Method init_swapchain

samples/api/hello_triangle/hello_triangle.cpp:462–595

* @brief Initializes the Vulkan swapchain. */

 * @brief Initializes the Vulkan swapchain.
 */
void HelloTriangle::init_swapchain()
{
	VkSurfaceCapabilitiesKHR surface_properties;
	VK_CHECK(vkGetPhysicalDeviceSurfaceCapabilitiesKHR(context.gpu, context.surface, &surface_properties));

	VkSurfaceFormatKHR format = vkb::select_surface_format(context.gpu, context.surface);

	VkExtent2D swapchain_size{};
	if (surface_properties.currentExtent.width == 0xFFFFFFFF)
	{
		swapchain_size.width  = context.swapchain_dimensions.width;
		swapchain_size.height = context.swapchain_dimensions.height;
	}
	else
	{
		swapchain_size = surface_properties.currentExtent;
	}

	// FIFO must be supported by all implementations.
	VkPresentModeKHR swapchain_present_mode = VK_PRESENT_MODE_FIFO_KHR;

	// Determine the number of VkImage's to use in the swapchain.
	// Ideally, we desire to own 1 image at a time, the rest of the images can
	// either be rendered to and/or being queued up for display.
	uint32_t desired_swapchain_images = surface_properties.minImageCount + 1;
	if ((surface_properties.maxImageCount > 0) && (desired_swapchain_images > surface_properties.maxImageCount))
	{
		// Application must settle for fewer images than desired.
		desired_swapchain_images = surface_properties.maxImageCount;
	}

	// Figure out a suitable surface transform.
	VkSurfaceTransformFlagBitsKHR pre_transform;
	if (surface_properties.supportedTransforms & VK_SURFACE_TRANSFORM_IDENTITY_BIT_KHR)
	{
		pre_transform = VK_SURFACE_TRANSFORM_IDENTITY_BIT_KHR;
	}
	else
	{
		pre_transform = surface_properties.currentTransform;
	}

	VkSwapchainKHR old_swapchain = context.swapchain;

	// Find a supported composite type.
	VkCompositeAlphaFlagBitsKHR composite = VK_COMPOSITE_ALPHA_OPAQUE_BIT_KHR;
	if (surface_properties.supportedCompositeAlpha & VK_COMPOSITE_ALPHA_OPAQUE_BIT_KHR)
	{
		composite = VK_COMPOSITE_ALPHA_OPAQUE_BIT_KHR;
	}
	else if (surface_properties.supportedCompositeAlpha & VK_COMPOSITE_ALPHA_INHERIT_BIT_KHR)
	{
		composite = VK_COMPOSITE_ALPHA_INHERIT_BIT_KHR;
	}
	else if (surface_properties.supportedCompositeAlpha & VK_COMPOSITE_ALPHA_PRE_MULTIPLIED_BIT_KHR)
	{
		composite = VK_COMPOSITE_ALPHA_PRE_MULTIPLIED_BIT_KHR;
	}