new brightness handling

[redPanther]

1. Tell us something about your changes.
this is a result of lot's of discussions. The new brightness stuff is based on @Funatiq new color correction. Setting the brightness modifies the values for color correction. This will limit the brightness of each color component. The new option "brightnessCompensation" handles the problem that e.g. white (255,255,255)has 3 times more energy than red (255,0,0).

additional: updatewebserver, now with initial ssl support

2. If this changes affect the .conf file. Please provide the changed section

• brightness are now int/percent values from 0 to 100
• new value brightnessCompensation. This is also a percent value. 100 means all colors are equal bright, 0 the opposite

3. Reference an issue (optional)
#422

Note: For further discussions use our forum: forum.hyperion-project.org

[Funatiq]

I like what you did with the brightness. I have some questions:

• You initialize every color value separately for every input (_initialized[input]). Any reason for this instead of the complete initialization?
• Can you explain your idea here:
  B_in = -0.093*_brightness+std::sqrt(_brightness);
if (_brightness< 57) B_in += std::sqrt(57)-std::sqrt(_brightness);
  Is a simple linear function not sufficient?

Btw I would have preferred if you had separated the brightness changes and the webserver changes in different PRs. Would have been easier to read ;)

[brindosch]

perfect so far, i didn't found weirdness. I wonder if you want to move the backlightThreshold to Integer too (for the visual touch :))

[redPanther]

The maping of config value is not linear because it feels better. I tried that 50% is half brightness
I update the mapping val's just in time, because do it in one piece means 7*256 calculations. The request for new brightness can come fast and I dont want to make unneccessary calculations.

[Funatiq]

The mapping of config value is not linear because it feels better. I tried that 50% is half brightness

Ok, I understand. But sqrt is quite expensive. I would suggest a piecewise linear function like this. It's almost the same as yours.

[redPanther]

thats a good idea, will modify the code tomorow

[redPanther]

now backlightThreshold is 0-100
brightness uses piecewise linear func as suggested

just for interessed:

this shows mapping of brightness value to max color value at brightnessCompensation=100