodBias = 0.0;
    samplerCreateInfo.anisotropyEnable = VK_FALSE,
    samplerCreateInfo.maxAnisotropy = 0;
    samplerCreateInfo.compareEnable = VK_FALSE;
    samplerCreateInfo.compareOp = VK_COMPARE_OP_NEVER;
    samplerCreateInfo.minLod = 0.0;
    samplerCreateInfo.maxLod = 0.0;
    samplerCreateInfo.borderColor = VK_BORDER_COLOR_FLOAT_OPAQUE_WHITE;

    /* create sampler */
    res =
        vkCreateSampler(info.device, &samplerCreateInfo, NULL, &texObj.sampler);
    assert(res == VK_SUCCESS);

    VkImageViewCreateInfo view_info = {};
    view_info.sType = VK_STRUCTURE_TYPE_IMAGE_VIEW_CREATE_INFO;
    view_info.pNext = NULL;
    view_info.image = VK_NULL_HANDLE;
    view_info.viewType = VK_IMAGE_VIEW_TYPE_2D;
    view_info.format = VK_FORMAT_R8G8B8A8_UNORM;
    view_info.components.r = VK_COMPONENT_SWIZZLE_R;
    view_info.components.g = VK_COMPONENT_SWIZZLE_G;
    view_info.components.b = VK_COMPONENT_SWIZZLE_B;
    view_info.components.a = VK_COMPONENT_SWIZZLE_A;
    view_info.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
    view_info.subresourceRange.baseMipLevel = 0;
    view_info.subresourceRange.levelCount = 1;
    view_info.subresourceRange.baseArrayLayer = 0;
    view_info.subresourceRange.layerCount = 1;

    /* create image view */
    view_info.image = texObj.image;
    res = vkCreateImageView(info.device, &view_info, NULL, &texObj.view);
    assert(res == VK_SUCCESS);

    info.textures.push_back(texObj);
    /* VULKAN_KEY_END */

    /* Clean Up */
    vkDestroySampler(info.device, texObj.sampler, NULL);
    vkDestroyImageView(info.device, texObj.view, NULL);
    vkDestroyImage(info.device, texObj.image, NULL);
    vkFreeMemory(info.device, texObj.mem, NULL);
    if (needStaging) {
        /* Release the resources for the staging image */
        vkFreeMemory(info.device, mappableMemory, NULL);
        vkDestroyImage(info.device, mappableImage, NULL);
    }
    destroy_command_buffer(info);
    destroy_command_pool(info);
    destroy_device(info);
    destroy_window(info);
    destroy_instance(info);
    return 0;
}
int sample_main() {
    VkResult U_ASSERT_ONLY res;

    char sample_title[] = "MT Cmd Buffer Sample";
    const bool depthPresent = false;

    init_global_layer_properties(info);
    init_instance_extension_names(info);
    init_device_extension_names(info);
    init_instance(info, sample_title);
    init_enumerate_device(info);
    init_window_size(info, 500, 500);
    init_connection(info);
    init_window(info);
    init_swapchain_extension(info);
    init_device(info);
    init_command_pool(info);
    init_command_buffer(info);
    execute_begin_command_buffer(info);
    init_device_queue(info);
    init_swap_chain(info);

    VkSemaphoreCreateInfo presentCompleteSemaphoreCreateInfo;
    presentCompleteSemaphoreCreateInfo.sType =
        VK_STRUCTURE_TYPE_SEMAPHORE_CREATE_INFO;
    presentCompleteSemaphoreCreateInfo.pNext = NULL;
    presentCompleteSemaphoreCreateInfo.flags = 0;

    res = vkCreateSemaphore(info.device, &presentCompleteSemaphoreCreateInfo,
                            NULL, &info.presentCompleteSemaphore);
    assert(res == VK_SUCCESS);

    // Get the index of the next available swapchain image:
    res = vkAcquireNextImageKHR(info.device, info.swap_chain, UINT64_MAX,
                                info.presentCompleteSemaphore, NULL,
                                &info.current_buffer);
    // TODO: Deal with the VK_SUBOPTIMAL_KHR and VK_ERROR_OUT_OF_DATE_KHR
    // return codes
    assert(res == VK_SUCCESS);

    VkPipelineLayoutCreateInfo pPipelineLayoutCreateInfo = {};
    pPipelineLayoutCreateInfo.sType =
        VK_STRUCTURE_TYPE_PIPELINE_LAYOUT_CREATE_INFO;
    pPipelineLayoutCreateInfo.pNext = NULL;
    pPipelineLayoutCreateInfo.pushConstantRangeCount = 0;
    pPipelineLayoutCreateInfo.pPushConstantRanges = NULL;
    pPipelineLayoutCreateInfo.setLayoutCount = 0;
    pPipelineLayoutCreateInfo.pSetLayouts = NULL;

    res = vkCreatePipelineLayout(info.device, &pPipelineLayoutCreateInfo, NULL,
                                 &info.pipeline_layout);
    assert(res == VK_SUCCESS);
    init_renderpass(
        info, depthPresent,
        false); // Can't clear in renderpass load because we re-use pipeline
    init_shaders(info, vertShaderText, fragShaderText);
    init_framebuffers(info, depthPresent);

    /* The binding and attributes should be the same for all 3 vertex buffers,
     * so init here */
    info.vi_binding.binding = 0;
    info.vi_binding.inputRate = VK_VERTEX_INPUT_RATE_VERTEX;
    info.vi_binding.stride = sizeof(triData[0]);

    info.vi_attribs[0].binding = 0;
    info.vi_attribs[0].location = 0;
    info.vi_attribs[0].format = VK_FORMAT_R32G32B32A32_SFLOAT;
    info.vi_attribs[0].offset = 0;
    info.vi_attribs[1].binding = 0;
    info.vi_attribs[1].location = 1;
    info.vi_attribs[1].format = VK_FORMAT_R32G32B32A32_SFLOAT;
    info.vi_attribs[1].offset = 16;

    init_pipeline_cache(info);
    init_pipeline(info, depthPresent);

    VkImageSubresourceRange srRange = {};
    srRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
    srRange.baseMipLevel = 0;
    srRange.levelCount = VK_REMAINING_MIP_LEVELS;
    srRange.baseArrayLayer = 0;
    srRange.layerCount = VK_REMAINING_ARRAY_LAYERS;

    VkClearColorValue clear_color[1];
    clear_color[0].float32[0] = 0.2f;
    clear_color[0].float32[1] = 0.2f;
    clear_color[0].float32[2] = 0.2f;
    clear_color[0].float32[3] = 0.2f;

    /* We need to do the clear here instead of as a load op since all 3 threads
     * share the same pipeline / renderpass */
    set_image_layout(info, info.buffers[info.current_buffer].image,
                     VK_IMAGE_ASPECT_COLOR_BIT,
                     VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL,
                     VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL);
    vkCmdClearColorImage(info.cmd, info.buffers[info.current_buffer].image,
                         VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL, clear_color, 1,
                         &srRange);
    set_image_layout(info, info.buffers[info.current_buffer].image,
                     VK_IMAGE_ASPECT_COLOR_BIT,
                     VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL,
                     VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL);

    res = vkEndCommandBuffer(info.cmd);
    const VkCommandBuffer cmd_bufs[] = {info.cmd};
    VkFence clearFence;
    init_fence(info, clearFence);
    VkPipelineStageFlags pipe_stage_flags =
        VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT;
    VkSubmitInfo submit_info[1] = {};
    submit_info[0].pNext = NULL;
    submit_info[0].sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
    submit_info[0].waitSemaphoreCount = 1;
    submit_info[0].pWaitSemaphores = &info.presentCompleteSemaphore;
    submit_info[0].pWaitDstStageMask = NULL;
    submit_info[0].commandBufferCount = 1;
    submit_info[0].pCommandBuffers = cmd_bufs;
    submit_info[0].signalSemaphoreCount = 0;
    submit_info[0].pSignalSemaphores = NULL;

    /* Queue the command buffer for execution */
    res = vkQueueSubmit(info.queue, 1, submit_info, clearFence);
    assert(!res);

    do {
        res = vkWaitForFences(info.device, 1, &clearFence, VK_TRUE,
                              FENCE_TIMEOUT);
    } while (res == VK_TIMEOUT);
    assert(res == VK_SUCCESS);
    vkDestroyFence(info.device, clearFence, NULL);

    /* VULKAN_KEY_START */

    /* Use the fourth slot in the command buffer array for the presentation */
    /* barrier using the command buffer in info                             */
    threadCmdBufs[3] = info.cmd;
    sample_platform_thread vk_threads[3];
    for (size_t i = 0; i < 3; i++) {
        sample_platform_thread_create(&vk_threads[i], &per_thread_code,
                                      (void *)i);
    }

    VkCommandBufferBeginInfo cmd_buf_info = {};
    cmd_buf_info.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;
    cmd_buf_info.pNext = NULL;
    cmd_buf_info.flags = 0;
    cmd_buf_info.pInheritanceInfo = NULL;
    res = vkBeginCommandBuffer(threadCmdBufs[3], &cmd_buf_info);
    assert(res == VK_SUCCESS);

    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.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
    prePresentBarrier.subresourceRange.baseMipLevel = 0;
    prePresentBarrier.subresourceRange.levelCount = 1;
    prePresentBarrier.subresourceRange.baseArrayLayer = 0;
    prePresentBarrier.subresourceRange.layerCount = 1;
    prePresentBarrier.image = info.buffers[info.current_buffer].image;
    vkCmdPipelineBarrier(threadCmdBufs[3], VK_PIPELINE_STAGE_ALL_COMMANDS_BIT,
                         VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT, 0, 0, NULL, 0,
                         NULL, 1, &prePresentBarrier);

    res = vkEndCommandBuffer(threadCmdBufs[3]);
    assert(res == VK_SUCCESS);

    pipe_stage_flags = VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT;
    submit_info[0].pNext = NULL;
    submit_info[0].sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
    submit_info[0].waitSemaphoreCount = 0;
    submit_info[0].pWaitSemaphores = NULL;
    submit_info[0].pWaitDstStageMask = &pipe_stage_flags;
    submit_info[0].commandBufferCount =
        4; /* 3 from threads + prePresentBarrier */
    submit_info[0].pCommandBuffers = threadCmdBufs;
    submit_info[0].signalSemaphoreCount = 0;
    submit_info[0].pSignalSemaphores = NULL;

    /* Wait for all of the threads to finish */
    for (int i = 0; i < 3; i++) {
        sample_platform_thread_join(vk_threads[i], NULL);
    }

    VkFenceCreateInfo fenceInfo;
    VkFence drawFence;
    fenceInfo.sType = VK_STRUCTURE_TYPE_FENCE_CREATE_INFO;
    fenceInfo.pNext = NULL;
    fenceInfo.flags = 0;
    vkCreateFence(info.device, &fenceInfo, NULL, &drawFence);

    /* Queue the command buffer for execution */
    res = vkQueueSubmit(info.queue, 1, submit_info, drawFence);
    assert(!res);

    /* Make sure command buffer is finished before presenting */
    do {
        res =
            vkWaitForFences(info.device, 1, &drawFence, VK_TRUE, FENCE_TIMEOUT);
    } while (res == VK_TIMEOUT);
    assert(res == VK_SUCCESS);

    execute_present_image(info);

    wait_seconds(1);
    /* VULKAN_KEY_END */

    vkDestroyBuffer(info.device, vertex_buffer[0].buf, NULL);
    vkDestroyBuffer(info.device, vertex_buffer[1].buf, NULL);
    vkDestroyBuffer(info.device, vertex_buffer[2].buf, NULL);
    vkFreeMemory(info.device, vertex_buffer[0].mem, NULL);
    vkFreeMemory(info.device, vertex_buffer[1].mem, NULL);
    vkFreeMemory(info.device, vertex_buffer[2].mem, NULL);
    for (int i = 0; i < 3; i++) {
        vkFreeCommandBuffers(info.device, threadCmdPools[i], 1,
                             &threadCmdBufs[i]);
        vkDestroyCommandPool(info.device, threadCmdPools[i], NULL);
    }
    vkDestroySemaphore(info.device, info.presentCompleteSemaphore, NULL);
    vkDestroyFence(info.device, drawFence, NULL);
    destroy_pipeline(info);
    destroy_pipeline_cache(info);
    destroy_framebuffers(info);
    destroy_shaders(info);
    destroy_renderpass(info);
    vkDestroyPipelineLayout(info.device, info.pipeline_layout, NULL);
    destroy_swap_chain(info);
    destroy_command_buffer(info);
    destroy_command_pool(info);
    destroy_window(info);
    destroy_device(info);
    destroy_instance(info);
    return 0;
}
int sample_main(int argc, char **argv) {
    VkResult U_ASSERT_ONLY res;
    struct sample_info info = {};
    char sample_title[] = "Memory Barriers";

    process_command_line_args(info, argc, argv);
    init_global_layer_properties(info);
    info.instance_extension_names.push_back(VK_KHR_SURFACE_EXTENSION_NAME);
#ifdef _WIN32
    info.instance_extension_names.push_back(VK_KHR_WIN32_SURFACE_EXTENSION_NAME);
#elif __ANDROID__
    info.instance_extension_names.push_back(VK_KHR_ANDROID_SURFACE_EXTENSION_NAME);
#else
    info.instance_extension_names.push_back(VK_KHR_XCB_SURFACE_EXTENSION_NAME);
#endif
    info.device_extension_names.push_back(VK_KHR_SWAPCHAIN_EXTENSION_NAME);
    init_instance(info, sample_title);
    init_enumerate_device(info);
    init_device(info);
    info.width = info.height = 500;
    init_connection(info);
    init_window(info);
    init_swapchain_extension(info);
    init_command_pool(info);
    init_command_buffer(info);
    execute_begin_command_buffer(info);
    init_device_queue(info);
    init_swap_chain(info, VK_IMAGE_USAGE_TRANSFER_DST_BIT | VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT);
    // CmdClearColorImage is going to require usage of TRANSFER_DST, but
    // it's not clear which format feature maps to the required TRANSFER_DST usage,
    // BLIT_DST is a reasonable guess and it seems to work
    init_texture(info, nullptr, VK_IMAGE_USAGE_TRANSFER_DST_BIT, VK_FORMAT_FEATURE_BLIT_DST_BIT);
    init_uniform_buffer(info);
    init_descriptor_and_pipeline_layouts(info, true);
    init_renderpass(info, DEPTH_PRESENT, false, VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL);
    init_shaders(info, vertShaderText, fragShaderText);
    init_framebuffers(info, DEPTH_PRESENT);
    init_vertex_buffer(info, vb_Data, sizeof(vb_Data), sizeof(vb_Data[0]), true);
    init_descriptor_pool(info, true);
    init_descriptor_set(info, true);
    init_pipeline_cache(info);
    init_pipeline(info, DEPTH_PRESENT);

    /* VULKAN_KEY_START */

    VkImageSubresourceRange srRange = {};
    srRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
    srRange.baseMipLevel = 0;
    srRange.levelCount = VK_REMAINING_MIP_LEVELS;
    srRange.baseArrayLayer = 0;
    srRange.layerCount = VK_REMAINING_ARRAY_LAYERS;

    VkClearColorValue clear_color[1];
    clear_color[0].float32[0] = 0.2f;
    clear_color[0].float32[1] = 0.2f;
    clear_color[0].float32[2] = 0.2f;
    clear_color[0].float32[3] = 0.2f;

    VkSemaphoreCreateInfo presentCompleteSemaphoreCreateInfo;
    presentCompleteSemaphoreCreateInfo.sType = VK_STRUCTURE_TYPE_SEMAPHORE_CREATE_INFO;
    presentCompleteSemaphoreCreateInfo.pNext = NULL;
    presentCompleteSemaphoreCreateInfo.flags = 0;

    res = vkCreateSemaphore(info.device, &presentCompleteSemaphoreCreateInfo, NULL, &info.imageAcquiredSemaphore);
    assert(res == VK_SUCCESS);

    // Get the index of the next available swapchain image:
    res = vkAcquireNextImageKHR(info.device, info.swap_chain, UINT64_MAX, info.imageAcquiredSemaphore, VK_NULL_HANDLE,
                                &info.current_buffer);
    // TODO: Deal with the VK_SUBOPTIMAL_KHR and VK_ERROR_OUT_OF_DATE_KHR
    // return codes
    assert(res == VK_SUCCESS);

    set_image_layout(info, info.buffers[info.current_buffer].image, VK_IMAGE_ASPECT_COLOR_BIT, VK_IMAGE_LAYOUT_UNDEFINED,
                     VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL, VK_PIPELINE_STAGE_TOP_OF_PIPE_BIT, VK_PIPELINE_STAGE_TRANSFER_BIT);

    // We need to do the clear here instead of using a renderpass load op since
    // we will use the same renderpass multiple times in the frame
    vkCmdClearColorImage(info.cmd, info.buffers[info.current_buffer].image, VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL, clear_color, 1,
                         &srRange);

    VkRenderPassBeginInfo rp_begin;
    rp_begin.sType = VK_STRUCTURE_TYPE_RENDER_PASS_BEGIN_INFO;
    rp_begin.pNext = NULL;
    rp_begin.renderPass = info.render_pass;
    rp_begin.framebuffer = info.framebuffers[info.current_buffer];
    rp_begin.renderArea.offset.x = 0;
    rp_begin.renderArea.offset.y = 0;
    rp_begin.renderArea.extent.width = info.width;
    rp_begin.renderArea.extent.height = info.height;
    rp_begin.clearValueCount = 0;
    rp_begin.pClearValues = NULL;

    // Draw a textured quad on the left side of the window
    vkCmdBeginRenderPass(info.cmd, &rp_begin, VK_SUBPASS_CONTENTS_INLINE);

    vkCmdBindPipeline(info.cmd, VK_PIPELINE_BIND_POINT_GRAPHICS, info.pipeline);
    vkCmdBindDescriptorSets(info.cmd, VK_PIPELINE_BIND_POINT_GRAPHICS, info.pipeline_layout, 0, NUM_DESCRIPTOR_SETS,
                            info.desc_set.data(), 0, NULL);

    const VkDeviceSize offsets[1] = {0};
    vkCmdBindVertexBuffers(info.cmd, 0, 1, &info.vertex_buffer.buf, offsets);

    init_viewports(info);
    init_scissors(info);

    vkCmdDraw(info.cmd, 2 * 3, 1, 0, 0);
    // We can't do a clear inside a renderpass, so end this one and start another one
    // for the next draw
    vkCmdEndRenderPass(info.cmd);

    // Send a barrier to change the texture image's layout from SHADER_READ_ONLY
    // to COLOR_ATTACHMENT_GENERAL because we're going to clear it
    VkImageMemoryBarrier textureBarrier = {};
    textureBarrier.sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
    textureBarrier.pNext = NULL;
    textureBarrier.srcAccessMask = VK_ACCESS_SHADER_READ_BIT;
    textureBarrier.dstAccessMask = VK_ACCESS_TRANSFER_WRITE_BIT;
    textureBarrier.oldLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
    textureBarrier.newLayout = VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL;
    textureBarrier.srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
    textureBarrier.dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
    textureBarrier.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
    textureBarrier.subresourceRange.baseMipLevel = 0;
    textureBarrier.subresourceRange.levelCount = 1;
    textureBarrier.subresourceRange.baseArrayLayer = 0;
    textureBarrier.subresourceRange.layerCount = 1;
    textureBarrier.image = info.textures[0].image;
    vkCmdPipelineBarrier(info.cmd, VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT, VK_PIPELINE_STAGE_TRANSFER_BIT, 0, 0, NULL, 0, NULL, 1,
                         &textureBarrier);

    clear_color[0].float32[0] = 0.0f;
    clear_color[0].float32[1] = 1.0f;
    clear_color[0].float32[2] = 0.0f;
    clear_color[0].float32[3] = 1.0f;
    /* Clear texture to green */
    vkCmdClearColorImage(info.cmd, info.textures[0].image, VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL, clear_color, 1, &srRange);

    // Send a barrier to change the texture image's layout back to SHADER_READ_ONLY
    // because we're going to use it as a texture again
    textureBarrier.sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
    textureBarrier.pNext = NULL;
    textureBarrier.srcAccessMask = VK_ACCESS_TRANSFER_WRITE_BIT;
    textureBarrier.dstAccessMask = VK_ACCESS_SHADER_READ_BIT;
    textureBarrier.oldLayout = VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL;
    textureBarrier.newLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
    textureBarrier.srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
    textureBarrier.dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
    textureBarrier.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
    textureBarrier.subresourceRange.baseMipLevel = 0;
    textureBarrier.subresourceRange.levelCount = 1;
    textureBarrier.subresourceRange.baseArrayLayer = 0;
    textureBarrier.subresourceRange.layerCount = 1;
    textureBarrier.image = info.textures[0].image;
    vkCmdPipelineBarrier(info.cmd, VK_PIPELINE_STAGE_TRANSFER_BIT, VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT, 0, 0, NULL, 0, NULL, 1,
                         &textureBarrier);

    // Draw the second quad to the right using the (now) green texture
    vkCmdBeginRenderPass(info.cmd, &rp_begin, VK_SUBPASS_CONTENTS_INLINE);

    // Draw starting with vertex index 6 to draw to the right of the first quad
    vkCmdDraw(info.cmd, 2 * 3, 1, 6, 0);
    vkCmdEndRenderPass(info.cmd);

    // Change the present buffer from COLOR_ATTACHMENT_OPTIMAL to
    // PRESENT_SOURCE_KHR
    // so it can be presented
    execute_pre_present_barrier(info);

    res = vkEndCommandBuffer(info.cmd);
    assert(res == VK_SUCCESS);

    VkSubmitInfo submit_info = {};
    VkPipelineStageFlags pipe_stage_flags = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
    init_submit_info(info, submit_info, pipe_stage_flags);
    assert(res == VK_SUCCESS);

    VkFence drawFence = {};
    init_fence(info, drawFence);

    // Queue the command buffer for execution
    res = vkQueueSubmit(info.graphics_queue, 1, &submit_info, drawFence);
    assert(res == VK_SUCCESS);

    // Now present the image in the window
    VkPresentInfoKHR present{};
    init_present_info(info, present);

    // Make sure command buffer is finished before presenting
    do {
        res = vkWaitForFences(info.device, 1, &drawFence, VK_TRUE, FENCE_TIMEOUT);
    } while (res == VK_TIMEOUT);
    assert(res == VK_SUCCESS);
    res = vkQueuePresentKHR(info.present_queue, &present);
    assert(res == VK_SUCCESS);
    /* VULKAN_KEY_END */

    wait_seconds(1);
    if (info.save_images) write_ppm(info, "memory_barriers");

    vkDestroySemaphore(info.device, info.imageAcquiredSemaphore, NULL);
    vkDestroyFence(info.device, drawFence, NULL);
    destroy_pipeline(info);
    destroy_pipeline_cache(info);
    destroy_textures(info);
    destroy_descriptor_pool(info);
    destroy_vertex_buffer(info);
    destroy_framebuffers(info);
    destroy_shaders(info);
    destroy_renderpass(info);
    destroy_descriptor_and_pipeline_layouts(info);
    destroy_uniform_buffer(info);
    destroy_swap_chain(info);
    destroy_command_buffer(info);
    destroy_command_pool(info);
    destroy_window(info);
    destroy_device(info);
    destroy_instance(info);
    return 0;
}
int sample_main(int argc, char *argv[]) {
    VkResult U_ASSERT_ONLY res;
    bool U_ASSERT_ONLY pass;

    struct sample_info info = {};
    char sample_title[] = "Depth Buffer Sample";

    /*
     * Make a depth buffer:
     * - Create an Image to be the depth buffer
     * - Find memory requirements
     * - Allocate and bind memory
     * - Set the image layout
     * - Create an attachment view
     */

    init_global_layer_properties(info);
    init_instance_extension_names(info);
    init_device_extension_names(info);
    init_instance(info, sample_title);
    init_enumerate_device(info);
    init_window_size(info, 500, 500);
    init_connection(info);
    init_window(info);
    init_swapchain_extension(info);
    init_device(info);
    init_command_pool(info);
    init_command_buffer(info);
    execute_begin_command_buffer(info);
    init_device_queue(info);

    /* VULKAN_KEY_START */
    VkImageCreateInfo image_info = {};
    const VkFormat depth_format = VK_FORMAT_D16_UNORM;
    VkFormatProperties props;
    vkGetPhysicalDeviceFormatProperties(info.gpus[0], depth_format, &props);
    if (props.linearTilingFeatures &
        VK_FORMAT_FEATURE_DEPTH_STENCIL_ATTACHMENT_BIT) {
        image_info.tiling = VK_IMAGE_TILING_LINEAR;
    } else if (props.optimalTilingFeatures &
               VK_FORMAT_FEATURE_DEPTH_STENCIL_ATTACHMENT_BIT) {
        image_info.tiling = VK_IMAGE_TILING_OPTIMAL;
    } else {
        /* Try other depth formats? */
        std::cout << "VK_FORMAT_D16_UNORM Unsupported.\n";
        exit(-1);
    }

    image_info.sType = VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO;
    image_info.pNext = NULL;
    image_info.imageType = VK_IMAGE_TYPE_2D;
    image_info.format = depth_format;
    image_info.extent.width = info.width;
    image_info.extent.height = info.height;
    image_info.extent.depth = 1;
    image_info.mipLevels = 1;
    image_info.arrayLayers = 1;
    image_info.samples = NUM_SAMPLES;
    image_info.initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
    image_info.usage = VK_IMAGE_USAGE_DEPTH_STENCIL_ATTACHMENT_BIT;
    image_info.queueFamilyIndexCount = 0;
    image_info.pQueueFamilyIndices = NULL;
    image_info.sharingMode = VK_SHARING_MODE_EXCLUSIVE;
    image_info.flags = 0;

    VkMemoryAllocateInfo mem_alloc = {};
    mem_alloc.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO;
    mem_alloc.pNext = NULL;
    mem_alloc.allocationSize = 0;
    mem_alloc.memoryTypeIndex = 0;

    VkImageViewCreateInfo view_info = {};
    view_info.sType = VK_STRUCTURE_TYPE_IMAGE_VIEW_CREATE_INFO;
    view_info.pNext = NULL;
    view_info.image = VK_NULL_HANDLE;
    view_info.format = depth_format;
    view_info.components.r = VK_COMPONENT_SWIZZLE_R;
    view_info.components.g = VK_COMPONENT_SWIZZLE_G;
    view_info.components.b = VK_COMPONENT_SWIZZLE_B;
    view_info.components.a = VK_COMPONENT_SWIZZLE_A;
    view_info.subresourceRange.aspectMask = VK_IMAGE_ASPECT_DEPTH_BIT;
    view_info.subresourceRange.baseMipLevel = 0;
    view_info.subresourceRange.levelCount = 1;
    view_info.subresourceRange.baseArrayLayer = 0;
    view_info.subresourceRange.layerCount = 1;
    view_info.viewType = VK_IMAGE_VIEW_TYPE_2D;
    view_info.flags = 0;

    VkMemoryRequirements mem_reqs;

    info.depth.format = depth_format;

    /* Create image */
    res = vkCreateImage(info.device, &image_info, NULL, &info.depth.image);
    assert(res == VK_SUCCESS);

    vkGetImageMemoryRequirements(info.device, info.depth.image, &mem_reqs);

    mem_alloc.allocationSize = mem_reqs.size;
    /* Use the memory properties to determine the type of memory required */
    pass = memory_type_from_properties(info, mem_reqs.memoryTypeBits,
                                       0, /* No Requirements */
                                       &mem_alloc.memoryTypeIndex);
    assert(pass);

    /* Allocate memory */
    res = vkAllocateMemory(info.device, &mem_alloc, NULL, &info.depth.mem);
    assert(res == VK_SUCCESS);

    /* Bind memory */
    res = vkBindImageMemory(info.device, info.depth.image, info.depth.mem, 0);
    assert(res == VK_SUCCESS);

    /* Set the image layout to depth stencil optimal */
    set_image_layout(info, info.depth.image, VK_IMAGE_ASPECT_DEPTH_BIT,
                     VK_IMAGE_LAYOUT_UNDEFINED,
                     VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL);

    /* Create image view */
    view_info.image = info.depth.image;
    res = vkCreateImageView(info.device, &view_info, NULL, &info.depth.view);
    assert(res == VK_SUCCESS);
    execute_end_command_buffer(info);
    execute_queue_command_buffer(info);

    /* VULKAN_KEY_END */

    /* Clean Up */

    vkDestroyImageView(info.device, info.depth.view, NULL);
    vkDestroyImage(info.device, info.depth.image, NULL);
    vkFreeMemory(info.device, info.depth.mem, NULL);
    destroy_command_buffer(info);
    destroy_command_pool(info);
    destroy_device(info);
    destroy_window(info);
    destroy_instance(info);

    return 0;
}
示例#10
0
/**
 *  Sample using multiple render passes per framebuffer (different x,y extents)
 *  and multiple subpasses per renderpass.
 */
int sample_main(int argc, char *argv[]) {
    VkResult U_ASSERT_ONLY res;
    struct sample_info info = {};
    char sample_title[] = "Multi-pass render passes";
    const bool depthPresent = true;

    process_command_line_args(info, argc, argv);
    init_global_layer_properties(info);
    init_instance_extension_names(info);
    init_device_extension_names(info);
    init_instance(info, sample_title);
    init_enumerate_device(info);
    init_window_size(info, 500, 500);
    init_connection(info);
    init_window(info);
    init_swapchain_extension(info);
    init_device(info);
    init_command_pool(info);
    init_command_buffer(info);
    execute_begin_command_buffer(info);
    init_device_queue(info);
    init_swap_chain(info);

    info.depth.format = VK_FORMAT_D32_SFLOAT_S8_UINT;
    init_depth_buffer(info);

    init_uniform_buffer(info);
    init_descriptor_and_pipeline_layouts(info, false);
    init_vertex_buffer(info, g_vb_solid_face_colors_Data,
                       sizeof(g_vb_solid_face_colors_Data),
                       sizeof(g_vb_solid_face_colors_Data[0]), false);
    init_descriptor_pool(info, false);
    init_descriptor_set(info, false);
    init_pipeline_cache(info);

    /* VULKAN_KEY_START */

    /**
     *  First renderpass in this sample.
     *  Stenciled rendering: subpass 1 draw to stencil buffer, subpass 2 draw to
     *  color buffer with stencil test
     */
    VkAttachmentDescription attachments[2];
    attachments[0].format = info.format;
    attachments[0].samples = VK_SAMPLE_COUNT_1_BIT;
    attachments[0].loadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
    attachments[0].storeOp = VK_ATTACHMENT_STORE_OP_STORE;
    attachments[0].stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE;
    attachments[0].stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
    attachments[0].initialLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
    attachments[0].finalLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
    attachments[0].flags = 0;

    attachments[1].format = info.depth.format;
    attachments[1].samples = VK_SAMPLE_COUNT_1_BIT;
    attachments[1].loadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
    attachments[1].storeOp = VK_ATTACHMENT_STORE_OP_STORE;
    attachments[1].stencilLoadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
    attachments[1].stencilStoreOp = VK_ATTACHMENT_STORE_OP_STORE;
    attachments[1].initialLayout =
        VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL;
    attachments[1].finalLayout =
        VK_IMAGE_LAYOUT_DEPTH_STENCIL_ATTACHMENT_OPTIMAL;
    attachments[1].flags = 0;

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

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

    VkSubpassDescription subpass = {};
    subpass.pipelineBindPoint = VK_PIPELINE_BIND_POINT_GRAPHICS;
    subpass.flags = 0;
    subpass.inputAttachmentCount = 0;
    subpass.pInputAttachments = NULL;
    subpass.colorAttachmentCount = 0;
    subpass.pColorAttachments = NULL;
    subpass.pResolveAttachments = NULL;
    subpass.pDepthStencilAttachment = &depth_reference;
    subpass.preserveAttachmentCount = 0;
    subpass.pPreserveAttachments = NULL;

    std::vector<VkSubpassDescription> subpasses;

    /* first a depthstencil-only subpass */
    subpasses.push_back(subpass);

    subpass.colorAttachmentCount = 1;
    subpass.pColorAttachments = &color_reference;

    /* then depthstencil and color */
    subpasses.push_back(subpass);

    /* Set up a dependency between the source and destination subpasses */
    VkSubpassDependency dependency = {};
    dependency.srcSubpass = 0;
    dependency.dstSubpass = 1;
    dependency.dependencyFlags = 0;
    dependency.srcStageMask = VK_PIPELINE_STAGE_ALL_GRAPHICS_BIT;
    dependency.dstStageMask = VK_PIPELINE_STAGE_ALL_GRAPHICS_BIT;
    dependency.dstAccessMask = VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_WRITE_BIT |
                               VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_READ_BIT;
    dependency.srcAccessMask = VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_WRITE_BIT |
                               VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_READ_BIT;

    VkRenderPassCreateInfo rp_info = {};
    rp_info.sType = VK_STRUCTURE_TYPE_RENDER_PASS_CREATE_INFO;
    rp_info.pNext = NULL;
    rp_info.attachmentCount = 2;
    rp_info.pAttachments = attachments;
    rp_info.subpassCount = subpasses.size();
    rp_info.pSubpasses = subpasses.data();
    rp_info.dependencyCount = 1;
    rp_info.pDependencies = &dependency;

    VkRenderPass stencil_render_pass;
    res = vkCreateRenderPass(info.device, &rp_info, NULL, &stencil_render_pass);
    assert(!res);

    /* now that we have the render pass, create framebuffer and pipelines */

    info.render_pass = stencil_render_pass;
    init_framebuffers(info, depthPresent);

    VkDynamicState dynamicStateEnables[VK_DYNAMIC_STATE_RANGE_SIZE];
    VkPipelineDynamicStateCreateInfo dynamicState = {};
    memset(dynamicStateEnables, 0, sizeof dynamicStateEnables);
    dynamicState.sType = VK_STRUCTURE_TYPE_PIPELINE_DYNAMIC_STATE_CREATE_INFO;
    dynamicState.pNext = NULL;
    dynamicState.pDynamicStates = dynamicStateEnables;
    dynamicState.dynamicStateCount = 0;

    VkPipelineVertexInputStateCreateInfo vi;
    vi.sType = VK_STRUCTURE_TYPE_PIPELINE_VERTEX_INPUT_STATE_CREATE_INFO;
    vi.pNext = NULL;
    vi.flags = 0;
    vi.vertexBindingDescriptionCount = 1;
    vi.pVertexBindingDescriptions = &info.vi_binding;
    vi.vertexAttributeDescriptionCount = 2;
    vi.pVertexAttributeDescriptions = info.vi_attribs;

    VkPipelineInputAssemblyStateCreateInfo ia;
    ia.sType = VK_STRUCTURE_TYPE_PIPELINE_INPUT_ASSEMBLY_STATE_CREATE_INFO;
    ia.pNext = NULL;
    ia.flags = 0;
    ia.primitiveRestartEnable = VK_FALSE;
    ia.topology = VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST;

    VkPipelineRasterizationStateCreateInfo rs;
    rs.sType = VK_STRUCTURE_TYPE_PIPELINE_RASTERIZATION_STATE_CREATE_INFO;
    rs.pNext = NULL;
    rs.flags = 0;
    rs.polygonMode = VK_POLYGON_MODE_FILL;
    rs.cullMode = VK_CULL_MODE_BACK_BIT;
    rs.frontFace = VK_FRONT_FACE_CLOCKWISE;
    rs.depthClampEnable = VK_FALSE;
    rs.rasterizerDiscardEnable = VK_FALSE;
    rs.depthBiasEnable = VK_FALSE;
    rs.depthBiasConstantFactor = 0;
    rs.depthBiasClamp = 0;
    rs.depthBiasSlopeFactor = 0;
    rs.lineWidth = 1.0f;

    VkPipelineColorBlendStateCreateInfo cb;
    cb.sType = VK_STRUCTURE_TYPE_PIPELINE_COLOR_BLEND_STATE_CREATE_INFO;
    cb.pNext = NULL;
    cb.flags = 0;
    VkPipelineColorBlendAttachmentState att_state[1];
    att_state[0].colorWriteMask = 0xf;
    att_state[0].blendEnable = VK_FALSE;
    att_state[0].alphaBlendOp = VK_BLEND_OP_ADD;
    att_state[0].colorBlendOp = VK_BLEND_OP_ADD;
    att_state[0].srcColorBlendFactor = VK_BLEND_FACTOR_ZERO;
    att_state[0].dstColorBlendFactor = VK_BLEND_FACTOR_ZERO;
    att_state[0].srcAlphaBlendFactor = VK_BLEND_FACTOR_ZERO;
    att_state[0].dstAlphaBlendFactor = VK_BLEND_FACTOR_ZERO;
    cb.attachmentCount = 1;
    cb.pAttachments = att_state;
    cb.logicOpEnable = VK_FALSE;
    cb.logicOp = VK_LOGIC_OP_NO_OP;
    cb.blendConstants[0] = 1.0f;
    cb.blendConstants[1] = 1.0f;
    cb.blendConstants[2] = 1.0f;
    cb.blendConstants[3] = 1.0f;

    VkPipelineViewportStateCreateInfo vp = {};
    vp.sType = VK_STRUCTURE_TYPE_PIPELINE_VIEWPORT_STATE_CREATE_INFO;
    vp.pNext = NULL;
    vp.viewportCount = NUM_VIEWPORTS;
    dynamicStateEnables[dynamicState.dynamicStateCount++] =
        VK_DYNAMIC_STATE_VIEWPORT;
    vp.scissorCount = NUM_SCISSORS;
    dynamicStateEnables[dynamicState.dynamicStateCount++] =
        VK_DYNAMIC_STATE_SCISSOR;

    VkPipelineDepthStencilStateCreateInfo ds;
    ds.sType = VK_STRUCTURE_TYPE_PIPELINE_DEPTH_STENCIL_STATE_CREATE_INFO;
    ds.pNext = NULL;
    ds.flags = 0;
    ds.depthTestEnable = VK_TRUE;
    ds.depthWriteEnable = VK_TRUE;
    ds.depthCompareOp = VK_COMPARE_OP_LESS_OR_EQUAL;
    ds.depthBoundsTestEnable = VK_FALSE;
    ds.minDepthBounds = 0;
    ds.maxDepthBounds = 0;

    ds.stencilTestEnable = VK_TRUE;
    ds.back.failOp = VK_STENCIL_OP_REPLACE;
    ds.back.depthFailOp = VK_STENCIL_OP_REPLACE;
    ds.back.passOp = VK_STENCIL_OP_REPLACE;
    ds.back.compareOp = VK_COMPARE_OP_ALWAYS;
    ds.back.compareMask = 0xff;
    ds.back.writeMask = 0xff;
    ds.back.reference = 0x44;
    ds.front = ds.back;

    VkPipelineMultisampleStateCreateInfo ms;
    ms.sType = VK_STRUCTURE_TYPE_PIPELINE_MULTISAMPLE_STATE_CREATE_INFO;
    ms.pNext = NULL;
    ms.flags = 0;
    ms.pSampleMask = NULL;
    ms.rasterizationSamples = NUM_SAMPLES;
    ms.sampleShadingEnable = VK_FALSE;
    ms.minSampleShading = 0.0;
    ms.alphaToCoverageEnable = VK_FALSE;
    ms.alphaToOneEnable = VK_FALSE;

    VkGraphicsPipelineCreateInfo pipeline;
    pipeline.sType = VK_STRUCTURE_TYPE_GRAPHICS_PIPELINE_CREATE_INFO;
    pipeline.pNext = NULL;
    pipeline.layout = info.pipeline_layout;
    pipeline.basePipelineHandle = VK_NULL_HANDLE;
    pipeline.basePipelineIndex = 0;
    pipeline.flags = 0;
    pipeline.pVertexInputState = &vi;
    pipeline.pInputAssemblyState = &ia;
    pipeline.pRasterizationState = &rs;
    pipeline.pColorBlendState = NULL;
    pipeline.pTessellationState = NULL;
    pipeline.pMultisampleState = &ms;
    pipeline.pDynamicState = &dynamicState;
    pipeline.pViewportState = &vp;
    pipeline.pDepthStencilState = &ds;
    pipeline.pStages = info.shaderStages;
    pipeline.stageCount = 2;
    pipeline.renderPass = stencil_render_pass;
    pipeline.subpass = 0;

    init_shaders(info, normalVertShaderText, fragShaderText);

    /* The first pipeline will render in subpass 0 to fill the stencil */
    pipeline.subpass = 0;

    VkPipeline stencil_cube_pipe = VK_NULL_HANDLE;
    res = vkCreateGraphicsPipelines(info.device, info.pipelineCache, 1,
                                    &pipeline, NULL, &stencil_cube_pipe);
    assert(res == VK_SUCCESS);

    /* destroy the shaders used for the above pipelin eand replace them with
       those for the
       fullscreen fill pass */
    destroy_shaders(info);
    init_shaders(info, fullscreenVertShaderText, fragShaderText);

    /* the second pipeline will stencil test but not write, using the same
     * reference */
    ds.back.failOp = VK_STENCIL_OP_KEEP;
    ds.back.depthFailOp = VK_STENCIL_OP_KEEP;
    ds.back.passOp = VK_STENCIL_OP_KEEP;
    ds.back.compareOp = VK_COMPARE_OP_EQUAL;
    ds.front = ds.back;

    /* don't test depth, only use stencil test */
    ds.depthTestEnable = VK_FALSE;

    /* the second pipeline will be a fullscreen triangle strip, with vertices
       generated purely from the vertex shader - no inputs needed */
    ia.topology = VK_PRIMITIVE_TOPOLOGY_TRIANGLE_STRIP;
    vi.vertexAttributeDescriptionCount = 0;
    vi.vertexBindingDescriptionCount = 0;

    /* this pipeline will run in the second subpass */
    pipeline.subpass = 1;
    pipeline.pColorBlendState = &cb;

    VkPipeline stencil_fullscreen_pipe = VK_NULL_HANDLE;
    res = vkCreateGraphicsPipelines(info.device, info.pipelineCache, 1,
                                    &pipeline, NULL, &stencil_fullscreen_pipe);
    assert(res == VK_SUCCESS);

    destroy_shaders(info);
    info.pipeline = VK_NULL_HANDLE;

    VkClearValue clear_values[2];
    clear_values[0].color.float32[0] = 0.2f;
    clear_values[0].color.float32[1] = 0.2f;
    clear_values[0].color.float32[2] = 0.2f;
    clear_values[0].color.float32[3] = 0.2f;
    clear_values[1].depthStencil.depth = 1.0f;
    clear_values[1].depthStencil.stencil = 0;

    VkSemaphore imageAcquiredSemaphore;
    VkSemaphoreCreateInfo imageAcquiredSemaphoreCreateInfo;
    imageAcquiredSemaphoreCreateInfo.sType =
        VK_STRUCTURE_TYPE_SEMAPHORE_CREATE_INFO;
    imageAcquiredSemaphoreCreateInfo.pNext = NULL;
    imageAcquiredSemaphoreCreateInfo.flags = 0;

    res = vkCreateSemaphore(info.device, &imageAcquiredSemaphoreCreateInfo,
                            NULL, &imageAcquiredSemaphore);
    assert(res == VK_SUCCESS);

    // Get the index of the next available swapchain image:
    res = vkAcquireNextImageKHR(info.device, info.swap_chain, UINT64_MAX,
                                imageAcquiredSemaphore, VK_NULL_HANDLE,
                                &info.current_buffer);
    // TODO: Deal with the VK_SUBOPTIMAL_KHR and VK_ERROR_OUT_OF_DATE_KHR
    // return codes
    assert(res == VK_SUCCESS);

    set_image_layout(info, info.buffers[info.current_buffer].image,
                     VK_IMAGE_ASPECT_COLOR_BIT, VK_IMAGE_LAYOUT_UNDEFINED,
                     VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL);

    VkRenderPassBeginInfo rp_begin;
    rp_begin.sType = VK_STRUCTURE_TYPE_RENDER_PASS_BEGIN_INFO;
    rp_begin.pNext = NULL;
    rp_begin.renderPass = stencil_render_pass;
    rp_begin.framebuffer = info.framebuffers[info.current_buffer];
    rp_begin.renderArea.offset.x = 0;
    rp_begin.renderArea.offset.y = 0;
    rp_begin.renderArea.extent.width = info.width / 2;
    rp_begin.renderArea.extent.height = info.height;
    rp_begin.clearValueCount = 2;
    rp_begin.pClearValues = clear_values;

    /* Begin the first render pass. This will render in the left half of the
       screen. Subpass 0 will render a cube, stencil writing but outputting
       no color. Subpass 1 will render a fullscreen pass, stencil testing and
       outputting color only where the cube filled in stencil */
    vkCmdBeginRenderPass(info.cmd, &rp_begin, VK_SUBPASS_CONTENTS_INLINE);

    vkCmdBindPipeline(info.cmd, VK_PIPELINE_BIND_POINT_GRAPHICS,
                      stencil_cube_pipe);
    vkCmdBindDescriptorSets(info.cmd, VK_PIPELINE_BIND_POINT_GRAPHICS,
                            info.pipeline_layout, 0, NUM_DESCRIPTOR_SETS,
                            info.desc_set.data(), 0, NULL);

    const VkDeviceSize offsets[1] = {0};
    vkCmdBindVertexBuffers(info.cmd, 0, 1, &info.vertex_buffer.buf, offsets);

    VkViewport viewport;
    viewport.height = (float)info.height;
    viewport.width = (float)info.width / 2;
    viewport.minDepth = (float)0.0f;
    viewport.maxDepth = (float)1.0f;
    viewport.x = 0;
    viewport.y = 0;
    vkCmdSetViewport(info.cmd, 0, NUM_VIEWPORTS, &viewport);

    VkRect2D scissor;
    scissor.extent.width = info.width / 2;
    scissor.extent.height = info.height;
    scissor.offset.x = 0;
    scissor.offset.y = 0;
    vkCmdSetScissor(info.cmd, 0, NUM_SCISSORS, &scissor);

    /* Draw the cube into stencil */
    vkCmdDraw(info.cmd, 12 * 3, 1, 0, 0);

    /* Advance to the next subpass */
    vkCmdNextSubpass(info.cmd, VK_SUBPASS_CONTENTS_INLINE);

    /* Bind the fullscreen pass pipeline */
    vkCmdBindPipeline(info.cmd, VK_PIPELINE_BIND_POINT_GRAPHICS,
                      stencil_fullscreen_pipe);

    vkCmdSetViewport(info.cmd, 0, NUM_VIEWPORTS, &viewport);
    vkCmdSetScissor(info.cmd, 0, NUM_SCISSORS, &scissor);

    /* Draw the fullscreen pass */
    vkCmdDraw(info.cmd, 4, 1, 0, 0);

    vkCmdEndRenderPass(info.cmd);

    /**
     * Second renderpass in this sample.
     * Blended rendering, each subpass blends continuously onto the color
     */

    /* note that we reuse a lot of the initialisation strutures from the first
       render pass, so this represents a 'delta' from that configuration */

    /* This time, the first subpass will use color */
    subpasses[0].colorAttachmentCount = 1;
    subpasses[0].pColorAttachments = &color_reference;

    /* The dependency between the subpasses now includes the color attachment */
    dependency.srcAccessMask |= VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT |
                                VK_ACCESS_COLOR_ATTACHMENT_READ_BIT;
    dependency.dstAccessMask |= VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT |
                                VK_ACCESS_COLOR_ATTACHMENT_READ_BIT;

    /* Otherwise, the render pass is identical */
    VkRenderPass blend_render_pass;
    res = vkCreateRenderPass(info.device, &rp_info, NULL, &blend_render_pass);
    assert(!res);

    pipeline.renderPass = blend_render_pass;

    /* We must recreate the framebuffers with this renderpass as the two render
       passes are not compatible. Store the current framebuffers for later
       deletion */
    VkFramebuffer *stencil_framebuffers = info.framebuffers;
    info.framebuffers = NULL;

    info.render_pass = blend_render_pass;
    init_framebuffers(info, depthPresent);

    /* Now create the pipelines for the second render pass */

    /* We are rendering the cube again, configure the vertex inputs */
    ia.topology = VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST;
    vi.vertexAttributeDescriptionCount = 2;
    vi.vertexBindingDescriptionCount = 1;

    /* The first pipeline will depth write and depth test */
    ds.depthWriteEnable = VK_TRUE;
    ds.depthTestEnable = VK_TRUE;

    /* We don't want to stencil test */
    ds.stencilTestEnable = VK_FALSE;

    /* This time, both pipelines will blend. the first pipeline uses the blend
     constant
     to determine the blend amount */
    att_state[0].colorWriteMask = 0xf;
    att_state[0].blendEnable = VK_TRUE;
    att_state[0].alphaBlendOp = VK_BLEND_OP_ADD;
    att_state[0].colorBlendOp = VK_BLEND_OP_ADD;
    att_state[0].srcColorBlendFactor = VK_BLEND_FACTOR_CONSTANT_ALPHA;
    att_state[0].dstColorBlendFactor = VK_BLEND_FACTOR_ONE;
    att_state[0].srcColorBlendFactor = VK_BLEND_FACTOR_CONSTANT_ALPHA;
    att_state[0].srcAlphaBlendFactor = VK_BLEND_FACTOR_ONE;

    cb.blendConstants[0] = 1.0f;
    cb.blendConstants[1] = 1.0f;
    cb.blendConstants[2] = 1.0f;
    cb.blendConstants[3] = 0.3f;

    init_shaders(info, normalVertShaderText, fragShaderText);

    /* This is the first subpass's pipeline, to blend a cube onto the color
     * image */
    pipeline.subpass = 0;

    VkPipeline blend_cube_pipe = VK_NULL_HANDLE;
    res = vkCreateGraphicsPipelines(info.device, info.pipelineCache, 1,
                                    &pipeline, NULL, &blend_cube_pipe);
    assert(res == VK_SUCCESS);

    /* Now we will set up the fullscreen pass to render on top. */
    destroy_shaders(info);
    init_shaders(info, fullscreenVertShaderText, fragShaderText);

    /* the second pipeline will be a fullscreen triangle strip with no inputs */
    ia.topology = VK_PRIMITIVE_TOPOLOGY_TRIANGLE_STRIP;
    vi.vertexAttributeDescriptionCount = 0;
    vi.vertexBindingDescriptionCount = 0;

    /* We'll use the alpha output from the shader */
    att_state[0].srcColorBlendFactor = VK_BLEND_FACTOR_SRC_ALPHA;
    att_state[0].dstColorBlendFactor = VK_BLEND_FACTOR_ONE;
    att_state[0].srcAlphaBlendFactor = VK_BLEND_FACTOR_SRC_ALPHA;
    att_state[0].dstAlphaBlendFactor = VK_BLEND_FACTOR_ONE;

    /* This renders in the second subpass */
    pipeline.subpass = 1;

    VkPipeline blend_fullscreen_pipe = VK_NULL_HANDLE;
    res = vkCreateGraphicsPipelines(info.device, info.pipelineCache, 1,
                                    &pipeline, NULL, &blend_fullscreen_pipe);
    assert(res == VK_SUCCESS);

    destroy_shaders(info);
    info.pipeline = VK_NULL_HANDLE;

    /* Now we are going to render in the right half of the screen */
    viewport.x = (float)info.width / 2;
    scissor.offset.x = info.width / 2;
    rp_begin.renderArea.offset.x = info.width / 2;

    /* Use our framebuffer and render pass */
    rp_begin.framebuffer = info.framebuffers[info.current_buffer];
    rp_begin.renderPass = blend_render_pass;
    vkCmdBeginRenderPass(info.cmd, &rp_begin, VK_SUBPASS_CONTENTS_INLINE);

    vkCmdBindPipeline(info.cmd, VK_PIPELINE_BIND_POINT_GRAPHICS,
                      blend_cube_pipe);
    vkCmdBindDescriptorSets(info.cmd, VK_PIPELINE_BIND_POINT_GRAPHICS,
                            info.pipeline_layout, 0, NUM_DESCRIPTOR_SETS,
                            info.desc_set.data(), 0, NULL);
    vkCmdBindVertexBuffers(info.cmd, 0, 1, &info.vertex_buffer.buf, offsets);
    vkCmdSetViewport(info.cmd, 0, NUM_VIEWPORTS, &viewport);
    vkCmdSetScissor(info.cmd, 0, NUM_SCISSORS, &scissor);

    /* Draw the cube blending */
    vkCmdDraw(info.cmd, 12 * 3, 1, 0, 0);

    /* Advance to the next subpass */
    vkCmdNextSubpass(info.cmd, VK_SUBPASS_CONTENTS_INLINE);

    vkCmdBindPipeline(info.cmd, VK_PIPELINE_BIND_POINT_GRAPHICS,
                      blend_fullscreen_pipe);

    /* Adjust the viewport to be a square in the centre, just overlapping the
     * cube */
    viewport.x += 25.0f;
    viewport.y += 150.0f;
    viewport.width -= 50.0f;
    viewport.height -= 300.0f;

    vkCmdSetViewport(info.cmd, 0, NUM_VIEWPORTS, &viewport);
    vkCmdSetScissor(info.cmd, 0, NUM_SCISSORS, &scissor);

    vkCmdDraw(info.cmd, 4, 1, 0, 0);

    /* The second renderpass is complete */
    vkCmdEndRenderPass(info.cmd);
    /* VULKAN_KEY_END */
    res = vkEndCommandBuffer(info.cmd);
    const VkCommandBuffer cmd_bufs[] = {info.cmd};
    VkFenceCreateInfo fenceInfo;
    VkFence drawFence;
    fenceInfo.sType = VK_STRUCTURE_TYPE_FENCE_CREATE_INFO;
    fenceInfo.pNext = NULL;
    fenceInfo.flags = 0;
    vkCreateFence(info.device, &fenceInfo, NULL, &drawFence);

    VkPipelineStageFlags pipe_stage_flags =
        VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
    VkSubmitInfo submit_info[1] = {};
    submit_info[0].pNext = NULL;
    submit_info[0].sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
    submit_info[0].waitSemaphoreCount = 1;
    submit_info[0].pWaitSemaphores = &imageAcquiredSemaphore;
    submit_info[0].commandBufferCount = 1;
    submit_info[0].pCommandBuffers = cmd_bufs;
    submit_info[0].pWaitDstStageMask = &pipe_stage_flags;
    submit_info[0].signalSemaphoreCount = 0;
    submit_info[0].pSignalSemaphores = NULL;

    /* Queue the command buffer for execution */
    res = vkQueueSubmit(info.graphics_queue, 1, submit_info, drawFence);
    assert(res == VK_SUCCESS);

    /* Now present the image in the window */

    VkPresentInfoKHR present;
    present.sType = VK_STRUCTURE_TYPE_PRESENT_INFO_KHR;
    present.pNext = NULL;
    present.swapchainCount = 1;
    present.pSwapchains = &info.swap_chain;
    present.pImageIndices = &info.current_buffer;
    present.pWaitSemaphores = NULL;
    present.waitSemaphoreCount = 0;
    present.pResults = NULL;

    /* Make sure command buffer is finished before presenting */
    do {
        res =
            vkWaitForFences(info.device, 1, &drawFence, VK_TRUE, FENCE_TIMEOUT);
    } while (res == VK_TIMEOUT);
    assert(res == VK_SUCCESS);
    res = vkQueuePresentKHR(info.present_queue, &present);
    assert(res == VK_SUCCESS);

    wait_seconds(1);
    /* VULKAN_KEY_END */
    if (info.save_images)
        write_ppm(info, "drawsubpasses");

    for (uint32_t i = 0; i < info.swapchainImageCount; i++)
        vkDestroyFramebuffer(info.device, stencil_framebuffers[i], NULL);
    free(stencil_framebuffers);

    vkDestroyRenderPass(info.device, stencil_render_pass, NULL);
    vkDestroyRenderPass(info.device, blend_render_pass, NULL);

    vkDestroyPipeline(info.device, blend_cube_pipe, NULL);
    vkDestroyPipeline(info.device, blend_fullscreen_pipe, NULL);

    vkDestroyPipeline(info.device, stencil_cube_pipe, NULL);
    vkDestroyPipeline(info.device, stencil_fullscreen_pipe, NULL);

    vkDestroySemaphore(info.device, imageAcquiredSemaphore, NULL);
    vkDestroyFence(info.device, drawFence, NULL);
    destroy_pipeline_cache(info);
    destroy_descriptor_pool(info);
    destroy_vertex_buffer(info);
    destroy_framebuffers(info);
    destroy_descriptor_and_pipeline_layouts(info);
    destroy_uniform_buffer(info);
    destroy_depth_buffer(info);
    destroy_swap_chain(info);
    destroy_command_buffer(info);
    destroy_command_pool(info);
    destroy_device(info);
    destroy_window(info);
    destroy_instance(info);
    return 0;
}