✨ Tests for point class

lib/point.ts

@@ -1,24 +1,25 @@
+import { round, rad2deg, deg2rad } from './utils';
+
 const PRECISION = 2;
-const RAD = 57.29577951308232;
+// A poor man's rad2deg()
 
-
-export default class Point {
+export class Point {
   x: number;
   y: number;
 
   constructor(x: number, y: number) {
-    this.x = +x.toFixed(PRECISION);
-    this.y = +y.toFixed(PRECISION);
+    this.x = round(x);
+    this.y = round(y);
 
     return this;
   }
 
   /** Returns the distance between this point and that point */
-  distance(that: Point): number {
+  dist(that: Point): number {
     let dx = this.x - that.x;
     let dy = this.y - that.y;
 
-    return Math.sqrt(Math.pow(dx, 2) + Math.pow(dy,2));
+    return round(Math.sqrt(Math.pow(dx, 2) + Math.pow(dy,2)));
   }
 
   /** Returns slope of a line made by this point and that point */
@@ -26,37 +27,76 @@ export default class Point {
     return (that.y - this.y) / (that.x - this.x);
   }
 
+  /** Returns the x-delta between this point and that point */
+  dx(that: Point): number {
+    return that.x - this.x;
+  }
+
+  /** Returns the y-delta between this point and that point */
+  dy(that: Point): number {
+    return that.y - this.y;
+  }
+
   /** Returns the angle between this point and that point */
   angle(that: Point): number {
-    let dx = this.x - that.x;
-    let dy = this.y - that.y;
-    let rad = Math.atan2(-1 * dy, dy);
+    let rad = Math.atan2(-1 * this.dy(that), this.dx(that));
     while (rad < 0) rad += 2 * Math.PI;
 
-    // A poor man's rad2deg()
-    return rad * RAD;
+    return rad2deg(rad);
   }
 
-  /** Rotate this point degrees around that point */
-  rotate(degrees: number, that: Point) {
-    let radius = this.distance(that);
+  /** Rotate this point deg around that point */
+  rotate(deg: number, that: Point): Point {
+    let radius = this.dist(that);
     let angle = this.angle(that);
-    let x = that.x + radius * Math.cos((angle + degrees) / RAD) * -1;
-    let y = that.y + radius * Math.sin((angle + degrees) / RAD);
+    let x = that.x + radius * Math.cos(deg2rad(angle + deg)) * -1;
+    let y = that.y + radius * Math.sin(deg2rad(angle + deg));
 
     return new Point(x, y);
   }
 
-  /** Shifts this point distance in the degrees direction */
-  shift(degrees: number, distance: number): Point {
-    let p = this.copy();
-    p.x += distance;
-
-    return p.rotate(degrees, this);
-  }
-
   /** returns an identical copy of this point */
   copy(): Point {
     return new Point(this.x, this.y);
   }
+
+  /** checks whether this point is equal to that point */
+  equals(that: Point): boolean {
+    return (this.x === that.x && this.y === that.y) ? true : false;
+  }
+
+  /** Mirrors this point around X value of that point */
+  flipX(that: Point): Point
+  {
+    return new Point(that.x + this.dx(that), that.y);
+  }
+
+  /** Mirrors this point around Y value of that point */
+  flipY(that: Point): Point
+  {
+    return new Point(that.x, that.y + this.dy(that));
+  }
+
+  /** Shifts this point distance in the deg direction */
+  shift(deg: number, distance: number): Point {
+    let p = this.copy();
+    p.x += distance;
+
+    return p.rotate(deg, this);
+  }
+
+  /** Shifts this point distance in the direction of that point */
+  shiftTowards(that: Point, distance: number): Point {
+    return this.shift(this.angle(that), distance);
+  }
+
+  /** Shifts this point fraction of the distance towards that point */
+  shiftFractionTowards(that: Point, fraction: number): Point {
+    return this.shiftTowards(that, this.dist(that) * fraction);
+  }
+
+  /** Shifts this point distance beyond that point */
+  shiftOutwards(that: Point, distance: number): Point {
+    return this.shiftTowards(that, this.dist(that) + distance);
+  }
 }