1 2[open,refpage='VkPresentTimesInfoGOOGLE',desc='The earliest time each image should be presented',type='structs'] 3-- 4 5When the `<<VK_GOOGLE_display_timing>>` extension is enabled, additional 6fields can: be specified that allow an application to specify the earliest 7time that an image should be displayed. 8This allows an application to avoid stutter that is caused by an image being 9displayed earlier than planned. 10Such stuttering can occur with both fixed and variable-refresh-rate 11displays, because stuttering occurs when the geometry is not correctly 12positioned for when the image is displayed. 13An application can: instruct the presentation engine that an image should 14not be displayed earlier than a specified time by including the 15sname:VkPresentTimesInfoGOOGLE structure in the pname:pNext chain of the 16sname:VkPresentInfoKHR structure. 17 18The sname:VkPresentTimesInfoGOOGLE structure is defined as: 19 20include::../../api/structs/VkPresentTimesInfoGOOGLE.txt[] 21 22 * pname:sType is the type of this structure. 23 * pname:pNext is `NULL` or a pointer to an extension-specific structure. 24 * pname:swapchainCount is the number of swapchains being presented to by 25 this command. 26 * pname:pTimes is `NULL` or a pointer to an array of 27 sname:VkPresentTimeGOOGLE elements with pname:swapchainCount entries. 28 If not `NULL`, each element of pname:pTimes contains the earliest time 29 to present the image corresponding to the entry in the 30 sname:VkPresentInfoKHR::pname:pImageIndices array. 31 32.Valid Usage 33**** 34 * [[VUID-VkPresentTimesInfoGOOGLE-swapchainCount-01247]] 35 pname:swapchainCount must: be the same value as 36 sname:VkPresentInfoKHR::pname:swapchainCount, where 37 sname:VkPresentInfoKHR is in the pname:pNext chain of this 38 sname:VkPresentTimesInfoGOOGLE structure. 39**** 40 41include::../../validity/structs/VkPresentTimesInfoGOOGLE.txt[] 42-- 43 44[open,refpage='VkPresentTimeGOOGLE',desc='The earliest time image should be presented',type='structs'] 45-- 46 47The sname:VkPresentTimeGOOGLE structure is defined as: 48 49include::../../api/structs/VkPresentTimeGOOGLE.txt[] 50 51 * pname:presentID is an application-provided identification value, that 52 can: be used with the results of 53 flink:vkGetPastPresentationTimingGOOGLE, in order to uniquely identify 54 this present. 55 In order to be useful to the application, it should: be unique within 56 some period of time that is meaningful to the application. 57 * pname:desiredPresentTime specifies that the image given should: not be 58 displayed to the user any earlier than this time. 59 pname:desiredPresentTime is a time in nanoseconds, relative to a 60 monotonically-increasing clock (e.g. `CLOCK_MONOTONIC` (see 61 clock_gettime(2)) on Android and Linux). 62 A value of zero specifies that the presentation engine may: display the 63 image at any time. 64 This is useful when the application desires to provide pname:presentID, 65 but doesn't need a specific pname:desiredPresentTime. 66 67-- 68