[tychedelia]

Objective

When users install our wheel via pypi, we need a way for them to be able to access the shader source for shader tooling via wgsl-analyzer.

This allows the root processing_py module to function as a CLI and adds a new command that allows users to create a wesl.toml:

python -m processing_py shaders init

Testing

Needs uv and a recent wgsl-analyzer (the editor extension, or a build from this year; older builds don't read
wesl.toml dependencies).

1. Build a wheel from this branch:

   gh pr checkout 271
   git submodule update --init
   cd crates/processing_pyo3
   uv run maturin build --release -o /tmp/pp-wheel
   

2. Make a fresh project and install it:

   mkdir /tmp/shader-demo && cd /tmp/shader-demo
   uv venv && uv pip install /tmp/pp-wheel/*.whl
   

3. Write the shader packages and the manifest:

   .venv/bin/python -m processing_py shaders init
   cat wesl.toml
   

   Expect a wesl.toml with processing and lygia path dependencies pointing into
   .venv/share/processing_py/shaders/.

4. Add a shader that imports from both packages, as shaders/noise.wesl:

   import { lygia::generative::snoise::snoise33 };
   import { processing::{globals, VertexOutput} };
   
   @group(3) @binding(0) var<uniform> color: vec4<f32>;
   
   @fragment
   fn fragment(mesh: VertexOutput) -> @location(0) vec4<f32> {
       let p = mesh.world_position.xyz * 0.02 + globals.time * 0.1;
       let n = snoise33(p) * 0.5 + 0.5;
       return vec4(vec3(n), 1.0) * color;
   }

   Open the folder in an editor with wgsl-analyzer. Go-to-definition on snoise33 and VertexOutput should jump
   into .venv/share/processing_py/shaders/, with no unresolved-import errors.

5. Check the runtime resolves the same imports. Save as sketch.py and run .venv/bin/python sketch.py:

   from processing_py import *
   
   mat = None
   
   def setup():
       global mat
       size(400, 300)
       mode_3d()
       mat = create_material(load_shader("shaders/noise.wesl"), color=[1.0, 0.2, 0.4, 1.0])
   
   def draw():
       camera_position(0.0, 0.0, 200.0)
       camera_look_at(0.0, 0.0, 0.0)
       background(12, 12, 18)
       material(mat)
       box(80.0, 80.0, 80.0)
   
   run()

   Expect a box shaded with animated noise.

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[github-actions]

Visual regression: 1 changed of 43 cases

case	status	detail
py_flocking_gpu	❌ changed	7.99% of pixels differ

If these changes are intentional, add the deliberate-rendering-change label.

_{baseline 21a2dda7ac · adapter llvmpipe (LLVM 20.1.2, 256 bits) (Vulkan, Mesa 25.2.8-0ubuntu0.24.04.4 (LLVM 20.1.2))}

Open the visual report · workflow run