Python graphic module: observations, assumptions, suggestions

[parisse]

I've found where the bugs are. As I guessed, it is in the Prime-specific implementation: c_draw_arc and c_draw_filled_arc both calls a method FillArc, draw_arc with angles theta1*4096/M_PI, theta2*4096/M_PI and c_draw_filled_arc with theta1_deg*4096/360, theta2_deg*4096/360.
Arguments for the first FillArc should be -theta1*2048/M_PI and -theta2*2048/M_PI and for the second one arguments should be negated. And the angles should probably be exchanged, FillArc seems to work with some specific angle unit (4096=2*pi radians) and clockwise.