[Bf-codereview] Normal Node for Cycles (issue 5440091)

[dfelinto at gmail.com]

Reviewers: bf-codereview_blender.org, brechtvl,

Description:
Hi Brecht,

I wanted to tackle a more complicated node and gave Normal Node a try.
(and failed *cough* ;)

I created a new NodeNormal for storage of the Normal, and whatever I put
as default in the node_shader_normal.c::node_shader_init_normal() is
passed to the shader correctly.

The problem now is to hook up the interface normal values to the cycles
storage node.

Maybe I don't need a storage node and could use the
bNodeSocketValueVector directly in blender_shader.cpp. I don't know if
it's possible (and the way to go).

Another idea was to create a custom get function in the RNA def_normal
for the direction and point this to the bNodeSocketValueVector. Again, I
don't know if is the correct way or even possible.

FInal Notes:
---------
My ultimate goal was to port the RGBCurves node to cycles, so I decided
to start with a 'similar' but simpler one. I used the SkyTexture for
some of the

Also, I was testing with a sample file created before I added the
storage node in node_shader_init_normal. That was crashing on
blender_shader.cpp (get_float3(b_normal_node.direction());) and I
couldn't figure out why. Luckily I had the insight of remove the node
and create it again :)

Thanks for any feedback and review.
OSL comes once those problems are sorted out.

Please review this at http://codereview.appspot.com/5440091/

Affected files:
   intern/cycles/app/cycles_xml.cpp
   intern/cycles/blender/blender_shader.cpp
   intern/cycles/kernel/CMakeLists.txt
   intern/cycles/kernel/svm/svm.h
   intern/cycles/kernel/svm/svm_normal.h
   intern/cycles/kernel/svm/svm_types.h
   intern/cycles/render/nodes.cpp
   intern/cycles/render/nodes.h
   source/blender/makesdna/DNA_node_types.h
   source/blender/makesrna/intern/rna_nodetree.c
   source/blender/makesrna/intern/rna_nodetree_types.h
   source/blender/nodes/shader/nodes/node_shader_normal.c