GL: implement EGL context creation in Dawn native.

An abstract base class (Device::Context) is used to avoid adding dependencies to Device, with ContextEGL derived from it. This also
leaves open the possibility of supporting other native GL contexts
in the future (e.g., glX). One temporary EGLContext is created by opengl::Backend during Adapter discovery, then one is created for and
owned by each Device.

Contexts for the desktop GL backend are also managed via EGL, which
works for most modern drivers. This also means that GLFW is now
always used in GLFW_NO_API mode.

Since contexts are now per-device, all of the default GL state
setting and debug output setup was moved from Adapter to Device.

Bug: dawn:810
Change-Id: Idfe30939f155d026fcad549787fc167cc43aa3cb
Commit-Queue: Stephen White <>
Reviewed-by: Austin Eng <>
Kokoro: Kokoro <>
26 files changed
tree: d16a0b36d4d84c181bfa7b6bfb4deae1bc68d09a
  1. .vscode/
  2. build_overrides/
  3. docs/
  4. generator/
  5. include/
  6. infra/
  7. scripts/
  8. src/
  9. test/
  10. third_party/
  11. tools/
  12. webgpu-cts/
  13. .clang-format
  14. .clang-tidy
  15. .gitattributes
  16. .gitignore
  17. .gn
  20. CMakeLists.txt
  21. CMakeSettings.json
  23. codereview.settings
  25. CPPLINT.cfg
  26. dawn.json
  27. dawn_wire.json
  28. DEPS
  30. Doxyfile
  31. go.mod
  32. go.sum
  34. OWNERS
  36. README.chromium
  38. tint_overrides_with_defaults.gni

Dawn's logo: a sun rising behind a stylized mountain inspired by the WebGPU logo. The text Dawn is written below it.

Dawn, a WebGPU implementation

Dawn is an open-source and cross-platform implementation of the work-in-progress WebGPU standard. More precisely it implements webgpu.h that is a one-to-one mapping with the WebGPU IDL. Dawn is meant to be integrated as part of a larger system and is the underlying implementation of WebGPU in Chromium.

Dawn provides several WebGPU building blocks:

  • WebGPU C/C++ headers that applications and other building blocks use.
    • The webgpu.h version that Dawn implements.
    • A C++ wrapper for the webgpu.h.
  • A “native” implementation of WebGPU using platforms' GPU APIs:
    • D3D12 on Windows 10
    • Metal on macOS and iOS
    • Vulkan on Windows, Linux, ChromeOS, Android and Fuchsia
    • OpenGL as best effort where available
  • A client-server implementation of WebGPU for applications that are in a sandbox without access to native drivers
  • Tint is a compiler for the WebGPU Shader Language (WGSL).

Helpful links:

Documentation table of content

Developer documentation:

User documentation: (TODO, figure out what overlaps with the webgpu.h docs)




Apache 2.0 Public License, please see LICENSE.


This is not an officially supported Google product.