# Advanced

Beyond the basics: writing custom operators in C#, writing shaders, and controlling parts of TiXL at the lowest level most users will touch.

## Pages in this section

- [Writing C# operators](WritingCodeOps.md)
- [Creating new operators](CreatingNewOps.md)
- [FAQ: writing C# operators](FaqDevOps.md)
- [Using custom shader operators](UsingCustomShaders.md)
- [A shader development example](ShaderDevelopmentExample.md)
- [Converting raymarching functions](ConvertSDFs.md)
- [Adding new fonts](AddingFonts.md)
- [Creating and using single-line SVG fonts](SvgLineFonts.md)

## Still to write

- **Shader reference** — HLSL conventions TiXL uses, built-in uniforms, coordinate spaces, common pitfalls.
- **Context variables deep dive** — how to pass values down a sub-graph, when to use them, when not.
- **Performance internals** — what the profiler columns mean, how to interpret flame graphs.
- **Extending the UI** — if/when a plugin surface emerges.

## What's *not* here

TiXL-contributor topics (building from source, coding conventions, release process, CI) live on the [GitHub wiki](https://github.com/tixl3d/tixl/wiki).