Added public GetMainLight API for HDRP

[adrien-de-tocqueville]

Added a public function to get the sun light from script in HDRP:

var sunLight = (RenderPipelineManager.currentPipeline as HDRenderPipeline).GetMainLight();

or simply

var sunLight = HDRenderPipeline.currentPipeline.GetMainLight();

Note: This will return null until hdrp renders a camera.

A SG node doing the same thing will be added by #5086

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[mert-dev-acc]

@adrien-de-tocqueville This is not just adding an api callback for GetMainLight but replaces/removes GetCurrentSunLight function. Adding a notice about "this replaces GetCurrentSunLight" to change log would be useful, unless adding a stub for

[System.Obsolete]
GetCurrentSunLight()=>GetMainLight() 

is an intention. Otherwise, it can be confusing for the people who upgrade from an earlier version. (Or for the asset devs)

[adrien-de-tocqueville]

@merpheus-dev That's right, however, the function GetCurrentSunLight was marked as internal, so it was not accessible to users. So I don't think renaming the function will break users project

[mert-dev-acc]

Ah sorry, I missed that.
Okay, thank you 🙂

[sebastienlagarde]

Guess is weird to expose this Method inside the LightLoop class. Guess it should be in another location, maybe HDRenderPipeline. What are your thought?

[adrien-de-tocqueville]

There isn't actually any lightloop class, it's just the name of the file. The function is inside the class HDRenderPipeline, which is partial, so defined in multiple files.

For user it will be accessible this way:

var sunLight = HDRenderPipeline.currentPipeline.GetMainLight();

[sebastienlagarde]

ah right :)