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org.lwjgl.vulkan

public Class GOOGLEDisplayTiming

extends Object
Class Inheritance
Imports
javax.annotation.*, java.nio.*, org.lwjgl.system.*
This device extension allows an application that uses the VK_KHR_swapchain extension to obtain information about the presentation engine’s display, to obtain timing information about each present, and to schedule a present to happen no earlier than a desired time. An application can use this to minimize various visual anomalies (e.g. stuttering).

Traditional game and real-time animation applications need to correctly position their geometry for when the presentable image will be presented to the user. To accomplish this, applications need various timing information about the presentation engine’s display. They need to know when presentable images were actually presented, and when they could have been presented. Applications also need to tell the presentation engine to display an image no sooner than a given time. This allows the application to avoid stuttering, so the animation looks smooth to the user.

This extension treats variable-refresh-rate (VRR) displays as if they are fixed-refresh-rate (FRR) displays.

Examples
Note

The example code for the this extension (like the VK_KHR_surface and VK_GOOGLE_display_timing extensions) is contained in the cube demo that is shipped with the official Khronos SDK, and is being kept up-to-date in that location (see: https://github.com/KhronosGroup/Vulkan-Tools/blob/master/cube/cube.c ).

VK_GOOGLE_display_timing
Name String
VK_GOOGLE_display_timing
Extension Type
Device extension
Registered Extension Number
93
Revision
1
Extension and Version Dependencies
VK_KHR_swapchain
Contact
Other Extension Metadata
Last Modified Date
2017-02-14
IP Status
No known IP claims.
Contributors
  • Ian Elliott, Google
  • Jesse Hall, Google

Field Summary

Modifier and TypeField and Description
public static final String
VK_GOOGLE_DISPLAY_TIMING_EXTENSION_NAME

The extension name.

public static final int
VK_GOOGLE_DISPLAY_TIMING_SPEC_VERSION

The extension specification version.

public static final int
VK_STRUCTURE_TYPE_PRESENT_TIMES_INFO_GOOGLE

Extends VkStructureType.

Constructor Summary

AccessConstructor and Description
protected
GOOGLEDisplayTiming()

Method Summary

Modifier and TypeMethod and Description
public static int
nvkGetPastPresentationTimingGOOGLE(VkDevice device, long swapchain, long
a pointer to an integer related to the number of VkPastPresentationTimingGOOGLE structures to query, as described below.
pPresentationTimingCount, long pPresentationTimings)

Unsafe version of: GetPastPresentationTimingGOOGLE

public static int
nvkGetRefreshCycleDurationGOOGLE(VkDevice device, long swapchain, long pDisplayTimingProperties)

Unsafe version of: GetRefreshCycleDurationGOOGLE

public static int
vkGetPastPresentationTimingGOOGLE(VkDevice
the device associated with swapchain.
device, long
the swapchain to obtain presentation timing information duration for.
swapchain, IntBuffer
a pointer to an integer related to the number of VkPastPresentationTimingGOOGLE structures to query, as described below.
pPresentationTimingCount, VkPastPresentationTimingGOOGLE.Buffer
either NULL or a pointer to an array of VkPastPresentationTimingGOOGLE structures.
pPresentationTimings)

Obtain timing of a previously-presented image.

public static int
vkGetPastPresentationTimingGOOGLE(VkDevice device, long swapchain, int[] pPresentationTimingCount, VkPastPresentationTimingGOOGLE.Buffer pPresentationTimings)

Array version of: GetPastPresentationTimingGOOGLE

public static int
vkGetRefreshCycleDurationGOOGLE(VkDevice
the device associated with swapchain.
device, long
the swapchain to obtain the refresh duration for.
swapchain, VkRefreshCycleDurationGOOGLE
a pointer to a VkRefreshCycleDurationGOOGLE structure.
pDisplayTimingProperties)

Obtain the RC duration of the PE’s display.

Inherited from java.lang.Object:
cloneequalsfinalizegetClasshashCodenotifynotifyAlltoStringwaitwaitwait

Field Detail

VK_GOOGLE_DISPLAY_TIMING_EXTENSION_NAMEback to summary
public static final String VK_GOOGLE_DISPLAY_TIMING_EXTENSION_NAME

The extension name.

VK_GOOGLE_DISPLAY_TIMING_SPEC_VERSIONback to summary
public static final int VK_GOOGLE_DISPLAY_TIMING_SPEC_VERSION

The extension specification version.

VK_STRUCTURE_TYPE_PRESENT_TIMES_INFO_GOOGLEback to summary
public static final int VK_STRUCTURE_TYPE_PRESENT_TIMES_INFO_GOOGLE

Extends VkStructureType.

Constructor Detail

GOOGLEDisplayTimingback to summary
protected GOOGLEDisplayTiming()

Method Detail

nvkGetPastPresentationTimingGOOGLEback to summary
public static int nvkGetPastPresentationTimingGOOGLE(VkDevice device, long swapchain, long pPresentationTimingCount, long pPresentationTimings)

Unsafe version of: GetPastPresentationTimingGOOGLE

Parameters
pPresentationTimingCount:long

a pointer to an integer related to the number of VkPastPresentationTimingGOOGLE structures to query, as described below.

nvkGetRefreshCycleDurationGOOGLEback to summary
public static int nvkGetRefreshCycleDurationGOOGLE(VkDevice device, long swapchain, long pDisplayTimingProperties)

Unsafe version of: GetRefreshCycleDurationGOOGLE

vkGetPastPresentationTimingGOOGLEback to summary
public static int vkGetPastPresentationTimingGOOGLE(VkDevice device, long swapchain, IntBuffer pPresentationTimingCount, VkPastPresentationTimingGOOGLE.Buffer pPresentationTimings)

Obtain timing of a previously-presented image.

C Specification

The implementation will maintain a limited amount of history of timing information about previous presents. Because of the asynchronous nature of the presentation engine, the timing information for a given QueuePresentKHR command will become available some time later. These time values can be asynchronously queried, and will be returned if available. All time values are in nanoseconds, relative to a monotonically-increasing clock (e.g. CLOCK_MONOTONIC (see clock_gettime(2)) on Android and Linux).

To asynchronously query the presentation engine, for newly-available timing information about one or more previous presents to a given swapchain, call:


VkResult vkGetPastPresentationTimingGOOGLE(
    VkDevice                                    device,
    VkSwapchainKHR                              swapchain,
    uint32_t*                                   pPresentationTimingCount,
    VkPastPresentationTimingGOOGLE*             pPresentationTimings);
Description

If pPresentationTimings is NULL, then the number of newly-available timing records for the given swapchain is returned in pPresentationTimingCount. Otherwise, pPresentationTimingCount must point to a variable set by the user to the number of elements in the pPresentationTimings array, and on return the variable is overwritten with the number of structures actually written to pPresentationTimings. If the value of pPresentationTimingCount is less than the number of newly-available timing records, at most pPresentationTimingCount structures will be written, and INCOMPLETE will be returned instead of SUCCESS, to indicate that not all the available timing records were returned.

Valid Usage (Implicit)
  • device must be a valid VkDevice handle
  • swapchain must be a valid VkSwapchainKHR handle
  • pPresentationTimingCount must be a valid pointer to a uint32_t value
  • If the value referenced by pPresentationTimingCount is not 0, and pPresentationTimings is not NULL, pPresentationTimings must be a valid pointer to an array of pPresentationTimingCount VkPastPresentationTimingGOOGLE structures
  • swapchain must have been created, allocated, or retrieved from device
Host Synchronization
  • Host access to swapchain must be externally synchronized
Return Codes
On success, this command returns
On failure, this command returns
See Also

VkPastPresentationTimingGOOGLE

Parameters
device:VkDevice

the device associated with swapchain.

swapchain:long

the swapchain to obtain presentation timing information duration for.

pPresentationTimingCount:IntBuffer

a pointer to an integer related to the number of VkPastPresentationTimingGOOGLE structures to query, as described below.

pPresentationTimings:VkPastPresentationTimingGOOGLE.Buffer

either NULL or a pointer to an array of VkPastPresentationTimingGOOGLE structures.

Annotations
@NativeType:VkResult
vkGetPastPresentationTimingGOOGLEback to summary
public static int vkGetPastPresentationTimingGOOGLE(VkDevice device, long swapchain, int[] pPresentationTimingCount, VkPastPresentationTimingGOOGLE.Buffer pPresentationTimings)

Array version of: GetPastPresentationTimingGOOGLE

Annotations
@NativeType:VkResult
vkGetRefreshCycleDurationGOOGLEback to summary
public static int vkGetRefreshCycleDurationGOOGLE(VkDevice device, long swapchain, VkRefreshCycleDurationGOOGLE pDisplayTimingProperties)

Obtain the RC duration of the PE’s display.

C Specification

To query the duration of a refresh cycle (RC) for the presentation engine’s display, call:


VkResult vkGetRefreshCycleDurationGOOGLE(
    VkDevice                                    device,
    VkSwapchainKHR                              swapchain,
    VkRefreshCycleDurationGOOGLE*               pDisplayTimingProperties);
Valid Usage (Implicit)
  • device must be a valid VkDevice handle
  • swapchain must be a valid VkSwapchainKHR handle
  • pDisplayTimingProperties must be a valid pointer to a VkRefreshCycleDurationGOOGLE structure
  • swapchain must have been created, allocated, or retrieved from device
Host Synchronization
  • Host access to swapchain must be externally synchronized
Return Codes
On success, this command returns
On failure, this command returns
See Also

VkRefreshCycleDurationGOOGLE

Parameters
device:VkDevice

the device associated with swapchain.

swapchain:long

the swapchain to obtain the refresh duration for.

pDisplayTimingProperties:VkRefreshCycleDurationGOOGLE

a pointer to a VkRefreshCycleDurationGOOGLE structure.

Annotations
@NativeType:VkResult