Description

FragCoord

Decorating a variable with the FragCoord built-in decoration will make that variable contain the framebuffer coordinate of the fragment being processed. The (x,y) coordinate (0,0) is the upper left corner of the upper left pixel in the framebuffer.

When Sample Shading is enabled, the x and y components of FragCoord reflect the location of one of the samples corresponding to the shader invocation.

Otherwise, the x and y components of FragCoord reflect the location of the center of the fragment.

The z component of FragCoord is the interpolated depth value of the primitive.

The w component is the interpolated .

The Centroid interpolation decoration is ignored, but allowed, on FragCoord.

Valid Usage

  • VUID-FragCoord-FragCoord-04210
    The FragCoord decoration must be used only within the Fragment Execution Model

  • VUID-FragCoord-FragCoord-04211
    The variable decorated with FragCoord must be declared using the Input Storage Class

  • VUID-FragCoord-FragCoord-04212
    The variable decorated with FragCoord must be declared as a four-component vector of 32-bit floating-point values

See Also

No cross-references are available

Document Notes

For more information, see the Vulkan Specification

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

Copyright

Copyright 2014-2023 The Khronos Group Inc.

SPDX-License-Identifier: CC-BY-4.0