Shapes, SVG and Ricard Marxer's Geomerative

[villares]

When I was working with Processing I counted on Geomerative (the site is not loading for me, but there is this repo) for a lot of computational geometry stuff that I now do with shapely.

Back then, before I knew about the undocumented PFont.get_shape() for glyph shape extraction, I had to use Geomerative to "distort letters" inspired by André Burnier, also, it had good SVG loading support if I remember correctly.

There are some things that I still have to find out how to do... Geomerative had a polygonizer feature that would simplify a shape, I think it would be useful to get bezier/cubic based SVGs and make a shapely.Polygon from them. I might have a look at its source maybe...

Why would I want those polygons? Because then I can "triangulate" them which is useful to simulate concave shapes in pymunk's 2D physics engine...

[hx2A]

Processing (and py5) can load an SVG file, and then you can get the vertices from the Py5Shape object. Does that work?

[villares]

Same on py5, if you want to play with it.

import py5

def setup():
    global shp
    py5.size(300, 300, py5.P2D)
    shp = py5.load_shape('a.svg')
    path = shp.get_children()[1].get_children()[0]
    py5.translate(50, 100)
    py5.shape(shp, 0,0)
    py5.shape(path, 0, 0)
    py5.shape(shp, 100, 0)
    py5.shape(shp, 0, 0)
    py5.scale(3.5)
    path.set_stroke(255)
    path.set_fill(py5.color(255, 0, 0, 10))
    py5.shape(path, 0, 0)
    py5.save('out.png')
    

py5.run_sketch(block=False)

And the SVG:

[hx2A]

Cool guess huh! P2D and P3D both act the same, but differently from the default renderer!

Yes, I figured that would be the case! The P2D and P3D renderers are similar to each other in that they use tessellated geometry internally. I default renderer does very different things for shapes.

[hx2A]

@villares I just came across this library:

https://github.com/regebro/svg.pathhttps://github.com/regebro/svg.path

It might be useful to you and to py5. I don't have time to do a deep dive into this but the first glance looked very promising.

If you think this is useful, I'll investigate it as a new py5 integration.

[villares]

Very nice! This other one also caught my eye: https://github.com/mathandy/svgpathtools
Ha:

Much of the core of this module was taken from the svg.path (v2.0) module. Interested svg.path users should see the compatibility notes at bottom of this readme.

[hx2A]

Yes, SVG Path tools is also useful! Another candidate for integration with py5.