Relative-coordinate version of curveTo().
All offsets are relative to the current point. Adds a
cubic Bézier spline to the path from the current point
to a point offset from the current point by rp3,
using points offset by rp1 and rp2 as the
control points. After this call the current point will
be offset by rp3.
Given a current point of (x, y),
cairo_rel_curve_to(cr, dx1, dy1, dx2, dy2, dx3, dy3) is logically
equivalent to
cairo_curve_to(cr, x+dx1, y+dy1, x+dx2, y+dy2, x+dx3, y+dy3).
It is an error to call this function with no current point.
Doing so will cause an CairoException with a
status of CAIRO_STATUS_NO_CURRENT_POINT.
Relative-coordinate version of curveTo(). All offsets are relative to the current point. Adds a cubic Bézier spline to the path from the current point to a point offset from the current point by rp3, using points offset by rp1 and rp2 as the control points. After this call the current point will be offset by rp3.
Given a current point of (x, y), cairo_rel_curve_to(cr, dx1, dy1, dx2, dy2, dx3, dy3) is logically equivalent to cairo_curve_to(cr, x+dx1, y+dy1, x+dx2, y+dy2, x+dx3, y+dy3).
It is an error to call this function with no current point. Doing so will cause an CairoException with a status of CAIRO_STATUS_NO_CURRENT_POINT.