add hover emissive effect for feature map (#205)

src/elements/FeatureMap.js

@@ -103,6 +103,9 @@ FeatureMap.prototype = {
 		cube.elementType = "featureMap";
 		cube.hoverable = true;
 		cube.draggable = true;
+		cube.emissiveable = true;
+
+		cube.context = this;
 
 		this.featureMap = cube;
 

src/tsp-model/AbstractModel.js

@@ -137,6 +137,8 @@ function AbstractModel( container, config ) {
 	 */
 
 	this.configuration = new ModelConfiguration( config );
+
+	this.hoveredEmissive = undefined;
 
 	// Pass configuration to three.js scene.
 

src/tsp-model/Model.js

@@ -218,6 +218,13 @@ Model.prototype = Object.assign( Object.create( AbstractModel.prototype ), {
 			model.hoveredLayer = undefined;
 
 		}
+
+		if ( model.hoveredEmissive !== undefined ) {
+
+			model.hoveredEmissive.context.darken();
+			model.hoveredEmissive = undefined;
+
+		}
 
 		// Use Raycaster to capture hovered element.
 
@@ -231,7 +238,14 @@ Model.prototype = Object.assign( Object.create( AbstractModel.prototype ), {
 				let selectedElement = intersects[ i ].object;
 
 				if ( selectedElement.hoverable === true ) {
-
+
+					if ( selectedElement.emissiveable ) {
+
+						model.hoveredEmissive = selectedElement;
+						selectedElement.context.emissive();
+
+					}
+
 					let selectedLayer = this.layers[ selectedElement.layerIndex ];
 
 					// Let the layer to handle actual hover event.

src/tsp-model/Sequential.js

@@ -188,6 +188,13 @@ Sequential.prototype = Object.assign( Object.create( AbstractModel.prototype ),
 			model.hoveredLayer = undefined;
 
 		}
+
+		if ( model.hoveredEmissive !== undefined ) {
+
+			model.hoveredEmissive.context.darken();
+			model.hoveredEmissive = undefined;
+
+		}
 
 		// Use Raycaster to capture hovered element.
 
@@ -202,6 +209,13 @@ Sequential.prototype = Object.assign( Object.create( AbstractModel.prototype ),
 
 				if ( selectedElement.hoverable === true ) {
 
+					if ( selectedElement.emissiveable ) {
+
+						model.hoveredEmissive = selectedElement;
+						selectedElement.context.emissive();
+
+					}
+
 					let selectedLayer = this.layers[ selectedElement.layerIndex - 1 ];
 
 					// Let the layer to handle actual hover event.