(* Examples by Ãyvind KolÃ¥s taken from http://cairographics.org/samples/ *) let pi = 4. *. atan 1. let draw_arc cr arc = let xc = 128. and yc = 128. in let radius = 100. in let angle1 = 45. *. pi /. 180.0 in let angle2 = 180. *. pi /. 180.0 in Cairo.set_line_width cr 10.; arc cr ~x:xc ~y:yc ~r:radius ~a1:angle1 ~a2:angle2; Cairo.stroke cr; (* draw helping lines *) Cairo.set_source_rgba cr 1. 0.2 0.2 0.6; Cairo.set_line_width cr 6.; Cairo.arc cr xc yc 10. 0. (2. *. pi); Cairo.fill cr; Cairo.arc cr xc yc radius angle1 angle1; Cairo.line_to cr xc yc; Cairo.arc cr xc yc radius angle2 angle2; Cairo.line_to cr xc yc; Cairo.stroke cr let () = let surface = Cairo.SVG.create "arcs.svg" 500. 300. in let cr = Cairo.create surface in (* Arc *) draw_arc cr Cairo.arc; Cairo.translate cr 200. 0.; (* Arc negative *) Cairo.set_source_rgb cr 0. 0.8 0.; draw_arc cr Cairo.arc_negative; Cairo.PNG.write surface "arcs.png"; Cairo.Surface.finish surface