Camera: Make reversedDepth read-only.

[WestLangley]

As suggested here and here -- so it must be a good idea. ;-)

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	338.39 78.91	338.39 78.91	+1 B +0 B
WebGPU	566.01 156.49	566.01 156.49	+0 B +0 B
WebGPU Nodes	564.61 156.25	564.61 156.25	+0 B +0 B

🌳 Bundle size after tree-shaking

Minimal build including a renderer, camera, empty scene, and dependencies.

	Before	After	Diff
WebGL	469.77 113.61	469.82 113.62	+49 B +14 B
WebGPU	637.21 172.44	637.26 172.46	+48 B +14 B
WebGPU Nodes	591.86 161.68	591.9 161.69	+48 B +15 B

[sunag]

I would only vote against this change if we planned to use this property in external components with addons in the future.

[Mugen87]

I think we can still do that. But if reversedDepth is a public and documented camera property, users might assign values to it which is probably not something we want.

[sunag]

camera.reversedDepth seems to follow the same logic as camera.coordinateSystem where only the renderer sets these properties. The current logic should apply to both.

Maybe because I come from C# too, but accessing private variables in external components doesn't seem to make much sense to me, could this just be documented?

[sunag]

But if reversedDepth is a public and documented camera property, users might assign values to it which is probably not something we want.

Maybe we can document it as a "volatile" value that is defined by the renderer. Alternatively, use get reversedDepth and set it through _reversedDepth in renderer.

[Mugen87]

Alternatively, use get reversedDepth and set it through _reversedDepth in renderer.

That sounds good to me.

[mrdoob]

Is this needed?

[WestLangley]

see #31512 (comment).

This should be read-only for users, and set only by the renderer.