Vec2d.java

/*
 * Codeable Objects by Jennifer Jacobs is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.
 * Based on a work at hero-worship.com/portfolio/codeable-objects.
 *
 * This file is part of the Codeable Objects Framework.
 *
 *     Codeable Objects is free software: you can redistribute it and/or modify
 *     it under the terms of the GNU General Public License as published by
 *     the Free Software Foundation, either version 3 of the License, or
 *     (at your option) any later version.
 *
 *     Codeable Objects is distributed in the hope that it will be useful,
 *     but WITHOUT ANY WARRANTY; without even the implied warranty of
 *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *     GNU General Public License for more details.
 *
 *     You should have received a copy of the GNU General Public License
 *     along with Codeable Objects.  If not, see <http://www.gnu.org/licenses/>.
 */

package com.pixelmaid.dresscode.drawing.math;

/**
 * User: jenniferjacobs
 * Date: 4/28/12
 * Time: 4:28 PM
 * To change this template use File | Settings | File Templates.
 */
public class Vec2d {
    public double x;
    public double y;

    public Vec2d(double x, double y) {

        this.x = x;
        this.y = y;

    }

    public Vec2d add(Vec2d val) {
        return new Vec2d(this.x + val.x, this.y + val.y);
    }

    public Vec2d sub(Vec2d val) {
        return new Vec2d(this.x - val.x, this.y - val.y);
    }

    public Vec2d div(double val) {
        return new Vec2d(this.x / val, this.y / val);
    }

    public Vec2d mul(double val) {
        return new Vec2d(this.x * val, this.y * val);
    }


    public double DistanceSqrd(Vec2d vec1, Vec2d vec2) {
        return (Math.pow(vec1.x - vec2.x, 2) + Math.pow(vec1.y - vec2.y, 2));
    }

    public double Distance(Vec2d vec1, Vec2d vec2) {
        //Returns the distance between two points
        return Math.sqrt(DistanceSqrd(vec1, vec2));
    }

    public double LengthSqrd(Vec2d vec) {
        //Returns the length of a vector sqaured. Faster than Length(), but only marginally
        return Math.pow(vec.x, 2) + Math.pow(vec.y, 2);
    }


    public double Length() {
        //Returns the length of a vector'
        return Math.sqrt(LengthSqrd(this));
    }

    public static Vec2d Normalize(Vec2d vec) {
        //Returns a new vector that has the same direction as vec, but has a length of one.
        if (vec.x == 0 && vec.y == 0) {
            return new Vec2d(0, 0);
        }

        return vec.div(vec.Length());
    }


    public double Dot(Vec2d b) {
        //Computes the dot product of a and b'
        return (this.x * b.x) + (this.y * b.y);
    }


    public Vec2d ProjectOnto(Vec2d v, Vec2d w) {
        //'Projects w onto v.'
        return v.mul(w.Dot(v) / LengthSqrd(v));
    }


}