vexflow/src/boundingbox.js

A JavaScript library for rendering music notation and guitar tablature

// Vex Music Notation
// Mohit Muthanna <mohit@muthanna.com>
//
// Copyright Mohit Muthanna 2010

// Bounding boxes for interactive notation

export class BoundingBox {
  static copy(that) {
    return new BoundingBox(that.x, that.y, that.w, that.h);
  }

  constructor(x, y, w, h) {
    this.x = x;
    this.y = y;
    this.w = w;
    this.h = h;
  }
  getX() { return this.x; }
  getY() { return this.y; }
  getW() { return this.w; }
  getH() { return this.h; }
  setX(x) { this.x = x; return this; }
  setY(y) { this.y = y; return this; }
  setW(w) { this.w = w; return this; }
  setH(h) { this.h = h; return this; }
  move(x, y) { this.x += x; this.y += y; }
  clone() { return BoundingBox.copy(this); }

  // Merge my box with given box. Creates a bigger bounding box unless
  // the given box is contained in this one.
  mergeWith(boundingBox, ctx) {
    const that = boundingBox;

    const new_x = this.x < that.x ? this.x : that.x;
    const new_y = this.y < that.y ? this.y : that.y;
    const new_w = Math.max(this.x + this.w, that.x + that.w) - new_x;
    const new_h = Math.max(this.y + this.h, that.y + that.h) - new_y;

    this.x = new_x;
    this.y = new_y;
    this.w = new_w;
    this.h = new_h;

    if (ctx) this.draw(ctx);
    return this;
  }

  draw(ctx, x, y) {
    if (!x) x = 0;
    if (!y) y = 0;
    ctx.rect(this.x + x, this.y + y, this.w, this.h);
    ctx.stroke();
  }
}