rel_cubic_to
Description:
Adds a [cubic Bézier curve](https://en.
wikipedia.org/wiki/B%C3a9zier_curve) from the current point to x3, y3 with x1
, y1 and x2, y2 as the control points.
All coordinates are given relative to the current point.
This is the relative version of [method@Gsk.PathBuilder.cubic_to].
Parameters:
| this |
a path builder |
| x1 |
x offset of first control point |
| y1 |
y offset of first control point |
| x2 |
x offset of second control point |
| y2 |
y offset of second control point |
| x3 |
x offset of the end of the curve |
| y3 |
y offset of the end of the curve |