Thank you for the hint Quad.

Here's the new version v1.1:

https://github.com/oliver2s/ShadeC-EVO

The setup call works a bit different now then before. You have to call sc_setup(mode) within the "mode" parameter. Parameter can be SHADEC_LOW, SHADEC_MEDIUM, SHADEC_HIGH, SHADEC_ULTRA. These predefined modes can be edited in sc_wrapper.c in function sc_get_settings(). As before you have also set sky with sc_sky and destroy Shade-C before level loading with sc_destroy(sc_screen_default).

I've updated the example levels, so you can clearly see how the setup call has to be made.

Code:
changes v1.1
- added simple global vertex fog (uses standard 3DGS fog variables
view.fog_start, view.fog_end, d3d_fogcolor1, etc...)
- rewrote the wrapper functions. After level loading call sc_create(mode) (mode can be SHADEC_LOW, SHADEC_MEDIUM, SHADEC_HIGH, SHADEC_ULTRA), these predefined modes can be edited in sc_wrapper.c in function sc_get_settings().
- fixed memory leaks
- added alpha clipping to PSSM sun shadow
- updated the example levels