Merge pull request #11612 from WestLangley/dev-plane

Plane.js: Refactoring and clean up

src/math/Plane.js

@@ -35,7 +35,7 @@ Object.assign( Plane.prototype, {
 	setFromNormalAndCoplanarPoint: function ( normal, point ) {
 
 		this.normal.copy( normal );
-		this.constant = - point.dot( this.normal );	// must be this.normal, not normal, as this.normal is normalized
+		this.constant = - point.dot( this.normal );
 
 		return this;
 
@@ -110,16 +110,9 @@ Object.assign( Plane.prototype, {
 
 	projectPoint: function ( point, optionalTarget ) {
 
-		return this.orthoPoint( point, optionalTarget ).sub( point ).negate();
-
-	},
-
-	orthoPoint: function ( point, optionalTarget ) {
-
-		var perpendicularMagnitude = this.distanceToPoint( point );
-
 		var result = optionalTarget || new Vector3();
-		return result.copy( this.normal ).multiplyScalar( perpendicularMagnitude );
+
+		return result.copy( this.normal ).multiplyScalar( - this.distanceToPoint( point ) ).add( point );
 
 	},
 
@@ -189,6 +182,7 @@ Object.assign( Plane.prototype, {
 	coplanarPoint: function ( optionalTarget ) {
 
 		var result = optionalTarget || new Vector3();
+
 		return result.copy( this.normal ).multiplyScalar( - this.constant );
 
 	},
@@ -200,14 +194,12 @@ Object.assign( Plane.prototype, {
 
 		return function applyMatrix4( matrix, optionalNormalMatrix ) {
 
+			var normalMatrix = optionalNormalMatrix || m1.getNormalMatrix( matrix );
+
 			var referencePoint = this.coplanarPoint( v1 ).applyMatrix4( matrix );
 
-			// transform normal based on theory here:
-			// http://www.songho.ca/opengl/gl_normaltransform.html
-			var normalMatrix = optionalNormalMatrix || m1.getNormalMatrix( matrix );
 			var normal = this.normal.applyMatrix3( normalMatrix ).normalize();
 
-			// recalculate constant (like in setFromNormalAndCoplanarPoint)
 			this.constant = - referencePoint.dot( normal );
 
 			return this;
@@ -218,7 +210,7 @@ Object.assign( Plane.prototype, {
 
 	translate: function ( offset ) {
 
-		this.constant = this.constant - offset.dot( this.normal );
+		this.constant -= offset.dot( this.normal );
 
 		return this;