import vec3 from './vec3'; import { epsilon } from './constants'; export default class vec2 { constructor(values) { this.values = new Float32Array(2); if (values !== undefined) { this.xy = values; } } get x() { return this.values[0]; } get y() { return this.values[1]; } get xy() { return [this.values[0], this.values[1]]; } set x(value) { this.values[0] = value; } set y(value) { this.values[1] = value; } set xy(values) { this.values[0] = values[0]; this.values[1] = values[1]; } at(index) { return this.values[index]; } reset() { this.x = 0; this.y = 0; } copy(dest) { if (!dest) { dest = new vec2(); } dest.x = this.x; dest.y = this.y; return dest; } negate(dest) { if (!dest) { dest = this; } dest.x = -this.x; dest.y = -this.y; return dest; } equals(vector, threshold = epsilon) { if (Math.abs(this.x - vector.x) > threshold) { return false; } if (Math.abs(this.y - vector.y) > threshold) { return false; } return true; } length() { return Math.sqrt(this.squaredLength()); } squaredLength() { const x = this.x; const y = this.y; return x * x + y * y; } add(vector) { this.x += vector.x; this.y += vector.y; return this; } subtract(vector) { this.x -= vector.x; this.y -= vector.y; return this; } multiply(vector) { this.x *= vector.x; this.y *= vector.y; return this; } divide(vector) { this.x /= vector.x; this.y /= vector.y; return this; } scale(value, dest) { if (!dest) { dest = this; } dest.x *= value; dest.y *= value; return dest; } normalize(dest) { if (!dest) { dest = this; } let length = this.length(); if (length === 1) { return this; } if (length === 0) { dest.x = 0; dest.y = 0; return dest; } length = 1.0 / length; dest.x *= length; dest.y *= length; return dest; } multiplyMat2(matrix, dest) { if (!dest) { dest = this; } return matrix.multiplyVec2(this, dest); } multiplyMat3(matrix, dest) { if (!dest) { dest = this; } return matrix.multiplyVec2(this, dest); } static cross(vector, vector2, dest) { if (!dest) { dest = new vec3(); } const x = vector.x; const y = vector.y; const x2 = vector2.x; const y2 = vector2.y; const z = x * y2 - y * x2; dest.x = 0; dest.y = 0; dest.z = z; return dest; } static dot(vector, vector2) { return vector.x * vector2.x + vector.y * vector2.y; } static distance(vector, vector2) { return Math.sqrt(this.squaredDistance(vector, vector2)); } static squaredDistance(vector, vector2) { const x = vector2.x - vector.x; const y = vector2.y - vector.y; return x * x + y * y; } static direction(vector, vector2, dest) { if (!dest) { dest = new vec2(); } const x = vector.x - vector2.x; const y = vector.y - vector2.y; let length = Math.sqrt(x * x + y * y); if (length === 0) { dest.x = 0; dest.y = 0; return dest; } length = 1 / length; dest.x = x * length; dest.y = y * length; return dest; } static mix(vector, vector2, time, dest) { if (!dest) { dest = new vec2(); } const x = vector.x; const y = vector.y; const x2 = vector2.x; const y2 = vector2.y; dest.x = x + time * (x2 - x); dest.y = y + time * (y2 - y); return dest; } static sum(vector, vector2, dest) { if (!dest) { dest = new vec2(); } dest.x = vector.x + vector2.x; dest.y = vector.y + vector2.y; return dest; } static difference(vector, vector2, dest) { if (!dest) { dest = new vec2(); } dest.x = vector.x - vector2.x; dest.y = vector.y - vector2.y; return dest; } static product(vector, vector2, dest) { if (!dest) { dest = new vec2(); } dest.x = vector.x * vector2.x; dest.y = vector.y * vector2.y; return dest; } static quotient(vector, vector2, dest) { if (!dest) { dest = new vec2(); } dest.x = vector.x / vector2.x; dest.y = vector.y / vector2.y; return dest; } } vec2.zero = new vec2([0, 0]); vec2.one = new vec2([1, 1]);