Add tests for all possible combinations of surface and output transforms
Submitted by Pekka Paalanen
Assigned to Wayland bug list
Taking advantage of screenshooting based testing (bug #83987), write tests that iterate through all combinations of surface and output transformations and also surface and output scales 1, 2 and 3.
The test client needs to draw an image that is not symmetric in any way.
For each combination: render, post, take screenshot, and verify image.
While doing this, extract more screenshot-testing helpers from subsurface-shot test and document them.
- Bug 83987 Screenshooting based testing: done.