== NLA Editor - Auto-Blending for ActionStrips ==

This is just a little time-saver for NLA-workflow. With the 'Auto-Blending' option
turned on in the Transform Properties (NKEY) for an ActionStrip, that strip's blendin/blendout values are determined based on the number of frames that the previous and/or next actionstrip(s) on overlap over the start and end of it.

It is turned on by default for new actionstrips added using the Shift-N hotkey.

Caveats:
* Only the actionstrips immediately on either side of the strip being evaluated, will
 have any effect
* A strip that is longer-than, and extends over the sides of the strip being evaluated,
 will have no effect

Additional Notes:
* Blendin/Blendout have been renamed In/Out in UI for brevity
* Button layout in NLA Transform Properties has changed slightly again, but hopefully that shouldn't be too much of an issue.

3 files changed, 170 insertions, 5 deletions

diff --git a/source/blender/makesdna/DNA_nla_types.h b/source/blender/makesdna/DNA_nla_types.h
index c1fce2772cd..914e6337474 100644
--- a/source/blender/makesdna/DNA_nla_types.h
+++ b/source/blender/makesdna/DNA_nla_types.h
@@ -45,10 +45,13 @@ typedef struct bActionModifier {
 	short type, flag;
 	char channel[32];
 	
-	/* path deform modifier */
-	short pad, no_rot_axis;
-	struct Object *ob;
+	/* noise modifier */
+	float noisesize, turbul;
+	short channels;
 	
+	/* path deform modifier */
+	short no_rot_axis;
+	struct Object *ob;	
 } bActionModifier;
 
 #define ACTSTRIP_MOD_DEFORM		0
@@ -94,6 +97,7 @@ typedef struct bActionStrip {
 #define ACTSTRIP_CYCLIC_USEX	0x100
 #define ACTSTRIP_CYCLIC_USEY	0x200
 #define ACTSTRIP_CYCLIC_USEZ	0x400
+#define ACTSTRIP_AUTO_BLENDS	0x800
 
 #endif
 
diff --git a/source/blender/src/drawnla.c b/source/blender/src/drawnla.c
index 6704d360f96..5d9334e452b 100644
--- a/source/blender/src/drawnla.c
+++ b/source/blender/src/drawnla.c
@@ -579,8 +579,18 @@ static void nla_panel_properties(short cntrl)	// NLA_HANDLER_PROPERTIES
 	}
 	
 	uiBlockBeginAlign(block);
-	uiDefButF(block, NUM, B_NLA_PANEL, "Blendin:",				10,100,145,19, &strip->blendin, 0.0, strip->end-strip->start, 100, 0, "Number of frames of ease-in");
-	uiDefButF(block, NUM, B_NLA_PANEL, "Blendout:",				10,80,145,19, &strip->blendout, 0.0, strip->end-strip->start, 100, 0, "Number of frames of ease-out");
+	uiDefButBitS(block, TOG, ACTSTRIP_AUTO_BLENDS, B_NLA_LOCK, "Auto-Blending", 10,100,145,19, &(strip->flag), 0, 0, 0, 0, "Toggles automatic calculation of blendin/out values");
+	if (strip->flag & ACTSTRIP_AUTO_BLENDS) {
+		char str[32];
+		sprintf(str, "In: %.2f", strip->blendin);
+		uiDefBut(block, LABEL, B_NOP, str,			10,80,77,19, NULL, 0.0, 0.0, 0, 0, "Number of frames of ease-in");
+		sprintf(str, "Out: %.2f", strip->blendout);
+		uiDefBut(block, LABEL, B_NOP, str,			77,80,78,19, NULL, 0.0, 0.0, 0, 0, "Number of frames of ease-out");
+	}
+	else {
+		uiDefButF(block, NUM, B_NLA_PANEL, "In:",	10,80,77,19, &strip->blendin, 0.0, strip->end-strip->start, 100, 0, "Number of frames of ease-in");
+		uiDefButF(block, NUM, B_NLA_PANEL, "Out:",	77,80,78,19, &strip->blendout, 0.0, strip->end-strip->start, 100, 0, "Number of frames of ease-out");
+	}
 	uiDefButBitS(block, TOG, ACTSTRIP_MUTE, B_NLA_PANEL, "Mute", 10,60,145,19, &strip->flag, 0, 0, 0, 0, "Toggles whether the strip contributes to the NLA solution");
 	
 	uiBlockBeginAlign(block);
diff --git a/source/blender/src/editnla.c b/source/blender/src/editnla.c
index 91bec5bc76a..b78e84522e1 100644
--- a/source/blender/src/editnla.c
+++ b/source/blender/src/editnla.c
@@ -62,6 +62,7 @@
 #include "BKE_library.h"
 #include "BKE_main.h"
 #include "BKE_nla.h"
+#include "BKE_utildefines.h"
 
 #include "BIF_screen.h"
 #include "BIF_interface.h"
@@ -188,6 +189,7 @@ void synchronize_action_strips(void)
 	bActionStrip *strip;
 	
 	for (base=G.scene->base.first; base; base=base->next) {
+		/* step 1: adjust strip-lengths */
 		for (strip = base->object->nlastrips.last; strip; strip=strip->prev) {
 			if (strip->flag & ACTSTRIP_LOCK_ACTION) {
 				float actstart, actend;
@@ -205,6 +207,153 @@ void synchronize_action_strips(void)
 				}
 			}
 		}
+		
+		/* step 2: adjust blendin/out values for each strip if option is turned on */
+		for (strip= base->object->nlastrips.first; strip; strip=strip->next) {
+			if (strip->flag & ACTSTRIP_AUTO_BLENDS) {
+				bActionStrip *prev= strip->prev;
+				bActionStrip *next= strip->next;
+				float pr[2], nr[2];
+				
+				strip->blendin = 0.0f;
+				strip->blendout = 0.0f;
+				
+				/* setup test ranges */
+				if (prev && next) {
+					/* init range for previous strip */
+					pr[0]= prev->start;
+					pr[1]= prev->end;
+					
+					/* init range for next strip */
+					nr[0]= next->start;
+					nr[1]= next->end;
+				}
+				else if (prev) {
+					/* next strip's range is same as previous strip's range  */
+					pr[0] = nr[0] = prev->start;
+					pr[1] = nr[1] = prev->end;
+				}
+				else if (next) {
+					/* previous strip's range is same as next strip's range */
+					pr[0] = nr[0] = next->start;
+					pr[1] = nr[1] = next->end;
+				}
+				else {
+					/* there shouldn't be any more strips to loop through for this operation */
+					break;
+				}
+				
+				/* test various cases */
+				if ( IN_RANGE(pr[1], strip->start, strip->end) && 
+					(IN_RANGE(pr[0], strip->start, strip->end)==0) )
+				{
+					/* previous strip intersects start of current */
+					
+					if ( IN_RANGE(nr[1], strip->start, strip->end) && 
+						(IN_RANGE(nr[0], strip->start, strip->end)==0) )
+					{
+						/* next strip also intersects start of current */
+						if (nr[1] < pr[1])
+							strip->blendin= nr[1] - strip->start;
+						else
+							strip->blendin= pr[1] - strip->start;
+					}
+					else if (IN_RANGE(nr[0], strip->start, strip->end) && 
+							(IN_RANGE(nr[1], strip->start, strip->end)==0))
+					{
+						/* next strip intersects end of current */
+						strip->blendout= strip->end - nr[0];
+						strip->blendin= pr[1] - strip->start;
+					}
+					else {
+						/* only previous strip intersects current */
+						strip->blendin= pr[1] - strip->start;
+					}
+				}
+				else if (IN_RANGE(pr[0], strip->start, strip->end) && 
+						(IN_RANGE(pr[1], strip->start, strip->end)==0) )
+				{
+					/* previous strip intersects end of current */
+					
+					if ( IN_RANGE(nr[0], strip->start, strip->end) && 
+						(IN_RANGE(nr[1], strip->start, strip->end)==0) )
+					{
+						/* next strip also intersects end of current */
+						if (nr[1] > pr[1])
+							strip->blendout= strip->end - nr[0];
+						else
+							strip->blendout= strip->end - pr[0];
+					}
+					else if (IN_RANGE(nr[1], strip->start, strip->end) && 
+							(IN_RANGE(nr[0], strip->start, strip->end)==0))
+					{
+						/* next strip intersects start of current */
+						strip->blendin= nr[1] - strip->start;
+						strip->blendout= strip->end - pr[0];
+					}
+					else {
+						/* only previous strip intersects current */
+						strip->blendout= strip->end - pr[0];
+					}
+				}
+				else if (IN_RANGE(nr[1], strip->start, strip->end) && 
+						(IN_RANGE(nr[0], strip->start, strip->end)==0) )
+				{
+					/* next strip intersects start of current */
+					
+					if ( IN_RANGE(pr[1], strip->start, strip->end) && 
+						(IN_RANGE(pr[0], strip->start, strip->end)==0) )
+					{
+						/* previous strip also intersects start of current */
+						if (pr[1] < nr[1])
+							strip->blendin= pr[1] - strip->start;
+						else
+							strip->blendin= nr[1] - strip->start;
+					}
+					else if (IN_RANGE(pr[0], strip->start, strip->end) && 
+							(IN_RANGE(pr[1], strip->start, strip->end)==0))
+					{
+						/* previous strip intersects end of current */
+						strip->blendout= strip->end - pr[0];
+						strip->blendin= nr[1] - strip->start;
+					}
+					else {
+						/* only next strip intersects current */
+						strip->blendin= nr[1] - strip->start;
+					}
+				}
+				else if (IN_RANGE(nr[0], strip->start, strip->end) && 
+						(IN_RANGE(nr[1], strip->start, strip->end)==0) )
+				{
+					/* next strip intersects end of current */
+					
+					if ( IN_RANGE(pr[0], strip->start, strip->end) && 
+						(IN_RANGE(pr[1], strip->start, strip->end)==0) )
+					{
+						/* previous strip also intersects end of current */
+						if (pr[1] > nr[1])
+							strip->blendout= strip->end - pr[0];
+						else
+							strip->blendout= strip->end - nr[0];
+					}
+					else if (IN_RANGE(pr[1], strip->start, strip->end) && 
+							(IN_RANGE(pr[0], strip->start, strip->end)==0))
+					{
+						/* previous strip intersects start of current */
+						strip->blendin= pr[1] - strip->start;
+						strip->blendout= strip->end - nr[0];
+					}
+					else {
+						/* only next strip intersects current */
+						strip->blendout= strip->end - nr[0];
+					}
+				}
+				
+				/* make sure blending stays in ranges */
+				CLAMP(strip->blendin, 0, (strip->end-strip->start));
+				CLAMP(strip->blendout, 0, (strip->end-strip->start));
+			}
+		}
 	}
 	
 }
@@ -502,6 +651,7 @@ void add_empty_nlablock(void)
 	
 	/* change some settings of the strip - try to avoid bad scaling */
 	if ((EFRA-CFRA) < 100) {
+		strip->flag |= ACTSTRIP_AUTO_BLENDS;
 		strip->flag &= ~ACTSTRIP_LOCK_ACTION;
 		strip->actstart = CFRA;
 		strip->actend = CFRA + 100;
@@ -510,6 +660,7 @@ void add_empty_nlablock(void)
 		strip->end = CFRA + 100;
 	}
 	else {
+		strip->flag |= ACTSTRIP_AUTO_BLENDS;
 		strip->flag &= ~ACTSTRIP_LOCK_ACTION;
 		strip->actstart = CFRA;
 		strip->actend = EFRA;