5 files changed, 17 insertions, 11 deletions
diff --git a/source/blender/blenlib/BLI_math_matrix.h b/source/blender/blenlib/BLI_math_matrix.h
index 8124e07dd47..d0dfad2a02f 100644
--- a/source/blender/blenlib/BLI_math_matrix.h
+++ b/source/blender/blenlib/BLI_math_matrix.h
@@ -219,7 +219,6 @@ void mat4_to_size(float r[3], float M[4][4]);
 
 void translate_m4(float mat[4][4], float tx, float ty, float tz);
 void rotate_m4(float mat[4][4], const char axis, const float angle);
-void rotate_m2(float mat[2][2], const float angle);
 void transform_pivot_set_m4(float mat[4][4], const float pivot[3]);
 
 void mat3_to_rot_size(float rot[3][3], float size[3], float mat3[3][3]);
diff --git a/source/blender/blenlib/BLI_math_rotation.h b/source/blender/blenlib/BLI_math_rotation.h
index 24c20ee7b50..d60be30e10d 100644
--- a/source/blender/blenlib/BLI_math_rotation.h
+++ b/source/blender/blenlib/BLI_math_rotation.h
@@ -122,8 +122,9 @@ void mat3_to_axis_angle(float axis[3], float *angle, float M[3][3]);
 void mat4_to_axis_angle(float axis[3], float *angle, float M[4][4]);
 void quat_to_axis_angle(float axis[3], float *angle, const float q[4]);
 
-void axis_angle_to_mat3_single(float R[3][3], const char axis, const float angle);
 void      angle_to_mat2(float R[2][2], const float angle);
+void axis_angle_to_mat3_single(float R[3][3], const char axis, const float angle);
+void axis_angle_to_mat4_single(float R[4][4], const char axis, const float angle);
 
 void axis_angle_to_quat_single(float q[4], const char axis, const float angle);
 
diff --git a/source/blender/blenlib/intern/math_geom.c b/source/blender/blenlib/intern/math_geom.c
index f31d0935b77..0790d65345d 100644
--- a/source/blender/blenlib/intern/math_geom.c
+++ b/source/blender/blenlib/intern/math_geom.c
@@ -3917,10 +3917,9 @@ void lookat_m4(float mat[4][4], float vx, float vy, float vz, float px, float py
 	float sine, cosine, hyp, hyp1, dx, dy, dz;
 	float mat1[4][4];
 
-	unit_m4(mat);
 	unit_m4(mat1);
 
-	rotate_m4(mat, 'Z', -twist);
+	axis_angle_to_mat3_single(mat, 'Z', -twist);
 
 	dx = px - vx;
 	dy = py - vy;
diff --git a/source/blender/blenlib/intern/math_matrix.c b/source/blender/blenlib/intern/math_matrix.c
index c9c61d5c878..7176686df54 100644
--- a/source/blender/blenlib/intern/math_matrix.c
+++ b/source/blender/blenlib/intern/math_matrix.c
@@ -1625,6 +1625,13 @@ void translate_m4(float mat[4][4], float Tx, float Ty, float Tz)
 	mat[3][2] += (Tx * mat[0][2] + Ty * mat[1][2] + Tz * mat[2][2]);
 }
 
+/**
+ * Rotate a matrix in-place.
+ *
+ * \note To create a new rotation matrix see:
+ * #axis_angle_to_mat4_single, #axis_angle_to_mat3_single, #angle_to_mat2
+ * (axis & angle args are compatible).
+ */
 void rotate_m4(float mat[4][4], const char axis, const float angle)
 {
 	int col;
@@ -1665,13 +1672,6 @@ void rotate_m4(float mat[4][4], const char axis, const float angle)
 	}
 }
 
-void rotate_m2(float mat[2][2], const float angle)
-{
-	mat[0][0] = mat[1][1] = cosf(angle);
-	mat[0][1] = sinf(angle);
-	mat[1][0] = -mat[0][1];
-}
-
 /**
  * Scale or rotate around a pivot point,
  * a convenience function to avoid having to do inline.
diff --git a/source/blender/blenlib/intern/math_rotation.c b/source/blender/blenlib/intern/math_rotation.c
index b285a74b8ac..9b5dad3f767 100644
--- a/source/blender/blenlib/intern/math_rotation.c
+++ b/source/blender/blenlib/intern/math_rotation.c
@@ -1009,6 +1009,13 @@ void mat4_to_axis_angle(float axis[3], float *angle, float mat[4][4])
 	quat_to_axis_angle(axis, angle, q);
 }
 
+void axis_angle_to_mat4_single(float mat[4][4], const char axis, const float angle)
+{
+	float mat3[3][3];
+	axis_angle_to_mat3_single(mat3, axis, angle);
+	copy_m4_m3(mat, mat3);
+}
+
 /* rotation matrix from a single axis */
 void axis_angle_to_mat3_single(float mat[3][3], const char axis, const float angle)
 {