function line(ctx, x1, y1, x2, y2) {
                ctx.beginPath();
                ctx.moveTo(x1, y1);
                ctx.lineTo(x2, y2);
                ctx.stroke();
              }
@typedef GlyphOptions
@type Object
@property {string} [name] - The glyph name
@property {number} [unicode]
@property {Array} [unicodes]
@property {number} [xMin]
@property {number} [yMin]
@property {number} [xMax]
@property {number} [yMax]
@property {number} [advanceWidth]