gsk:path-builder-rel-quad-to (builder x1 y1 x2 y2)

builder -- a gsk:path-builder instance
x1 -- a number coerced to a single float with the X coordinate of the first control point
y1 -- a number coerced to a single float with the Y coordinate of the first control point
x2 -- a number coerced to a single float with the X coordinate of the end of the curve
y2 -- a number coerced to a single float with the Y coordinate of the end of the curve

Adds a quadratic Bézier curve from the current point to x2, y2 with x1, y1 as the control point. All coordinates are given relative to the current point. This is the relative version of the gsk:path-builder-quad-to function.