////////////////////////////////////////////////////////////////////////////////
// js-graphics-mathlib
// Math library for JavaScript 2D/3D graphics rendering.
//
// MIT License (c) 2015-2019 Jingwood, All rights reserved.
////////////////////////////////////////////////////////////////////////////////

import { Vec2 } from "./vec2.js"
import { Vec3 } from "./vec3.js"
import { Vec4 } from "./vec4.js"
import { MathFunctions3 } from "./functions3.js";
import { MathFunctions2 } from "./functions2.js";
import { EPSILON, PIAngleDelta } from "./const.js";

export function approxiEquals(v1, v2, epsilon = EPSILON) {
	if (v1 === v2) return true;
	return Math.abs(v1 - v2) < epsilon;
}

export class MathFunctions {
	static degreeToAngle(d) {
		return d * 180.0 / Math.PI;
	}

	static angleToDegree(a) {
		return a * PIAngleDelta;
	}

	static fixAngle(angle) {
		if (angle < 0) {
			while (angle < 0) angle += 360;
		} else {
			while (angle > 360) angle -= 360;
		}
		return angle;
	}

	static angleToArc(width, height, angle) {
		return (180.0 / Math.PI * Math.atan2(
			Math.sin(angle * PIAngleDelta) * height / width,
			Math.cos(angle * PIAngleDelta)));
	}

	static abs(v) {
		if (v instanceof Vec3) {
			return new Vec3(Math.abs(v.x), Math.abs(v.y), Math.abs(v.z));
		}
	}

	static clamp(v, min = 0, max = 1) {
		if (!isNaN(v)) {
			if (v < min) return min;
			else if (v > max) return max;
			else return v;
		} else if (v instanceof Vec2) {
			return MathFunctions2.clamp2(v, min, max);
		} else if (v instanceof Vec3) {
			return MathFunctions3.clamp3(v, min, max);
		} else if (v instanceof Vec4) {
			return new Vec4(MathFunctions.clamp(v.x, min, max),
				MathFunctions.clamp(v.y, min, max),
				MathFunctions.clamp(v.z, min, max),
				MathFunctions.clamp(v.w, min, max));
		}
	}

	static smoothstep(edge0, edge1, x) {
		var t = MathFunctions.clamp((x - edge0) / (edge1 - edge0), 0.0, 1.0);
		return t * t * (3.0 - 2.0 * t);
	}
}