VkPresentModeKHR
Possible values of elements of the
vkGetPhysicalDeviceSurfacePresentModesKHR::pPresentModes
array,
indicating the supported presentation modes for a surface, are:
typedef enum VkPresentModeKHR {
VK_PRESENT_MODE_IMMEDIATE_KHR = 0,
VK_PRESENT_MODE_MAILBOX_KHR = 1,
VK_PRESENT_MODE_FIFO_KHR = 2,
VK_PRESENT_MODE_FIFO_RELAXED_KHR = 3,
} VkPresentModeKHR;
VK_PRESENT_MODE_IMMEDIATE_KHR
specifies that the presentation engine does not wait for a vertical blanking period to update the current image, meaning this mode may result in visible tearing. No internal queuing of presentation requests is needed, as the requests are applied immediately.VK_PRESENT_MODE_MAILBOX_KHR
specifies that the presentation engine waits for the next vertical blanking period to update the current image. Tearing cannot be observed. An internal single-entry queue is used to hold pending presentation requests. If the queue is full when a new presentation request is received, the new request replaces the existing entry, and any images associated with the prior entry become available for reuse by the application. One request is removed from the queue and processed during each vertical blanking period in which the queue is non-empty.VK_PRESENT_MODE_FIFO_KHR
specifies that the presentation engine waits for the next vertical blanking period to update the current image. Tearing cannot be observed. An internal queue is used to hold pending presentation requests. New requests are appended to the end of the queue, and one request is removed from the beginning of the queue and processed during each vertical blanking period in which the queue is non-empty. This is the only value ofpresentMode
that is required to be supported.VK_PRESENT_MODE_FIFO_RELAXED_KHR
specifies that the presentation engine generally waits for the next vertical blanking period to update the current image. If a vertical blanking period has already passed since the last update of the current image then the presentation engine does not wait for another vertical blanking period for the update, meaning this mode may result in visible tearing in this case. This mode is useful for reducing visual stutter with an application that will mostly present a new image before the next vertical blanking period, but may occasionally be late, and present a new image just after the next vertical blanking period. An internal queue is used to hold pending presentation requests. New requests are appended to the end of the queue, and one request is removed from the beginning of the queue and processed during or after each vertical blanking period in which the queue is non-empty.VK_PRESENT_MODE_FIFO_LATEST_READY_EXT
specifies that the presentation engine waits for the next vertical blanking period to update the current image. Tearing cannot be observed. An internal queue is used to hold pending presentation requests. New requests are appended to the end of the queue. At each vertical blanking period, the presentation engine dequeues all successive requests that are ready to be presented from the beginning of the queue. If using VK_GOOGLE_display_timing to provide a target present time, the presentation engine will check the specified time for each image. If the target present time is less-than or equal-to the current time, the presentation engine will dequeue the image and check the next one. The image of the last dequeued request will be presented. The other dequeued requests will be dropped.VK_PRESENT_MODE_SHARED_DEMAND_REFRESH_KHR
specifies that the presentation engine and application have concurrent access to a single image, which is referred to as a shared presentable image. The presentation engine is only required to update the current image after a new presentation request is received. Therefore the application must make a presentation request whenever an update is required. However, the presentation engine may update the current image at any point, meaning this mode may result in visible tearing.VK_PRESENT_MODE_SHARED_CONTINUOUS_REFRESH_KHR
specifies that the presentation engine and application have concurrent access to a single image, which is referred to as a shared presentable image. The presentation engine periodically updates the current image on its regular refresh cycle. The application is only required to make one initial presentation request, after which the presentation engine must update the current image without any need for further presentation requests. The application can indicate the image contents have been updated by making a presentation request, but this does not guarantee the timing of when it will be updated. This mode may result in visible tearing if rendering to the image is not timed correctly.
The supported VkImageUsageFlagBits of the presentable images of a swapchain created for a surface may differ depending on the presentation mode, and can be determined as per the table below:
Presentation mode | Image usage flags |
---|---|
VkSurfaceCapabilitiesKHR:: | |
VkSurfaceCapabilitiesKHR:: | |
VkSurfaceCapabilitiesKHR:: | |
VkSurfaceCapabilitiesKHR:: | |
VkSurfaceCapabilitiesKHR:: | |
VkSharedPresentSurfaceCapabilitiesKHR:: | |
VkSharedPresentSurfaceCapabilitiesKHR:: |
For reference, the mode indicated by VK_PRESENT_MODE_FIFO_KHR
is
equivalent to the behavior of {wgl|glX|egl}SwapBuffers with a swap interval
of 1, while the mode indicated by VK_PRESENT_MODE_FIFO_RELAXED_KHR
is
equivalent to the behavior of {wgl|glX}SwapBuffers with a swap interval of
-1 (from the {WGL|GLX}_EXT_swap_control_tear extensions).