code: function BezierCanvas(canvas, bezier, padding) {
          this.canvas  = canvas;
          this.bezier  = bezier;
          this.padding = this.getPadding(padding);
  
          // Convert to a cartesian coordinate system with axes from 0 to 1
          var ctx = this.canvas.getContext("2d"),
              p = this.padding;
  
          ctx.scale(canvas.width * (1 - p[1] - p[3]), -canvas.height * 0.5 * (1 - p[0] - p[2]));
          ctx.translate(p[3] / (1 - p[1] - p[3]), (-1 - p[0] / (1 - p[0] - p[2])) - 0.5);
      }
docs: BezierCanvas object constructor
  
  @param {Element} canvas Inline editor <canvas> element
  @param {CubicBezier} bezier Associated CubicBezier object
  @param {number|Array.number} padding Element padding