stitch_block.py

"""
Take 2 - trying to minimize jump stitches

Stitch a row \ / \ /, then back
"""
import itertools
import pyembroidery as em
from collections import namedtuple
import click


class Stitch(namedtuple("Stitch", "x y")):
    """
    Quick utility Stitch object

    Access x/y as fields, and also supports -stitch to easily reverse direction
    """

    def __neg__(self):
        return Stitch(-self.x, -self.y)


@click.command()
@click.argument("destination", type=click.File("wb"))
@click.option("--png", type=click.File("wb"))
@click.option("--size", type=int, default=16)
@click.option("--xmax", type=int, default=6)
@click.option("--ymax", type=int, default=4)
@click.option("--repeats", type=int, default=3)
def stitch(destination, png, size, xmax, ymax, repeats):
    pattern = em.EmbPattern()
    pattern.add_thread("red")

    # The various diagonal stitches
    DOWN_RIGHT = Stitch(+size, +size)
    UP_RIGHT = Stitch(+size, -size)
    UP_LEFT = Stitch(-size, -size)
    DOWN_LEFT = Stitch(-size, +size)

    # start with a stitch at the origin to get the needle down (see the docs)
    pattern.stitch_abs(0, 0)

    for y in range(ymax):
        # Jump to the beginning of the row - upper left
        pattern.stitch_abs(0, y * size)

        # stitch \ / \ / forward
        forward_stitches = itertools.cycle([DOWN_RIGHT, UP_RIGHT])
        for x, stitch in zip(range(xmax), forward_stitches):
            pattern.stitch(*stitch)
            for i in range(repeats - 1):
                stitch = -stitch
                pattern.stitch(*stitch)

        # tie off & trim end of row (I don't actually know my machine does this but
        # let's find out)
        pattern.add_stitch_relative(em.TIE_OFF)
        pattern.trim()

        # jump to end of row and tie on - up right
        pattern.add_stitch_absolute(em.TIE_ON, xmax * size, (y + 1) * size)

        # stitch backwards, opposite crosses
        reverse_stitches = itertools.cycle([UP_LEFT, DOWN_LEFT])
        for x, stitch in zip(range(xmax), reverse_stitches):
            pattern.stitch(*stitch)
            for i in range(repeats - 1):
                stitch = -stitch
                pattern.stitch(*stitch)

        # we finish in the right spot for the next row so no need to tie on/off
        # here. but in the future might need to do that as above.

    em.write_pes(pattern, destination, settings={"tie_on": True, "tie_off": True})
    if png:
        em.write_png(pattern, png, settings={"background": "white"})


if __name__ == "__main__":
    stitch()