int w=(int)(desc.get_w()*zoom);
int h=(int)(desc.get_h()*zoom);
+ // ensure that the size we draw is at least one pixel in each dimension
+ int min_size = low_resolution ? low_res_pixel_size : 1;
+ if (w < min_size) w = min_size;
+ if (h < min_size) h = min_size;
+
// Setup the description parameters
desc.set_antialias(1);
desc.set_time(cur_time);