Class AMDShaderFragmentMask

  • public final class AMDShaderFragmentMask
    extends java.lang.Object
    This extension provides efficient read access to the fragment mask in compressed multisampled color surfaces. The fragment mask is a lookup table that associates color samples with color fragment values.

    From a shader, the fragment mask can be fetched with a call to fragmentMaskFetchAMD, which returns a single uint where each subsequent four bits specify the color fragment index corresponding to the color sample, starting from the least significant bit. For example, when eight color samples are used, the color fragment index for color sample 0 will be in bits 0-3 of the fragment mask, for color sample 7 the index will be in bits 28-31.

    The color fragment for a particular color sample may then be fetched with the corresponding fragment mask value using the fragmentFetchAMD shader function.


    This example shows a shader that queries the fragment mask from a multisampled compressed surface and uses it to query fragment values.

     #version 450 core
     #extension GL_AMD_shader_fragment_mask: enable
     layout(binding = 0) uniform sampler2DMS       s2DMS;
     layout(binding = 1) uniform isampler2DMSArray is2DMSArray;
     layout(binding = 2, input_attachment_index = 0) uniform usubpassInputMS usubpassMS;
     layout(location = 0) out vec4 fragColor;
     void main()
         vec4 fragOne = vec4(0.0);
         uint fragMask = fragmentMaskFetchAMD(s2DMS, ivec2(2, 3));
         uint fragIndex = (fragMask & 0xF0) >> 4;
         fragOne += fragmentFetchAMD(s2DMS, ivec2(2, 3), 1);
         fragMask = fragmentMaskFetchAMD(is2DMSArray, ivec3(2, 3, 1));
         fragIndex = (fragMask & 0xF0) >> 4;
         fragOne += fragmentFetchAMD(is2DMSArray, ivec3(2, 3, 1), fragIndex);
         fragMask = fragmentMaskFetchAMD(usubpassMS);
         fragIndex = (fragMask & 0xF0) >> 4;
         fragOne += fragmentFetchAMD(usubpassMS, fragIndex);
         fragColor = fragOne;
    Name String
    Extension Type
    Device extension
    Registered Extension Number
    Extension and Version Dependencies
    • Requires Vulkan 1.0
    Last Modified Date
    IP Status
    No known IP claims.
    • Aaron Hagan, AMD
    • Daniel Rakos, AMD
    • Timothy Lottes, AMD
    • Field Detail


        public static final int VK_AMD_SHADER_FRAGMENT_MASK_SPEC_VERSION
        The extension specification version.
        See Also:
        Constant Field Values

        public static final java.lang.String VK_AMD_SHADER_FRAGMENT_MASK_EXTENSION_NAME
        The extension name.
        See Also:
        Constant Field Values