Circle Drawing
========================================
This example shows how to generate a gcode ( drawing a circle with drawing toolhead ) , translate it into fcode ( moving commands ) , and upload it to the machine.

::

    from math import sin, cos, pi
    from io import BytesIO, StringIO
    from time import sleep

    from fluxclient.fcode.g_to_f import GcodeToFcode
    from fluxclient.robot import FluxRobot
    from fluxclient.commands.misc import get_or_create_default_key


    def circle_generate(r):
        gcode = []
        for i in range(101):
            theta = 2 * pi / 100 * i
            gcode.append("G1 F500 X{} Y{}\n".format(round(r * cos(theta), 4), round(r * sin(theta), 4)))
        return gcode


    def send_task(fcode_stream):
        # open the rsa key
        client_key = get_or_create_default_key("./sdk_connection.pem")

        # connect to delta, don't change the port 23811
        robot = FluxRobot(('192.168.18.114', 23811), client_key)

        # callback for uploading
        def upload_progress(*args):
            print(args)

        # upload fcode in delta
        robot.upload_stream(fcode_stream, 'application/fcode', size=len(fcode_stream.getvalue()), process_callback=upload_progress)

        # start the task
        robot.start_play()

        # report progress
        report = robot.report_play()
        while report['st_id'] != 64:
            report = robot.report_play()
            print('report:', report)
            sleep(1)

        # complete, quit the task
        robot.quit_play()


    def main():
        r = 50
        gcode = StringIO()
        fcode_output = BytesIO()

        gcode.write('G1 F5000 X{} Y0 Z10\n'.format(r))
        for line in circle_generate(r):
            gcode.write(line)
        gcode.seek(0)

        m_GcodeToFcode = GcodeToFcode(head_type='N/A')
        m_GcodeToFcode.process(gcode, fcode_output)
        fcode_output.seek(0)

        send_task(fcode_output)

    if __name__ == '__main__':
        main()