ContrastAdjustmentFilter: A filter to adjust the colors of a rendered scene

[pavly-gerges]

A color filter used to adjust the color contrast and brightness based on a simple tone map operator function and adjust scales on the final result at the final pass before rendering.

Supports and tested on both OGL and OGLES (android).

Discussion : https://hub.jmonkeyengine.org/t/gammacorrectionfilter/45076/33

[pavly-gerges]

Targeting both : #781 #809

[stephengold]

Thanks for working to resolve these issues.

[stephengold]

Let us know when this is ready for review.

[pavly-gerges]

Let us know when this is ready for review.

I have changed the default exp value to 2.2, and documented some default values.

It's now ready for review.

[Ali-RS]

I did a quick look through and noticed fields scale_r,exp_r,... and getters getScale_r, getExp_r,... I think to follow JME (and generally Java conventions) it is better to name them like rScale, rExp,... and getRScale, getRExp,.... that's how the rest of the JME code is following.

[pavly-gerges]

Alright, I will change them, please continue reviewing.

[stephengold]

This is a partial review. Many of my comments are about issues that arise throughout ContrastAdjustmentFilter.java: the choice of defaults, the use of underscores in variable names, the terminology used to discuss colors, etcetera. Please apply my requested changes throughout the PR. I'd like to review this PR again after my requested changes are made.

[pavly-gerges]

@stephengold @Ali-RS Hello there, i have made the requested changes, i hope everything is clear now, please review it again.
Thanks.

[stephengold]

Unless there's further discussion, I plan to integrate this PR in about 24 hours.

[stephengold]

Additional work will be required to resolve #809.

[pavly-gerges]

Additional work will be required to resolve #809.

Like what ? Predefining the filter in the harness activity for sRGB exponent if the srgbFrame is true ?

[stephengold]

Something like that, yes. #809 specifically refers to the harness.