+ if ($this->aViewBox[0] < -180
+ || $this->aViewBox[2] > 180
+ || $this->aViewBox[0] >= $this->aViewBox[2]
+ || $this->aViewBox[1] < -90
+ || $this->aViewBox[3] > 90
+ || $this->aViewBox[1] >= $this->aViewBox[3]
+ ) {
+ userError("Bad parameter 'viewbox'. Out of range.");
+ }
+