void cpdf_arc (int pdf document, double x-coor, double y-coor, double radius, double start, double end [, int mode])
The cpdf_arc() function draws an arc with center at point (x-coor, y-coor) and radius radius, starting at angle start and ending at angle end.
The optional parameter mode determines the unit length. If it's 0 or omitted the default unit as specified for the page is used. Otherwise the coordinates are measured in postscript points disregarding the current unit.
See also cpdf_circle().