Add WarpByScalar effect

Signed-off-by: martinRenou <martin.renou@gmail.com>

src/Effects/WarpByScalar.ts

@@ -0,0 +1,81 @@
+import * as Nodes from 'three/examples/jsm/nodes/Nodes';
+
+import {
+  Effect, Input, InputDimension
+} from '../EffectBlock';
+
+import {
+  Block
+} from '../Block';
+
+import {
+  NodeOperation
+} from '../NodeMesh';
+
+
+/**
+ * Transform the vertices positions. The new vertice position is equal to `factor * input * normal + initialPosition`
+ **/
+export
+class WarpByScalar extends Effect {
+
+  constructor (parent: Block, input: Input, factor: number) {
+    super(parent, input);
+
+    this.factorNode = new Nodes.FloatNode(factor);
+
+    this.intermediateTransformNode = new Nodes.OperatorNode(
+      this.factorNode,
+      this.inputNode,
+      Nodes.OperatorNode.MUL
+    );
+
+    this.transformNode = new Nodes.OperatorNode(
+      this.intermediateTransformNode,
+      new Nodes.NormalNode(Nodes.NormalNode.WORLD),
+      Nodes.OperatorNode.MUL
+    );
+
+    this.addTransformNode(NodeOperation.ADD, this.transformNode);
+
+    this.buildMaterial();
+
+    this.initialized = true;
+
+    // There is no new geometry specific to this effect, we forward the parent event
+    this.parent.on('change:geometry', () => { this.trigger('change:geometry'); });
+
+    this.updateMatrix();
+  }
+
+  setInput(input?: Input) : void {
+    super.setInput(input);
+
+    if (this.initialized) {
+      this.intermediateTransformNode.b = this.inputNode;
+
+      this.buildMaterial();
+    }
+  }
+
+  set factor (value: number) {
+    this.factorNode.value = value;
+  }
+
+  get factor () {
+    return this.factorNode.value;
+  }
+
+  get inputDimension () : InputDimension {
+    return 1;
+  }
+
+  private initialized: boolean = false;
+
+  private factorNode: Nodes.FloatNode;
+  private intermediateTransformNode: Nodes.OperatorNode;
+  private transformNode: Nodes.OperatorNode;
+
+  protected inputNode: Nodes.Node;
+
+}

src/Effects/effects.ts

@@ -7,6 +7,7 @@ export * from './IsoSurface';
 export * from './Threshold';
 
 export * from './Warp';
+export * from './WarpByScalar';
 
 export * from './Water/Water';
 export * from './Water/UnderWater';