More modularity in the Uber shader

Describe the problem

I'm trying to implement a custom shader (adds elevation contour lines) that also leverages the clipping primitive, and it seems harder than it should be. The Uber shader is a monolith of code.

Describe the solution you'd like

Consider breaking up the hlsl into modules. Perhaps even modules could be leveraged by custom functions in shader graph. (That use out parameters.)

I should be able to include a module or subgraph that will make my shader clip the same way as the Uber shader (for example).

Describe alternatives you've considered

Better support for shader graph in general. Either subgraphs and custom functions or both. #34

Additional context

Caveat is I am rather new to hlsl and unfamiliar with best practices. If performance suffers from breaking out the code, I'd be curious to know exactly how much.

Beginne damit, den Uber shader zu lokalisieren und zu prüfen, wie sein HLSL das Clipping-Primitive behandelt. Vergleiche diese Struktur mit den im Issue erwähnten Möglichkeiten für shader graph, subgraph und custom-function. Als abgeschlossen gilt die Aufgabe, wenn ein dokumentierter modularer Ansatz zur Wiederverwendung des Clipping-Verhaltens vorliegt und etwaige Auswirkungen auf die Performance bewertet wurden.