Prefix user-defined names in GLSL output

Now user-defined names are prefixed by _u in GLSL output in case name
hashing is not on. Internal names such as names of temporary variables
created in AST transformations are written out as such.

This makes handling of internal function names and internal variable
names consistent. It also removes the possibility of name conflicts
between user-defined names and internal names in case name hashing is
not on. In the same vein, it makes it safe to use GLSL reserved words
that are not reserved in ESSL as variable names in case name hashing
is not on.

This also makes the GLSL output more consistent with how names are
handled in HLSL output. Name hashing code is shared between
VariableInfo and OutputGLSLBase to ensure names are handled
consistently in both. The name that's used in the shader source for a
given interface variable is written out to ShaderVariable::mappedName.

An exception needs to be made for identifiers close to the length
limit, since adding any prefix would take them over the limit. But
they can be just written out as such, since we don't have any builtins
or ANGLE internal variables that have as long names and could create a

TEST=angle_unittests, angle_end2end_tests, WebGL conformance tests

Change-Id: Id6ed052c4fab2d091227dc9a3668083053b67a38
Commit-Queue: Olli Etuaho <>
Reviewed-by: Jamie Madill <>
34 files changed
tree: 80c0f2fa96d6d4114b4a2c162faeeeea26bee844
  1. doc/
  2. extensions/
  3. gni/
  4. gyp/
  5. include/
  6. infra/
  7. samples/
  8. scripts/
  9. src/
  10. third_party/
  11. util/
  12. .clang-format
  13. .gitattributes
  14. .gitignore
  17. codereview.settings
  19. DEPS
  20. DEPS.chromium
  22. README.chromium

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
Mac OS Xin progress
Chrome OScompleteplanned

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.


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

git clone


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