int sample_main(int argc, char *argv[]) {
    VkResult U_ASSERT_ONLY res;
    struct sample_info info = {};
    char sample_title[] = "Separate Image Sampler";
    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_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);

    /* VULKAN_KEY_START */

    // Sample from a green texture to easily see that we've pulled correct texel
    // value

    // Create our separate image
    struct texture_object texObj;
    const char *textureName = "green.ppm";
    init_image(info, texObj, textureName);

    info.textures.push_back(texObj);

    info.texture_data.image_info.sampler = 0;
    info.texture_data.image_info.imageView = info.textures[0].view;
    info.texture_data.image_info.imageLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;

    // Create our separate sampler
    VkSampler separateSampler = {};
    init_sampler(info, separateSampler);

    VkDescriptorImageInfo samplerInfo = {};
    samplerInfo.sampler = separateSampler;

    // Set up one descriptor set
    static const unsigned descriptor_set_count = 1;
    static const unsigned resource_count = 3;
    static const unsigned resource_type_count = 3;

    // Create binding and layout for the following, matching contents of shader
    //   binding 0 = uniform buffer (MVP)
    //   binding 1 = texture2D
    //   binding 2 = sampler

    VkDescriptorSetLayoutBinding resource_binding[resource_count] = {};
    resource_binding[0].binding = 0;
    resource_binding[0].descriptorType = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
    resource_binding[0].descriptorCount = 1;
    resource_binding[0].stageFlags = VK_SHADER_STAGE_VERTEX_BIT;
    resource_binding[0].pImmutableSamplers = NULL;
    resource_binding[1].binding = 1;
    resource_binding[1].descriptorType = VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE;
    resource_binding[1].descriptorCount = 1;
    resource_binding[1].stageFlags = VK_SHADER_STAGE_FRAGMENT_BIT;
    resource_binding[1].pImmutableSamplers = NULL;
    resource_binding[2].binding = 2;
    resource_binding[2].descriptorType = VK_DESCRIPTOR_TYPE_SAMPLER;
    resource_binding[2].descriptorCount = 1;
    resource_binding[2].stageFlags = VK_SHADER_STAGE_FRAGMENT_BIT;
    resource_binding[2].pImmutableSamplers = NULL;

    VkDescriptorSetLayoutCreateInfo resource_layout_info[1] = {};
    resource_layout_info[0].sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_CREATE_INFO;
    resource_layout_info[0].pNext = NULL;
    resource_layout_info[0].bindingCount = resource_count;
    resource_layout_info[0].pBindings = resource_binding;

    VkDescriptorSetLayout descriptor_layouts[1] = {};
    res = vkCreateDescriptorSetLayout(info.device, resource_layout_info, NULL, &descriptor_layouts[0]);

    assert(res == VK_SUCCESS);

    // Create pipeline layout
    VkPipelineLayoutCreateInfo pipelineLayoutCreateInfo[1] = {};
    pipelineLayoutCreateInfo[0].sType = VK_STRUCTURE_TYPE_PIPELINE_LAYOUT_CREATE_INFO;
    pipelineLayoutCreateInfo[0].pNext = NULL;
    pipelineLayoutCreateInfo[0].pushConstantRangeCount = 0;
    pipelineLayoutCreateInfo[0].pPushConstantRanges = NULL;
    pipelineLayoutCreateInfo[0].setLayoutCount = descriptor_set_count;
    pipelineLayoutCreateInfo[0].pSetLayouts = descriptor_layouts;
    res = vkCreatePipelineLayout(info.device, pipelineLayoutCreateInfo, NULL, &info.pipeline_layout);
    assert(res == VK_SUCCESS);

    // Create a single pool to contain data for our descriptor set
    VkDescriptorPoolSize pool_sizes[resource_type_count] = {};
    pool_sizes[0].type = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
    pool_sizes[0].descriptorCount = 1;
    pool_sizes[1].type = VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE;
    pool_sizes[1].descriptorCount = 1;
    pool_sizes[2].type = VK_DESCRIPTOR_TYPE_SAMPLER;
    pool_sizes[2].descriptorCount = 1;

    VkDescriptorPoolCreateInfo pool_info[1] = {};
    pool_info[0].sType = VK_STRUCTURE_TYPE_DESCRIPTOR_POOL_CREATE_INFO;
    pool_info[0].pNext = NULL;
    pool_info[0].maxSets = descriptor_set_count;
    pool_info[0].poolSizeCount = resource_type_count;
    pool_info[0].pPoolSizes = pool_sizes;

    VkDescriptorPool descriptor_pool[1] = {};
    res = vkCreateDescriptorPool(info.device, pool_info, NULL, descriptor_pool);
    assert(res == VK_SUCCESS);

    VkDescriptorSetAllocateInfo alloc_info[1];
    alloc_info[0].sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_ALLOCATE_INFO;
    alloc_info[0].pNext = NULL;
    alloc_info[0].descriptorPool = descriptor_pool[0];
    alloc_info[0].descriptorSetCount = descriptor_set_count;
    alloc_info[0].pSetLayouts = descriptor_layouts;

    // Populate descriptor sets
    VkDescriptorSet descriptor_sets[descriptor_set_count] = {};
    res = vkAllocateDescriptorSets(info.device, alloc_info, descriptor_sets);
    assert(res == VK_SUCCESS);

    VkWriteDescriptorSet descriptor_writes[resource_count];

    // Populate with info about our uniform buffer for MVP
    descriptor_writes[0] = {};
    descriptor_writes[0].sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
    descriptor_writes[0].pNext = NULL;
    descriptor_writes[0].dstSet = descriptor_sets[0];
    descriptor_writes[0].descriptorCount = 1;
    descriptor_writes[0].descriptorType = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
    descriptor_writes[0].pBufferInfo = &info.uniform_data.buffer_info;  // populated by init_uniform_buffer()
    descriptor_writes[0].dstArrayElement = 0;
    descriptor_writes[0].dstBinding = 0;

    // Populate with info about our image
    descriptor_writes[1] = {};
    descriptor_writes[1].sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
    descriptor_writes[1].pNext = NULL;
    descriptor_writes[1].dstSet = descriptor_sets[0];
    descriptor_writes[1].descriptorCount = 1;
    descriptor_writes[1].descriptorType = VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE;
    descriptor_writes[1].pImageInfo = &info.texture_data.image_info;  // populated by init_texture()
    descriptor_writes[1].dstArrayElement = 0;
    descriptor_writes[1].dstBinding = 1;

    // Populate with info about our sampler
    descriptor_writes[2] = {};
    descriptor_writes[2].sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
    descriptor_writes[2].pNext = NULL;
    descriptor_writes[2].dstSet = descriptor_sets[0];
    descriptor_writes[2].descriptorCount = 1;
    descriptor_writes[2].descriptorType = VK_DESCRIPTOR_TYPE_SAMPLER;
    descriptor_writes[2].pImageInfo = &samplerInfo;
    descriptor_writes[2].dstArrayElement = 0;
    descriptor_writes[2].dstBinding = 2;

    vkUpdateDescriptorSets(info.device, resource_count, descriptor_writes, 0, NULL);

    /* VULKAN_KEY_END */

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

    VkClearValue clear_values[2];
    init_clear_color_and_depth(info, clear_values);

    VkRenderPassBeginInfo rp_begin;
    init_render_pass_begin_info(info, rp_begin);
    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,
                            descriptor_sets, 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);
    res = vkEndCommandBuffer(info.cmd);
    assert(res == VK_SUCCESS);

    VkFence drawFence = {};
    init_fence(info, drawFence);
    VkPipelineStageFlags pipe_stage_flags = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
    VkSubmitInfo submit_info = {};
    init_submit_info(info, submit_info, pipe_stage_flags);

    /* 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);

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

    vkDestroyFence(info.device, drawFence, NULL);
    vkDestroySemaphore(info.device, info.imageAcquiredSemaphore, NULL);
    destroy_pipeline(info);
    destroy_pipeline_cache(info);

    vkDestroySampler(info.device, separateSampler, NULL);
    vkDestroyImageView(info.device, info.textures[0].view, NULL);
    vkDestroyImage(info.device, info.textures[0].image, NULL);
    vkFreeMemory(info.device, info.textures[0].mem, NULL);

    // instead of destroy_descriptor_pool(info);
    vkDestroyDescriptorPool(info.device, descriptor_pool[0], NULL);

    destroy_vertex_buffer(info);
    destroy_framebuffers(info);
    destroy_shaders(info);
    destroy_renderpass(info);

    // instead of destroy_descriptor_and_pipeline_layouts(info);
    for (int i = 0; i < descriptor_set_count; i++) vkDestroyDescriptorSetLayout(info.device, descriptor_layouts[i], NULL);
    vkDestroyPipelineLayout(info.device, info.pipeline_layout, NULL);

    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[] = "SPIR-V Specialization";
    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);

    /* VULKAN_KEY_START */

    // Pass in nullptr for fragment shader so we can setup specialization
    init_shaders(info, vertShaderText, nullptr);

    // This structure maps constant ids to data locations.
    // NOTE: Padding bool to 32-bits for simplicity
    const VkSpecializationMapEntry entries[] =
        // id,  offset,                size
        {{5, 0, sizeof(uint32_t)},
         {7, 1 * sizeof(uint32_t), sizeof(uint32_t)},
         {8, 2 * sizeof(uint32_t), sizeof(uint32_t)},
         {9, 3 * sizeof(uint32_t), sizeof(uint32_t)}};

    // Initialize the values we want our mini-ubershader to use
    const bool drawUserColor = true;
    const float userColor[] = {0.0f, 0.0f, 1.0f};

    // Populate our data entry
    uint32_t data[4] = {};
    data[0] = drawUserColor ? 1 : 0;
    ((float *)data)[1] = userColor[0];
    ((float *)data)[2] = userColor[1];
    ((float *)data)[3] = userColor[2];

    // Set up the info describing our spec map and data
    const VkSpecializationInfo specInfo = {
        4,                  // mapEntryCount
        entries,            // pMapEntries
        4 * sizeof(float),  // dataSize
        data,               // pData
    };

    // Provide the specialization data to fragment stage
    info.shaderStages[1].sType = VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO;
    info.shaderStages[1].pNext = NULL;
    info.shaderStages[1].pSpecializationInfo = &specInfo;
    info.shaderStages[1].flags = 0;
    info.shaderStages[1].stage = VK_SHADER_STAGE_FRAGMENT_BIT;
    info.shaderStages[1].pName = "main";

    VkShaderModuleCreateInfo moduleCreateInfo;
    moduleCreateInfo.sType = VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO;
    moduleCreateInfo.pNext = NULL;
    moduleCreateInfo.flags = 0;

    if (use_SPIRV_asm) {
        // Use the hand edited SPIR-V assembly
        spv_context spvContext = spvContextCreate(SPV_ENV_VULKAN_1_0);
        spv_binary fragmentBinary = {};
        spv_diagnostic fragmentDiag = {};
        spv_result_t fragmentResult = spvTextToBinary(spvContext, fragmentSPIRV_specialized.c_str(),
                                                      fragmentSPIRV_specialized.length(), &fragmentBinary, &fragmentDiag);
        if (fragmentDiag) {
            printf("Diagnostic info from fragment shader:\n");
            spvDiagnosticPrint(fragmentDiag);
        }
        assert(fragmentResult == SPV_SUCCESS);
        moduleCreateInfo.codeSize = fragmentBinary->wordCount * sizeof(unsigned int);
        moduleCreateInfo.pCode = fragmentBinary->code;
        spvDiagnosticDestroy(fragmentDiag);
        spvContextDestroy(spvContext);

    } else {
        // Convert GLSL to SPIR-V
        init_glslang();
        std::vector<unsigned int> fragSpv;
        bool U_ASSERT_ONLY retVal = GLSLtoSPV(VK_SHADER_STAGE_FRAGMENT_BIT, fragShaderText, fragSpv);
        assert(retVal);
        finalize_glslang();

        moduleCreateInfo.codeSize = fragSpv.size() * sizeof(unsigned int);
        moduleCreateInfo.pCode = fragSpv.data();
    }

    res = vkCreateShaderModule(info.device, &moduleCreateInfo, NULL, &info.shaderStages[1].module);
    assert(res == VK_SUCCESS);

    /* VULKAN_KEY_END */

    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);
    init_presentable_image(info);

    VkClearValue clear_values[2];
    init_clear_color_and_depth(info, clear_values);

    VkRenderPassBeginInfo rp_begin;
    init_render_pass_begin_info(info, rp_begin);
    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);
    res = vkEndCommandBuffer(info.cmd);
    assert(res == VK_SUCCESS);

    VkFence drawFence = {};
    init_fence(info, drawFence);
    VkPipelineStageFlags pipe_stage_flags = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
    VkSubmitInfo submit_info = {};
    init_submit_info(info, submit_info, pipe_stage_flags);

    /* 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);

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

    vkDestroyFence(info.device, drawFence, NULL);
    vkDestroySemaphore(info.device, info.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;
    struct sample_info info = {};
    char sample_title[] = "Simple Push Constants";
    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_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);

    // Set up one descriptor sets
    static const unsigned descriptor_set_count = 1;
    static const unsigned resource_count = 1;

    // Create binding and layout for the following, matching contents of shader
    //   binding 0 = uniform buffer (MVP)

    VkDescriptorSetLayoutBinding resource_binding[resource_count] = {};
    resource_binding[0].descriptorType = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
    resource_binding[0].descriptorCount = 1;
    resource_binding[0].stageFlags = VK_SHADER_STAGE_VERTEX_BIT;
    resource_binding[0].pImmutableSamplers = NULL;

    VkDescriptorSetLayoutCreateInfo resource_layout_info[1] = {};
    resource_layout_info[0].sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_CREATE_INFO;
    resource_layout_info[0].pNext = NULL;
    resource_layout_info[0].bindingCount = resource_count;
    resource_layout_info[0].pBindings = resource_binding;

    VkDescriptorSetLayout descriptor_layouts[1] = {};
    res = vkCreateDescriptorSetLayout(info.device, resource_layout_info, NULL, &descriptor_layouts[0]);
    assert(res == VK_SUCCESS);

    /* VULKAN_KEY_START */

    // Set up our push constant range, which mirrors the declaration of
    const unsigned push_constant_range_count = 1;
    VkPushConstantRange push_constant_ranges[push_constant_range_count] = {};
    push_constant_ranges[0].stageFlags = VK_SHADER_STAGE_FRAGMENT_BIT;
    push_constant_ranges[0].offset = 0;
    push_constant_ranges[0].size = 8;

    // Create pipeline layout, including push constant info.

    // Create pipeline layout with multiple descriptor sets
    VkPipelineLayoutCreateInfo pipelineLayoutCreateInfo[1] = {};
    pipelineLayoutCreateInfo[0].sType = VK_STRUCTURE_TYPE_PIPELINE_LAYOUT_CREATE_INFO;
    pipelineLayoutCreateInfo[0].pNext = NULL;
    pipelineLayoutCreateInfo[0].pushConstantRangeCount = push_constant_range_count;
    pipelineLayoutCreateInfo[0].pPushConstantRanges = push_constant_ranges;
    pipelineLayoutCreateInfo[0].setLayoutCount = descriptor_set_count;
    pipelineLayoutCreateInfo[0].pSetLayouts = descriptor_layouts;
    res = vkCreatePipelineLayout(info.device, pipelineLayoutCreateInfo, NULL, &info.pipeline_layout);
    assert(res == VK_SUCCESS);

    // Create a single pool to contain data for our descriptor set
    VkDescriptorPoolSize type_count[2] = {};
    type_count[0].type = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
    type_count[0].descriptorCount = 1;
    type_count[1].type = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
    type_count[1].descriptorCount = 1;

    VkDescriptorPoolCreateInfo pool_info[1] = {};
    pool_info[0].sType = VK_STRUCTURE_TYPE_DESCRIPTOR_POOL_CREATE_INFO;
    pool_info[0].pNext = NULL;
    pool_info[0].maxSets = descriptor_set_count;
    pool_info[0].poolSizeCount = sizeof(type_count) / sizeof(VkDescriptorPoolSize);
    pool_info[0].pPoolSizes = type_count;

    VkDescriptorPool descriptor_pool[1] = {};
    res = vkCreateDescriptorPool(info.device, pool_info, NULL, descriptor_pool);
    assert(res == VK_SUCCESS);

    VkDescriptorSetAllocateInfo alloc_info[1];
    alloc_info[0].sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_ALLOCATE_INFO;
    alloc_info[0].pNext = NULL;
    alloc_info[0].descriptorPool = descriptor_pool[0];
    alloc_info[0].descriptorSetCount = descriptor_set_count;
    alloc_info[0].pSetLayouts = descriptor_layouts;

    // Populate descriptor sets
    VkDescriptorSet descriptor_sets[descriptor_set_count] = {};
    res = vkAllocateDescriptorSets(info.device, alloc_info, descriptor_sets);
    assert(res == VK_SUCCESS);

    // Using empty brace initializer on the next line triggers a bug in older
    // versions of gcc, so memset instead
    VkWriteDescriptorSet descriptor_writes[resource_count];
    memset(descriptor_writes, 0, sizeof(descriptor_writes));

    // Populate with info about our uniform buffer for MVP
    descriptor_writes[0] = {};
    descriptor_writes[0].sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
    descriptor_writes[0].pNext = NULL;
    descriptor_writes[0].dstSet = descriptor_sets[0];
    descriptor_writes[0].descriptorCount = 1;
    descriptor_writes[0].descriptorType = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
    descriptor_writes[0].pBufferInfo = &info.uniform_data.buffer_info;  // populated by init_uniform_buffer()
    descriptor_writes[0].dstArrayElement = 0;
    descriptor_writes[0].dstBinding = 0;

    vkUpdateDescriptorSets(info.device, resource_count, descriptor_writes, 0, NULL);

    // Create our push constant data, which matches shader expectations
    unsigned pushConstants[2] = {};
    pushConstants[0] = (unsigned)2;
    pushConstants[1] = (unsigned)0x3F800000;

    // Ensure we have enough room for push constant data
    if (sizeof(pushConstants) > info.gpu_props.limits.maxPushConstantsSize) assert(0 && "Too many push constants");

    vkCmdPushConstants(info.cmd, info.pipeline_layout, VK_SHADER_STAGE_FRAGMENT_BIT, 0, sizeof(pushConstants), pushConstants);

    /* VULKAN_KEY_END */

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

    VkClearValue clear_values[2];
    init_clear_color_and_depth(info, clear_values);

    VkRenderPassBeginInfo rp_begin;
    init_render_pass_begin_info(info, rp_begin);
    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,
                            descriptor_sets, 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);
    res = vkEndCommandBuffer(info.cmd);
    assert(res == VK_SUCCESS);

    VkFence drawFence = {};
    init_fence(info, drawFence);
    VkPipelineStageFlags pipe_stage_flags = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
    VkSubmitInfo submit_info = {};
    init_submit_info(info, submit_info, pipe_stage_flags);

    /* 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);

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

    vkDestroyFence(info.device, drawFence, NULL);
    vkDestroySemaphore(info.device, info.imageAcquiredSemaphore, NULL);
    destroy_pipeline(info);
    destroy_pipeline_cache(info);
    // instead of destroy_descriptor_pool(info);
    vkDestroyDescriptorPool(info.device, descriptor_pool[0], NULL);
    destroy_vertex_buffer(info);
    destroy_framebuffers(info);
    destroy_shaders(info);
    destroy_renderpass(info);
    // instead of destroy_descriptor_and_pipeline_layouts(info);
    for (int i = 0; i < descriptor_set_count; i++) vkDestroyDescriptorSetLayout(info.device, descriptor_layouts[i], NULL);
    vkDestroyPipelineLayout(info.device, info.pipeline_layout, NULL);
    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[] = "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);
    init_presentable_image(info);

    VkClearValue clear_values[2];
    init_clear_color_and_depth(info, clear_values);

    VkRenderPassBeginInfo rp_begin;
    init_render_pass_begin_info(info, rp_begin);
    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);

    execute_pre_present_barrier(info);

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

    VkFence drawFence = {};
    init_fence(info, drawFence);
    VkPipelineStageFlags pipe_stage_flags =
        VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT;
    VkSubmitInfo submit_info = {};
    init_submit_info(info, submit_info, pipe_stage_flags);

    /* 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 = {};
    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.queue, &present);
    assert(res == VK_SUCCESS);

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

    vkDestroyFence(info.device, drawFence, NULL);
    vkDestroySemaphore(info.device, info.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[] = "Pipeline Cache";
    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, "blue.ppm");
    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);

    /* VULKAN_KEY_START */

    // Check disk for existing cache data
    size_t startCacheSize = 0;
    void *startCacheData = nullptr;

    std::string directoryName = get_file_directory();
    std::string readFileName = directoryName + "pipeline_cache_data.bin";
    FILE *pReadFile = fopen(readFileName.c_str(), "rb");

    if (pReadFile) {

        // Determine cache size
        fseek(pReadFile, 0, SEEK_END);
        startCacheSize = ftell(pReadFile);
        rewind(pReadFile);

        // Allocate memory to hold the initial cache data
        startCacheData = (char *)malloc(sizeof(char) * startCacheSize);
        if (startCacheData == nullptr) {
            fputs("Memory error", stderr);
            exit(EXIT_FAILURE);
        }

        // Read the data into our buffer
        size_t result = fread(startCacheData, 1, startCacheSize, pReadFile);
        if (result != startCacheSize) {
            fputs("Reading error", stderr);
            free(startCacheData);
            exit(EXIT_FAILURE);
        }

        // Clean up and print results
        fclose(pReadFile);
        printf("  Pipeline cache HIT!\n");
        printf("  cacheData loaded from %s\n", readFileName.c_str());

    } else {
        // No cache found on disk
        printf("  Pipeline cache miss!\n");
    }

    if (startCacheData != nullptr) {
        // clang-format off
        //
        // Check for cache validity
        //
        // TODO: Update this as the spec evolves. The fields are not defined by the header.
        //
        // The code below supports SDK 0.10 Vulkan spec, which contains the following table:
        //
        // Offset	 Size            Meaning
        // ------    ------------    ------------------------------------------------------------------
        //      0               4    a device ID equal to VkPhysicalDeviceProperties::DeviceId written
        //                           as a stream of bytes, with the least significant byte first
        //
        //      4    VK_UUID_SIZE    a pipeline cache ID equal to VkPhysicalDeviceProperties::pipelineCacheUUID
        //
        //
        // The code must be updated for latest Vulkan spec, which contains the following table:
        //
        // Offset	 Size            Meaning
        // ------    ------------    ------------------------------------------------------------------
        //      0               4    length in bytes of the entire pipeline cache header written as a
        //                           stream of bytes, with the least significant byte first
        //      4               4    a VkPipelineCacheHeaderVersion value written as a stream of bytes,
        //                           with the least significant byte first
        //      8               4    a vendor ID equal to VkPhysicalDeviceProperties::vendorID written
        //                           as a stream of bytes, with the least significant byte first
        //     12               4    a device ID equal to VkPhysicalDeviceProperties::deviceID written
        //                           as a stream of bytes, with the least significant byte first
        //     16    VK_UUID_SIZE    a pipeline cache ID equal to VkPhysicalDeviceProperties::pipelineCacheUUID
        //
        // clang-format on
        uint32_t headerLength = 0;
        uint32_t cacheHeaderVersion = 0;
        uint32_t vendorID = 0;
        uint32_t deviceID = 0;
        uint8_t pipelineCacheUUID[VK_UUID_SIZE] = {};

        memcpy(&headerLength, (uint8_t *)startCacheData + 0, 4);
        memcpy(&cacheHeaderVersion, (uint8_t *)startCacheData + 4, 4);
        memcpy(&vendorID, (uint8_t *)startCacheData + 8, 4);
        memcpy(&deviceID, (uint8_t *)startCacheData + 12, 4);
        memcpy(pipelineCacheUUID, (uint8_t *)startCacheData + 16, VK_UUID_SIZE);

        // Check each field and report bad values before freeing existing cache
        bool badCache = false;

        if (headerLength <= 0) {
            badCache = true;
            printf("  Bad header length in %s.\n", readFileName.c_str());
            printf("    Cache contains: 0x%.8x\n", headerLength);
        }

        if (cacheHeaderVersion != VK_PIPELINE_CACHE_HEADER_VERSION_ONE) {
            badCache = true;
            printf("  Unsupported cache header version in %s.\n", readFileName.c_str());
            printf("    Cache contains: 0x%.8x\n", cacheHeaderVersion);
        }

        if (vendorID != info.gpu_props.vendorID) {
            badCache = true;
            printf("  Vendor ID mismatch in %s.\n", readFileName.c_str());
            printf("    Cache contains: 0x%.8x\n", vendorID);
            printf("    Driver expects: 0x%.8x\n", info.gpu_props.vendorID);
        }

        if (deviceID != info.gpu_props.deviceID) {
            badCache = true;
            printf("  Device ID mismatch in %s.\n", readFileName.c_str());
            printf("    Cache contains: 0x%.8x\n", deviceID);
            printf("    Driver expects: 0x%.8x\n", info.gpu_props.deviceID);
        }

        if (memcmp(pipelineCacheUUID, info.gpu_props.pipelineCacheUUID,
                   sizeof(pipelineCacheUUID)) != 0) {
            badCache = true;
            printf("  UUID mismatch in %s.\n", readFileName.c_str());
            printf("    Cache contains: ");
            print_UUID(pipelineCacheUUID);
            printf("\n");
            printf("    Driver expects: ");
            print_UUID(info.gpu_props.pipelineCacheUUID);
            printf("\n");
        }

        if (badCache) {
            // Don't submit initial cache data if any version info is incorrect
            free(startCacheData);
            startCacheSize = 0;
            startCacheData = nullptr;

            // And clear out the old cache file for use in next run
            printf("  Deleting cache entry %s to repopulate.\n", readFileName.c_str());
            if (remove(readFileName.c_str()) != 0) {
                fputs("Reading error", stderr);
                exit(EXIT_FAILURE);
            }
        }
    }

    // Feed the initial cache data into pipeline creation
    VkPipelineCacheCreateInfo pipelineCache;
    pipelineCache.sType = VK_STRUCTURE_TYPE_PIPELINE_CACHE_CREATE_INFO;
    pipelineCache.pNext = NULL;
    pipelineCache.initialDataSize = startCacheSize;
    pipelineCache.pInitialData = startCacheData;
    pipelineCache.flags = 0;
    res = vkCreatePipelineCache(info.device, &pipelineCache, nullptr,
                                &info.pipelineCache);
    assert(res == VK_SUCCESS);

    // Free our initialData now that pipeline has been created
    free(startCacheData);

    // Time (roughly) taken to create the graphics pipeline
    timestamp_t start = get_milliseconds();
    init_pipeline(info, depthPresent);
    timestamp_t elapsed = get_milliseconds() - start;
    printf("  vkCreateGraphicsPipeline time: %0.f ms\n", (double)elapsed);

    // Begin standard draw stuff

    init_presentable_image(info);
    VkClearValue clear_values[2];
    init_clear_color_and_depth(info, clear_values);
    VkRenderPassBeginInfo rp_begin;
    init_render_pass_begin_info(info, rp_begin);
    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);
    execute_pre_present_barrier(info);
    res = vkEndCommandBuffer(info.cmd);
    assert(res == VK_SUCCESS);
    VkFence drawFence = {};
    init_fence(info, drawFence);
    VkPipelineStageFlags pipe_stage_flags =
        VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT;
    VkSubmitInfo submit_info = {};
    init_submit_info(info, submit_info, pipe_stage_flags);
    /* 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 = {};
    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.queue, &present);
    assert(res == VK_SUCCESS);
    wait_seconds(1);
    if (info.save_images)
        write_ppm(info, "pipeline_cache");

    // End standard draw stuff

    if (startCacheData) {
        // TODO: Create another pipeline, preferably different from the first
        // one and merge it here.  Then store the merged one.
    }

    // Store away the cache that we've populated.  This could conceivably happen
    // earlier, depends on when the pipeline cache stops being populated
    // internally.
    size_t endCacheSize = 0;
    void *endCacheData = nullptr;

    // Call with nullptr to get cache size
    res = vkGetPipelineCacheData(info.device, info.pipelineCache, &endCacheSize,
                           nullptr);
    assert(res == VK_SUCCESS);

    // Allocate memory to hold the populated cache data
    endCacheData = (char *)malloc(sizeof(char) * endCacheSize);
    if (!endCacheData) {
        fputs("Memory error", stderr);
        exit(EXIT_FAILURE);
    }

    // Call again with pointer to buffer
    res = vkGetPipelineCacheData(info.device, info.pipelineCache, &endCacheSize,
                           endCacheData);
    assert(res == VK_SUCCESS);

    // Write the file to disk, overwriting whatever was there
    FILE *pWriteFile;
    std::string writeFileName = directoryName + "pipeline_cache_data.bin";
    pWriteFile = fopen(writeFileName.c_str(), "wb");
    if (pWriteFile) {
        fwrite(endCacheData, sizeof(char), endCacheSize, pWriteFile);
        fclose(pWriteFile);
        printf("  cacheData written to %s\n", writeFileName.c_str());
    } else {
        // Something bad happened
        printf("  Unable to write cache data to disk!\n");
    }

    /* VULKAN_KEY_END */

    vkDestroyFence(info.device, drawFence, NULL);
    vkDestroySemaphore(info.device, info.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;
}
// clang-format on
int main(int argc, char *argv[]) {
    VkResult U_ASSERT_ONLY res;
    struct sample_info info = {};
    char sample_title[] = "SPIR-V Assembly";
    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);

    /* VULKAN_KEY_START */

    // Init the assembler context
    spv_context spvContext = spvContextCreate();

    // Convert the vertex assembly into binary format
    spv_binary vertexBinary = {};
    spv_diagnostic vertexDiag = {};
    spv_result_t vertexResult =
        spvTextToBinary(spvContext, vertexSPIRV.c_str(), vertexSPIRV.length(),
                        &vertexBinary, &vertexDiag);
    if (vertexDiag) {
        printf("Diagnostic info from vertex shader:\n");
        spvDiagnosticPrint(vertexDiag);
    }
    assert(vertexResult == SPV_SUCCESS);

    // Convert the fragment assembly into binary format
    spv_binary fragmentBinary = {};
    spv_diagnostic fragmentDiag = {};
    spv_result_t fragmentResult =
        spvTextToBinary(spvContext, fragmentSPIRV.c_str(),
                        fragmentSPIRV.length(), &fragmentBinary, &fragmentDiag);
    if (fragmentDiag) {
        printf("Diagnostic info from fragment shader:\n");
        spvDiagnosticPrint(fragmentDiag);
    }
    assert(fragmentResult == SPV_SUCCESS);

    info.shaderStages[0].sType =
        VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO;
    info.shaderStages[0].pNext = NULL;
    info.shaderStages[0].pSpecializationInfo = NULL;
    info.shaderStages[0].flags = 0;
    info.shaderStages[0].stage = VK_SHADER_STAGE_VERTEX_BIT;
    info.shaderStages[0].pName = "main";
    VkShaderModuleCreateInfo moduleCreateInfo;
    moduleCreateInfo.sType = VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO;
    moduleCreateInfo.pNext = NULL;
    moduleCreateInfo.flags = 0;
    // Use wordCount and code pointers from the spv_binary
    moduleCreateInfo.codeSize = vertexBinary->wordCount * sizeof(unsigned int);
    moduleCreateInfo.pCode = vertexBinary->code;
    res = vkCreateShaderModule(info.device, &moduleCreateInfo, NULL,
                               &info.shaderStages[0].module);
    assert(res == VK_SUCCESS);

    info.shaderStages[1].sType =
        VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO;
    info.shaderStages[1].pNext = NULL;
    info.shaderStages[1].pSpecializationInfo = NULL;
    info.shaderStages[1].flags = 0;
    info.shaderStages[1].stage = VK_SHADER_STAGE_FRAGMENT_BIT;
    info.shaderStages[1].pName = "main";
    moduleCreateInfo.sType = VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO;
    moduleCreateInfo.pNext = NULL;
    moduleCreateInfo.flags = 0;
    // Use wordCount and code pointers from the spv_binary
    moduleCreateInfo.codeSize =
        fragmentBinary->wordCount * sizeof(unsigned int);
    moduleCreateInfo.pCode = fragmentBinary->code;
    res = vkCreateShaderModule(info.device, &moduleCreateInfo, NULL,
                               &info.shaderStages[1].module);
    assert(res == VK_SUCCESS);

    // Clean up the diagnostics
    spvDiagnosticDestroy(vertexDiag);
    spvDiagnosticDestroy(fragmentDiag);

    // Clean up the assembler context
    spvContextDestroy(spvContext);

    /* VULKAN_KEY_END */

    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);
    init_presentable_image(info);

    VkClearValue clear_values[2];
    init_clear_color_and_depth(info, clear_values);

    VkRenderPassBeginInfo rp_begin;
    init_render_pass_begin_info(info, rp_begin);
    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);

    execute_pre_present_barrier(info);

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

    VkFence drawFence = {};
    init_fence(info, drawFence);
    VkPipelineStageFlags pipe_stage_flags =
        VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT;
    VkSubmitInfo submit_info = {};
    init_submit_info(info, submit_info, pipe_stage_flags);

    /* 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 = {};
    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.queue, &present);
    assert(res == VK_SUCCESS);

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

    vkDestroyFence(info.device, drawFence, NULL);
    vkDestroySemaphore(info.device, info.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 main(int argc, char *argv[]) {
    VkResult U_ASSERT_ONLY res;
    struct sample_info info = {};
    char sample_title[] = "Pipeline Derivative";
    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);

    /* VULKAN_KEY_START */

    //
    // Create two pipelines.
    //
    // First pipeline is the same as that generated by init_pipeline(),
    // but with VK_PIPELINE_CREATE_ALLOW_DERIVATIVES_BIT set.
    //
    // Second pipeline has a modified fragment shader and sets the
    // VK_PIPELINE_CREATE_DERIVATIVE_BIT flag.
    //

    bool include_depth = true;
    bool include_vi = true;
    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 = include_depth;
    rs.rasterizerDiscardEnable = VK_FALSE;
    rs.depthBiasEnable = VK_FALSE;
    rs.depthBiasConstantFactor = 0;
    rs.depthBiasClamp = 0;
    rs.depthBiasSlopeFactor = 0;
    rs.lineWidth = 0;

    VkPipelineColorBlendStateCreateInfo cb;
    cb.sType = VK_STRUCTURE_TYPE_PIPELINE_COLOR_BLEND_STATE_CREATE_INFO;
    cb.flags = 0;
    cb.pNext = NULL;
    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.flags = 0;
    vp.viewportCount = NUM_VIEWPORTS;
    dynamicStateEnables[dynamicState.dynamicStateCount++] =
        VK_DYNAMIC_STATE_VIEWPORT;
    vp.scissorCount = NUM_SCISSORS;
    dynamicStateEnables[dynamicState.dynamicStateCount++] =
        VK_DYNAMIC_STATE_SCISSOR;
    vp.pScissors = NULL;
    vp.pViewports = NULL;

    VkPipelineDepthStencilStateCreateInfo ds;
    ds.sType = VK_STRUCTURE_TYPE_PIPELINE_DEPTH_STENCIL_STATE_CREATE_INFO;
    ds.pNext = NULL;
    ds.flags = 0;
    ds.depthTestEnable = include_depth;
    ds.depthWriteEnable = include_depth;
    ds.depthCompareOp = VK_COMPARE_OP_LESS_OR_EQUAL;
    ds.depthBoundsTestEnable = VK_FALSE;
    ds.stencilTestEnable = VK_FALSE;
    ds.back.failOp = VK_STENCIL_OP_KEEP;
    ds.back.passOp = VK_STENCIL_OP_KEEP;
    ds.back.compareOp = VK_COMPARE_OP_ALWAYS;
    ds.back.compareMask = 0;
    ds.back.reference = 0;
    ds.back.depthFailOp = VK_STENCIL_OP_KEEP;
    ds.back.writeMask = 0;
    ds.minDepthBounds = 0;
    ds.maxDepthBounds = 0;
    ds.stencilTestEnable = VK_FALSE;
    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.alphaToCoverageEnable = VK_FALSE;
    ms.alphaToOneEnable = VK_FALSE;
    ms.minSampleShading = 0.0;

    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;

    // Specify that we will be creating a derivative of this pipeline.
    pipeline.flags = VK_PIPELINE_CREATE_ALLOW_DERIVATIVES_BIT;

    pipeline.pVertexInputState = include_vi ? &vi : NULL;
    pipeline.pInputAssemblyState = &ia;
    pipeline.pRasterizationState = &rs;
    pipeline.pColorBlendState = &cb;
    pipeline.pTessellationState = NULL;
    pipeline.pMultisampleState = &ms;
    pipeline.pDynamicState = &dynamicState;
    pipeline.pViewportState = &vp;
    pipeline.pDepthStencilState = &ds;
    pipeline.pStages = info.shaderStages;
    pipeline.stageCount = 2;
    pipeline.renderPass = info.render_pass;
    pipeline.subpass = 0;

    // Create the base pipeline without storing it in the info struct
    // NOTE:  If desired, we can add timing info around pipeline creation to
    //        demonstrate any perf benefits to derivation.
    VkPipeline basePipeline;
    res = vkCreateGraphicsPipelines(info.device, info.pipelineCache, 1,
                                    &pipeline, NULL, &basePipeline);
    assert(res == VK_SUCCESS);

    // Now create the derivative pipeline, using a different fragment shader
    // This shader will shade the cube faces with interpolated colors
    // NOTE:  If this step is too heavyweight to show any benefit of derivation,
    // then
    //        create a pipeline that differs in some other, simpler way.
    const char *fragShaderText2 = "#version 450\n"
                                  "layout (location = 0) in vec2 texcoord;\n"
                                  "layout (location = 0) out vec4 outColor;\n"
                                  "void main() {\n"
                                  "   outColor = vec4(texcoord.x, texcoord.y, "
                                  "1.0 - texcoord.x - texcoord.y, 1.0f);\n"
                                  "}\n";

    // Convert GLSL to SPIR-V
    init_glslang();
    std::vector<unsigned int> fragSpv;
    bool U_ASSERT_ONLY retVal =
        GLSLtoSPV(VK_SHADER_STAGE_FRAGMENT_BIT, fragShaderText2, fragSpv);
    assert(retVal);
    finalize_glslang();

    // Replace the module entry of info.shaderStages to change the fragment
    // shader
    vkDestroyShaderModule(info.device, info.shaderStages[1].module, NULL);
    VkShaderModuleCreateInfo moduleCreateInfo = {};
    moduleCreateInfo.sType = VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO;
    moduleCreateInfo.pNext = NULL;
    moduleCreateInfo.flags = 0;
    moduleCreateInfo.codeSize = fragSpv.size() * sizeof(unsigned int);
    moduleCreateInfo.pCode = fragSpv.data();
    res = vkCreateShaderModule(info.device, &moduleCreateInfo, NULL,
                               &info.shaderStages[1].module);
    assert(res == VK_SUCCESS);

    // Modify pipeline info to reflect derivation
    pipeline.flags = VK_PIPELINE_CREATE_DERIVATIVE_BIT;
    pipeline.basePipelineHandle = basePipeline;
    pipeline.basePipelineIndex = -1;

    // And create the derived pipeline, assigning to info.pipeline for use by
    // later helpers
    res = vkCreateGraphicsPipelines(info.device, info.pipelineCache, 1,
                                    &pipeline, NULL, &info.pipeline);
    assert(res == VK_SUCCESS);

    /* VULKAN_KEY_END */

    init_presentable_image(info);

    VkClearValue clear_values[2];
    init_clear_color_and_depth(info, clear_values);

    VkRenderPassBeginInfo rp_begin;
    init_render_pass_begin_info(info, rp_begin);
    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);

    execute_pre_present_barrier(info);

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

    VkFence drawFence = {};
    init_fence(info, drawFence);
    VkPipelineStageFlags pipe_stage_flags =
        VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT;
    VkSubmitInfo submit_info = {};
    init_submit_info(info, submit_info, pipe_stage_flags);

    /* 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 = {};
    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.queue, &present);
    assert(res == VK_SUCCESS);

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

    vkDestroyFence(info.device, drawFence, NULL);
    vkDestroySemaphore(info.device, info.presentCompleteSemaphore, NULL);
    vkDestroyPipeline(info.device, basePipeline, 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;
}