From a8aaec6f210626d2beb2d23f297c1a412b047e8e Mon Sep 17 00:00:00 2001
From: Ton Roosendaal <ton@blender.org>
Date: Thu, 22 Nov 2007 20:25:59 +0000
Subject: [PATCH] Bugfix #7573

NLA Window, Strip blending mode "Add" didn't work at all.
It was using very bad quaternion addition. Replaced with proper code.

For devs; new is the function QuatMulFac(quat, factor) which allows to
multiply a rotation with a value (make it rotate more or less)
---
 source/blender/blenkernel/intern/action.c |  6 ++++--
 source/blender/blenlib/BLI_arithb.h       |  3 ++-
 source/blender/blenlib/intern/arithb.c    | 15 +++++++++++++++
 source/blender/src/drawipo.c              |  8 +++++---
 4 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/source/blender/blenkernel/intern/action.c b/source/blender/blenkernel/intern/action.c
index bd5e5d612c6..e30d7dd4ac9 100644
--- a/source/blender/blenkernel/intern/action.c
+++ b/source/blender/blenkernel/intern/action.c
@@ -607,8 +607,10 @@ void blend_poses(bPose *dst, bPose *src, float srcweight, short mode)
 				QUATCOPY(squat, schan->quat);
 				if(mode==ACTSTRIPMODE_BLEND)
 					QuatInterpol(dchan->quat, dquat, squat, srcweight);
-				else
-					QuatAdd(dchan->quat, dquat, squat, srcweight);
+				else {
+					QuatMulFac(squat, srcweight);
+					QuatMul(dchan->quat, dquat, squat);
+				}
 				
 				NormalQuat (dchan->quat);
 			}
diff --git a/source/blender/blenlib/BLI_arithb.h b/source/blender/blenlib/BLI_arithb.h
index 9e4412d3cd3..32308f89a15 100644
--- a/source/blender/blenlib/BLI_arithb.h
+++ b/source/blender/blenlib/BLI_arithb.h
@@ -119,6 +119,8 @@ void QuatToEul(float *quat, float *eul);
 void QuatOne(float *);
 void QuatMul(float *, float *, float *);
 void QuatMulVecf(float *q, float *v);
+void QuatMulf(float *q, float f);
+void QuatMulFac(float *q, float fac);
 
 void NormalQuat(float *);
 void VecRotToQuat(float *vec, float phi, float *quat);
@@ -126,7 +128,6 @@ void VecRotToQuat(float *vec, float phi, float *quat);
 void QuatSub(float *q, float *q1, float *q2);
 void QuatConj(float *q);
 void QuatInv(float *q);
-void QuatMulf(float *q, float f);
 float QuatDot(float *q1, float *q2);
 void QuatCopy(float *q1, float *q2);
 
diff --git a/source/blender/blenlib/intern/arithb.c b/source/blender/blenlib/intern/arithb.c
index 5a37205af01..2888a684af1 100644
--- a/source/blender/blenlib/intern/arithb.c
+++ b/source/blender/blenlib/intern/arithb.c
@@ -1109,6 +1109,7 @@ void QuatInv(float *q)
 	QuatMulf(q, 1.0f/f);
 }
 
+/* simple mult */
 void QuatMulf(float *q, float f)
 {
 	q[0] *= f;
@@ -1124,6 +1125,20 @@ void QuatSub(float *q, float *q1, float *q2)
 	q2[0]= -q2[0];
 }
 
+/* angular mult factor */
+void QuatMulFac(float *q, float fac)
+{
+	float angle= fac*saacos(q[0]);	/* quat[0]= cos(0.5*angle), but now the 0.5 and 2.0 rule out */
+	
+	float co= (float)cos(angle);
+	float si= (float)sin(angle);
+	q[0]= co;
+	Normalize(q+1);
+	q[1]*= si;
+	q[2]*= si;
+	q[3]*= si;
+	
+}
 
 void QuatToMat3( float *q, float m[][3])
 {
diff --git a/source/blender/src/drawipo.c b/source/blender/src/drawipo.c
index d9ef3349ec1..9b64d350b9f 100644
--- a/source/blender/src/drawipo.c
+++ b/source/blender/src/drawipo.c
@@ -2014,7 +2014,7 @@ static char *ipodriver_modeselect_pup(Object *ob)
 	return (string);
 }
 
-static char *ipodriver_channelselect_pup(void)
+static char *ipodriver_channelselect_pup(int is_armature)
 {
 	static char string[1024];
 	char *tmp;
@@ -2031,7 +2031,8 @@ static char *ipodriver_channelselect_pup(void)
 	tmp+= sprintf(tmp, "|Scale X %%x%d", OB_SIZE_X);
 	tmp+= sprintf(tmp, "|Scale Y %%x%d", OB_SIZE_Y);
 	tmp+= sprintf(tmp, "|Scale Z %%x%d", OB_SIZE_Z);
-	tmp+= sprintf(tmp, "|Rotation Differance %%x%d", OB_ROT_DIFF);
+	if(is_armature)
+		tmp+= sprintf(tmp, "|Rotation Differance %%x%d", OB_ROT_DIFF);
 	
 	return (string);
 }
@@ -2094,7 +2095,8 @@ static void ipo_panel_properties(short cntrl)	// IPO_HANDLER_PROPERTIES
 									  ipodriver_modeselect_pup(driver->ob), 165,240,145,20, &(driver->blocktype), 0, 0, 0, 0, "Driver type");
 
 					uiDefButS(block, MENU, B_IPO_REDR, 
-								ipodriver_channelselect_pup(),			165,220,145,20, &(driver->adrcode), 0, 0, 0, 0, "Driver channel");
+								ipodriver_channelselect_pup(driver->ob->type==OB_ARMATURE && driver->blocktype==ID_AR),			
+														165,220,145,20, &(driver->adrcode), 0, 0, 0, 0, "Driver channel");
 				}
 				uiBlockEndAlign(block);
 			}