org.lwjgl.vulkan

Class AMDShaderFragmentMask

java.lang.Object

org.lwjgl.vulkan.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.

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;
 }

Name String

VK_AMD_shader_fragment_mask

Extension Type

Device extension

Registered Extension Number

138

Revision

1

Extension and Version Dependencies

• Requires Vulkan 1.0

Contact

• Aaron Hagan AaronHaganAMD

Last Modified Date

2017-08-16

IP Status

No known IP claims.

Dependencies

• Requires the SPV_AMD_shader_fragment_mask SPIR-V extension.

Contributors

• Aaron Hagan, AMD
• Daniel Rakos, AMD
• Timothy Lottes, AMD

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	VK_AMD_SHADER_FRAGMENT_MASK_EXTENSION_NAME The extension name.
static int	VK_AMD_SHADER_FRAGMENT_MASK_SPEC_VERSION The extension specification version.

Method Summary

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

VK_AMD_SHADER_FRAGMENT_MASK_SPEC_VERSION

public static final int VK_AMD_SHADER_FRAGMENT_MASK_SPEC_VERSION

The extension specification version.

See Also:

Constant Field Values

VK_AMD_SHADER_FRAGMENT_MASK_EXTENSION_NAME

public static final java.lang.String VK_AMD_SHADER_FRAGMENT_MASK_EXTENSION_NAME

The extension name.

See Also:

Constant Field Values