+ // make sure that at least one pixel is blitted, and inside the screen
+ // (else nothing is blitted, causing the animations not to be updated)
+ x1 = MIN(MAX(0, x1), WIN_XSIZE - 1);
+ y1 = MIN(MAX(0, y1), WIN_YSIZE - 1);
+ x2 = MIN(MAX(1, x2), WIN_XSIZE);
+ y2 = MIN(MAX(1, y2), WIN_YSIZE);
+