PointUtil.qerp

CHANGELOG.md

@@ -2,6 +2,13 @@
 
 All notable changes to this project will be documented in this file. See [standard-version](https://github.com/conventional-changelog/standard-version) for commit guidelines.
 
+### [0.1.24](https://github.com/rdarida/gameforge/compare/v0.1.23...v0.1.24) (2025-09-23)
+
+
+### Features
+
+* implement PointUtil.qerp function ([4156223](https://github.com/rdarida/gameforge/commit/41562237f0b21a84c78e5b2eb412df6152dcae7f))
+
 ### [0.1.23](https://github.com/rdarida/gameforge/compare/v0.1.22...v0.1.23) (2025-09-23)
 
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "gameforge",
-  "version": "0.1.23",
+  "version": "0.1.24",
   "description": "Lightweight HTML5 boilerplate for quick 2D game prototyping",
   "keywords": [
     "lightweight",

src/index.ts

@@ -1,6 +1,6 @@
 export * as Pixi from 'pixi.js';
 export * as PixiSound from '@pixi/sound';
-export { default as WebFontLoader} from 'webfontloader';
+export { default as WebFontLoader } from 'webfontloader';
 
 export * from './animation';
 export * from './events';

src/utils/PointUtil.ts

@@ -8,20 +8,48 @@ import * as MathUtil from './MathUtil';
  * @param start The start point.
  * @param end The end point.
  * @param t The interpolation factor.
- * @returns A new `Point` representing the interpolated position.
+ * @param result A `PIXI.Point` object to store the result.
+ * @returns A new `PIXI.Point` representing the interpolated position.
  */
 export function lerp(
   start: Point,
   end: Point,
   t: number,
-  point?: Point
+  result?: Point
 ): Point {
-  if (!point) {
-    point = new Point();
+  if (!result) {
+    result = new Point();
   }
 
-  point.x = MathUtil.lerp(start.x, end.x, t);
-  point.y = MathUtil.lerp(start.y, end.y, t);
+  result.x = MathUtil.lerp(start.x, end.x, t);
+  result.y = MathUtil.lerp(start.y, end.y, t);
 
-  return point;
+  return result;
+}
+
+/**
+ * Quadratic interpolation between two `PIXI.Point` objects.
+ *
+ * @param start The start point.
+ * @param control The control point.
+ * @param end The end point.
+ * @param t The interpolation factor.
+ * @param result A `PIXI.Point` object to store the result.
+ * @returns A new `PIXI.Point` representing the interpolated position.
+ */
+export function qerp(
+  start: Point,
+  control: Point,
+  end: Point,
+  t: number,
+  result?: Point
+): Point {
+  if (!result) {
+    result = new Point();
+  }
+
+  result.x = MathUtil.qerp(start.x, control.x, end.x, t);
+  result.y = MathUtil.qerp(start.y, control.y, end.y, t);
+
+  return result;
 }

tests/utils/PointUtil.test.ts

@@ -27,4 +27,30 @@ describe('Test PointUtil functions', () => {
     expect(actual.x).toBe(5.1);
     expect(actual.y).toBe(-5.1);
   });
+
+  it('should compute quadratic interpolation between two numbers', () => {
+    const start = new Point(-5, 5);
+    const control = new Point(0, 0);
+    const end = new Point(5, -5);
+
+    let actual = PointUtil.qerp(start, control, end, -0.01);
+    expect(actual.x).toBeCloseTo(-5.1);
+    expect(actual.y).toBeCloseTo(5.1);
+
+    actual = PointUtil.qerp(start, control, end, 0);
+    expect(actual.x).toBe(-5);
+    expect(actual.y).toBe(5);
+
+    actual = PointUtil.qerp(start, control, end, 0.5);
+    expect(actual.x).toBe(0);
+    expect(actual.y).toBe(0);
+
+    PointUtil.qerp(start, control, end, 1, actual);
+    expect(actual.x).toBe(5);
+    expect(actual.y).toBe(-5);
+
+    PointUtil.qerp(start, control, end, 1.01, actual);
+    expect(actual.x).toBeCloseTo(5.1);
+    expect(actual.y).toBeCloseTo(-5.1);
+  });
 });