Vulkan-Docs/appendices/VK_AMD_shader_fragment_mask.txt
Jon Leech f1a7c4b4f3 Change log for January 13, 2019 Vulkan 1.1.98 spec update:
* Update release number to 98.

Public Issues:

  * Fix missing markup in flink:vkDestroyPipelineLayout valid usage
    statement (pull request 882).
  * Add missing contributors for `<<VK_EXT_buffer_device_address>>` (public
    pull request 891).

Internal Issues:

  * Detect nested bullet points in valid usage blocks and warn about them
    during VUID assignment (internal issue 1382).
  * Update the style guide to document the process for reserving new bits in
    bitmask types (internal issue 1411).
  * Clarify for slink:VkApplicationInfo::pname:apiVersion and in the
    <<fundamentals-validusage-versions, Valid Usage for Newer Core
    Versions>> section when it is valid for an application to use a certain
    version of Vulkan API functionality (for an instance and for a
    device/physical device); and when the validation layers must generate an
    error (internal issue 1412).
  * Add optional <<memory-model-availability-visibility, transitive
    availability/visibility operations to the memory model, including a new
    pname:vulkanMemoryModelAvailabilityVisibilityChains feature for
    slink:VkPhysicalDeviceVulkanMemoryModelFeaturesKHR (internal issue
    1460).
  * Add the code:StorageBuffer storage class to those in the
    <<interfaces-resources-descset, Descriptor Set Interface>> (internal
    issue 1480).
  * Add missing `returnedonly` tags for a number of returned extension
    structures that can be passed in pname:pNext chains (internal issue
    1515).
  * Clean up and rearrange some spec language for
    slink:VkRenderPassCreateInfo and slink:VkAttachmentReference.txt
    (internal issue 1522).
  * Correctly round the code:OpVectorTimesScalar and
    code:OpMatrixTimesScalar SPIR-V operations in the <<Precision of core
    SPIR-V Instructions>> table (internal merge request 2996).
  * Work around cases in flink:vkCmdBeginTransformFeedbackEXT,
    flink:vkCmdEndTransformFeedbackEXT, and
    slink:VkPipelineCoverageModulationStateCreateInfoNV where an array
    parameter is `optional` but the length is not in `vk.xml`. This is an
    interim fix using `noautovalidity` + handcoded VU replacing those that
    should be autogenerated (internal issue 2944 and
    https://github.com/KhronosGroup/Vulkan-ValidationLayers/issues/480).
  * Remove redundant capability validation of the code:float16 and code:int8
    SPIR-V capabilities from the <<spirvenv-capabilities, Capabilities>>
    section, since they are already covered in the preceding table.
  * Update check_spec_links script, including validation for reference page
    open blocks. Fix errors identified by the script.
2019-01-13 05:53:27 -08:00

99 lines
2.6 KiB
Plaintext

include::meta/VK_AMD_shader_fragment_mask.txt[]
*Last Modified Date*::
2017-08-16
*IP Status*::
No known IP claims.
*Dependencies*::
- Requires the
https://www.khronos.org/registry/spir-v/extensions/AMD/SPV_AMD_shader_fragment_mask.html[`SPV_AMD_shader_fragment_mask`]
SPIR-V extension.
*Contributors*::
- Aaron Hagan, AMD
- Daniel Rakos, AMD
- Timothy Lottes, AMD
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
code:fragmentMaskFetchAMD, which returns a single code: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 code:fragmentFetchAMD shader
function.
=== New Object Types
None.
=== New Enum Constants
None.
=== New Enums
None.
=== New SPIR-V Capabilities
* <<spirvenv-capabilities-table-fragmentmaskamd, code:FragmentMaskAMD>>
=== New Structures
None.
=== New Functions
None.
=== Examples
This example shows a shader that queries the fragment mask from a
multisampled compressed surface and uses it to query fragment values.
[source,c++]
----------------------------------------
#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;
}
----------------------------------------
=== Version History
* Revision 1, 2017-08-16 (Aaron Hagan)
- Initial draft