PR: Implement clamping support to chromaticity inspector.

[KelSolaar]

I added some new buttons to clamp the chromaticity inspector chromaticities by default in range [0, 1]. This helps giving some control over the transformation chain and alleviate some problems pointed out in #2010.

No Clamp

Note how the negative values exceed the boundaries of sRGB.

Clamped

[doug-walker]

@KelSolaar , I'm looking at the second screenshot you posted but I don't see the new button. This has the potential for confusion if ocioview is doing something different than applications that just apply the config "as is". My advice would be:

1. Make the UI clearly indicate when a clamp is being applied.
2. Have the default be "no clamp".

[KelSolaar]

Hello @doug-walker,

The buttons are here, clamping negative and positive values:

This only affects the chromaticity inspector and is enabled by default, like with DCC typically, if we want something application wide for the Display Transforms, we will need to discuss about it.

Note that DCC do not tell you when they clamp, they do it, here we can toggle the behaviour for inspection.

Cheers,

Thomas

[doug-walker]

Ah, thanks for pointing out the buttons @KelSolaar ! It was not obvious to me what those did (I was thinking "previous" and "next" rather than clamp). Would it be clearer to change them to "< 0" and "> 1" rather than just "<" and ">"?

Regarding the default, yes, if the DCC needs to send the values to a display eventually they will become integers and lose the extended range values. However, not all DCCs will insert an explicit clamp. Furthermore, not all DisplayViewTransform output will go to a display, for example, it could go into a file format which may or may not clamp. Even the integer video file formats often allow some amount of extended range. That was my thinking for making the default "no clamp".

That's my opinion, but I will defer to you and Michael on all of this.