Normalize Node - Tile

as discussed during IRC the normalize node for tile.

The implementation is simple. Fancy alternatives to gather the minimum and maximum through recursive loop in the tiles proved inefficient (Jeroen Bakker's tests/words).

edit: committed 43800

[jbkkavt, 2012-01-31 10:39:08]

Hi Dalai, 

great work!, just some small things, poke me if you need to.

Jeroen

http://codereview.appspot.com/5576078/diff/1/source/blender/compositor/operat...
File source/blender/compositor/operations/COM_NormalizeOperation.cpp (right):

http://codereview.appspot.com/5576078/diff/1/source/blender/compositor/operat...
source/blender/compositor/operations/COM_NormalizeOperation.cpp:79: float minv,
maxv;
minv and maxv are not initialized with blenderminz and blendermaxz. 

Original code is min = 1.0f + BLENDER_ZMAX, max = 1.0f-BLENDER_ZMAX

Crucial part for correct working of the normalize node.

http://codereview.appspot.com/5576078/diff/1/source/blender/compositor/operat...
File source/blender/compositor/operations/COM_NormalizeOperation.h (right):

http://codereview.appspot.com/5576078/diff/1/source/blender/compositor/operat...
source/blender/compositor/operations/COM_NormalizeOperation.h:31: typedef struct
MinMax {
Naming the struct MinMax can be faulty when in the future more of these structs
will be defined.

You can also use NodeTwoFloats struct in DNA_node_types.h with comments how and
when the x and y are used.

See what you like as best solution.

[dfelinto, 2012-01-31 18:00:51]

implemented Jeroen's suggestions.comments coming next

[dfelinto, 2012-01-31 18:03:23]

The min and max initialization was indeed missing. it was a late night lapse :)
No wonder my quick test didn't work and I decided to test later.

I think the NodeTwoFloats is indeed a simpler solution (if documented),
so be it.

Patch ready for commit, looking for final 'go'

[jbkkavt, 2012-01-31 19:00:34]

Fine by me, ready to commit

http://codereview.appspot.com/5576078/diff/4001/source/blender/compositor/ope...
File source/blender/compositor/operations/COM_TonemapOperation.cpp (right):

http://codereview.appspot.com/5576078/diff/4001/source/blender/compositor/ope...
source/blender/compositor/operations/COM_TonemapOperation.cpp:159: +	return
this->cachedInstance;
Did I missed this! :)

[dfelinto, 2012-01-31 20:00:08]

commiited. I added a check to avoid division by zero. It's in the TIledata code
so it's fine.
(more details int he commit log)

>> source/blender/compositor/operations/COM_TonemapOperation.cpp:159: +	return
>> this->cachedInstance;
> Did I missed this! :)
;) this is what happens when you get people copy/pasting your code.

Actually, strange enough, for the Normalize code this line was mandatory
(otherwise *data was never defined before). It's strange that the ToneMap code
never ran into that.