Implement color grading effects

[vanruesc]

Description

Implement a CDLEffect BrightnessContrastEffect, HueSaturationEffect and SepiaEffect.

Reference:

• https://en.wikipedia.org/wiki/ASC_CDL

Tasks

• Create CDLEffect.
• Create cdl demo.
• Add unit test.

Implementation Details

• Use brightness-contrast, hue-saturation and sepia manual demos from v6 as reference.

[donmccurdy]

I might suggest going an additional step and include a CDLEffect, based on ASC CDL v1.2 color grading. It's a single effect with four parameters (vec3 slope, vec3 offset, vec3 power, float saturation) that should be able to accomplish everything supported by the other effects listed here. I'm making a similar proposal for three.js core fairly soon.

[vanruesc]

That's even better 👍 I'll update the task.

[vanruesc]

FYI: this ticket is not a blocker for v7 and since I'm not familiar with CDL, I'll leave you to it @donmccurdy. Meaning I won't be checking in here 😄

[donmccurdy]

Thanks @vanruesc! Next on my list after a glTF Transform v4 release that has been taking me longer than planned. 😅