I've written a convenient function that returns the sibling of a node in the
red-black tree implementation originally implemented by Joshua Leung.
I want to use this get_sibling() function in the future to implement the missing
removal function of the red-black tree implementation.
For now the get_sibling() function just simplifies the get_uncle() function.
Just like the rest of the red-black tree implementation this diff is based on
Wikipedia: http://en.wikipedia.org/wiki/Red%E2%80%93black_tree#Removal
Added some more methods for the Red-Black Tree implementation in Blender (used for runtime viewing and searching of keyframes) which abstract away some of the lower-level handling of the BST (i.e. adding nodes without balancing and searching for nodes).
Also, improved the implementation of the jump next/prev keyframe operator so that it pops up an error message when the last keyframe in whatever direction is encountered.
Constraints:
* Adding constraints with targets should now work.
-- (When no target is provided, the code to create a new target is not yet in place again yet)
* Constraints can be added in Object and PoseModes again using the Ctrl-Shift-C hotkey.
* All constraints can now be cleared from the active Object or selected Bones using the Ctrl-Alt-C hotkey.
* Added warnings when adding constraints invalid for the current context, and removed the old add_constraint() function.
* Buttons window updates correctly after adding keyframes now
Keyframes Drawing:
* Removed un-necessary extra function-call for RB-Tree implementation, by inlining a special one-off case.
* Keyframe diamonds which are not within the viewable area are now not drawn (but filtering will still need to find them).
Keyframes are now prepared for drawing by being added to a binary-tree structure instead of using insertion-sort on a Double-Linked List. This gives rather significant improvements on a few bad cases (*).
I've implemented a basic Red-Black Tree whose nodes/data-structures can also be used as a simple Double-Linked List (ListBase) for this purpose. The implementation of this tree currently does not have support for removing individual nodes, since such capabilities aren't needed yet.
Stats (using keyframes from an imported .bvh animation file):
* When only the keyframes are drawn (i.e. long keyframes are not identified), the time needed to draw the DopeSheet region 10 times went down from 4000ms to about 300ms.
* When long keyframes are considered as well, the same test has gone from 6000ms to 3000ms. There is still a bottleneck there that I haven't been able to remove yet (an attempt at this made the runtimes go through the roof - 32000 ms for the test done here).
Assorted Notes:
* Added missing headers for some files
* Fixed profiling flags for mingw. There was an extra space which prevented the sound-code from compiling.
