drm-tests: add option for showing a banding-revealing pattern
This CL adds a command line option and logic to draw a horizontal
pattern that makes it easy to see if there's any banding; with a
patched kernel (so dithering is enabled), this shows a difference
between XR24 and XR30 framebuffers akin to what can be seen in e.g.
http://www.lagom.nl/lcd-test/gradient.php
BUG=chromium:776093
TEST=null_platform_test -p XR30 -b on nocturne
Change-Id: I1d6666030cc5b377586b5361024126943b06b7ea
Reviewed-on: https://chromium-review.googlesource.com/1534876
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: Miguel Casas <mcasas@chromium.org>
Reviewed-by: Stéphane Marchesin <marcheu@chromium.org>
Reviewed-by: Daniele Castagna <dcastagna@chromium.org>
1 file changed
