transform_distance
Description:
Transforms the distance vector (dx,dy) by this.
This is similar to [method@Pango.Matrix.transform_point], except that the translation components of the transformation are ignored. The calculation of the returned vector is as follows:
``` dx2 = dx1 * xx + dy1 * xy; dy2 = dx1 * yx + dy1 * yy; ```
Affine transformations are position invariant, so the same vector always transforms to the same vector. If (x1,y1)
transforms to (x2,y2) then (x1+dx1,y1+dy1) will transform to (
x1+dx2,y1+dy2) for all values of x1 and x2.
Parameters:
| this |
a `PangoMatrix` |
| dx |
in/out X component of a distance vector |
| dy |
in/out Y component of a distance vector |