aosp12/external/angle

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, 3.0 and 3.1 to Vulkan, desktop OpenGL, OpenGL ES, Direct3D 9, and Direct3D 11. Future plans include ES 3.2, translation to Metal and MacOS, Chrome OS, and Fuchsia support.

Level of OpenGL ES support via backing renderers

	Direct3D 9	Direct3D 11	Desktop GL	GL ES	Vulkan	Metal
OpenGL ES 2.0	complete	complete	complete	complete	complete	complete
OpenGL ES 3.0		complete	complete	complete	complete	in progress
OpenGL ES 3.1		incomplete	complete	complete	complete
OpenGL ES 3.2			in progress	in progress	in progress

Platform support via backing renderers

	Direct3D 9	Direct3D 11	Desktop GL	GL ES	Vulkan	Metal
Windows	complete	complete	complete	complete	complete
Linux			complete		complete
Mac OS X			complete			in progress
iOS						planned
Chrome OS				complete	planned
Android				complete	complete
GGP (Stadia)					complete
Fuchsia					complete

ANGLE v1.0.772 was certified compliant by passing the OpenGL ES 2.0.3 conformance tests in October 2011.

ANGLE has received the following certifications with the Vulkan backend:

• OpenGL ES 2.0: ANGLE 2.1.0.d46e2fb1e341 (Nov, 2019)
• OpenGL ES 3.0: ANGLE 2.1.0.f18ff947360d (Feb, 2020)
• OpenGL ES 3.1: ANGLE 2.1.0.f5dace0f1e57 (Jul, 2020)

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, Vulkan 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.

Contributing

• Join our Google group to keep up to date.

• Join us on IRC in the #ANGLEproject channel on FreeNode.

• Join us on Slack in the #angle channel.

• File bugs in the issue tracker (preferably with an isolated test-case).

• Choose an ANGLE branch to track in your own project.

• Read ANGLE development documentation.

• Look at pending and merged changes.

• Become a code contributor.

• Use ANGLE's coding standard.

• Learn how to build ANGLE for Chromium development.

• Get help on debugging ANGLE.

• Go through ANGLE's orientation and sift through starter projects.

• Read about WebGL on the Khronos WebGL Wiki.

• Learn about implementation details in the OpenGL Insights chapter on ANGLE and this ANGLE presentation.

• Learn about the past, present, and future of the ANGLE implementation in this presentation.

• Watch a short presentation on the Vulkan back-end.

• Track the dEQP test conformance

• Read design docs on the Vulkan back-end

• Read about ANGLE's testing infrastructure

• If you use ANGLE in your own project, we'd love to hear about it!