Merge pull request #856 from garrettmichaelgeorge/dev

Add fanIn()

Tone/core/context/ToneAudioNode.test.ts

@@ -3,7 +3,7 @@ import { Merge } from "Tone/component";
 import { Split } from "Tone/component/channel/Split";
 import { Oscillator } from "Tone/source";
 import { Gain } from "./Gain";
-import { connect, disconnect } from "./ToneAudioNode";
+import { connect, disconnect, fanIn } from "./ToneAudioNode";
 import { PassAudio } from "test/helper/PassAudio";
 import { Offline } from "test/helper/Offline";
 
@@ -218,6 +218,16 @@ describe("ToneAudioNode", () => {
 				disconnect(input);
 			}, false);
 		});
+
+		it("can fan in multiple nodes to a destination", () => {
+			return PassAudio(input => {
+				const context = input.context;
+				const gain0 = context.createGain();
+				const gain1 = context.createGain();
+				const output = context.destination;
+				fanIn(gain0, gain1, input, output);
+			});
+		});
 		
 		it("can connect one channel to another", () => {
 			return PassAudio(input => {
@@ -320,6 +330,16 @@ describe("ToneAudioNode", () => {
 				disconnect(gain, output);
 			});
 		});
+
+		it("can fan in multiple nodes to a destination", async () => {
+			await Offline(() => {
+				const output = new Gain();
+				const input0 = new Gain();
+				const input1 = new Gain();
+				const input2 = new Gain();
+				fanIn(input0, input1, input2, output);
+			});
+		});
 	});
 
 });

Tone/core/context/ToneAudioNode.ts

@@ -376,3 +376,21 @@ export function disconnect(
 		srcNode.disconnect();
 	}
 }
+
+/**
+ * Connect the output of one or more source nodes to a single destination node
+ * @param nodes One or more source nodes followed by one destination node
+ * @example
+ * const player = new Tone.Player("https://tonejs.github.io/audio/drum-samples/conga-rhythm.mp3");
+ * const player1 = new Tone.Player("https://tonejs.github.io/audio/drum-samples/conga-rhythm.mp3");
+ * const filter = new Tone.Filter("G5").toDestination();
+ * // connect nodes to a common destination
+ * fanIn(player, player1, filter);
+ */
+export function fanIn(...nodes: OutputNode[]): void {
+	const dstNode = nodes.pop();
+
+	if (isDefined(dstNode)) {
+		nodes.forEach(node => connect(node, dstNode));
+	}
+}