[3.x] CPU lightmapper environment energy fixes.

[JFonS]

• Better handling of the scene's environment energy in the lightmapper bakes. Fixes BakedLightmap ignores environmental light energy settings #47785.
• Fixed a bug where ProceduralSky::get_panorama() returned a reference instead of a copy.
• Removed includes to Embree's internal header files. Should allow for linking against system-packaged Embree, see embree: Allow building against system library on Linux #48073.

[akien-mga]

Fixed a bug where ProceduralSky::get_panorama() returned a reference instead of a copy.

It's only used in BakedLightmap so it's probably fine (not exposed to the scripting API), but isn't it uncommon in Godot for a getter to actually return a copy instead of a reference?

PanoramaSky does have a public panorama property which is a reference as expected. Maybe ProceduralSky's getter should be get_panorama_copy() to avoid confusion?

[JFonS]

Yeah, I added the function just so I could use it in BakedLightmap so the issue was only there.

The difference between PanoramaSky and ProceduralSky is that the former takes a user defined image and uses it, while ProceduralSky generates it from a set of parameters, so it should be read-only.

I think ProceduralSky::get_data() sounds better and aligns with Texture::get_data() which also returns a copy (although it was renamed to get_image() in master, so maybe PanoramaSky::get_image()??).

[akien-mga]

I guess get_data() for 3.x and get_image() if there's an equivalent in master now or in the future :)

[JFonS]

Makes sense, I will update the PR in a bit.

[akien-mga]

Thanks!

[akien-mga]

Cherry-picked for 3.3.1.

[kalbfled]

With floating point numbers, should this be a tolerance test?
if (abs(p_energy - 1.0) > TOLERANCE)

[JFonS]

The check is only a shortcut optimization when the energy value is exactly 1, since x * 1 = x. Any other value would give a different result.