Add OpenSCAD to JS with ManifoldCAD

[codex826]

Implementation of OpenSCAD-to-Manifold Compiler

Issue no: #117

Description

This PR introduces the first functional version of the OpenSCAD-to-Manifold Compiler, a tool designed to translate OpenSCAD source code (.scad) into executable JavaScript optimized for the Manifold-3D geometry library.

This compiler allows developers to utilize OpenSCAD's familiar declarative syntax while leveraging the performance and topologically robust geometry processing of Manifold in modern JavaScript/TypeScript environments (like Node.js or the browser).

Key Features

• Full AST Visitor Implementation: Completed all required visitor methods for the openscad-parser AST.
• Robust Runtime Environment:
  • RuntimeScope: Manages variable, module, and function scopes, supporting both global and nested definitions.
  • Custom Modules & Functions: Full support for declaring and calling custom OpenSCAD modules and functions from within the generated JS.
  • Geometry Collection System: Implemented a results stack to ensure nested transformations and boolean operations are applied correctly to their children.
• Core OpenSCAD Support:
  • Leaf Geometry: cube, sphere, cylinder.
  • Transformations: translate, rotate, scale.
  • Booleans: union, difference, intersection.
  • Control flow: if-else statements and for loops (including ranges like [0:5:100]).
  • Expressions: Mathematical operations, ternary expressions, array lookups, and built-in functions (sin, cos, sqrt, etc.).
• CLI Utility: Includes a command-line tool (cli.ts) to easily compile files from the terminal.

Technical Details

• Language: TypeScript
• Target: Node.js (ESM)
• Primary Dependencies: openscad-parser, manifold-3d, yargs.
• Formatting: The generated code handles named vs positional arguments, ensuring that parameters like cube(size=10) are correctly mapped to { size: 10 } in the target library.

How to Test

1. Compile the tool

npm install
npm run build

2. Run the test bench

npm test

This runs a comprehensive test case in test-compiler.ts and verifies the output.

3. Compile a SCAD file

node cli.js -i example.scad -o example.js

Future Work

• Support for 2D primitives (square, circle).
• Implementation of more advanced geometry like polyhedron and hull.
• Full support for $children and more complex list comprehensions.

Checklist

• Code compiles without errors
• All core OpenSCAD modules are implemented
• Variables, modules, and loops are supported
• CLI tool is functional
• Documentation/README is relevant