## C Specification

If the pNext chain of VkPresentInfoKHR includes a VkDeviceGroupPresentInfoKHR structure, then that structure includes an array of device masks and a device group present mode.

The VkDeviceGroupPresentInfoKHR structure is defined as:

typedef struct VkDeviceGroupPresentInfoKHR {
VkStructureType                        sType;
const void*                            pNext;
uint32_t                               swapchainCount;
const uint32_t*                        pDeviceMasks;
VkDeviceGroupPresentModeFlagBitsKHR    mode;
} VkDeviceGroupPresentInfoKHR;

## Members

• sType is the type of this structure.

• pNext is NULL or a pointer to an extension-specific structure.

• swapchainCount is zero or the number of elements in pDeviceMasks.

• pDeviceMasks is an array of device masks, one for each element of VkPresentInfoKHR::pSwapchains.

• mode is the device group present mode that will be used for this present.

## Description

If mode is VK_DEVICE_GROUP_PRESENT_MODE_LOCAL_BIT_KHR, then each element of pDeviceMasks selects which instance of the swapchain image is presented. Each element of pDeviceMasks must have exactly one bit set, and the corresponding physical device must have a presentation engine as reported by VkDeviceGroupPresentCapabilitiesKHR.

If mode is VK_DEVICE_GROUP_PRESENT_MODE_REMOTE_BIT_KHR, then each element of pDeviceMasks selects which instance of the swapchain image is presented. Each element of pDeviceMasks must have exactly one bit set, and some physical device in the logical device must include that bit in its VkDeviceGroupPresentCapabilitiesKHR::presentMask.

If mode is VK_DEVICE_GROUP_PRESENT_MODE_SUM_BIT_KHR, then each element of pDeviceMasks selects which instances of the swapchain image are component-wise summed and the sum of those images is presented. If the sum in any component is outside the representable range, the value of that component is undefined. Each element of pDeviceMasks must have a value for which all set bits are set in one of the elements of VkDeviceGroupPresentCapabilitiesKHR::presentMask.

If mode is VK_DEVICE_GROUP_PRESENT_MODE_LOCAL_MULTI_DEVICE_BIT_KHR, then each element of pDeviceMasks selects which instance(s) of the swapchain images are presented. For each bit set in each element of pDeviceMasks, the corresponding physical device must have a presentation engine as reported by VkDeviceGroupPresentCapabilitiesKHR.

If VkDeviceGroupPresentInfoKHR is not provided or swapchainCount is zero then the masks are considered to be 1. If VkDeviceGroupPresentInfoKHR is not provided, mode is considered to be VK_DEVICE_GROUP_PRESENT_MODE_LOCAL_BIT_KHR.

Valid Usage
• swapchainCount must equal 0 or VkPresentInfoKHR::swapchainCount

• If mode is VK_DEVICE_GROUP_PRESENT_MODE_LOCAL_BIT_KHR, then each element of pDeviceMasks must have exactly one bit set, and the corresponding element of VkDeviceGroupPresentCapabilitiesKHR::presentMask must be non-zero

• If mode is VK_DEVICE_GROUP_PRESENT_MODE_REMOTE_BIT_KHR, then each element of pDeviceMasks must have exactly one bit set, and some physical device in the logical device must include that bit in its VkDeviceGroupPresentCapabilitiesKHR::presentMask.

• If mode is VK_DEVICE_GROUP_PRESENT_MODE_SUM_BIT_KHR, then each element of pDeviceMasks must have a value for which all set bits are set in one of the elements of VkDeviceGroupPresentCapabilitiesKHR::presentMask

• If mode is VK_DEVICE_GROUP_PRESENT_MODE_LOCAL_MULTI_DEVICE_BIT_KHR, then for each bit set in each element of pDeviceMasks, the corresponding element of VkDeviceGroupPresentCapabilitiesKHR::presentMask must be non-zero

• The value of each element of pDeviceMasks must be equal to the device mask passed in VkAcquireNextImageInfoKHR::deviceMask when the image index was last acquired

• mode must have exactly one bit set, and that bit must have been included in VkDeviceGroupSwapchainCreateInfoKHR::modes

Valid Usage (Implicit)
• sType must be VK_STRUCTURE_TYPE_DEVICE_GROUP_PRESENT_INFO_KHR

• If swapchainCount is not 0, pDeviceMasks must be a valid pointer to an array of swapchainCount uint32_t values

• mode must be a valid VkDeviceGroupPresentModeFlagBitsKHR value

## Document Notes

For more information, see the Vulkan Specification at URL

This page is extracted from the Vulkan Specification. Fixes and changes should be made to the Specification, not directly.

Copyright (c) 2014-2019 Khronos Group. This work is licensed under a Creative Commons Attribution 4.0 International License.