frame.js

1// FRAME23class Frame {4  constructor(x, y, w, h) {5    this.x = x;6    this.y = y;7    this.w = w;8    this.h = h;9  }1011  inset(px) {12    return new Frame(this.x + px, this.y + px, this.w - 2 * px, this.h - 2 * px);13  }1415  cell(n) {16    return this.w / n;17  }1819  at(u, v) {20    return [this.x + u * this.w, this.y + v * this.h];21  }2223  center() {24    return this.at(0.5, 0.5);25  }2627  square() {28    const side = Math.min(this.w, this.h);29    return new Frame(this.x + (this.w - side) / 2, this.y + (this.h - side) / 2, side, side);30  }3132  radius() {33    return Math.min(this.w, this.h) / 2;34  }3536  cols(n) {37    const w = this.w / n;38    return Array.from({ length: n }, (_, i) => new Frame(this.x + i * w, this.y, w, this.h));39  }4041  rows(n) {42    const h = this.h / n;43    return Array.from({ length: n }, (_, i) => new Frame(this.x, this.y + i * h, this.w, h));44  }45}4647export function frame(x, y, w, h) {48  return new Frame(x, y, w, h);49}5051// BOARD5253export const CLEAR = Object.freeze([0, 0, 0, 0]);5455export function board(width, height) {56  return {57    width,58    height,59    frame(margin) {60      const side = Math.min(width, height) * (1 - 2 * margin);61      return new Frame((width - side) / 2, (height - side) / 2, side, side);62    },63    area(margin) {64      return new Frame(0, 0, width, height).inset(Math.min(width, height) * margin);65    },66  };67}