Introduce NodeHandler

Author: sunag

src/nodes/Nodes.js

@@ -34,6 +34,7 @@ export { default as UniformNode, uniform } from './core/UniformNode.js';
 export { default as VaryingNode, varying } from './core/VaryingNode.js';
 export { default as OutputStructNode, outputStruct } from './core/OutputStructNode.js';
 export { default as MRTNode, mrt } from './core/MRTNode.js';
+export { default as NodeHandler } from './core/NodeHandler.js';
 
 import * as NodeUtils from './core/NodeUtils.js';
 export { NodeUtils };

src/nodes/core/NodeBuilder.js

@@ -572,6 +572,14 @@ class NodeBuilder {
 
 	}
 
+	handle( name, node ) {
+
+		const handler = this.renderer.nodeHandler;
+
+		return handler !== null ? handler.handle( name, node, this ) : node;
+
+	}
+
 	getPropertyName( node/*, shaderStage*/ ) {
 
 		return node.name;

src/nodes/core/NodeHandler.js

@@ -0,0 +1,33 @@
+class NodeHandler {
+
+	constructor() {
+
+		this.handlers = [];
+
+	}
+
+	onHandle( name, callback ) {
+
+		this.handlers[ name ] = callback;
+
+		return this;
+
+	}
+
+	handle( name, node, builder ) {
+
+		const callback = this.handlers[ name ];
+
+		if ( callback !== undefined ) {
+
+			node = callback( node, builder );
+
+		}
+
+		return node || null;
+
+	}
+
+}
+
+export default NodeHandler;

src/nodes/materials/NodeMaterial.js

@@ -415,14 +415,26 @@ class NodeMaterial extends Material {
 
 		}
 
+		// AO
+
+		let aoNode = null;
+
 		if ( this.aoNode !== null || builder.material.aoMap ) {
 
-			const aoNode = this.aoNode !== null ? this.aoNode : materialAOMap;
+			aoNode = this.aoNode !== null ? this.aoNode : materialAOMap;
+
+		}
+
+		aoNode = builder.handle( 'ao', aoNode );
+
+		if ( aoNode !== null ) {
 
 			materialLightsNode.push( new AONode( aoNode ) );
 
 		}
 
+		//
+
 		let lightsN = this.lightsNode || builder.lightsNode;
 
 		if ( materialLightsNode.length > 0 ) {

src/renderers/common/Renderer.js

@@ -135,6 +135,8 @@ class Renderer {
 
 		// backwards compatibility
 
+		this.nodeHandler = null;
+
 		this.shadowMap = {
 			enabled: false,
 			type: null