openlayers/ol3 — pull request #1467 by twpayne (2014-01-06 14:41:40+00:00)
Title: [vector-api] Fix rotation of WebGL tile layers

As reported by @fredj in #1461, rotation of WebGL tile layers broke.

This PR fixes it.

Note that we cannot use `ol.vec.Mat4.makeTransform2D` here because we need to scale before rotating, whereas `ol.vec.Mat4.makeTransform2D` rotates before scaling.