On Thu, 22 Mar 2018 19:44:34 -0400, "Mayayana"
wrote:

"Eric Stevens" wrote

| You said you want to know what the code
| is doing. I gave you a brief outline of what the
| code is doing. For any more you'd be getting
| into the actual code.
|
| And the code is doing all this for what (slightly) higher level
| purpose?
|

Maybe it's me, but I just don't get what level
you want to investigate. And there are numerous
levels of abstraction between the CPU and what
you see in Photoshop. There's code. The code
deals with bytes that represent pixels. (Did you
see the extensive description from earlier today?)

That's pretty much it, in terms of going up from
code level. The next level up from bytes is basically
the GUI, which allows you to process those groups
of bytes with the mouse.

If you do something like decide to lighten an
image -- or just about any other operation -- it's
all math. The byte values are raised to make for
lighter pixel colors. There isn't any other step in
between, except for the conveniences that allow
us to just move the mouse and click buttons to
do the job. So you perhaps drag a control to make
the image lighter, the editor calculates how to increase
the byte values to get the pixel colors that action
specifies, then the editor paints the new image
(A DIB, or stream of bytes representing the image)
onto the screen.

If you've enabled "auto proof" then it's painting
new DIBs at a very fast rate, and probably storing
one each time you release the mouse from the slide
control.

And perhaps most importantly, it stores the data
from those steps in order to "remember" and offer
multiple undo options. Each time you change the
lightness, the editor will store a DIB that it can
back up to if necessary.

I'm sorry if that's not what you're looking for. I
just don't know what else you can find out. That's
how it works, soup to nuts.

--

Regards,

Eric Stevens