## C Specification

Possible values of VkDisplaySurfaceCreateInfoKHR::alphaMode, specifying the type of alpha blending to use on a display, are:

// Provided by VK_KHR_display
typedef enum VkDisplayPlaneAlphaFlagBitsKHR {
VK_DISPLAY_PLANE_ALPHA_OPAQUE_BIT_KHR = 0x00000001,
VK_DISPLAY_PLANE_ALPHA_GLOBAL_BIT_KHR = 0x00000002,
VK_DISPLAY_PLANE_ALPHA_PER_PIXEL_BIT_KHR = 0x00000004,
VK_DISPLAY_PLANE_ALPHA_PER_PIXEL_PREMULTIPLIED_BIT_KHR = 0x00000008,
} VkDisplayPlaneAlphaFlagBitsKHR;

## Description

• VK_DISPLAY_PLANE_ALPHA_OPAQUE_BIT_KHR specifies that the source image will be treated as opaque.

• VK_DISPLAY_PLANE_ALPHA_GLOBAL_BIT_KHR specifies that a global alpha value must be specified that will be applied to all pixels in the source image.

• VK_DISPLAY_PLANE_ALPHA_PER_PIXEL_BIT_KHR specifies that the alpha value will be determined by the alpha channel of the source image’s pixels. If the source format contains no alpha values, no blending will be applied. The source alpha values are not premultiplied into the source image’s other color channels.

• VK_DISPLAY_PLANE_ALPHA_PER_PIXEL_PREMULTIPLIED_BIT_KHR is equivalent to VK_DISPLAY_PLANE_ALPHA_PER_PIXEL_BIT_KHR, except the source alpha values are assumed to be premultiplied into the source image’s other color channels.