So, I'm tired, and my eyeballs hurt, so I sought out some
isobutylphenylpropionic acid and a gin & tonic.

Warp and clipka always went at it with gusto!   :D
We should email Warp and drag him back in....

I think, if we're going to play with these things, and be able to reliably and
usefully understand WTH is going on, then some sort of visual correspondence
roadmap ought to be made.

Consider:

A box has a pigment with 2 image_maps, blended in a pigment_map, illuminated by
a light source, rendered by POV-Ray, displayed on a monitor, and seen by you.

Each of those things has a gamma associated with it.

My idea is to start with a point on the light source graph, draw a line to the
object graph, then the monitor, then the observer.

I'm almost over here crying with laughter, because I can just hear my girlfriend
now:
"And this....   ***THIS*** is what you do ..... for "fun" ???!"

Let the games begin.

=================================================================

The new tone-adjusting formulas are:

#declare SRGB_Encode = function (C, M) {
 select (C-0.0031308, C*12.92*M, C*12.92*M, (1.055 * pow (C, 1/2.4) - 0.055)*M)
}

#declare SRGB_Decode = function (C, M) {
 select (C-0.040449936, C/12.92, pow ((C+0.055)/1.055, 2.4)*M)
}

using M as a multiplier.  Looks like it works correctly, even with  M > 1.
Perhaps it's not "right", but it's the way I envisioned its usage.


The gradients are made with the following syntax:
Note the gray in the interpolation across the 0 saturation region.
This is what Jerome was pointing out in that thread.

 box {<0, 0, 0> <1, 0.25, 0.01>
  pigment {gradient x
   pigment_map {
    blend_gamma 1
    blend_mode 2
    [0 rgb <1, 0, 1>]
    [1 rgb <0, 1, 0>]
   }
  }
  scale <6.5, 1, 1>
 }

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