VkSwapchainCreateInfoKHR

The VkSwapchainCreateInfoKHR structure is defined as:

typedef struct VkSwapchainCreateInfoKHR {
    VkStructureType sType;
    const void* pNext;
    VkSwapchainCreateFlagsKHR flags;
    VkSurfaceKHR surface;
    uint32_t minImageCount;
    VkFormat imageFormat;
    VkColorSpaceKHR imageColorSpace;
    VkExtent2D imageExtent;
    uint32_t imageArrayLayers;
    VkImageUsageFlags imageUsage;
    VkSharingMode imageSharingMode;
    uint32_t queueFamilyIndexCount;
    const uint32_t* pQueueFamilyIndices;
    VkSurfaceTransformFlagBitsKHR preTransform;
    VkCompositeAlphaFlagBitsKHR compositeAlpha;
    VkPresentModeKHR presentMode;
    VkBool32 clipped;
    VkSwapchainKHR oldSwapchain;
} VkSwapchainCreateInfoKHR;

• sType is a VkStructureType value identifying this structure.
• pNext is NULL or a pointer to a structure extending this structure.
• flags is a bitmask of VkSwapchainCreateFlagBitsKHR indicating parameters of the swapchain creation.
• surface is the surface onto which the swapchain will present images. If the creation succeeds, the swapchain becomes associated with surface.
• minImageCount is the minimum number of presentable images that the application needs. The implementation will either create the swapchain with at least that many images, or it will fail to create the swapchain.
• imageFormat is a VkFormat value specifying the format the swapchain image(s) will be created with.
• imageColorSpace is a VkColorSpaceKHR value specifying the way the swapchain interprets image data.
• imageExtent is the size (in pixels) of the swapchain image(s). The behavior is platform-dependent if the image extent does not match the surface’s currentExtent as returned by vkGetPhysicalDeviceSurfaceCapabilitiesKHR.

  On some platforms, it is normal that maxImageExtent may become (0, 0), for example when the window is minimized. In such a case, it is not possible to create a swapchain due to the Valid Usage requirements , unless scaling is selected through VkSwapchainPresentScalingCreateInfoEXT, if supported .

• imageArrayLayers is the number of views in a multiview/stereo surface. For non-stereoscopic-3D applications, this value is 1.
• imageUsage is a bitmask of VkImageUsageFlagBits describing the intended usage of the (acquired) swapchain images.
• imageSharingMode is the sharing mode used for the image(s) of the swapchain.
• queueFamilyIndexCount is the number of queue families having access to the image(s) of the swapchain when imageSharingMode is VK_SHARING_MODE_CONCURRENT.
• pQueueFamilyIndices is a pointer to an array of queue family indices having access to the images(s) of the swapchain when imageSharingMode is VK_SHARING_MODE_CONCURRENT.
• preTransform is a VkSurfaceTransformFlagBitsKHR value describing the transform, relative to the presentation engine’s natural orientation, applied to the image content prior to presentation. If it does not match the currentTransform value returned by vkGetPhysicalDeviceSurfaceCapabilitiesKHR, the presentation engine will transform the image content as part of the presentation operation.
• compositeAlpha is a VkCompositeAlphaFlagBitsKHR value indicating the alpha compositing mode to use when this surface is composited together with other surfaces on certain window systems.
• presentMode is the presentation mode the swapchain will use. A swapchain’s present mode determines how incoming present requests will be processed and queued internally.
• clipped specifies whether the Vulkan implementation is allowed to discard rendering operations that affect regions of the surface that are not visible.
  • If set to VK_TRUE, the presentable images associated with the swapchain may not own all of their pixels. Pixels in the presentable images that correspond to regions of the target surface obscured by another window on the desktop, or subject to some other clipping mechanism will have undefined: content when read back. Fragment shaders may not execute for these pixels, and thus any side effects they would have had will not occur. Setting VK_TRUE does not guarantee any clipping will occur, but allows more efficient presentation methods to be used on some platforms.
  • If set to VK_FALSE, presentable images associated with the swapchain will own all of the pixels they contain.

    Applications should set this value to VK_TRUE if they do not expect to read back the content of presentable images before presenting them or after reacquiring them, and if their fragment shaders do not have any side effects that require them to run for all pixels in the presentable image.

• oldSwapchain is VK_NULL_HANDLE, or the existing non-retired swapchain currently associated with surface. Providing a valid oldSwapchain may aid in the resource reuse, and also allows the application to still present any images that are already acquired from it.

Upon calling vkCreateSwapchainKHR with an oldSwapchain that is not VK_NULL_HANDLE, oldSwapchain is retired — even if creation of the new swapchain fails. The new swapchain is created in the non-retired state whether or not oldSwapchain is VK_NULL_HANDLE.

Upon calling vkCreateSwapchainKHR with an oldSwapchain that is not VK_NULL_HANDLE, any images from oldSwapchain that are not acquired by the application may be freed by the implementation, which may occur even if creation of the new swapchain fails. The application can destroy oldSwapchain to free all memory associated with oldSwapchain.