add vsketch and nixos

content/nixos/vsketch-and-NixOS/index.md

@@ -0,0 +1,169 @@
+---
+title: "vsketch and NixOS"
+date: 2023-07-09T15:26:24+02:00
+tags:
+  - NixOS
+  - Plotting
+  - vsketch
+summary: >
+  Adventures with vsketch, axidraw and NixOS.
+---
+
+
+# vsketch and NixOS
+I like to plotter. I like to draw pictures with my [axidraw](https://axidraw.com/) and ogle with the [terrapen](https://terrapen.xyz/products/terrapen-a2-pen-plotter) .
+
+I had a few runs on using [vsketch](https://vsketch.readthedocs.io/en/latest/) in [NixOS](https://nixos.org) but because I don't know much about Python, I had never found enough time to make [vsketch](https://vsketch.readthedocs.io/en/latest/) work under NixOS. Same holds for the [axidraw cli](https://axidraw.com/doc/cli_api/#introduction).
+
+But lately I got introduced to [pipenv](https://pipenv.pypa.io/en/latest/) which made everything possible and very easy.
+
+Setup
+-----
+
+I simple use a combination of `direnv` `shell.nix` , `steam-run` and `pipenv` to make everything work.
+
+### shell.nix
+
+The shell nix is called by `direnv` simply by putting
+
+```text-plain
+use nix
+```
+
+in the repositories `.envrc` file.
+
+In the `shell.nix` I simple define a all packages I need and override the `steam-run` binary to add some package. Getting to this point, was a bit fiddly, but once it works, it works :D This is my `shell.nix`
+
+```text-plain
+{ pkgs ? import <nixpkgs> { } }:
+pkgs.mkShell {
+  buildInputs =
+    let
+      steamrun = (pkgs.steam.override {
+        extraPkgs = pkgs: [
+          (pkgs.python3.withPackages (ps: with ps; [
+            matplotlib
+            pyside6
+            setuptools
+            scikitlearn
+            toml
+          ]))
+          pkgs.qt6.qtbase
+        ];
+        extraLibraries = pkgs: [ pkgs.libkrb5 ];
+      }).run;
+    in
+    [
+      (pkgs.writers.writeDashBin "vsk" ''
+        ${steamrun}/bin/steam-run pipenv run vsk "$@"
+      '')
+      (pkgs.writers.writeDashBin "axicli" ''
+        ${steamrun}/bin/steam-run pipenv run axicli "$@"
+      '')
+      (pkgs.writers.writeDashBin "pipenv-shell" ''
+        ${steamrun}/bin/steam-run pipenv shell
+      '')
+    ];
+}
+```
+
+### Pipenv
+
+Now `pipenv` has all needed dependencies for it's thing to do. But we need to set up `pipenv` itself as well, of course. Here is my `Pipfile`:
+
+```text-plain
+[[source]]
+url = "https://pypi.org/simple"
+verify_ssl = true
+name = "pypi"
+
+[packages]
+vsketch = {editable = true, git = "https://github.com/abey79/vsketch"}
+axicli = {file = "https://cdn.evilmadscientist.com/dl/ad/public/AxiDraw_API.zip" }
+
+[dev-packages]
+
+[requires]
+python_version = "3.10"
+python_full_version = "3.10.11"
+```
+
+Now I can run
+
+```text-plain
+pipenv install
+```
+
+and magically the shell command `vsk` (which is defined in the `shell.nix`) works like charm.
+
+My first sketch
+---------------
+
+After running
+
+```text-plain
+vsk init SimpleRings
+```
+
+I could instantly start fiddling around with the code.
+
+I'm amazed how fast my development cycle was. I could instantly see results, and play around with seed and parameters. And once I liked something. I can just hit **Like** and it will be saved as svg.
+
+Here is my first script + some screenshots and photos of the results:
+
+```text-plain
+import vsketch
+
+class SimpleRingsSketch(vsketch.SketchClass):
+    amount = vsketch.Param(3)
+    space = vsketch.Param(30, min_value=10)
+    min_radius = vsketch.Param(30, min_value=1)
+    base_rotation = vsketch.Param(1)
+    show_rings = vsketch.Param(True)
+    show_rings_randomly = vsketch.Param(True)
+    show_lines = vsketch.Param(True)
+
+    def draw(self, vsk: vsketch.Vsketch) -> None:
+        vsk.size("a4", landscape=False)
+
+        # vsk.scale("mm")
+        # height and width are in pixels (not mm)
+        max_radius = min(vsk.height / 2, vsk.width / 2) - self.space
+
+        for i in range(self.amount):
+            radius = vsk.random(self.min_radius, max_radius)
+            amount_of_lines = int(vsk.random(1, radius))
+            line_length = vsk.random(1, 20)
+            circle_line_height = vsk.random(1, line_length)
+
+            # vsk.random() consumes the seed, so we have to consume it in every step, other changing the
+            # options would result in different results in the other routines.
+            if vsk.random(0, 1) > 0.5 or not self.show_rings_randomly:
+                if self.show_rings:
+                    vsk.circle(0, 0, radius - circle_line_height, mode="radius")
+
+            if not self.show_lines:
+                continue
+            vsk.rotate(self.base_rotation, degrees=True)
+            with vsk.pushMatrix():
+                angle = 360.0 / amount_of_lines
+                for j in range(0, amount_of_lines):
+                    vsk.rotate(angle, degrees=True)
+                    vsk.line(0, radius, 0, radius - line_length)
+
+    def finalize(self, vsk: vsketch.Vsketch) -> None:
+        vsk.vpype("linemerge linesimplify reloop linesort")
+
+
+if __name__ == "__main__":
+    SimpleRingsSketch.display()
+```
+
+{{< card >}}
+{{<figure src="./images/screenshot.png" width=100% >}}
+{{< /card >}}
+
+{{< card >}}
+{{<figure src="./images/plot01.jpg" width=100% >}}
+{{<figure src="./images/plot02.jpg" width=100% >}}
+{{< /card >}}

shell.nix

@@ -1,8 +1,6 @@
 { pkgs ?  import <nixpkgs> {} }:
 pkgs.mkShell {
 
-  # needed pkgs
-  # -----------
   buildInputs = with pkgs; [
     hugo
 
@@ -20,11 +18,8 @@ pkgs.mkShell {
     inotify-tools
 
     pandoc
+
+    go-task
   ];
 
-  # run this on start
-  # -----------------
-  shellHook = ''
-    export HELLO="world"
-  '';
 }