// pathfinder/demo2/geometry.ts
//
// Copyright © 2018 The Pathfinder Project Developers.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

export const EPSILON: number = 1e-6;

export class Point2D {
    x: number;
    y: number;

    constructor(x: number, y: number) {
        this.x = x;
        this.y = y;
    }

    approxEq(other: Point2D): boolean {
        return approxEq(this.x, other.x) && approxEq(this.y, other.y);
    }

    lerp(other: Point2D, t: number): Point2D {
        return new Point2D(lerp(this.x, other.x, t), lerp(this.y, other.y, t));
    }
}

export interface Size2D {
    width: number;
    height: number;
}

export interface Rect {
    origin: Point2D;
    size: Size2D;
}

export interface Vector3D {
    x: number;
    y: number;
    z: number;
}

export class Matrix2D {
    a: number; b: number;
    c: number; d: number;
    tx: number; ty: number;

    constructor(a: number, b: number, c: number, d: number, tx: number, ty: number) {
        this.a = a; this.b = b;
        this.c = c; this.d = d;
        this.tx = tx; this.ty = ty;
    }
}

export function approxEq(a: number, b: number): boolean {
    return Math.abs(a - b) <= EPSILON;
}

export function lerp(a: number, b: number, t: number): number {
    return a + (b - a) * t;
}