Halo 2 skybox fix (& realtime lighting shadow casting in other games)

[polymetal0]

Clamping depth value to 1 apparently fixes this. Skybox is also affected by the see through issue:

EDIT: In case you are caching shaders in disk, you will need to delete your shader cache file.

[Shoegzer]

Fantastic! And yeah, the see-through textures issue still exists as per #55 but this is quite a welcome fix.

[polymetal0]

I noticed that this changes also restore dynamic shadows (tested on Conker and Halo CE).

Some screenshots:

Latest release:

Clamping z to 1:

[GXTX]

Ideally you'd test with https://github.com/abaire/nxdk_pgraph_tests

[polymetal0]

Thanks! I don't expect these changes to make it to the main branch anyway, but I hope someone with more understanding of the project can get a better clue about where the issue might be.