OrbitControls: Add keyRotateSpeed. (mrdoob#29988)

* feat: Add keyRotateSpeed to OrbitControls

This allows for setting a different speed of rotation when using the
keyboard vs when using a mouse. Similar in approach to the existing
keyPanSpeed.

* fix: reduce keyRotateSpeed down to 1

docs/examples/en/controls/OrbitControls.html

@@ -141,6 +141,11 @@ <h3>[property:Float keyPanSpeed]</h3>
 			How fast to pan the camera when the keyboard is used. Default is 7.0 pixels per keypress.
 		</p>
 
+		<h3>[property:Float keyRotateSpeed]</h3>
+		<p>
+			How fast to rotate the camera when the keyboard is used. Default is 1.
+		</p>
+
 		<h3>[property:Object keys]</h3>
 		<p>
 			This object contains references to the keycodes for controlling camera panning. Default is the 4 arrow keys.

examples/jsm/controls/OrbitControls.js

@@ -92,6 +92,7 @@ class OrbitControls extends Controls {
 		// Set to false to disable rotating
 		this.enableRotate = true;
 		this.rotateSpeed = 1.0;
+		this.keyRotateSpeed = 1.0;
 
 		// Set to false to disable panning
 		this.enablePan = true;
@@ -786,7 +787,7 @@ class OrbitControls extends Controls {
 
 					if ( this.enableRotate ) {
 
-						this._rotateUp( _twoPI * this.rotateSpeed / this.domElement.clientHeight );
+						this._rotateUp( _twoPI * this.keyRotateSpeed / this.domElement.clientHeight );
 
 					}
 
@@ -809,7 +810,7 @@ class OrbitControls extends Controls {
 
 					if ( this.enableRotate ) {
 
-						this._rotateUp( - _twoPI * this.rotateSpeed / this.domElement.clientHeight );
+						this._rotateUp( - _twoPI * this.keyRotateSpeed / this.domElement.clientHeight );
 
 					}
 
@@ -832,7 +833,7 @@ class OrbitControls extends Controls {
 
 					if ( this.enableRotate ) {
 
-						this._rotateLeft( _twoPI * this.rotateSpeed / this.domElement.clientHeight );
+						this._rotateLeft( _twoPI * this.keyRotateSpeed / this.domElement.clientHeight );
 
 					}
 
@@ -855,7 +856,7 @@ class OrbitControls extends Controls {
 
 					if ( this.enableRotate ) {
 
-						this._rotateLeft( - _twoPI * this.rotateSpeed / this.domElement.clientHeight );
+						this._rotateLeft( - _twoPI * this.keyRotateSpeed / this.domElement.clientHeight );
 
 					}