Simplification of node muting and new detach operator

Implements a new operator for detaching nodes. In the process i overhauled the node muting system as well.

There are a number of features that use a kind of "internal linking" in nodes:
1. muting
2. delete + reconnect (restore link to/from node after delete)
3. the new detach operator (same as 2, but don't delete the node)

The desired behavior in all cases is the same: find a sensible mapping of inputs-to-outputs of a node. In the case of muting these links are displayed in red on the node itself. For the other operators they are used to relink connections, such that one gets the best possible ongoing link between previous up- and downstream nodes.

Muting previously used a complicated callback system to ensure consistent behavior in the editor as well as execution in compositor, shader cpu/gpu and texture nodes. This has been greatly simplified by moving the muting step into the node tree localization functions. Any muted node is now bypassed using the generalized nodeInternalRelink function and then removed from the local tree. This way the internal execution system doesn't have to deal with muted nodes at all, as if they are non-existent.

The same function is also used by the delete_reconnect and the new links_detach operators (which work directly in the editor node tree). Detaching nodes is currently keymapped as a translation variant (macro operator): pressing ALTKEY + moving node first detaches and then continues with regular transform operator.

[mont29, 2012-02-25 16:27:09]

Big +1 for me, muting code is mush nicer this way, regrouping similar code is
always great, and new detach op indeed useful… :D

Only real "problem" found, alt-G is already used to ungroup nodes, currently, so
I had to change detach to ctrl-alt-G…

http://codereview.appspot.com/5695063/diff/1/source/blender/editors/transform...
File source/blender/editors/transform/transform_ops.c (right):

http://codereview.appspot.com/5695063/diff/1/source/blender/editors/transform...
source/blender/editors/transform/transform_ops.c:953: WM_keymap_add_item(keymap,
"NODE_OT_move_detach_links", GKEY, KM_PRESS, KM_ALT, 0);
Alt-G is already taken by ungroup, had to change it to ctrl-alt-G…

http://codereview.appspot.com/5695063/diff/1/source/blender/gpu/GPU_material.h
File source/blender/gpu/GPU_material.h (right):

http://codereview.appspot.com/5695063/diff/1/source/blender/gpu/GPU_material....
source/blender/gpu/GPU_material.h:118: //int GPU_stack_link_mute(GPUMaterial
*mat, const char *name, struct LinkInOutsMuteNode *mlnk);
You can remove those funcs, imho. They were only added for shader muting…

http://codereview.appspot.com/5695063/diff/1/source/blender/gpu/intern/gpu_co...
File source/blender/gpu/intern/gpu_codegen.c (right):

http://codereview.appspot.com/5695063/diff/1/source/blender/gpu/intern/gpu_co...
source/blender/gpu/intern/gpu_codegen.c:1257: #if 0
To be removed too, imho; :)

Also, you should remove the OpenGL shader code from gpu_shader_material.gsl (the
copy_raw() funcs) and regenerate gpu_shader_material.gsl.c file. I think they
are only used by current muting code.

[lukas.toenne, 2012-02-25 16:58:21]

Removed unused code from previous node muting

[lukas.toenne, 2012-02-25 16:58:30]

http://codereview.appspot.com/5695063/diff/1/source/blender/editors/transform...
File source/blender/editors/transform/transform_ops.c (right):

http://codereview.appspot.com/5695063/diff/1/source/blender/editors/transform...
source/blender/editors/transform/transform_ops.c:953: WM_keymap_add_item(keymap,
"NODE_OT_move_detach_links", GKEY, KM_PRESS, KM_ALT, 0);
On 2012/02/25 16:27:09, mont29 wrote:
> Alt-G is already taken by ungroup, had to change it to ctrl-alt-G…

Hmm yes, didn't think of that ... Even though ALT+G for ungroup is established
for a long time, the GKEY is more generally used for translation. So if ALTKEY
is supposed to be the modifier for detaching, i'd rather have a different key
combination for ungroup.

Hopefully ungroup will become much less necessary with the group node changes as
well, currently it seems mostly needed for extending a group or for making
another variant (ungroup + make new group). So maybe a new key combination for
it wouldn't be that bad.

http://codereview.appspot.com/5695063/diff/1/source/blender/gpu/GPU_material.h
File source/blender/gpu/GPU_material.h (right):

http://codereview.appspot.com/5695063/diff/1/source/blender/gpu/GPU_material....
source/blender/gpu/GPU_material.h:118: //int GPU_stack_link_mute(GPUMaterial
*mat, const char *name, struct LinkInOutsMuteNode *mlnk);
On 2012/02/25 16:27:09, mont29 wrote:
> You can remove those funcs, imho. They were only added for shader muting…

Done.

http://codereview.appspot.com/5695063/diff/1/source/blender/gpu/intern/gpu_co...
File source/blender/gpu/intern/gpu_codegen.c (right):

http://codereview.appspot.com/5695063/diff/1/source/blender/gpu/intern/gpu_co...
source/blender/gpu/intern/gpu_codegen.c:1257: #if 0
On 2012/02/25 16:27:09, mont29 wrote:
> To be removed too, imho; :)
> 
> Also, you should remove the OpenGL shader code from gpu_shader_material.gsl
(the
> copy_raw() funcs) and regenerate gpu_shader_material.gsl.c file. I think they
> are only used by current muting code.

Done.

[brechtvl, 2012-02-27 15:06:50]

I'd just use a different shortcut like Alt+D here, I don't really see much
reason this shortcut should include G key and then break user automatisms. Tools
like Duplicate or Rip in the 3d view also don't.

Further looks good to me.

[lukas.toenne, 2012-02-27 17:21:53]

Changed key mapping to ALT+DKEY