Revert editbone roll correction changes.

This reverts commit f72acc38d 65c5be967 eff6b385e 3fe487217

4 files changed, 27 insertions, 50 deletions

diff --git a/source/blender/editors/include/ED_armature.h b/source/blender/editors/include/ED_armature.h
index b78fa4ffdfb..dea4b2448ff 100644
--- a/source/blender/editors/include/ED_armature.h
+++ b/source/blender/editors/include/ED_armature.h
@@ -59,10 +59,7 @@ typedef struct EditBone {
 	struct EditBone *parent; /* Editbones have a one-way link  (i.e. children refer
 	                          * to parents.  This is converted to a two-way link for
 	                          * normal bones when leaving editmode. */
-	union {                  /* Used to store temporary data */
-		void    *temp;
-		float    temp_f;
-	};
+	void    *temp;          /* Used to store temporary data */
 
 	char    name[64];       /* MAXBONENAME */
 	float   roll;           /* Roll along axis.  We'll ultimately use the axis/angle method
diff --git a/source/blender/editors/transform/transform.h b/source/blender/editors/transform/transform.h
index d1085cf9933..5cac49aff34 100644
--- a/source/blender/editors/transform/transform.h
+++ b/source/blender/editors/transform/transform.h
@@ -257,7 +257,7 @@ typedef struct TransData {
 	float *loc;          /* Location of the data to transform                                              */
 	float  iloc[3];      /* Initial location                                                               */
 	float *val;          /* Value pointer for special transforms */
-	float  ival;         /* Old value */
+	float  ival;         /* Old value*/
 	float  center[3];	 /* Individual data center                                                         */
 	float  mtx[3][3];    /* Transformation matrix from data space to global space                          */
 	float  smtx[3][3];   /* Transformation matrix from global space to data space                          */
diff --git a/source/blender/editors/transform/transform_conversions.c b/source/blender/editors/transform/transform_conversions.c
index 91bac74e8e6..31123827c4c 100644
--- a/source/blender/editors/transform/transform_conversions.c
+++ b/source/blender/editors/transform/transform_conversions.c
@@ -1061,27 +1061,6 @@ static void createTransPose(TransInfo *t, Object *ob)
 
 /* ********************* armature ************** */
 
-static void createTransArmatureVerts_init_roll_fix(TransData *td, EditBone *ebo)
-{
-	/* To fix roll, see comments in transform_generic.c::recalcData_objects() */
-	const float z_axis[3] = {0.0f, 0.0f, 1.0f};
-	float vec[3];
-
-	sub_v3_v3v3(vec, ebo->tail, ebo->head);
-	normalize_v3(vec);
-
-	td->extra = ebo;
-
-	if (fabsf(dot_v3v3(vec, z_axis)) > 0.999999f) {
-		/* If nearly aligned with Z axis, do not alter roll. See T38843. */
-		ebo->temp_f = ebo->roll;
-	}
-	else {
-		ebo->temp_f = ebo->roll - ED_rollBoneToVector(ebo, z_axis, false);
-	}
-	td->ival = ebo->roll;
-}
-
 static void createTransArmatureVerts(TransInfo *t)
 {
 	EditBone *ebo;
@@ -1217,7 +1196,8 @@ static void createTransArmatureVerts(TransInfo *t)
 					ED_armature_ebone_to_mat3(ebo, td->axismtx);
 
 					if ((ebo->flag & BONE_ROOTSEL) == 0) {
-						createTransArmatureVerts_init_roll_fix(td, ebo);
+						td->extra = ebo;
+						td->ival = ebo->roll;
 					}
 
 					td->ext = NULL;
@@ -1239,7 +1219,8 @@ static void createTransArmatureVerts(TransInfo *t)
 
 					ED_armature_ebone_to_mat3(ebo, td->axismtx);
 
-					createTransArmatureVerts_init_roll_fix(td, ebo);
+					td->extra = ebo; /* to fix roll */
+					td->ival = ebo->roll;
 
 					td->ext = NULL;
 					td->val = NULL;
diff --git a/source/blender/editors/transform/transform_generics.c b/source/blender/editors/transform/transform_generics.c
index 4e93d3a89a3..af4beff4bc9 100644
--- a/source/blender/editors/transform/transform_generics.c
+++ b/source/blender/editors/transform/transform_generics.c
@@ -798,35 +798,34 @@ static void recalcData_objects(TransInfo *t)
 			
 			if (!ELEM3(t->mode, TFM_BONE_ROLL, TFM_BONE_ENVELOPE, TFM_BONESIZE)) {
 				/* fix roll */
-				/* Previous method basically tried to get a rotation transform from org ebo Y axis to final ebo Y axis,
-				 * apply this same rotation to org ebo Z axis to get an "up_axis", and compute a new roll value
-				 * so that final ebo's Z axis would be "aligned" with that up_axis.
-				 * There are two issues with that method:
-				 *   - There are many cases where the computed up_axis does not gives a result people would expect.
-				 *   - Applying a same transform in a single step or in several smaller ones would not give the same
-				 *     result! See e.g. T38407.
-				 * Now, instead of trying to be smart with complex axis/angle handling, just store diff roll
-				 * (diff between real init roll and virtual init roll where bone's Z axis would be "aligned" with
-				 * armature's Z axis), and do the reverse to get final roll.
-				 * This method at least gives predictable, consistent results (the bone basically keeps "facing"
-				 * the armature's Z axis).
-				 * Note we need some special handling when bone is Z-aligned... sigh.
-				 */
 				for (i = 0; i < t->total; i++, td++) {
 					if (td->extra) {
-						const float z_axis[3] = {0.0f, 0.0f, 1.0f};
-						float vec[3];
-
+						float vec[3], up_axis[3];
+						float qrot[4];
+						float roll;
+						
 						ebo = td->extra;
-						sub_v3_v3v3(vec, ebo->tail, ebo->head);
-						normalize_v3(vec);
 
-						if (fabsf(dot_v3v3(vec, z_axis)) > 0.999999f) {
-							/* If our bone is Z-aligned, do not alter roll. See T38843. */
+						if (t->state == TRANS_CANCEL) {
+							/* restore roll */
 							ebo->roll = td->ival;
 						}
 						else {
-							ebo->roll = ebo->temp_f + ED_rollBoneToVector(ebo, z_axis, false);
+							copy_v3_v3(up_axis, td->axismtx[2]);
+							
+							if (t->mode != TFM_ROTATION) {
+								sub_v3_v3v3(vec, ebo->tail, ebo->head);
+								normalize_v3(vec);
+								rotation_between_vecs_to_quat(qrot, td->axismtx[1], vec);
+								mul_qt_v3(qrot, up_axis);
+							}
+							else {
+								mul_m3_v3(t->mat, up_axis);
+							}
+							
+							/* roll has a tendency to flip in certain orientations - [#34283], [#33974] */
+							roll = ED_rollBoneToVector(ebo, up_axis, false);
+							ebo->roll = angle_compat_rad(roll, td->ival);
 						}
 					}
 				}