feat: added scrollDelta() function to app state

src/app/app.ts

@@ -205,6 +205,7 @@ export const initAppState = (opt: {
         capsOn: false,
         mousePos: new Vec2(0),
         mouseDeltaPos: new Vec2(0),
+        scrollDelta: new Vec2(0),
         keyState: new ButtonState<Key>(
             "keyPress",
             "keyPressRepeat",
@@ -465,6 +466,10 @@ export const initApp = (
         return state.mouseDeltaPos.clone();
     }
 
+    function scrollDelta(): Vec2 {
+        return state.scrollDelta.clone();
+    }
+
     function isMousePressed(m: MouseButton = "left"): boolean {
         return state.mouseState.pressed.has(m);
     }
@@ -818,6 +823,7 @@ export const initApp = (
         state.charInputted = [];
         state.isMouseMoved = false;
         state.mouseDeltaPos = new Vec2(0);
+        state.scrollDelta = new Vec2(0);
 
         state.gamepadStates.forEach((s) => {
             s.buttonState.update();
@@ -1233,8 +1239,10 @@ export const initApp = (
     // TODO: option to not prevent default?
     canvasEvents.wheel = (e) => {
         e.preventDefault();
+        state.scrollDelta.set(e.deltaX, e.deltaY);
+
         state.events.onOnce("input", () => {
-            state.events.trigger("scroll", new Vec2(e.deltaX, e.deltaY));
+            state.events.trigger("scroll", state.scrollDelta);
         });
     };
 
@@ -1333,6 +1341,7 @@ export const initApp = (
         isTouchscreen,
         mousePos,
         mouseDeltaPos,
+        scrollDelta,
         isKeyDown,
         isKeyPressed,
         isKeyPressedRepeat,

src/core/context.ts

@@ -470,6 +470,7 @@ export const createContext = (
         onButtonRelease: defaultScope.onButtonRelease,
         mousePos: app.mousePos,
         mouseDeltaPos: app.mouseDeltaPos,
+        scrollDelta: app.scrollDelta,
         isKeyDown: app.isKeyDown,
         isKeyPressed: app.isKeyPressed,
         isKeyPressedRepeat: app.isKeyPressedRepeat,

src/core/contextType.ts

@@ -4651,6 +4651,15 @@ export interface KAPLAYCtx {
      * @subgroup Mouse
      */
     mouseDeltaPos(): Vec2;
+    /**
+     * How much the mouse wheel scrolled since last frame.
+     *
+     * @returns The delta scroll.
+     * @since v4000.0
+     * @group Input
+     * @subgroup Mouse
+     */
+    scrollDelta(): Vec2;
     /**
      * If any or certain key(s) are currently down.
      *

tests/playtests/largeTexture.js

@@ -37,11 +37,12 @@ onUpdate(() => {
         );
         setCamPos(cameraPosition);
     }
+
+    const scroll = scrollDelta();
+    if (scroll.y !== 0) {
+        cameraScale *= 1 - 0.1 * Math.sign(scroll.y);
+        setCamScale(cameraScale);
+    }
 });
 
 let cameraScale = 1;
-
-onScroll((delta) => {
-    cameraScale = cameraScale * (1 - 0.1 * Math.sign(delta.y));
-    setCamScale(cameraScale);
-});