Question on nsvg__xformInverse for gradient colors

[chenwu054]

One question on "nsvg__xformInverse(shape->fill.gradient->xform, t);" for gradient paints in nsvg__scaleToViewbox function. I wonder why do we need to do inverse in the "scale" function? Is there any math formula to reference? Thank you!

[memononen]

The gradient transform is stored as inverse so that passing a point to it will return a point in gradient space. In retrospect sound wierd, but made sense at the time as I working on the rasterizer.