pygrbl-build 0.1.0

G-code generation algorithms for GRBL diode lasers from different sources; raster Line-to-Line (LaserGRBL-faithful) available today

PyGrbl_Build 0.1.0

A collection of algorithms to generate G-code for GRBL diode lasers from different sources. Three algorithms today:

• Line-to-Line (l2l_gcode) — raster engraving from an image, with LaserGRBL fidelity.
• SVG vector (svg_gcode) — vector tracing from an SVG (paths, basic shapes, groups, transforms), a faithful port of LaserGRBL's SVG import. Pure Python, no extra dependency.
• Image vector (img2vector_gcode) — outline tracing from a raster image (LaserGRBL's "Vectorize!"): the image is reduced to black/white, Potrace traces its outlines as closed contours, and each curve is emitted as G2/G3 arcs. Pure Python, Pillow only. Outlines only today (no interior filling yet).

Part of the pygrbl family, a set of libraries to manage GRBL. Companion to pygrbl_streamer

Speed

This is the whole point. A full 300 mm @ 10 lines/mm raster job — nearly 4.7 million lines of G-code — comes out in ~0.34 s. LaserGRBL can take around 2 minutes to produce the same job: that's roughly a 350× speedup, and byte-for-byte the same output.

Install

pip install pygrbl-build

The only requirements are Pillow and a C compiler. Pillow is the single Python dependency (image loading and resizing); the C compiler is needed at install time because the raster engine ships as a C extension. Nothing else — no numpy, no runtime toolchain.

Usage

Each algorithm pairs a *_gcode generator with its own *Profile config, so adding one never touches the others.

Raster Line-to-Line (l2l_gcode + L2LProfile):

from pygrbl_build import L2LProfile, l2l_gcode, write_gcode

profile = L2LProfile(width_mm=300.0, lines_per_mm=10.0, feed=3000, s_max=100)
write_gcode(l2l_gcode("shield.png", profile), "shield.nc")

SVG vector (svg_gcode + SvgProfile):

from pygrbl_build import SvgProfile, svg_gcode, write_gcode

profile = SvgProfile(feed=1000, s_max=255)
write_gcode(svg_gcode("logo.svg", profile), "logo.nc")

SvgProfile's defaults reproduce LaserGRBL's own SVG-import defaults, so the output matches the desktop app for the same drawing. text and image elements are skipped — convert text to paths in your editor first.

Image vector (img2vector_gcode + Img2VectorProfile):

from pygrbl_build import Img2VectorProfile, img2vector_gcode, write_gcode

profile = Img2VectorProfile(width_mm=80.0, quality=10.0, feed=1000, s_max=1000)
write_gcode(img2vector_gcode("logo.png", profile), "logo.nc")

img2vector_gcode is a faithful port of LaserGRBL's "Vectorize!": the image is reduced to black/white (resize, grayscale, white-clip, optional threshold), Potrace traces its outlines, and each cubic Bezier is approximated by biarcs and emitted as G2/G3 arcs (with a G1 fallback). width_mm sets the physical width and quality the tracing resolution in pixels/mm. The Img2VectorProfile defaults follow Potrace's classic settings (smooth curves, optimization on); set alphamax=0.0 and opticurve=False to mimic LaserGRBL's own out-of-the-box UI defaults.

write_gcode writes the path verbatim, so you choose the extension (.nc, .gcode, .g, ...). It's just a convenience: every *_gcode generator is a lazy iterator of lines, so anything beyond writing a plain file (compression, network shipping, streaming to the machine) is the upper layer's job — consume the iterator with whatever sink you need.

Public API: L2LProfile, l2l_gcode, SvgProfile, svg_gcode, Img2VectorProfile, img2vector_gcode, write_gcode. See the docstrings.