Add workaround for unused std140 and shared uniform blocks on MacOS

On some Mac drivers with shader version 4.1, they will
treat unused std140 and shared uniform blocks' members as inactive. However,
WebGL2.0 based on OpenGL ES3.0.4 requires all members of a named uniform block
declared with a shared or std140 layout qualifier to be considered active.
The uniform block itself is also considered active.

This workaround is to reference all members of unused std140 and shared uniform blocks
at the beginning of the vertex/fragment shader's main().

BUG=chromium:618464
TEST=UniformBufferTest.ActiveUniformBlockNumber

Change-Id: I1d2c5e3e8da04786ac6a37fd26f7bb9c14cd76ed
Reviewed-on: https://chromium-review.googlesource.com/387169
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
13 files changed
tree: 360e977da8ee9bcb244c6335c1701721f4a87796
  1. build/
  2. doc/
  3. extensions/
  4. include/
  5. infra/
  6. samples/
  7. scripts/
  8. src/
  9. third_party/
  10. util/
  11. .clang-format
  12. .gitattributes
  13. .gitignore
  14. AUTHORS
  15. BUILD.gn
  16. codereview.settings
  17. CONTRIBUTORS
  18. DEPS
  19. DEPS.chromium
  20. LICENSE
  21. README.chromium
  22. README.md
README.md

ANGLE - Almost Native Graphics Layer Engine

The goal of ANGLE is to allow users of multiple operating systems to seamlessly run WebGL and other OpenGL ES content by translating OpenGL ES API calls to one of the hardware-supported APIs available for that platform. ANGLE currently provides translation from OpenGL ES 2.0 and 3.0 to desktop OpenGL, OpenGL ES, Direct3D 9, and Direct3D 11. Support for translation from OpenGL ES to Vulkan is underway, and future plans include compute shader support (ES 3.1) and MacOS support.

Level of OpenGL ES support via backing renderers

Direct3D 9Direct3D 11Desktop GLGL ESVulkan
OpenGL ES 2.0completecompletecompletecompletein progress
OpenGL ES 3.0completecompletein progressnot started
OpenGL ES 3.1not startedin progressin progressnot started

Platform support via backing renderers

Direct3D 9Direct3D 11Desktop GLGL ESVulkan
Windowscompletecompletecompletecompletein progress
Linuxcompleteplanned
Mac OS Xin progress
Chrome OScompleteplanned
Androidcompleteplanned

ANGLE v1.0.772 was certified compliant by passing the ES 2.0.3 conformance tests in October 2011. ANGLE also provides an implementation of the EGL 1.4 specification.

ANGLE is used as the default WebGL backend for both Google Chrome and Mozilla Firefox on Windows platforms. Chrome uses ANGLE for all graphics rendering on Windows, including the accelerated Canvas2D implementation and the Native Client sandbox environment.

Portions of the ANGLE shader compiler are used as a shader validator and translator by WebGL implementations across multiple platforms. It is used on Mac OS X, Linux, and in mobile variants of the browsers. Having one shader validator helps to ensure that a consistent set of GLSL ES shaders are accepted across browsers and platforms. The shader translator can be used to translate shaders to other shading languages, and to optionally apply shader modifications to work around bugs or quirks in the native graphics drivers. The translator targets Desktop GLSL, Direct3D HLSL, and even ESSL for native GLES2 platforms.

Sources

ANGLE repository is hosted by Chromium project and can be browsed online or cloned with

git clone https://chromium.googlesource.com/angle/angle

Building

View the Dev setup instructions. For generating a Windows Store version of ANGLE view the Windows Store instructions

Contributing