Applying Stephan Kassemeyer's patch (#6750) to add a curve modifier for sculpting.
A few changes from the patch:
* The default curve is closer to the old behavior
* Fixed loading files already saved in sculpt mode
* Changed the interface; split the brush texture controls off into a third sculpt tab, and put the curve (and curve reset) into the Brush tab.
Added a new input control that smooths the brush stroke.
This option controlled by the menu item Sculpt>Input Control>Smooth Stroke. When enabled, the brush has a delayed effect on the model; a green line is drawn to indicate the smoothed path of the stroke. After ~200 pixels, the first half of the stroke will be applied to the model; the process then repeats, with a new segment of the stroke being applied to the model after every 200 pixels. On mouse up, any remaining portion of the stroke will be applied.
Other changes:
* Added a flags field to SculptData; currently only used for smooth stroke but other flags can be moved into it
* Moved the damaged_rects/verts into SculptSession
* Simplified brush application by moving init_editdata into do_symmetrical_brush_actions
* Removed Averaging from sculpt Input menu; smooth stroke should take its place
TODO:
* Fix display of the smooth line in Partial Redraw mode
* Make the smoothing and delay factors adjustable
* Optimize the stroke application (currently using the old 'dot' style of applying the brush)
Removed special Sculpt Mode undo code. Sculpt Mode undo is no longer so useful, since in order to make it more correct it has gotten slower, so normal BIF_undo_push is used now. Fixes bug with Shape Keys, sculpting on a shape key wasn't doing undo properly.
* Replaced get_tex_angle() with tex_angle() and set_tex_angle(). This removes the need to do a bunch of error-prone NULL checking everywhere the texture angle is used.
When in sculptmode, enter editmode, add faces or vertices, exit editmode,
then undos/redos screw up mesh.
Now the stack for sculpt is freed. Later on one could precisely test why
this undo isn't resistant to such changes.
http://projects.blender.org/pipermail/bf-committers/2006-November/016311.html
As recommended on bf-committers, I created an entirely separate section for
sculptmode hotkeys, so none of the standard hotkeys in space.c carry over.
(However, the standard hotkeys in toets.c are left unchanged.)
There are probably some useful hotkeys that have been disabled with this commit,
and other hotkeys that still need to be added, so this needs review.
