Find a file
Erik Faye-Lund dd8fb7139d mesa/main: rewrite mipmap generation code
The old mipmap generation code has a few problems:

1. It open-codes the format conversion, which is error prone, and it's
   hard to know if we're missing some formats. Manual inspection shows
   that we're indeed missing some less commonly used formats.

2. When downsampling between two miplevels with the same width (e.g a
   width of one), the code would read from outside the image.

3. It averages sRGB textures in gamma space. Whilte that's legal in GL
   (the filtering algorithm is undefined), it doesn't produce very good
   results. And it's not the same thing as util_gen_mipmap() does.

4. Similarly, it uses a box-filter for the stencil values. And while
   that's actually what the spec recomments (regardless of format), it's
   absolutely *not* what most applications would want. Using nearest
   sampling would make more sense.

5. It has requirements about the type and format returned by
   _mesa_uncompressed_format_to_type_and_comps() which other call-sites
   in mesa doesn't have. This is the real reason I want to get rid of
   it, because it ends up complicating the GLES read formats / types.

So, let's rewrite all of this, fixing all of the above. The result is
quite a bit shorter, and if this ends up being less performant, it's
unlikely that this matters, because we almost always use the GPU
accelerated code-path provided by util_gen_mipmap() anyway.

The new code works by a few identities: It uses the pack / unpack
helpers to convert the texture to a few reasonable intermediate formats,
so we keep the amount of open-coded averaging to a minimum. To do this
without heap-allocations, we introduce a concept of a "span", which has
a max fixed size, that can trivially be allocated on the stack.

We also add some more requirements to keep things sane; the higher level
do_row functions only allow the dest image to be half of the source
width or one (whichever is larger). This matches the high-level needs of
mipmap generation. The lower level do_span() function is a bit more
flexible, because that turns out to be helpful when implementing
do_span_3D(), where we want to avoid collapsing the inner dimension
twice.

Tested-by: Eric R. Smith <eric.smith@collabora.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/29380>
2024-05-28 15:04:14 +00:00
.ci-farms ci: lima farm maintenance 2024-05-20 12:15:15 +02:00
.ci-farms-disabled ci: lima farm maintenance 2024-05-20 12:15:15 +02:00
.github/workflows add zink to macos ci 2022-11-22 19:04:13 +00:00
.gitlab gitlab: Reference hang debugging documenttion 2024-05-16 09:47:53 +00:00
.gitlab-ci ci/lava: move wayland-protocols to the main section 2024-05-25 06:28:45 +00:00
android nouveau: import libdrm_nouveau 2024-03-13 15:21:07 +00:00
bin ci: fix stress counter in run'n'monitor 2024-05-27 20:30:36 +00:00
build-support meson: move tsan-blacklist.txt to build-support with the other build support files 2024-05-01 07:05:12 +00:00
docs tu: Expose VK_EXT_nested_command_buffer 2024-05-24 12:21:07 +00:00
include drm-uapi: Update v3d_drm.h 2024-05-22 05:37:47 +00:00
src mesa/main: rewrite mipmap generation code 2024-05-28 15:04:14 +00:00
subprojects subprojects: uprev perfetto to v45.0 2024-05-21 20:02:00 +00:00
.clang-format meson: enable the clang-format target 2023-05-29 11:57:08 +00:00
.clang-format-ignore ci: enforce formatting for RADV & ACO 2023-06-16 19:59:52 +00:00
.clang-format-include teflon: Initial commit 2024-01-24 10:02:10 +00:00
.dir-locals.el
.editorconfig glsl: Fixes ident issue in glsl_parser.yy and update editorconfig for it 2022-12-16 19:02:17 +00:00
.git-blame-ignore-revs freedreno: Add reformatting commits to .git-blame-ignore-revs 2023-09-22 02:07:36 +00:00
.gitattributes gitlab: Highlight .cl as C 2023-11-02 11:37:46 +00:00
.gitignore .gitignore: add .cache folder 2024-05-13 14:32:12 +00:00
.gitlab-ci.yml ci/image-tags: rename DEBIAN_X86_64_TEST_*_TAG to drop the x86 mention 2024-05-23 06:00:50 +02:00
.graphqlrc.yml ci/bin: Add utility to find jobs dependencies 2022-08-03 23:10:37 +00:00
.mailmap mailmap: add entry to unify Roman Stratiienko's contributions 2024-05-16 12:05:27 +00:00
.mr-label-maker.yml mr-label-maker: label src/vulkan/wsi/ as wsi 2024-05-24 19:12:49 +02:00
CODEOWNERS CODEOWNERS: update Imagination maintainers 2024-01-19 10:26:15 +00:00
meson.build meson: use glslang --depfile argument when possible 2024-05-20 17:34:17 +00:00
meson_options.txt meson: implement split-debug 2024-04-23 18:31:39 +00:00
README.rst README: update links to our own docs 2024-05-15 17:13:10 +00:00
VERSION VERSION: bump to 20.2 2024-04-24 19:51:59 +00:00

`Mesa <https://mesa3d.org>`_ - The 3D Graphics Library
======================================================


Source
------

This repository lives at https://gitlab.freedesktop.org/mesa/mesa.
Other repositories are likely forks, and code found there is not supported.


Build & install
---------------

You can find more information in our documentation (`docs/install.rst
<https://docs.mesa3d.org/install.html>`_), but the recommended way is to use
Meson (`docs/meson.rst <https://docs.mesa3d.org/meson.html>`_):

.. code-block:: sh

  $ mkdir build
  $ cd build
  $ meson ..
  $ sudo ninja install


Support
-------

Many Mesa devs hang on IRC; if you're not sure which channel is
appropriate, you should ask your question on `OFTC's #dri-devel
<irc://irc.oftc.net/dri-devel>`_, someone will redirect you if
necessary.
Remember that not everyone is in the same timezone as you, so it might
take a while before someone qualified sees your question.
To figure out who you're talking to, or which nick to ping for your
question, check out `Who's Who on IRC
<https://dri.freedesktop.org/wiki/WhosWho/>`_.

The next best option is to ask your question in an email to the
mailing lists: `mesa-dev\@lists.freedesktop.org
<https://lists.freedesktop.org/mailman/listinfo/mesa-dev>`_


Bug reports
-----------

If you think something isn't working properly, please file a bug report
(`docs/bugs.rst <https://docs.mesa3d.org/bugs.html>`_).


Contributing
------------

Contributions are welcome, and step-by-step instructions can be found in our
documentation (`docs/submittingpatches.rst
<https://docs.mesa3d.org/submittingpatches.html>`_).

Note that Mesa uses gitlab for patches submission, review and discussions.