Summary:
WindowVertex contains the x position and also the relative texture x position
Our textures are scaled bigger than kwin's resolution, so this makes sure we set the right
texture position.
Otherwise our final array ends up using 0 to 0.5 of the texture, not 0 to 1.
Test Plan:
Opened some 2x windows, on a 1x output.
It looked how it should do, instead of it being double the size and cropped
Tested some things that use quads, like wobbly windows
Reviewers: #plasma
Subscribers: plasma-devel, kwin
Tags: #kwin
Differential Revision: https://phabricator.kde.org/D3502
ebebc6ca82