refs #12339. use class type flags instead of instanceof checks in OrbitControls.

examples/js/controls/OrbitControls.js

@@ -334,7 +334,7 @@ THREE.OrbitControls = function ( object, domElement ) {
 
 			var element = scope.domElement === document ? scope.domElement.body : scope.domElement;
 
-			if ( scope.object instanceof THREE.PerspectiveCamera ) {
+			if ( scope.object.isPerspectiveCamera ) {
 
 				// perspective
 				var position = scope.object.position;
@@ -348,7 +348,7 @@ THREE.OrbitControls = function ( object, domElement ) {
 				panLeft( 2 * deltaX * targetDistance / element.clientHeight, scope.object.matrix );
 				panUp( 2 * deltaY * targetDistance / element.clientHeight, scope.object.matrix );
 
-			} else if ( scope.object instanceof THREE.OrthographicCamera ) {
+			} else if ( scope.object.isOrthographicCamera ) {
 
 				// orthographic
 				panLeft( deltaX * ( scope.object.right - scope.object.left ) / scope.object.zoom / element.clientWidth, scope.object.matrix );
@@ -368,11 +368,11 @@ THREE.OrbitControls = function ( object, domElement ) {
 
 	function dollyIn( dollyScale ) {
 
-		if ( scope.object instanceof THREE.PerspectiveCamera ) {
+		if ( scope.object.isPerspectiveCamera ) {
 
 			scale /= dollyScale;
 
-		} else if ( scope.object instanceof THREE.OrthographicCamera ) {
+		} else if ( scope.object.isOrthographicCamera ) {
 
 			scope.object.zoom = Math.max( scope.minZoom, Math.min( scope.maxZoom, scope.object.zoom * dollyScale ) );
 			scope.object.updateProjectionMatrix();
@@ -389,11 +389,11 @@ THREE.OrbitControls = function ( object, domElement ) {
 
 	function dollyOut( dollyScale ) {
 
-		if ( scope.object instanceof THREE.PerspectiveCamera ) {
+		if ( scope.object.isPerspectiveCamera ) {
 
 			scale *= dollyScale;
 
-		} else if ( scope.object instanceof THREE.OrthographicCamera ) {
+		} else if ( scope.object.isOrthographicCamera ) {
 
 			scope.object.zoom = Math.max( scope.minZoom, Math.min( scope.maxZoom, scope.object.zoom / dollyScale ) );
 			scope.object.updateProjectionMatrix();