gl-renderer: Assume axis alignment using node's valid_transform
Version 1
Derive axis alignment directly from the quad instead of relying on the transform flags of the weston_view
struct. This is more reliable since
matrix flags could erroneously hang around after a series of transforms. The axis alignment test now also includes rectangles rotated by multiples of 90°.
Version 2
Assume axis alignment using node's valid_transform
boolean instead of relying on the transform flags of the weston_view
struct. This is more reliable since matrix flags could erroneously hang around after a series of transforms. Additionally, nodes with standard output transforms like translations, flips and rotations by 90° can now take the fast axis aligned path.