VkSwapchainPresentScalingCreateInfoEXT

When an application presents a swapchain image with dimensions different than those of the target surface, different behavior is possible on different platforms per their respective specifications:

• Presentation fails and VK_ERROR_OUT_OF_DATE_KHR is returned
• Scaling is done and VK_SUCCESS or VK_SUBOPTIMAL_KHR is returned
• Unspecified scaling using an arbitrary combination of stretching, centering and/or clipping.

Applications can define specific behavior when creating a swapchain by including the VkSwapchainPresentScalingCreateInfoEXT structure in the pNext chain of the VkSwapchainCreateInfoKHR structure.

The VkSwapchainPresentScalingCreateInfoEXT structure is defined as:

typedef struct VkSwapchainPresentScalingCreateInfoEXT {
    VkStructureType sType;
    const void* pNext;
    VkPresentScalingFlagsEXT scalingBehavior;
    VkPresentGravityFlagsEXT presentGravityX;
    VkPresentGravityFlagsEXT presentGravityY;
} VkSwapchainPresentScalingCreateInfoEXT;

• sType is a VkStructureType value identifying this structure.
• pNext is NULL or a pointer to a structure extending this structure.
• scalingBehavior is 0 or the scaling method to use when the dimensions of the surface and swapchain images differ.
• presentGravityX is 0 or the x-axis direction in which swapchain image pixels gravitate relative to the surface when scalingBehavior does not result in a one-to-one pixel mapping between the scaled swapchain image and the surface.
• presentGravityY is 0 or the y-axis direction in which swapchain image pixels gravitate relative to the surface when scalingBehavior does not result in a one-to-one pixel mapping between the scaled swapchain image and the surface.

If scalingBehavior is 0, the result of presenting a swapchain image with dimensions that do not match the surface dimensions is implementation and platform-dependent. If presentGravityX or presentGravityY are 0, the presentation gravity must match that defined by the native platform surface on platforms which define surface gravity.