Using Chromium with SwiftShader

SwiftShader is an open-source high-performance implementation of the Vulkan and OpenGL ES graphics APIs which runs purely on the CPU. Thus no graphics processor (GPU) is required for advanced (3D) graphics.

Chromium uses SwiftShader in two different ways:

1. As the OpenGL ES driver

When Chromium uses SwiftShader as the OpenGL ES driver, Chromium behaves as if it was running a on regular GPU, while actually running on SwiftShader. This allows Chromium to exercise hardware only code paths on GPU-less bots.

2. As the WebGL fallback

When Chromium uses SwiftShader as the WebGL fallback, Chromium runs in all software mode and only uses SwiftShader to render WebGL content.

Relevant Chromium command line switches

When running the chrome executable from the command line, SwiftShader can be enabled using the following Switches:

1. As the OpenGL ES driver, SwANGLE (ANGLE + SwiftShader Vulkan)

--use-gl=angle --use-angle=swiftshader

2. As the WebGL fallback, SwANGLE (ANGLE + SwiftShader Vulkan)

--use-gl=angle --use-angle=swiftshader-webgl

3. As the Vulkan driver (requires the enable_swiftshader_vulkan feature)

--use-vulkan=swiftshader