func (self *pane) setTransform() {
// generate transform matrix to convert to (zoomed & panned) pixel space
m := mgl32.Translate2D(-1.0, -1.0) // move origin to corner
zm := mgl32.Scale2D(
self.zoom[0]*2.0/float32(self.width),
self.zoom[1]*2.0/float32(self.height))
pm := mgl32.Translate2D(self.pan[0], self.pan[1])
m = m.Mul3(zm)
self.transform = m.Mul3(pm)
// generate untransform from pixel space to unzoomed & unpanned mesh space
upm := mgl32.Translate2D(-self.pan[0], -self.pan[1])
uzm := mgl32.Scale2D(1.0/self.zoom[0], 1.0/self.zoom[1])
self.untransform = upm.Mul3(uzm)
t := []float32{}
for _, s := range self.transform {
t = append(t, float32(s))
}
self.gl.UniformMatrix3fv(self.uTransform, false, t)
}
func (s *Sprite) transform() mgl.Mat4 {
S := mgl.Scale2D(s.scale, s.scale).Mat4()
R := mgl.Rotate2D(mgl.DegToRad(s.rotation)).Mat4()
T := mgl.Translate3D(s.x, s.y, 0)
return T.Mul4(R).Mul4(S)
}