Adds an elliptical arc from the current point to x2, y2 with x1, y1 determining the
tangent directions.
All coordinates are given relative to the current point.
This is the relative version of [method@Gsk.PathBuilder.arc_to].
| this |
a path builder |
| x1 |
x coordinate of first control point |
| y1 |
y coordinate of first control point |
| x2 |
x coordinate of second control point |
| y2 |
y coordinate of second control point |