Currently, curves can only be filled the same material as their outline. The aim of this patch is to provide an easy way to create 2d curves with different outline and fill materials.

To support multiple different curves with different materials under one Object, a material offset as opposed to a direct material "pointer" field was used.
Here's an example of how it would be used with multiple fill and rim materials in one Object:

A large positive or negative offset can be used to force all curves regardless of their material to use the last/first material for fill geometry.

A Linux build + example scene is available here :
https://github.com/kiriri/blender/releases/tag/1

And here's an example of where this feature can be used.

Without this feature, all outlines would have to be separate curves.

This feature is very small and does not introduce any new logic. It does not decrease performance in any meaningful way.