Gamelib/src/com/uulm/marvelous/gamelibrary/IntVector2.java

package com.uulm.marvelous.gamelibrary;

import java.io.Serializable;
import java.util.Objects;

/** Represents a 2d vector of integers.
 */
public class IntVector2 implements Serializable {
    private int x;
    private int y;

    public final static IntVector2 X = new IntVector2(1, 0);
    public final static IntVector2 Y = new IntVector2(0, 1);
    public final static IntVector2 Zero = new IntVector2(0, 0);

    private final static float nearZero = 0.000000001f;

    public IntVector2(int x, int y) {
        set(x, y);
    }

    public IntVector2(IntVector2 v) {
        set(v);
    }

    public IntVector2 copy() {
        return new IntVector2(this);
    }

    public int getX() {
        return x;
    }

    public int getY() {
        return y;
    }

    public static float length(int x, int y) {
        return (float)Math.sqrt(x * x + y * y);
    }

    public float length() {
        return IntVector2.length(this.x, this.y);
    }

    public static float length2(int x, int y) {
        return x * x + y * y;
    }

    public float length2 () {
        return IntVector2.length2(this.x, this.y);
    }

    public IntVector2 set(int x, int y) {
        this.x = x;
        this.y = y;
        return this;
    }

    public IntVector2 set(IntVector2 v) {
        return set(v.x, v.y);
    }

    public IntVector2 sub(int x, int y) {
        this.x -= x;
        this.y -= y;
        return this;
    }

    public IntVector2 sub(IntVector2 v) {
        return sub(v.x, v.y);
    }

    public IntVector2 add(int x, int y) {
        this.x += x;
        this.y += y;
        return this;
    }

    public IntVector2 add(IntVector2 v) {
        return add(v.x, v.y);
    }

    public static float dot(float x1, float y1, float x2, float y2) {
        return x1 * x2 + y1 * y2;
    }

    public float dot(float ox, float oy) {
        return IntVector2.dot(this.x, this.y, ox, oy);
    }

    public float dot(IntVector2 v) {
        return dot(v.x, v.y);
    }

    public IntVector2 scale(float x, float y) {
        this.x *= x;
        this.y *= y;
        return this;
    }

    public IntVector2 scale(float scalar) {
        return scale(scalar, scalar);
    }

    public IntVector2 scale(IntVector2 v) {
        return scale(v.x, v.y);
    }

    public static float distance(int x1, int y1, int x2, int y2) {
        final float x_d = x2 - x1;
        final float y_d = y2 - y1;
        return (float)Math.sqrt(x_d * x_d + y_d * y_d);
    }

    public float distance(int x, int y) {
        return IntVector2.distance(this.x, this.y, x, y);
    }

    public float distance(IntVector2 v) {
        return distance(v.x, v.y);
    }

    public static float distance2(int x1, int y1, int x2, int y2) {
        final float x_d = x2 - x1;
        final float y_d = y2 - y1;
        return x_d * x_d + y_d * y_d;
    }

    public float distance2(int x, int y) {
        return IntVector2.distance2(this.x, this.y, x, y);
    }

    public float distance2(IntVector2 v) {
        return distance2(v.x, v.y);
    }

    public IntVector2 setLength(float len) {
        return setLength2(len * len);
    }

    public IntVector2 setLength2(float len2) {
        float oldLen2 = length2();
        return (oldLen2 == 0 || oldLen2 == len2) ? this : scale((float)Math.sqrt(len2 / oldLen2));
    }

    public String toString() {
        return "(" + x + "," + y + ")";
    }

    public IntVector2 fromString(String v) throws NumberFormatException {
        int s = v.indexOf(',', 1);
        if (s != -1 && v.charAt(0) == '(' && v.charAt(v.length() - 1) == ')') {
            try {
                int x = Integer.parseInt(v.substring(1, s));
                int y = Integer.parseInt(v.substring(s + 1, v.length() - 1));
                return this.set(x, y);
            }catch (NumberFormatException ex) {
                //ok
            }
        }
        throw new NumberFormatException("Malformed IntVector2: " + v);
    }

    public float cross(float x, float y) {
        return this.x * y - this.y * x;
    }

    public float cross(IntVector2 v) {
        return cross(v.x, v.y);
    }

    public boolean isUnit(final float margin) {
        return Math.abs(length2() - 1f) < margin;
    }

    public boolean isUnit() {
        return isUnit(nearZero);
    }

    public boolean isZero() {
        return x == 0 && y == 0;
    }

    public boolean isZero(final float margin) {
        return length2() < margin;
    }

    public boolean isOnLine(IntVector2 other, float epsilon) {
        return Math.abs(x * other.y - y * other.x) <= epsilon;
    }

    public boolean isOnLine(IntVector2 other) {
        return isOnLine(other, nearZero);
    }

    public boolean isCollinear(IntVector2 other, float epsilon) {
        return isOnLine(other, epsilon) && dot(other) > 0f;
    }

    public boolean isCollinear(IntVector2 other) {
        return isOnLine(other) && dot(other) > 0f;
    }

    public boolean isCollinearOpposite(IntVector2 other, float epsilon) {
        return isOnLine(other, epsilon) && dot(other) < 0f;
    }

    public boolean isCollinearOpposite(IntVector2 other) {
        return isOnLine(other) && dot(other) < 0f;
    }

    public boolean isPerpendicular(IntVector2 vector) {
        return isPerpendicular(vector,nearZero);
    }

    public boolean isPerpendicular(IntVector2 vector, float epsilon) {
        return Math.abs(dot(vector)) <= epsilon;
    }

    public boolean hasSameDirection(IntVector2 vector) {
        return dot(vector) > 0;
    }

    public boolean hasOppositeDirection(IntVector2 vector) {
        return dot(vector) < 0;
    }

    public IntVector2 setZero() {
        this.x = 0;
        this.y = 0;
        return this;
    }

    @Override
    public boolean equals(Object o) {
        if(this == o) return true;
        if(o == null || getClass() != o.getClass()) return false;
        IntVector2 that = (IntVector2) o;
        return x == that.x && y == that.y;
    }

    @Override
    public int hashCode() {
        return Objects.hash(x, y);
    }
}