Math lib: add axis_angle_normalized_to_quat, use when length is known

5 files changed, 17 insertions, 13 deletions

diff --git a/source/blender/blenlib/BLI_math_rotation.h b/source/blender/blenlib/BLI_math_rotation.h
index 42161279bfd..c9f553c6fa5 100644
--- a/source/blender/blenlib/BLI_math_rotation.h
+++ b/source/blender/blenlib/BLI_math_rotation.h
@@ -95,6 +95,7 @@ void print_qt(const char *str, const float q[4]);
 /******************************** Axis Angle *********************************/
 
 /* conversion */
+void axis_angle_normalized_to_quat(float r[4], const float axis[3], const float angle);
 void axis_angle_to_quat(float r[4], const float axis[3], const float angle);
 void axis_angle_to_mat3(float R[3][3], const float axis[3], const float angle);
 void axis_angle_normalized_to_mat3(float R[3][3], const float axis[3], const float angle);
diff --git a/source/blender/blenlib/intern/math_rotation.c b/source/blender/blenlib/intern/math_rotation.c
index 6559c3723bb..0392598769f 100644
--- a/source/blender/blenlib/intern/math_rotation.c
+++ b/source/blender/blenlib/intern/math_rotation.c
@@ -677,19 +677,22 @@ void print_qt(const char *str, const float q[4])
 
 /******************************** Axis Angle *********************************/
 
-/* Axis angle to Quaternions */
+void axis_angle_normalized_to_quat(float q[4], const float axis[3], const float angle)
+{
+	const float phi = 0.5f * angle;
+	const float si = sinf(phi);
+	const float co = cosf(phi);
+	BLI_ASSERT_UNIT_V3(axis);
+	q[0] = co;
+	mul_v3_v3fl(q + 1, axis, si);
+}
+
 void axis_angle_to_quat(float q[4], const float axis[3], const float angle)
 {
 	float nor[3];
 
 	if (LIKELY(normalize_v3_v3(nor, axis) != 0.0f)) {
-		const float phi = angle / 2.0f;
-		float si;
-		si   = sinf(phi);
-		q[0] = cosf(phi);
-		q[1] = nor[0] * si;
-		q[2] = nor[1] * si;
-		q[3] = nor[2] * si;
+		axis_angle_normalized_to_quat(q, nor, angle);
 	}
 	else {
 		unit_qt(q);
diff --git a/source/blender/editors/space_view3d/view3d_edit.c b/source/blender/editors/space_view3d/view3d_edit.c
index 323bc6bc436..7d37326740c 100644
--- a/source/blender/editors/space_view3d/view3d_edit.c
+++ b/source/blender/editors/space_view3d/view3d_edit.c
@@ -834,7 +834,7 @@ static void viewrotate_apply(ViewOpsData *vod, int x, int y)
 		}
 
 		/* Perform the orbital rotation */
-		axis_angle_to_quat(q1, zvec_global, sensitivity * vod->reverse * (x - vod->oldx));
+		axis_angle_normalized_to_quat(q1, zvec_global, sensitivity * vod->reverse * (x - vod->oldx));
 		mul_qt_qtqt(vod->viewquat, vod->viewquat, q1);
 
 		if (vod->use_dyn_ofs) {
@@ -3562,7 +3562,7 @@ static int vieworbit_exec(bContext *C, wmOperator *op)
 				}
 
 				/* z-axis */
-				axis_angle_to_quat(quat_mul, zvec, angle);
+				axis_angle_normalized_to_quat(quat_mul, zvec, angle);
 			}
 			else {
 
@@ -3615,7 +3615,7 @@ static void view_roll_angle(ARegion *ar, float quat[4], const float orig_quat[4]
 	float quat_mul[4];
 
 	/* camera axis */
-	axis_angle_to_quat(quat_mul, dvec, angle);
+	axis_angle_normalized_to_quat(quat_mul, dvec, angle);
 
 	mul_qt_qtqt(quat, orig_quat, quat_mul);
 	rv3d->view = RV3D_VIEW_USER;
diff --git a/source/blender/editors/space_view3d/view3d_walk.c b/source/blender/editors/space_view3d/view3d_walk.c
index 26f942b3ecd..31bb37e98f6 100644
--- a/source/blender/editors/space_view3d/view3d_walk.c
+++ b/source/blender/editors/space_view3d/view3d_walk.c
@@ -973,7 +973,7 @@ static int walkApply(bContext *C, WalkInfo *walk)
 					copy_v3_fl3(upvec, 0.0f, 0.0f, 1.0f);
 
 					/* Rotate about the relative up vec */
-					axis_angle_to_quat(tmp_quat, upvec, x);
+					axis_angle_normalized_to_quat(tmp_quat, upvec, x);
 					mul_qt_qtqt(rv3d->viewquat, rv3d->viewquat, tmp_quat);
 				}
 			}
diff --git a/source/blender/editors/transform/transform_manipulator.c b/source/blender/editors/transform/transform_manipulator.c
index fc4e5fcb8e5..98afa2a3c46 100644
--- a/source/blender/editors/transform/transform_manipulator.c
+++ b/source/blender/editors/transform/transform_manipulator.c
@@ -162,7 +162,7 @@ static void stats_editbone(RegionView3D *rv3d, EditBone *ebo)
 }
 
 /* could move into BLI_math however this is only useful for display/editing purposes */
-static void axis_angle_to_gimbal_axis(float gmat[3][3], float axis[3], float angle)
+static void axis_angle_to_gimbal_axis(float gmat[3][3], const float axis[3], const float angle)
 {
 	/* X/Y are arbitrary axies, most importantly Z is the axis of rotation */