;
        }

        commands.forEach(({command, args}, idx) => {
          if(command === 'pen') {
            lineWidth = args.lineWidth;
            color = args.color;
          } else if(command === 'put') {
            const {x, y} = project(args);
            x0 = x;
            y0 = y;
          } else if(command === 'forward') {
            const {x, y} = project(args);
            line(x0, y0, x, y);
            x0 = x;
            y0 = y;
          }
        });

        panel.appendChild(d);
   