Relative-coordinate version of lineTo(). Adds a line
to the path from the current point to a point that is
offset from the current point by rp1 in user space.
After this call the current point will be offset by rp1.
Given a current point of (x, y), cairo_rel_line_to(cr, dx, dy)
is logically equivalent to cairo_line_to(cr, x + dx, y + dy).
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 lineTo(). Adds a line to the path from the current point to a point that is offset from the current point by rp1 in user space. After this call the current point will be offset by rp1.
Given a current point of (x, y), cairo_rel_line_to(cr, dx, dy) is logically equivalent to cairo_line_to(cr, x + dx, y + dy).
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.