HPGLWrap/HPGLWrap.py

#!/usr/bin/env python3

import os
import re
import sys

# Based off of notes from
# https://github.com/fellesverkstedet/gcc-laserpro-driver
# and http://www.wiki.cl.cam.ac.uk/rowiki/CompArch/HardwareLab/LaserCutter
# and src/core/path_gcc.c from
# https://github.com/fellesverkstedet/fabmodules

def write_pen_values(values, char):
    return "!v64" + char + "".join(["{:04d}".format(value) for value in values])

def pre_content(filename, power, speed, rate, pen_settings):
    jobName = os.path.basename(filename)[:80]
    # Start
    outString = "@PJL JOB NAME={}\r\n".format(jobName)
    outString += "E@PJL ENTER LANGUAGE=PCL\r\n%-12345X"

    # Reset
    outString += "E"

    # Unit
    outString += "&u254D"

    # Cursor
    outString += "*p100X"
    outString += "*p100Y"

    # Set filename
    outString += "!m{:d}N".format(len(jobName)) + jobName

    # Set raster power+velocity. Only affects raster. Shows in display before start
    outString += "!r{:d}I".format(speed * 10)
    outString += "!r{:d}P".format(power * 10);

    # Select first (and only) pen (commented out in original source)
    # outString += "!v1D"
    # outString += "!m2A" # triggers autofocus

    # Use same value for all 16 pens
    # doesn't seem to affect vector settings
    # TODO: try unsetting values in HPGL and see if these take over
    outString += write_pen_values(pen_settings['power'], 'P') # Power, 1000=100%
    outString += write_pen_values(pen_settings['speed'], 'V') # Velocity, 1000=100%
    outString += write_pen_values(pen_settings['rate'], 'I') # PPI, does affect vector

    # Enter HPGL vector mode
    outString += "%1B"

    return outString

def set_vector_pens(content, pen_settings):
    settings = "".join(
        ["FS{power:d},{penNum:d};VS{speed:d},{penNum:d};".format(
            power=pen_settings['power'][num],
            speed=pen_settings['speed'][num],
            penNum=num+1) for num in range(0, 16)])
    # TODO: find out why slow movement in PU (pen up) until first PD (pen down)
    content = re.sub(
        "FS\d{1,4};VS\d{1,4};SP1;",
        settings + "SP1;",
        content, count=1)
    return content

def post_content():
    outString = "%1A" # Leave HPGL vector mode
    outString += "E" # Reset
    outString += "%-12345X@PJL EOJ \r\n" # End
    return outString

def main(infile, outfile, power=50, speed=50, rate=100):
    # set all pens the same
    pen_settings = {'power': [int(power) * 10] * 16,
                    'speed': [int(speed) * 10] * 16,
                    'rate': [int(rate)] * 16}

    with open(outfile, 'w') as f:
        f.write(pre_content(
            outfile, int(power), int(speed), int(rate), pen_settings))
        with open(infile, 'r') as input_f:
            f.write(set_vector_pens(input_f.read(), pen_settings))
        f.write(post_content())

if __name__ == '__main__':
    print(sys.argv)
    main(*sys.argv[1:])