Class AMDShaderFragmentMask

java.lang.Object
org.lwjgl.vulkan.AMDShaderFragmentMask

public final class AMDShaderFragmentMask extends 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.

Examples

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;
 }
VK_AMD_shader_fragment_mask
Name String
VK_AMD_shader_fragment_mask
Extension Type
Device extension
Registered Extension Number
138
Revision
1
Contact
Other Extension Metadata
Last Modified Date
2017-08-16
IP Status
No known IP claims.
Interactions and External Dependencies
Contributors
  • Aaron Hagan, AMD
  • Daniel Rakos, AMD
  • Timothy Lottes, AMD
  • Field Details

    • VK_AMD_SHADER_FRAGMENT_MASK_SPEC_VERSION

      public static final int VK_AMD_SHADER_FRAGMENT_MASK_SPEC_VERSION
      The extension specification version.
      See Also:
    • VK_AMD_SHADER_FRAGMENT_MASK_EXTENSION_NAME

      public static final String VK_AMD_SHADER_FRAGMENT_MASK_EXTENSION_NAME
      The extension name.
      See Also: