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var ArrayCtor = typeof Float32Array === 'undefined'
|
? Array
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: Float32Array;
|
|
/**
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* 创建一个向量
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* @param {number} [x=0]
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* @param {number} [y=0]
|
* @return {Vector2}
|
*/
|
export function create(x, y) {
|
var out = new ArrayCtor(2);
|
if (x == null) {
|
x = 0;
|
}
|
if (y == null) {
|
y = 0;
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}
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out[0] = x;
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out[1] = y;
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return out;
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}
|
|
/**
|
* 复制向量数据
|
* @param {Vector2} out
|
* @param {Vector2} v
|
* @return {Vector2}
|
*/
|
export function copy(out, v) {
|
out[0] = v[0];
|
out[1] = v[1];
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return out;
|
}
|
|
/**
|
* 克隆一个向量
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* @param {Vector2} v
|
* @return {Vector2}
|
*/
|
export function clone(v) {
|
var out = new ArrayCtor(2);
|
out[0] = v[0];
|
out[1] = v[1];
|
return out;
|
}
|
|
/**
|
* 设置向量的两个项
|
* @param {Vector2} out
|
* @param {number} a
|
* @param {number} b
|
* @return {Vector2} 结果
|
*/
|
export function set(out, a, b) {
|
out[0] = a;
|
out[1] = b;
|
return out;
|
}
|
|
/**
|
* 向量相加
|
* @param {Vector2} out
|
* @param {Vector2} v1
|
* @param {Vector2} v2
|
*/
|
export function add(out, v1, v2) {
|
out[0] = v1[0] + v2[0];
|
out[1] = v1[1] + v2[1];
|
return out;
|
}
|
|
/**
|
* 向量缩放后相加
|
* @param {Vector2} out
|
* @param {Vector2} v1
|
* @param {Vector2} v2
|
* @param {number} a
|
*/
|
export function scaleAndAdd(out, v1, v2, a) {
|
out[0] = v1[0] + v2[0] * a;
|
out[1] = v1[1] + v2[1] * a;
|
return out;
|
}
|
|
/**
|
* 向量相减
|
* @param {Vector2} out
|
* @param {Vector2} v1
|
* @param {Vector2} v2
|
*/
|
export function sub(out, v1, v2) {
|
out[0] = v1[0] - v2[0];
|
out[1] = v1[1] - v2[1];
|
return out;
|
}
|
|
/**
|
* 向量长度
|
* @param {Vector2} v
|
* @return {number}
|
*/
|
export function len(v) {
|
return Math.sqrt(lenSquare(v));
|
}
|
export var length = len; // jshint ignore:line
|
|
/**
|
* 向量长度平方
|
* @param {Vector2} v
|
* @return {number}
|
*/
|
export function lenSquare(v) {
|
return v[0] * v[0] + v[1] * v[1];
|
}
|
export var lengthSquare = lenSquare;
|
|
/**
|
* 向量乘法
|
* @param {Vector2} out
|
* @param {Vector2} v1
|
* @param {Vector2} v2
|
*/
|
export function mul(out, v1, v2) {
|
out[0] = v1[0] * v2[0];
|
out[1] = v1[1] * v2[1];
|
return out;
|
}
|
|
/**
|
* 向量除法
|
* @param {Vector2} out
|
* @param {Vector2} v1
|
* @param {Vector2} v2
|
*/
|
export function div(out, v1, v2) {
|
out[0] = v1[0] / v2[0];
|
out[1] = v1[1] / v2[1];
|
return out;
|
}
|
|
/**
|
* 向量点乘
|
* @param {Vector2} v1
|
* @param {Vector2} v2
|
* @return {number}
|
*/
|
export function dot(v1, v2) {
|
return v1[0] * v2[0] + v1[1] * v2[1];
|
}
|
|
/**
|
* 向量缩放
|
* @param {Vector2} out
|
* @param {Vector2} v
|
* @param {number} s
|
*/
|
export function scale(out, v, s) {
|
out[0] = v[0] * s;
|
out[1] = v[1] * s;
|
return out;
|
}
|
|
/**
|
* 向量归一化
|
* @param {Vector2} out
|
* @param {Vector2} v
|
*/
|
export function normalize(out, v) {
|
var d = len(v);
|
if (d === 0) {
|
out[0] = 0;
|
out[1] = 0;
|
}
|
else {
|
out[0] = v[0] / d;
|
out[1] = v[1] / d;
|
}
|
return out;
|
}
|
|
/**
|
* 计算向量间距离
|
* @param {Vector2} v1
|
* @param {Vector2} v2
|
* @return {number}
|
*/
|
export function distance(v1, v2) {
|
return Math.sqrt(
|
(v1[0] - v2[0]) * (v1[0] - v2[0])
|
+ (v1[1] - v2[1]) * (v1[1] - v2[1])
|
);
|
}
|
export var dist = distance;
|
|
/**
|
* 向量距离平方
|
* @param {Vector2} v1
|
* @param {Vector2} v2
|
* @return {number}
|
*/
|
export function distanceSquare(v1, v2) {
|
return (v1[0] - v2[0]) * (v1[0] - v2[0])
|
+ (v1[1] - v2[1]) * (v1[1] - v2[1]);
|
}
|
export var distSquare = distanceSquare;
|
|
/**
|
* 求负向量
|
* @param {Vector2} out
|
* @param {Vector2} v
|
*/
|
export function negate(out, v) {
|
out[0] = -v[0];
|
out[1] = -v[1];
|
return out;
|
}
|
|
/**
|
* 插值两个点
|
* @param {Vector2} out
|
* @param {Vector2} v1
|
* @param {Vector2} v2
|
* @param {number} t
|
*/
|
export function lerp(out, v1, v2, t) {
|
out[0] = v1[0] + t * (v2[0] - v1[0]);
|
out[1] = v1[1] + t * (v2[1] - v1[1]);
|
return out;
|
}
|
|
/**
|
* 矩阵左乘向量
|
* @param {Vector2} out
|
* @param {Vector2} v
|
* @param {Vector2} m
|
*/
|
export function applyTransform(out, v, m) {
|
var x = v[0];
|
var y = v[1];
|
out[0] = m[0] * x + m[2] * y + m[4];
|
out[1] = m[1] * x + m[3] * y + m[5];
|
return out;
|
}
|
|
/**
|
* 求两个向量最小值
|
* @param {Vector2} out
|
* @param {Vector2} v1
|
* @param {Vector2} v2
|
*/
|
export function min(out, v1, v2) {
|
out[0] = Math.min(v1[0], v2[0]);
|
out[1] = Math.min(v1[1], v2[1]);
|
return out;
|
}
|
|
/**
|
* 求两个向量最大值
|
* @param {Vector2} out
|
* @param {Vector2} v1
|
* @param {Vector2} v2
|
*/
|
export function max(out, v1, v2) {
|
out[0] = Math.max(v1[0], v2[0]);
|
out[1] = Math.max(v1[1], v2[1]);
|
return out;
|
}
|
