public void PopActive()
 {
     base.VerifyAccess();
     this.isActiveCount--;
     if (this.isActiveCount == 0)
     {
         for (int i = 0; i < this.tileMathHelper.TileRows; i++)
         {
             for (int j = 0; j < this.tileMathHelper.TileColumns; j++)
             {
                 PointInt32 tileOffset = new PointInt32(j, i);
                 this.CancelTileRendering(tileOffset);
                 this.invalidTileOffsets.TryEnqueue(tileOffset);
             }
         }
         Work.QueueFreeStreamContents <IBitmap <ColorPbgra32> >(this.tileBuffers);
         ArrayUtil.Clear2D <bool>(this.tileIsValid);
         this.owner.NotifyTileCacheIsActiveChanged(this, false);
     }
 }