Adding mouseX() and mouseY() to arrays

src/ArrayExtensions.ts

@@ -8,6 +8,8 @@ declare global {
     sub(amount: number): number[];
     mult(amount: number): number[];
     div(amount: number): number[];
+    mouseX(): T[],
+    mouseY(): T[],
     palindrome(): T[];
     random(index: number): T;
     rand(index: number): T;
@@ -34,6 +36,28 @@ declare global {
 }
 
 export const makeArrayExtensions = (api: UserAPI) => {
+
+  Array.prototype.mouseX = function <T>(this: T[]): T {
+    /**
+     * @returns Value from list based on mouse X position
+     */
+    const mouse_position = api.mouseX();
+    const screenWidth = window.innerWidth;
+    const zoneWidth = screenWidth / this.length;
+    const zoneIndex = Math.floor(mouse_position / zoneWidth);
+
+    return this[zoneIndex];
+  };
+
+  Array.prototype.mouseY = function <T>(this: T[]): T {
+    const mouse_position = api.mouseY();
+    const screenHeight = window.innerHeight;
+    const zoneHeight = screenHeight / this.length;
+    const zoneIndex = Math.floor(mouse_position / zoneHeight);
+
+    return this[zoneIndex];
+  };
+
   Array.prototype.square = function(): number[] {
     /**
      * @returns New array with squared values.

src/documentation/patterns.ts

@@ -73,6 +73,18 @@ beat([1, 0.5].beat()) :: sound(['bass3'].bar())
 `
   )}
 
+- <ic>mouseX()</ic> / <ic>mouseY()</ic>: divides the screen in <ic>n</ic> zones and returns the value corresponding to the mouse position on screen.</ic>
+
+${makeExample(
+    "Controlling an arpeggio (octave and note) with mouse", `
+beat(0.25)::sound('wt_piano')
+  .note([0,2,3,4,5,7,8,9,11,12].scale(
+    'minor', 30 + [0,12,24].mouseY()).mouseX())
+  .room(0.5).size(4).lpad(-2, .2).lpf(500, 0.3)
+  .ad(0, .2).out()
+`, true
+  )}
+
 - <ic>palindrome()</ic>: Concatenates a list with the same list in reverse.
 
 ${makeExample(