Runner example.js

Runner.prototype.update = function () {
            this.updatePending = false;

            var now = getTimeStamp();
            var deltaTime = now - (this.time || now);
            this.time = now;

            if (this.playing) {
                this.clearCanvas();

                if (this.tRex.jumping) {
                    this.tRex.updateJump(deltaTime);
                }

              /* ....... */