/* <copyright>
This file contains proprietary software owned by Motorola Mobility, Inc.<br/>
No rights, expressed or implied, whatsoever to this software are provided by Motorola Mobility, Inc. hereunder.<br/>
(c) Copyright 2011 Motorola Mobility, Inc.  All Rights Reserved.
</copyright> */

/**
* RDGE.vec4 = {}
* This library contains functions for operating on 4D vectors. Any JS array 
* containing at least 4 numeric components can represent a 4D vector. 
*
* For example, all of these are valid RDGE.vec4 declarations:
*		var a = [0, 0, 0, 1];
*		var b = RDGE.RDGE.vec4.identity();
*		var c = RDGE.RDGE.vec4.zero();
*
*/
var RDGE = RDGE || {};
RDGE.vec4 = {};

/**
* RDGE.vec4.string
*/
RDGE.vec4.string = function (v) {
    return "{ " + v[0] + ", " + v[1] + ", " + v[2] + ", " + v[3] + " }";
};

/**
* RDGE.vec4.verify
*/
RDGE.vec4.verify = function (v) {
    if (v == undefined || v.length == undefined || v.length < 4) {
        return false;
    }

    if (typeof (v[0]) != "number" || typeof (v[1]) != "number" || typeof (v[2]) != "number" || typeof (v[3]) != "number") {
        return false;
    }

    return true;
};

/**
* RDGE.vec4.inplace_copy
*/
RDGE.vec4.inplace_copy = function (dst, src) {
    dst[0] = src[0];
    dst[1] = src[1];
    dst[2] = src[2];
    dst[3] = src[3];
};

/**
* RDGE.vec4.copy
*/
RDGE.vec4.copy = function (v) {
    if (v.length == undefined) {
        return [v, v, v, v];
    }

    if (v.length == 3) {
        return [v[0], v[1], v[2], 1.0];
    }

    return [v[0], v[1], v[2], v[3]];
};

/**
* RDGE.vec4.zero
*/
RDGE.vec4.zero = function () {
    return [0.0, 0.0, 0.0, 0.0];
};

/**
* RDGE.vec4.identity
*/
RDGE.vec4.identity = function () {
    return [0.0, 0.0, 0.0, 1.0];
};

/**
* RDGE.vec4.up
*/
RDGE.vec4.up = function () {
    return [0.0, 1.0, 0.0, 0.0];
};

/**
* RDGE.vec4.forward
*/
RDGE.vec4.forward = function () {
    return [0.0, 0.0, 1.0, 0.0];
};

/**
* RDGE.vec4.right
*/
RDGE.vec4.right = function () {
    return [1.0, 0.0, 0.0, 0.0];
};

/**
* RDGE.vec4.random
*/
RDGE.vec4.random = function (min, max) {
    return [min[0] + (max[0] - min[0]) * Math.random(),
             min[1] + (max[1] - min[1]) * Math.random(),
             min[2] + (max[2] - min[2]) * Math.random(),
             min[3] + (max[3] - min[3]) * Math.random()];
};

/**
* RDGE.vec4.add
*/
RDGE.vec4.add = function (a, b) {
    return [a[0] + b[0],
				a[1] + b[1],
				a[2] + b[2],
				a[3] + b[3]];
};

/**
* RDGE.vec4.sub
*/
RDGE.vec4.sub = function (a, b) {
    return [a[0] - b[0],
				a[1] - b[1],
				a[2] - b[2],
				a[3] - b[3]];
};

/**
* RDGE.vec4.mul
*/
RDGE.vec4.mul = function (a, b) {
    return [a[0] * b[0],
				a[1] * b[1],
				a[2] * b[2],
				a[3] * b[3]];
};

/**
* RDGE.vec4.addMul
*/
RDGE.vec4.addMul = function (a, b, s) {
    if (s.length != undefined && s.length >= 4) {
        return [a[0] + b[0] * s[0], a[1] + b[1] * s[1], a[2] + b[2] * s[2], a[3] + b[3] * s[3]];
    } else {
        return [a[0] + b[0] * s, a[1] + b[1] * s, a[2] + b[2] * s, a[3] + b[3] * s];
    }
};

/**
* RDGE.vec4.scale
*/
RDGE.vec4.scale = function (v, s) {
    if (s.length != undefined && s.length >= 4) {
        return [v[0] * s[0], v[1] * s[1], v[2] * s[2], v[3] * s[3]];
    } else {
        return [v[0] * s, v[1] * s, v[2] * s, v[3] * s];
    }
};

/**
* RDGE.vec4.negate
*/
RDGE.vec4.negate = function (v) {
    return [-v[0], -v[1], -v[2], -v[3]];
};

/**
* RDGE.vec4.dot
*/
RDGE.vec4.dot = function (a, b) {
    return a[0] * b[0] + a[1] * b[1] + a[2] * b[2] + a[3] * b[3];
};

/**
* RDGE.vec4.normalize
*/
RDGE.vec4.normalize = function (v) {
    var l = Math.sqrt(v[0] * v[0] + v[1] * v[1] + v[2] * v[2] + v[3] * v[3]);
    if (Math.abs(1.0 - l) > 0.0001) {
        var ool = 1.0 / l;
        return [v[0] * ool, v[1] * ool, v[2] * ool, v[3] * ool];
    }
    return v;
};

/**
* RDGE.vec4.lengthSq
*/
RDGE.vec4.lengthSq = function (v) {
    return v[0] * v[0] +
			v[1] * v[1] +
			v[2] * v[2] +
			v[3] * v[3];
};

/**
* RDGE.vec4.length
*/
RDGE.vec4.length = function (v) {
    return Math.sqrt(v[0] * v[0] +
						v[1] * v[1] +
						v[2] * v[2] +
						v[3] * v[3]);
};

/**
* RDGE.vec4.abs
*/
RDGE.vec4.abs = function (v) {
    return [Math.abs(v[0]), Math.abs(v[1]), Math.abs(v[2]), Math.abs(v[3])];
};

/**
* RDGE.vec4.min
*/
RDGE.vec4.min = function (a, b) {
    return [Math.min(a[0], b[0]), Math.min(a[1], b[1]), Math.min(a[2], b[2]), Math.min(a[3], b[3])];
};

/**
* RDGE.vec4.max
*/
RDGE.vec4.max = function (a, b) {
    return [Math.max(a[0], b[0]), Math.max(a[1], b[1]), Math.max(a[2], b[2]), Math.min(a[3], b[3])];
};

/**
* RDGE.vec4.clamp
*/
RDGE.vec4.clamp = function (v, vmin, vmax) {
    return RDGE.vec4.min(vmax, RDGE.vec4.max(v, vmin));
};

/**
* RDGE.vec4.equal
*/
RDGE.vec4.equal = function (a, b, t) {
    if (!t) {
        t = 0.001;
    }
    return (RDGE.vec4.distanceSq(a, b) < (t * t));
};

/**
* RDGE.vec4.lerp
*/
RDGE.vec4.lerp = function (a, b, t) {
    return [
		a[0] + (b[0] - a[0]) * t,
		a[1] + (b[1] - a[1]) * t,
		a[2] + (b[2] - a[2]) * t,
		a[3] + (b[3] - a[3]) * t
	];
};