Relative-coordinate version of cairo_line_to(). Adds a line to the
path from the current point to a point that is offset from the
current point by (dx, dy) in user space. After this call the
current point will be offset by (dx, dy).
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 cr to shutdown with a status of
CAIRO_STATUS_NO_CURRENT_POINT.
Since 1.0
Relative-coordinate version of cairo_line_to(). Adds a line to the path from the current point to a point that is offset from the current point by (dx, dy) in user space. After this call the current point will be offset by (dx, dy). 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 cr to shutdown with a status of CAIRO_STATUS_NO_CURRENT_POINT. Since 1.0