Compatibility: Fix cubemap faces order when setting texture data

[BlueCube3310]

Fixes #85440

The cube face order used to be incorrect in the Compatibility renderer, compared to the Forward+ or mobile renderers.

Comparison:

Forward+	master	PR

MRP: gles-cubemap.zip

[bruvzg]

Tested on macOS with Vulkan, Metal and GL, works as expected.

Should we consider this for 4.5? It's clearly a bug, but existing GL projects might expect this behavior. Also, what was face order in 3.x?

[BlueCube3310]

It seems like the order in Compatibility was copied directly from 3.x:

godot/drivers/gles3/rasterizer_scene_gles3.cpp

Lines 44 to 53 in 17b5769

	const GLenum RasterizerSceneGLES3::_cube_side_enum[6] = {
	GL_TEXTURE_CUBE_MAP_NEGATIVE_X,
	GL_TEXTURE_CUBE_MAP_POSITIVE_X,
	GL_TEXTURE_CUBE_MAP_NEGATIVE_Y,
	GL_TEXTURE_CUBE_MAP_POSITIVE_Y,
	GL_TEXTURE_CUBE_MAP_NEGATIVE_Z,
	GL_TEXTURE_CUBE_MAP_POSITIVE_Z,
	};

[BlueCube3310]

Should we consider this for 4.5? It's clearly a bug, but existing GL projects might expect this behavior. Also, what was face order in 3.x?

I don't think so, there may be some regressions, so it would be better suited for 4.6

[Calinou]

Code looks good to me.

Given this will change visuals in existing Compatibility projects that use custom cubemaps, we should only merge this for 4.6 (early on in the development cycle) and not cherry-pick it for 4.5.x.

[Repiteo]

Thanks!