[Mesa-dev] [PATCH v4 0/9] Implementation of the VK_EXT_sample_locations

[Eleni Maria Stea]

Implemented the requirements from the VK_EXT_sample_locations extension
specification to allow setting custom sample locations on Intel Gen >= 7.

Some decisions explained:

The grid size was set to 1x1 because the hardware only supports a single
set of sample locations for the whole framebuffer.

The user can set custom sample locations either per pipeline, by filling
the extension provided structs, or dynamically the way it is described
in sections 26.5, 36.1, 36.2 of the Vulkan specification.

Sections 6.7.3 and 7.4 describe how to use sample locations with images
when a layout transition is about to take place. These sections were
ignored as currently we aren't using sample locations with images in the
driver.

Variable sample locations aren't required and have not been implemented.

(v2): Initially, we were sorting the samples because according to the
      Skylake PRM (vol 2a SAMPLE_PATTERN) the samples should be sent in
      a monotonically increasing distance from the center to get the
      correct centroid computation in the device. However the Vulkan
      spec seems to require that the samples occur in the order provided
      through the API. As long as this requirement only affects centroid
      calculations we should be ok without the ordering because OpenGL
      and Vulkan only require the centroid to be some lit sample and
      that it's the same for all samples in a pixel. They have no
      requirement that it be the one closest to the center. (Jason
      Ekstrand)

We have 754 vk-gl-cts tests for this extension:
690 of the tests pass on Gen >= 9 (where we can support 16 samples).
The remaining 64 tests aren't supported because they test the variable
sample locations.

Eleni Maria Stea (9):
  anv: Added the VK_EXT_sample_locations extension to the anv_extensions
    list
  anv: Set the values for the
    VkPhysicalDeviceSampleLocationsPropertiesEXT
  anv: Implemented the vkGetPhysicalDeviceMultisamplePropertiesEXT
  anv: Added support for non-dynamic sample locations on Gen8+
  anv: Added support for dynamic sample locations on Gen8+
  anv: Added support for dynamic and non-dynamic sample locations on
    Gen7
  anv: Optimized the emission of the default locations on Gen8+
  anv: Removed unused header file
  anv: Enabled the VK_EXT_sample_locations extension

 src/intel/Makefile.sources              |   1 +
 src/intel/common/gen_sample_positions.h |  53 ++++++++++
 src/intel/vulkan/anv_cmd_buffer.c       |  19 ++++
 src/intel/vulkan/anv_device.c           |  21 ++++
 src/intel/vulkan/anv_extensions.py      |   1 +
 src/intel/vulkan/anv_genX.h             |   7 ++
 src/intel/vulkan/anv_private.h          |  18 ++++
 src/intel/vulkan/anv_sample_locations.c |  96 ++++++++++++++++++
 src/intel/vulkan/anv_sample_locations.h |  29 ++++++
 src/intel/vulkan/genX_blorp_exec.c      |   1 -
 src/intel/vulkan/genX_cmd_buffer.c      |  24 +++++
 src/intel/vulkan/genX_pipeline.c        |  92 +++++++++--------
 src/intel/vulkan/genX_state.c           | 128 ++++++++++++++++++++++++
 src/intel/vulkan/meson.build            |   1 +
 14 files changed, 450 insertions(+), 41 deletions(-)
 create mode 100644 src/intel/vulkan/anv_sample_locations.c
 create mode 100644 src/intel/vulkan/anv_sample_locations.h

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2.20.1