+ if(b.xmax > (int)(MAX_WIDTH*zoom))
+ b.xmax = (int)(MAX_WIDTH*zoom);
+ if(b.ymax > (int)(MAX_HEIGHT*zoom))
+ b.ymax = (int)(MAX_HEIGHT*zoom);
+ if(b.xmin < -(int)(MAX_WIDTH*zoom))
+ b.xmin = -(int)(MAX_WIDTH*zoom);
+ if(b.ymin < -(int)(MAX_HEIGHT*zoom))
+ b.ymin = -(int)(MAX_HEIGHT*zoom);
+
+ if(b.xmin > b.xmax)
+ b.xmin = b.xmax;
+ if(b.ymin > b.ymax)
+ b.ymin = b.ymax;
+