give some love

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2021 Max Halford
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

@@ -1,6 +1,49 @@
+# svg2stl
+
+This repository provides a script which takes as input an SVG such as this one:
+
+![example.svg]
+
+It outputs an [STL file](https://www.wikiwand.com/en/STL_(file_format)) like this one:
+
+![example.png]
+
+The resulting solid is a cuboid with holes in it. It essentially adds a third dimension to the SVG file. The purpose of the output STL is to be fed into a 3D printer. The end goal is to make a physical [stencil](https://www.wikiwand.com/en/Stencil) for artistic purposes.
+
+## Installation
+
 ```sh
 git clone https://github.com/MaxHalford/svg2stl
 cd svg2stl
 pip install -r requirements.txt
+```
+
+## Usage
+
+You can generate an STL with the same name as the input file like this:
+
+```py
 python svg2stl.py example.svg --thickness 4
 ```
+
+You can also show what this looks like in a GUI:
+
+```py
+python svg2stl.py example.svg --thickness 4 --show
+```
+
+## How it works
+
+- The SVG file is parsed into a sequence of steps thanks to [`svg.path`](https://github.com/regebro/svg.path).
+- Each step is turned into 2D geometric coordinates by sampling from each step's parametric equation with [`numpy`](https://numpy.org/).
+- Each coordinate is duplicated so that there are top and bottom coordinates.
+- The coordinates are stitched together to define panes: a floor, a ceiling, and many walls.
+- [`pygmsh`](https://github.com/nschloe/pygmsh) does the heavy lifting. It generates a mesh of triangles from the panes through [constrained Delaunay triangulation](https://www.wikiwand.com/en/Constrained_Delaunay_triangulation).
+
+## Motivation
+
+There are some websites out there that already do this. Like [this](https://svg2stl.com/), [this](https://activmap.github.io/svg-to-stl/), and [this](https://github.com/rcalme/svg-to-stl). But they're websites, and sometimes it's nice to be able to do this from the command line. Especially if you want to process many SVGs.
+
+## License
+
+The MIT License (MIT). Please see the [license file](LICENSE) for more information.

svg2stl.py

@@ -1,4 +1,5 @@
 import argparse
+import pathlib
 from xml.dom import minidom
 
 import gmsh
@@ -17,6 +18,7 @@ if __name__ == "__main__":
     parser = argparse.ArgumentParser(description="Convert an SVG into an STL.")
     parser.add_argument("svg_path", type=str, help="path towards an SVG file")
     parser.add_argument("--thickness", default=1, type=float)
+    parser.add_argument("--show", dest="show", action="store_true", default=False)
     args = parser.parse_args()
 
     steps = parse_svg_into_steps(args.svg_path)
@@ -147,4 +149,7 @@ if __name__ == "__main__":
     gmsh.model.geo.synchronize()
     gmsh.model.mesh.generate()
 
+    gmsh.write(str(pathlib.Path(args.svg_path).with_suffix(".stl")))
+
+    if args.show:
         gmsh.fltk.run()