Wraps torwanbukaj/ikea-brio-others-compatible-train-tracks-generator
( https://github.com/torwanbukaj/... ) as a third generator alongside
holder and the universal scad playground.
Approach
--------
The upstream .scad ships as "library + one active example call". Used
include<> (rather than use<>) so the library's top-level globals
(track_width, plug/nest dimensions, $fn = 150, etc.) are available
to the modules — `use<>` does NOT propagate variables. Commented out
the upstream `track_tester();` call so include<> doesn't also emit
the tester geometry every time.
Per-render the backend builds a tiny wrapper SCAD on the fly:
include <scad/train_tracks.scad>
track(length=100, end1="plug", end2="nest", cutout=true, ...);
and hands it to holder.render_source().
Part types exposed (9)
----------------------
- tester Calibration block (15-60mm)
- track Straight (length + chamfers + grooves + plug/nest ends)
- arc Curved (radius + angle, IKEA/Brio/J'adore radii in help text)
- dogbone Nest-nest connector
- intersection Crossing (angle + 2 lengths + 4 ends)
- switch Turnout (left/right radius+angle, straight branch, common end)
- snake S-curve (raised default target_length to 200 — the upstream
modules's natural curvy-span at angle=45/radius=86 is ~150
and the assert fires below that)
- adapter BRIO <-> IKEA system adapter (plug + nest side)
- bridge Multi-part (overview/ground/slope/pillar — value_map
translates the UI labels to the int 0..3 the SCAD wants)
Files
-----
- scad/train_tracks.scad Downloaded upstream (57 999 bytes), only
modification is the // before the top-level
track_tester() call.
- tracks.py PART_SCHEMAS dict, build_wrapper_scad,
render() that delegates to render_source.
- app.py GET /api/tracks/params, POST /api/tracks/render,
GET /tracks page route.
- static/tracks.html Page with part selector + dynamic param form +
shared viewer markup. Reuses holder.css.
- static/js/tracks-app.js Controller. Switching the part select redraws
the form (each part has its own schema).
Ctrl+Enter renders, Cancel uses AbortController.
Nav
---
Tracks link added to topbar on holder / index / scad.
Smoke test
----------
All 9 parts render with default params on the Manifold backend in
under 0.5s each (output sizes 440 KB - 1.8 MB).
Phase 2 — SCAD editor on /holder
================================
Some adjustments need more control than the parameter form gives
(e.g. tweaking the .scad logic itself). A collapsible CodeMirror-based
editor now slides up from the bottom of the viewport when you click
the "</> Source" button at the bottom-right.
- holder.html / holder.css: editor panel, toggle button, Reset and
Close buttons. CodeMirror 5 loaded from cdnjs (single CSS + JS
pair, clike mode for syntax highlighting since OpenSCAD is C-like).
- holder-app.js: lazy-initialises the editor on first show, fetches
bundled source from /api/holder/source, tracks whether the editor
content has been modified ("modified" tag in the panel title).
When the editor is visible AND content differs from bundled,
_doRender() switches from /api/holder/render -> /api/scad/render
with {source, params}. Cell-count cap doesn't apply in that mode
(the source may not even use the holder schema).
Phase 3 — Universal OpenSCAD playground at /scad
================================================
A standalone page for rendering arbitrary OpenSCAD. Paste code, click
Render (or Ctrl+Enter), see STL in the same Three.js viewer the
holder uses. Useful for prototyping new generators before wiring
them into a parameter form.
- New page: static/scad.html + scad.css + js/scad-app.js. Reuses
holder-viewer.js (the Three.js scene module is generic enough).
- "Load example" populates a 6-hole rounded bracket so new users
can verify the renderer works in two clicks.
- Same progress UI (elapsed timer + indeterminate bar + Cancel
via AbortController) as /holder.
- Top nav now has Holder / Busbars / SCAD on every page.
Backend (shared by phase 2 & 3)
================================
- holder.py: split _run_openscad() out of render_stl(). New
render_source(source, params=None) writes the source to a temp
file and renders it; enforces MAX_SOURCE_BYTES (default 512 KB)
and RENDER_TIMEOUT but skips the cell-count cap. New bundled_source()
returns the hex_cell.scad text for editor pre-population.
- app.py: GET /api/holder/source returns the bundled .scad text.
POST /api/scad/render takes {source, params?} and returns STL +
X-Holder-Dimensions header. ValueError -> 400, RuntimeError -> 500.
_stl_response() factored out so both render endpoints emit the same
headers consistently.
wenil