VkColorSpaceKHR - Supported color space of the presentation engine

Description

In the initial release of the VK_KHR_surface and VK_KHR_swapchain extensions, the token COLORSPACE_SRGB_NONLINEAR_KHR was used. Starting in the 2016-05-13 updates to the extension branches, matching release 1.0.13 of the core API specification, COLOR_SPACE_SRGB_NONLINEAR_KHR is used instead for consistency with Vulkan naming rules. The older enum is still available for backwards compatibility.

In older versions of this extension COLOR_SPACE_DISPLAY_P3_LINEAR_EXT was misnamed COLOR_SPACE_DCI_P3_LINEAR_EXT. This has been updated to indicate that it uses RGB color encoding, not XYZ. The old name is deprecated but is maintained for backwards compatibility.

In older versions of the VK_EXT_swapchain_colorspace extension, COLOR_SPACE_DOLBYVISION_EXT was exposed. The intent was to indicate the presentation engine shall decode an image using the SMPTE ST 2084 Perceptual Quantizer (PQ) EOTF, and then apply a proprietary OOTF to process the image. However, Dolby Vision profile 8.4 describes an encoding using the Hybrid Log Gamma (HLG) OETF, and there is no swapchain extension for signaling Dolby Vision metadata to be used by a proprietary OOTF. This enum is deprecated but is maintained for backwards compatibility.

Note

For a traditional “Linear” or non-gamma transfer function color space use COLOR_SPACE_PASS_THROUGH_EXT.

The presentation engine interprets the pixel values of the R, G, and B components as having been encoded using an appropriate transfer function. Applications should ensure that the appropriate transfer function has been applied. Textures Output Format Conversion requires that all implementations implicitly apply the sRGB EOTF-1 on R, G, and B components when shaders write to an sRGB pixel format image, which is useful for sRGB color spaces. For sRGB color spaces with other pixel formats, or other non-linear color spaces, applications can apply the transfer function explicitly in a shader. The A channel is always interpreted as linearly encoded.

This extension defines enums for ColorSpaceKHR that correspond to the following color spaces:

Color Spaces and Attributes

The transfer functions are described in the “Transfer Functions” chapter of the Khronos Data Format Specification.

Except Display-P3 OETF, which is:

[begin{aligned} E & = begin{cases} 1.055 times L^{1 over 2.4} - 0.055 & text{for} 0.0030186 leq L leq 1 -- 12.92 times L & text{for} 0 leq L < 0.0030186