com.kaka.util.Vector2 Maven / Gradle / Ivy
package com.kaka.util;
import java.io.Serializable;
/**
* 二维向量，坐标点
*
* @author zkpursuit
*/
public class Vector2 implements Serializable {
public final static Vector2 Zero = new Vector2(0, 0);
public float x;
public float y;
public Vector2() {
}
public Vector2(float x, float y) {
this.x = x;
this.y = y;
}
public Vector2(Vector2 v) {
set(v);
}
public final Vector2 set(Vector2 v) {
x = v.x;
y = v.y;
return this;
}
public final Vector2 set(float x, float y) {
this.x = x;
this.y = y;
return this;
}
public final Vector2 copy() {
return new Vector2(this);
}
public final boolean isZero() {
return x == 0 && y == 0;
}
public final Vector2 setZero() {
this.x = 0;
this.y = 0;
return this;
}
public float getX() {
return x;
}
public void setX(float x) {
this.x = x;
}
public float getY() {
return y;
}
public void setY(float y) {
this.y = y;
}
/**
* 减去向量
*
* @param x
* @param y
* @return
*/
public Vector2 sub(float x, float y) {
this.x -= x;
this.y -= y;
return this;
}
/**
* 减去向量
*
* @param v
* @return
*/
public Vector2 sub(Vector2 v) {
this.x -= v.x;
this.y -= v.y;
return this;
}
/**
* 增加向量
*
* @param x
* @param y
* @return
*/
public Vector2 add(float x, float y) {
this.x += x;
this.y += y;
return this;
}
/**
* 增加向量
*
* @param v
* @return
*/
public Vector2 add(Vector2 v) {
this.x += v.x;
this.y += v.y;
return this;
}
/**
* 本向量乘以某个数值
*
* @param v
* @return 乘以数值后新的向量
*/
public Vector2 mult(float v) {
return new Vector2(this.x * v, this.y * v);
}
/**
* 本向量除以某数值
*
* @param v
* @return 除以数值后新的向量
*/
public Vector2 divi(float v) {
return new Vector2(this.x / v, this.y / v);
}
/**
* 两点距离
*
* @param x1
* @param y1
* @param x2
* @param y2
* @return
*/
public static float dist(float x1, float y1, float x2, float 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);
}
/**
* 与另一点的距离
*
* @param v
* @return
*/
public float dist(Vector2 v) {
final float x_d = v.x - x;
final float y_d = v.y - y;
return (float) Math.sqrt(x_d * x_d + y_d * y_d);
}
/**
* 与另一点的距离
*
* @param x
* @param y
* @return
*/
public float dist(float x, float y) {
final float x_d = x - this.x;
final float y_d = y - this.y;
return (float) Math.sqrt(x_d * x_d + y_d * y_d);
}
/**
* 点积
*
* @param x1
* @param y1
* @param x2
* @param y2
* @return
*/
public static float dot(float x1, float y1, float x2, float y2) {
return x1 * x2 + y1 * y2;
}
/**
* 点积
*
* @param v
* @return
*/
public float dot(Vector2 v) {
return x * v.x + y * v.y;
}
/**
* 点积
*
* @param ox
* @param oy
* @return
*/
public float dot(float ox, float oy) {
return x * ox + y * oy;
}
/**
* 叉积
*
* @param v
* @return
*/
public float crs(Vector2 v) {
return this.x * v.y - this.y * v.x;
}
/**
* 叉积
*
* @param x
* @param y
* @return
*/
public float crs(float x, float y) {
return this.x * y - this.y * x;
}
/**
* 与x轴的夹角
*
* 角度朝向正y轴（通常为逆时针方向），介于0和360之间。
*
* @return 角度，非弧度
*/
public float angle() {
float angle = (float) (Math.atan2(y, x) * MathUtils.radiansToDegrees);
if (angle < 0) {
angle += 360;
}
return angle;
}
/**
* 两向量夹角
*
* 角度朝向正y轴（通常为逆时针方向），介于-180和+180之间。
*
* @param reference
* @return 角度，非弧度
*/
public float angle(Vector2 reference) {
return (float) (Math.atan2(crs(reference), dot(reference)) * MathUtils.radiansToDegrees);
}
/**
* 向量长度平方
*
* @return 向量长度平方
*/
public double lenSQ() {
return x * x + y * y;
}
/**
* 向量长度
*
* @return 向量长度
*/
public float len() {
return (float) Math.sqrt(lenSQ());
}
/**
* 设置向量长度并改变坐标
*
* @param v 新的向量长度
*/
public void len(float v) {
double angle = Math.atan2(y, x);
x = (float) Math.cos(angle) * v;
y = (float) Math.sin(angle) * v;
}
/**
* 使本向量变为长度为1的单位向量
*
* @return 本向量
*/
public Vector2 normalize() {
float len = len();
if (len == 0) {
x = 1;
return this;
}
x /= len;
y /= len;
return this;
}
/**
* 是否为单位向量
*
* @return true为单位向量
*/
public boolean isNormalized() {
return this.len() == 1;
}
/**
* 向量反转
*
* @return 反转后的本向量
*/
public Vector2 reverse() {
this.x = -this.x;
this.y = -this.y;
return this;
}
/**
* 以角度旋转向量
*
* @param degrees 角度
* @return 旋转后的本向量
*/
public Vector2 rotate(float degrees) {
return rotateRradians((float) (degrees * MathUtils.degreesToRadians));
}
/**
* 以弧度旋转向量
*
* @param radians 弧度
* @return 旋转后的本向量
*/
public Vector2 rotateRradians(float radians) {
float cos = (float) Math.cos(radians);
float sin = (float) Math.sin(radians);
float newX = this.x * cos - this.y * sin;
float newY = this.x * sin + this.y * cos;
this.x = newX;
this.y = newY;
return this;
}
/**
* 以X轴为中轴垂直于本向量的向量点
*
* @return 垂直于本向量的向量点
*/
public Vector2 perp() {
return new Vector2(-y, x);
}
/**
* 判断给定的向量在本向量的左边还是右边
*
* @param v 给定的向量
* @return -1左边，1右边
*/
public int sign(Vector2 v) {
return perp().dot(v) < 0 ? -1 : 1;
}
@Override
public int hashCode() {
int hash = 7;
hash = 59 * hash + Float.floatToIntBits(this.x);
hash = 59 * hash + Float.floatToIntBits(this.y);
return hash;
}
@Override
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
final Vector2 other = (Vector2) obj;
if (Float.floatToIntBits(this.x) != Float.floatToIntBits(other.x)) {
return false;
}
if (Float.floatToIntBits(this.y) != Float.floatToIntBits(other.y)) {
return false;
}
return true;
}
}