+ This->dirty_box.x = MAX2(This->dirty_box.x, 0);
+ This->dirty_box.y = MAX2(This->dirty_box.y, 0);
+ This->dirty_box.z = MAX2(This->dirty_box.z, 0);
+ This->dirty_box.width = MIN2(This->dirty_box.width,
+ This->base.base.info.width0 - This->dirty_box.x);
+ This->dirty_box.height = MIN2(This->dirty_box.height,
+ This->base.base.info.height0 - This->dirty_box.y);
+ This->dirty_box.depth = MIN2(This->dirty_box.depth,
+ This->base.base.info.depth0 - This->dirty_box.z);