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Issue 657678 link

Starred by 1 user

Issue metadata

Status: Fixed
Owner:
Closed: Oct 2016
Cc:
Components:
EstimatedDays: ----
NextAction: ----
OS: ----
Pri: 2
Type: Bug

Blocking:
issue 649087



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WebGL S3TC restrictions incorrectly applied to non-WebGL contexts

Project Member Reported by piman@chromium.org, Oct 20 2016

Issue description

The WebGL extension [1] has specific restrictions on the S3TC texture image sizes, notably:
"When level equals zero width and height must be a multiple of 4. When level is greater than 0 width and height must be 0, 1, 2 or a multiple of 4."

These restrictions are not present on the ES2/3 extension [2], which allows arbitrary sizes. However they are incorrectly applied to all types of contexts [3], breaking some pepper (edge) cases [4].


[1] https://www.khronos.org/registry/webgl/extensions/WEBGL_compressed_texture_s3tc/
[2] https://www.opengl.org/registry/specs/EXT/texture_compression_s3tc.txt
[3] https://cs.chromium.org/chromium/src/gpu/command_buffer/service/gles2_cmd_decoder.cc?q=IsValidDX&sq=package:chromium&l=12514
[4] https://bugs.chromium.org/p/chromium/issues/detail?id=649087
 

Comment 1 by piman@chromium.org, Oct 20 2016

Blocking: 649087
Project Member

Comment 2 by bugdroid1@chromium.org, Oct 20 2016

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/6b129d16c110e756516a7ce973faf5432224c4f1

commit 6b129d16c110e756516a7ce973faf5432224c4f1
Author: piman <piman@chromium.org>
Date: Thu Oct 20 18:05:15 2016

Fix S3TC size validation for non-webgl contexts

The (formerly) IsValidDXTSize check is specific to the
WEBGL_compressed_texture_s3tc semantics, but doesn't
correspond to constraints in the native extension
(EXT_texture_compression_s3tc), so only apply this check to
WebGL contexts.

BUG= 657678 
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel

Review-Url: https://chromiumcodereview.appspot.com/2439643003
Cr-Commit-Position: refs/heads/master@{#426529}

[modify] https://crrev.com/6b129d16c110e756516a7ce973faf5432224c4f1/gpu/command_buffer/service/gles2_cmd_decoder.cc
[modify] https://crrev.com/6b129d16c110e756516a7ce973faf5432224c4f1/gpu/command_buffer/service/gles2_cmd_decoder_unittest_textures.cc

Comment 3 by piman@chromium.org, Oct 20 2016

Status: Fixed (was: Untriaged)

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