Vector2.java

/*    Dice in the dark. D & D app for the blind and seeing impaired,
*    Copyright (C) <2013r>  <Lovisa Irpa Helgadottir>
*
*    This program 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.
*
*    This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
*/
package com.example.framework.math;

import android.util.FloatMath;

public class Vector2 {
    public static float TO_RADIANS = (1 / 180.0f) * (float) Math.PI;
    public static float TO_DEGREES = (1 / (float) Math.PI) * 180;
    public float x, y;

    public Vector2() {
    }

    public Vector2(float x, float y) {
        this.x = x;
        this.y = y;
    }

    public Vector2(Vector2 other) {
        this.x = other.x;
        this.y = other.y;
    }

    public Vector2 cpy() {
        return new Vector2(x, y);
    }

    public Vector2 set(float x, float y) {
        this.x = x;
        this.y = y;
        return this;
    }

    public Vector2 set(Vector2 other) {
        this.x = other.x;
        this.y = other.y;
        return this;
    }

    public Vector2 add(float x, float y) {
        this.x += x;
        this.y += y;
        return this;
    }

    public Vector2 add(Vector2 other) {
        this.x += other.x;
        this.y += other.y;
        return this;
    }

    public Vector2 sub(float x, float y) {
        this.x -= x;
        this.y -= y;
        return this;
    }

    public Vector2 sub(Vector2 other) {
        this.x -= other.x;
        this.y -= other.y;
        return this;
    }

    public Vector2 mul(float scalar) {
        this.x *= scalar;
        this.y *= scalar;
        return this;
    }

    public float len() {
        return FloatMath.sqrt(x * x + y * y);
    }

    public Vector2 nor() {
        float len = len();
        if (len != 0) {
            this.x /= len;
            this.y /= len;
        }
        return this;
    }

    public float angle() {
        float angle = (float) Math.atan2(y, x) * TO_DEGREES;
        if (angle < 0)
            angle += 360;
        return angle;
    }

    public Vector2 rotate(float angle) {
        float rad = angle * TO_RADIANS;
        float cos = FloatMath.cos(rad);
        float sin = FloatMath.sin(rad);

        float newX = this.x * cos - this.y * sin;
        float newY = this.x * sin + this.y * cos;

        this.x = newX;
        this.y = newY;

        return this;
    }

    public float dist(Vector2 other) {
        float distX = this.x - other.x;
        float distY = this.y - other.y;
        return FloatMath.sqrt(distX * distX + distY * distY);
    }

    public float dist(float x, float y) {
        float distX = this.x - x;
        float distY = this.y - y;
        return FloatMath.sqrt(distX * distX + distY * distY);
    }
    
    public float distSquared(Vector2 other) {
        float distX = this.x - other.x;
        float distY = this.y - other.y;        
        return distX*distX + distY*distY;
    }   
    
    public float distSquared(float x, float y) {
        float distX = this.x - x;
        float distY = this.y - y;        
        return distX*distX + distY*distY;
    }   

}