wrench

wrench is a tool for debugging webrender outside of a browser engine.

Build

Build wrench with cargo build --release within the wrench directory.

headless

wrench has an optional headless mode for use in continuous integration. To run in headless mode, instead of using cargo run -- args, use ./headless.py args.

show

If you are working on gecko integration you can capture a frame via the following steps.

• Visit about:support and check that the "Compositing" value in the "Graphics" table says "WebRender". Enable gfx.webrender.all in about:config if necessary to enable WebRender.
• Hit ctrl-shift-3 to capture the frame. The data will be put in ~/wr-capture.
• View the capture with wrench show ~/wr-capture.

reftest

Wrench also has a reftest system for catching regressions.

• To run all reftests, run script/headless.py reftest
• To run specific reftests, run script/headless.py reftest path/to/test/or/dir
• To examine test failures, use the reftest analyzer
• To add a new reftest, create an example frame and a reference frame in reftests/ and then add an entry to reftests/reftest.list