i found the problem... you did not allocate a big enough window... On Wed, Jan 15, 2014 at 9:19 PM, Conor Williams wrote: > did you divide by 10? > > > On Wed, Jan 15, 2014 at 7:08 PM, wrote: > >> its wrong. >> >> look at the code comments. it draws the same thing twice. one time, >> on to a offscreen image and one time on screen (a layer) directly. >> >> they should be identical, they are not. >> >> comment out the 2nd one to see how its supposed to look. >> >> it should be just a blue rectangle overlapping a red one (one >> pixel shifted apart). >> >> -- >> cinap >> >> >