Three new features:

1) Stride Bone

For walkcycles, you could already set an NLA strip to cycle over a path
based on a preset distance value. This cycling happens based on a linear
interpolation, with constant speed.
Not all cycles have a constant speed however, like hopping or jumping.
To ensure a perfect slipping-less foot contact, you now can set a Bone
in an Armature to define the stride. This "Stride Bone" then becomes a
sort-of ruler, a conveyor belt, on which the character walks. When using
the NLA "Use Path" option, it then tries to keep the Stride Bone entirely
motionless on the path, by cancelling out its motion (for the entire
Armature). This means that the animation keys for a Stride Bone have to be
exactly negative of the desired path. Only, at choice, the X,Y or Z Ipo
curve is used for this stride.

Examples:

http://www.blender.org/bf/0001_0040.avi
The top armature shows the actual Action, the bottom armature has been
parented to a Path, using the Stride Bone feature.

http://www.blender.org/bf/0001_0080.avi
Here the Stride Bone has a number of children, creating a ruler to be
used as reference while animating.

Test .blend:
http://www.blender.org/bf/motionblender1.blend

Notes:
- Note that action keys for Bones work local, based on the Bone's
  orientation as set in EditMode. Therefore, an Y translation always
  goes in the Bone's direction.
- To be able to get a "solvable" stride, the animation curve has
  to be inverse evaluated, using a Newton Raphson root solver. That
  means you can only create stride curves that keep moving forward, and
  cannot return halfway.
- Set the Stride Bone in the Editing Buttons, Bone Panel. You can set
  change the name or set the axis in the NLA Window, Strip Properties Panel.
- Files in this commit will move to the blender.org release section.

2) Armature Ghosting

In EditButtons, Armature Panel, you can set an armature to draw ghosts.
The number value denotes the amount of frames that have to be drawn extra
(for the active action!) around the current frame.
Ghosts only evaluate its own Pose, executing it's Actions, Constraints and
IK. No external dependencies are re-evaluated for it.

3) NLA/Action time control

If you click in the NLA window on the action (linked to Object), it makes
sure the Timing as drawn in the Action editor is not corrected for NLA.
If you also set the Object to "Action", this timing will be executed on the
Object as well (not NLA time).
(It's a bit confusing... will make a good doc & maybe review UI!)

1 files changed, 37 insertions, 36 deletions

diff --git a/source/blender/src/drawnla.c b/source/blender/src/drawnla.c
index b558750647b..007238224de 100644
--- a/source/blender/src/drawnla.c
+++ b/source/blender/src/drawnla.c
@@ -58,6 +58,7 @@
 #include "MEM_guardedalloc.h"
 
 #include "BKE_action.h"
+#include "BKE_depsgraph.h"
 #include "BKE_global.h"
 
 #include "BSE_drawnla.h"
@@ -148,6 +149,15 @@ static void draw_nla_channels(void)
 				glRasterPos2f(x+32,  y-4);
 				BMF_DrawString(G.font, ob->action->id.name+2);
 				
+				/* icon for active action (no strip mapping) */
+				for (strip = ob->nlastrips.first; strip; strip=strip->next)
+					if(strip->flag & ACTSTRIP_ACTIVE) break;
+				if(strip==NULL) {
+					glEnable(GL_BLEND);
+					BIF_draw_icon_blended(x, y-8, ICON_DOT, TH_BACK, 0);
+					glDisable(GL_BLEND);
+				}
+				
 				y-=NLACHANNELHEIGHT+NLACHANNELSKIP;
 			}
 
@@ -417,24 +427,8 @@ void do_nlabuts(unsigned short event)
 		allqueue(REDRAWNLA, 0);
 		break;
 	case B_NLA_PANEL:
-		if (strip->end<strip->start)
-			strip->end=strip->start;
-	
-	
-		if (strip->blendin>(strip->end-strip->start))
-			strip->blendin = strip->end-strip->start;
-	
-		if (strip->blendout>(strip->end-strip->start))
-			strip->blendout = strip->end-strip->start;
-	
-		if (strip->blendin > (strip->end-strip->start-strip->blendout))
-			strip->blendin = (strip->end-strip->start-strip->blendout);
-	
-		if (strip->blendout > (strip->end-strip->start-strip->blendin))
-			strip->blendout = (strip->end-strip->start-strip->blendin);
-		
 		
-		update_for_newframe_muted();
+		DAG_object_flush_update(G.scene, OBACT, OB_RECALC_OB|OB_RECALC_DATA);
 		allqueue (REDRAWNLA, 0);
 		allqueue (REDRAWVIEW3D, 0);
 		break;
@@ -463,39 +457,46 @@ static void nla_panel_properties(short cntrl)	// NLA_HANDLER_PROPERTIES
 	
 	/* first labels, for simpler align code :) */
 	uiDefBut(block, LABEL, 0, "Timeline Range:",	10,180,300,19, 0, 0, 0, 0, 0, "");
-	uiDefBut(block, LABEL, 0, "Action Range:",		10,140,300,19, 0, 0, 0, 0, 0, "");
-	uiDefBut(block, LABEL, 0, "Blending:",			10,100,300,19, 0, 0, 0, 0, 0, "");
-	uiDefBut(block, LABEL, 0, "Options:",			10,60,300,19, 0, 0, 0, 0, 0, "");
+	uiDefBut(block, LABEL, 0, "Blending:",			10,120,300,19, 0, 0, 0, 0, 0, "");
+	uiDefBut(block, LABEL, 0, "Options:",			10,80,300,19, 0, 0, 0, 0, 0, "");
+	uiDefBut(block, LABEL, 0, "Stride Support:",	10,40,300,19, 0, 0, 0, 0, 0, "");
 
 	uiBlockBeginAlign(block);
-	uiDefButF(block, NUM, B_REDR, "Strip Start:",	10,160,150,19, &strip->start, -1000.0, strip->end-1, 100, 0, "First frame in the timeline");
-	uiDefButF(block, NUM, B_REDR, "Strip End:", 	160,160,150,19, &strip->end, strip->start+1, MAXFRAMEF, 100, 0, "Last frame in the timeline");
+	uiDefButF(block, NUM, B_NLA_PANEL, "Strip Start:",	10,160,150,19, &strip->start, -1000.0, strip->end-1, 100, 0, "First frame in the timeline");
+	uiDefButF(block, NUM, B_NLA_PANEL, "Strip End:", 	160,160,150,19, &strip->end, strip->start+1, MAXFRAMEF, 100, 0, "Last frame in the timeline");
 
-	uiBlockBeginAlign(block);
-	uiDefIconButBitS(block, ICONTOG, ACTSTRIP_LOCK_ACTION, B_NLA_LOCK, ICON_UNLOCKED,	10,120,20,19, &(strip->flag), 0, 0, 0, 0, "Toggles Action end/start to be automatic mapped to strip duration");
+	uiDefIconButBitS(block, ICONTOG, ACTSTRIP_LOCK_ACTION, B_NLA_LOCK, ICON_UNLOCKED,	10,140,20,19, &(strip->flag), 0, 0, 0, 0, "Toggles Action end/start to be automatic mapped to strip duration");
 	if(strip->flag & ACTSTRIP_LOCK_ACTION) {
 		char str[40];
 		sprintf(str, "Action Start: %.2f", strip->actstart);
-		uiDefBut(block, LABEL, B_NOP, str,			30,120,140,19, NULL, 0.0, 0.0, 0, 0, "First frame of the action to map to the playrange");
+		uiDefBut(block, LABEL, B_NOP, str,			30,140,140,19, NULL, 0.0, 0.0, 0, 0, "First frame of the action to map to the playrange");
 		sprintf(str, "Action End: %.2f", strip->actend);
-		uiDefBut(block, LABEL, B_NOP, str,			170,120,140,19, NULL, 0.0, 0.0, 0, 0, "Last frame of the action to map to the playrange");
+		uiDefBut(block, LABEL, B_NOP, str,			170,140,140,19, NULL, 0.0, 0.0, 0, 0, "Last frame of the action to map to the playrange");
 	}
 	else {
-		uiDefButF(block, NUM, B_REDR, "Action Start:",	30,120,140,19, &strip->actstart, -1000.0, strip->actend-1, 100, 0, "First frame of the action to map to the playrange");
-		uiDefButF(block, NUM, B_REDR, "Action End:",	170,120,140,19, &strip->actend, strip->actstart+1, MAXFRAMEF, 100, 0, "Last frame of the action to map to the playrange");
+		uiDefButF(block, NUM, B_NLA_PANEL, "Action Start:",	30,140,140,19, &strip->actstart, -1000.0, strip->actend-1, 100, 0, "First frame of the action to map to the playrange");
+		uiDefButF(block, NUM, B_NLA_PANEL, "Action End:",	170,140,140,19, &strip->actend, strip->actstart+1, MAXFRAMEF, 100, 0, "Last frame of the action to map to the playrange");
 	}
+	
 	uiBlockBeginAlign(block);
-	uiDefButF(block, NUM, B_REDR, "Blendin:", 	10,80,150,19, &strip->blendin, 0.0, strip->actend-strip->actstart, 100, 0, "Number of frames of ease-in");
-	uiDefButF(block, NUM, B_REDR, "Blendout:", 	160,80,150,19, &strip->blendout, 0.0, strip->actend-strip->actstart, 100, 0, "Number of frames of ease-out");
+	uiDefButF(block, NUM, B_NLA_PANEL, "Blendin:", 	10,100,150,19, &strip->blendin, 0.0, strip->actend-strip->actstart, 100, 0, "Number of frames of ease-in");
+	uiDefButF(block, NUM, B_NLA_PANEL, "Blendout:", 160,100,150,19, &strip->blendout, 0.0, strip->actend-strip->actstart, 100, 0, "Number of frames of ease-out");
 
 	uiBlockBeginAlign(block);
-	uiDefButF(block, NUM, B_REDR, "Repeat:", 	10,40,150,19, &strip->repeat, 0.0001, 1000.0f, 100, 0, "Number of times the action should repeat");
-	uiDefButF(block, NUM, B_REDR, "Stride:", 	160,40,150,19, &strip->stridelen, 0.0001, 1000.0, 100, 0, "Distance covered by one complete cycle of the action specified in the Action Range");
-
+	uiDefButF(block, NUM, B_NLA_PANEL, "Repeat:", 	10,60,150,19, &strip->repeat, 0.001, 1000.0f, 100, 0, "Number of times the action should repeat");
+	uiDefButBitS(block, TOG, ACTSTRIP_HOLDLASTFRAME, B_NLA_PANEL, "Hold",	160,60,75,19, &strip->flag, 0, 0, 0, 0, "Toggles whether to continue displaying the last frame past the end of the strip");
+	uiDefButS(block, TOG, B_NLA_PANEL, "Add",								230,60,75,19, &strip->mode, 0, 0, 0, 0, "Toggles additive blending mode");
+	
 	uiBlockBeginAlign(block);
-	uiDefButBitS(block, TOG, ACTSTRIP_USESTRIDE, B_REDR, "Use Path",	10,0,100,19, &strip->flag, 0, 0, 0, 0, "Plays action based on path position & stride");
-	uiDefButBitS(block, TOG, ACTSTRIP_HOLDLASTFRAME, B_REDR, "Hold",	110,0,100,19, &strip->flag, 0, 0, 0, 0, "Toggles whether to continue displaying the last frame past the end of the strip");
-	uiDefButS(block, TOG, B_REDR, "Add",	210,0,100,19, &strip->mode, 0, 0, 0, 0, "Toggles additive blending mode");
+	uiDefButBitS(block, TOG, ACTSTRIP_USESTRIDE, B_NLA_PANEL, "Use Path",	10,20,100,19, &strip->flag, 0, 0, 0, 0, "Plays action based on path position & stride");
+	uiDefButF(block, NUM, B_NLA_PANEL, "Stride:",		110,20,200,19, &strip->stridelen, 0.0001, 1000.0, 100, 0, "Distance covered by one complete cycle of the action specified in the Action Range");
+	
+	uiDefButS(block, ROW, B_NLA_PANEL, "X",				10, 0, 33, 19, &strip->stride_axis, 1, 0, 0, 0, "Dominant axis for Stride Bone");
+	uiDefButS(block, ROW, B_NLA_PANEL, "Y",				43, 0, 33, 19, &strip->stride_axis, 1, 1, 0, 0, "Dominant axis for Stride Bone");
+	uiDefButS(block, ROW, B_NLA_PANEL, "Z",				76, 0, 34, 19, &strip->stride_axis, 1, 2, 0, 0, "Dominant axis for Stride Bone");
+	
+	uiDefBut(block, TEX, B_NLA_PANEL, "Stride Bone:",	110, 0, 200, 19, strip->stridechannel, 1, 31, 0, 0, "Name of Bone used for stride");
+
 }
 
 static void nla_blockhandlers(ScrArea *sa)