photonstorm/phaser — pull request #1392 by Steve-3d (2014-12-01 15:50:02+00:00)
Title: Wrong scaling factors for transformation matrix

wt.a and wt.b are x components, wt.c and wt.d y.

This error can be seen when using non-uniform scaling for sprites adding these with zero
rotation to a group and then rotating the group.