Cleanup: pass const matrices

Also order return matrices last.

28 files changed, 213 insertions, 187 deletions

diff --git a/source/blender/blenkernel/BKE_armature.h b/source/blender/blenkernel/BKE_armature.h
index 6fb6675a05a..301aa4538a7 100644
--- a/source/blender/blenkernel/BKE_armature.h
+++ b/source/blender/blenkernel/BKE_armature.h
@@ -123,22 +123,24 @@ void get_objectspace_bone_matrix(struct Bone *bone,
                                  float M_accumulatedMatrix[4][4],
                                  int root,
                                  int posed);
-void vec_roll_to_mat3(const float vec[3], const float roll, float mat[3][3]);
-void vec_roll_to_mat3_normalized(const float nor[3], const float roll, float mat[3][3]);
+void vec_roll_to_mat3(const float vec[3], const float roll, float r_mat[3][3]);
+void vec_roll_to_mat3_normalized(const float nor[3], const float roll, float r_mat[3][3]);
 void mat3_to_vec_roll(const float mat[3][3], float r_vec[3], float *r_roll);
 void mat3_vec_to_roll(const float mat[3][3], const float vec[3], float *r_roll);
 
 /* Common Conversions Between Co-ordinate Spaces */
-void BKE_armature_mat_world_to_pose(struct Object *ob, float inmat[4][4], float outmat[4][4]);
+void BKE_armature_mat_world_to_pose(struct Object *ob,
+                                    const float inmat[4][4],
+                                    float outmat[4][4]);
 void BKE_armature_loc_world_to_pose(struct Object *ob, const float inloc[3], float outloc[3]);
 void BKE_armature_mat_pose_to_bone(struct bPoseChannel *pchan,
-                                   float inmat[4][4],
+                                   const float inmat[4][4],
                                    float outmat[4][4]);
 void BKE_armature_loc_pose_to_bone(struct bPoseChannel *pchan,
                                    const float inloc[3],
                                    float outloc[3]);
 void BKE_armature_mat_bone_to_pose(struct bPoseChannel *pchan,
-                                   float inmat[4][4],
+                                   const float inmat[4][4],
                                    float outmat[4][4]);
 void BKE_armature_mat_pose_to_delta(float delta_mat[4][4],
                                     float pose_mat[4][4],
@@ -147,13 +149,13 @@ void BKE_armature_mat_pose_to_delta(float delta_mat[4][4],
 void BKE_armature_mat_pose_to_bone_ex(struct Depsgraph *depsgraph,
                                       struct Object *ob,
                                       struct bPoseChannel *pchan,
-                                      float inmat[4][4],
+                                      const float inmat[4][4],
                                       float outmat[4][4]);
 
-void BKE_pchan_mat3_to_rot(struct bPoseChannel *pchan, float mat[3][3], bool use_compat);
-void BKE_pchan_rot_to_mat3(const struct bPoseChannel *pchan, float mat[3][3]);
-void BKE_pchan_apply_mat4(struct bPoseChannel *pchan, float mat[4][4], bool use_comat);
-void BKE_pchan_to_mat4(const struct bPoseChannel *pchan, float chan_mat[4][4]);
+void BKE_pchan_mat3_to_rot(struct bPoseChannel *pchan, const float mat[3][3], bool use_compat);
+void BKE_pchan_rot_to_mat3(const struct bPoseChannel *pchan, float r_mat[3][3]);
+void BKE_pchan_apply_mat4(struct bPoseChannel *pchan, const float mat[4][4], bool use_comat);
+void BKE_pchan_to_mat4(const struct bPoseChannel *pchan, float r_mat[4][4]);
 void BKE_pchan_calc_mat(struct bPoseChannel *pchan);
 
 /* Simple helper, computes the offset bone matrix. */
diff --git a/source/blender/blenkernel/BKE_curve.h b/source/blender/blenkernel/BKE_curve.h
index ca41e51984b..3f7b978287d 100644
--- a/source/blender/blenkernel/BKE_curve.h
+++ b/source/blender/blenkernel/BKE_curve.h
@@ -98,15 +98,15 @@ bool BKE_curve_minmax(struct Curve *cu, bool use_radius, float min[3], float max
 bool BKE_curve_center_median(struct Curve *cu, float cent[3]);
 bool BKE_curve_center_bounds(struct Curve *cu, float cent[3]);
 void BKE_curve_transform_ex(struct Curve *cu,
-                            float mat[4][4],
+                            const float mat[4][4],
                             const bool do_keys,
                             const bool do_props,
                             const float unit_scale);
 void BKE_curve_transform(struct Curve *cu,
-                         float mat[4][4],
+                         const float mat[4][4],
                          const bool do_keys,
                          const bool do_props);
-void BKE_curve_translate(struct Curve *cu, float offset[3], const bool do_keys);
+void BKE_curve_translate(struct Curve *cu, const float offset[3], const bool do_keys);
 void BKE_curve_material_index_remove(struct Curve *cu, int index);
 bool BKE_curve_material_index_used(struct Curve *cu, int index);
 void BKE_curve_material_index_clear(struct Curve *cu);
diff --git a/source/blender/blenkernel/BKE_gpencil_geom.h b/source/blender/blenkernel/BKE_gpencil_geom.h
index 964764d99e7..c97461fb0c8 100644
--- a/source/blender/blenkernel/BKE_gpencil_geom.h
+++ b/source/blender/blenkernel/BKE_gpencil_geom.h
@@ -76,7 +76,7 @@ void BKE_gpencil_stroke_fill_triangulate(struct bGPDstroke *gps);
 void BKE_gpencil_stroke_geometry_update(struct bGPDstroke *gps);
 void BKE_gpencil_stroke_uv_update(struct bGPDstroke *gps);
 
-void BKE_gpencil_transform(struct bGPdata *gpd, float mat[4][4]);
+void BKE_gpencil_transform(struct bGPdata *gpd, const float mat[4][4]);
 
 typedef struct GPencilPointCoordinates {
   /* This is used when doing "move only origin" in object_data_transform.c.
diff --git a/source/blender/blenkernel/BKE_lattice.h b/source/blender/blenkernel/BKE_lattice.h
index bb23ad63020..fdcea95704f 100644
--- a/source/blender/blenkernel/BKE_lattice.h
+++ b/source/blender/blenkernel/BKE_lattice.h
@@ -67,8 +67,8 @@ void BKE_lattice_minmax_dl(struct Object *ob, struct Lattice *lt, float min[3],
 void BKE_lattice_minmax(struct Lattice *lt, float min[3], float max[3]);
 void BKE_lattice_center_median(struct Lattice *lt, float cent[3]);
 void BKE_lattice_center_bounds(struct Lattice *lt, float cent[3]);
-void BKE_lattice_translate(struct Lattice *lt, float offset[3], bool do_keys);
-void BKE_lattice_transform(struct Lattice *lt, float mat[4][4], bool do_keys);
+void BKE_lattice_translate(struct Lattice *lt, const float offset[3], bool do_keys);
+void BKE_lattice_transform(struct Lattice *lt, const float mat[4][4], bool do_keys);
 
 bool BKE_lattice_is_any_selected(const struct Lattice *lt);
 
diff --git a/source/blender/blenkernel/BKE_mesh.h b/source/blender/blenkernel/BKE_mesh.h
index b2510be656e..e0bedd20617 100644
--- a/source/blender/blenkernel/BKE_mesh.h
+++ b/source/blender/blenkernel/BKE_mesh.h
@@ -231,7 +231,7 @@ void BKE_mesh_nomain_to_meshkey(struct Mesh *mesh_src, struct Mesh *mesh_dst, st
 /* vertex level transformations & checks (no derived mesh) */
 
 bool BKE_mesh_minmax(const struct Mesh *me, float r_min[3], float r_max[3]);
-void BKE_mesh_transform(struct Mesh *me, float mat[4][4], bool do_keys);
+void BKE_mesh_transform(struct Mesh *me, const float mat[4][4], bool do_keys);
 void BKE_mesh_translate(struct Mesh *me, const float offset[3], const bool do_keys);
 
 void BKE_mesh_ensure_navmesh(struct Mesh *me);
diff --git a/source/blender/blenkernel/BKE_object.h b/source/blender/blenkernel/BKE_object.h
index f2a022c84a3..7f2bdccf3a4 100644
--- a/source/blender/blenkernel/BKE_object.h
+++ b/source/blender/blenkernel/BKE_object.h
@@ -144,21 +144,21 @@ struct Object *BKE_object_duplicate(struct Main *bmain,
 
 void BKE_object_obdata_size_init(struct Object *ob, const float scale);
 
-void BKE_object_scale_to_mat3(struct Object *ob, float mat[3][3]);
-void BKE_object_rot_to_mat3(const struct Object *ob, float mat[3][3], bool use_drot);
-void BKE_object_mat3_to_rot(struct Object *ob, float mat[3][3], bool use_compat);
-void BKE_object_to_mat3(struct Object *ob, float mat[3][3]);
-void BKE_object_to_mat4(struct Object *ob, float mat[4][4]);
+void BKE_object_scale_to_mat3(struct Object *ob, float r_mat[3][3]);
+void BKE_object_rot_to_mat3(const struct Object *ob, float r_mat[3][3], bool use_drot);
+void BKE_object_mat3_to_rot(struct Object *ob, float r_mat[3][3], bool use_compat);
+void BKE_object_to_mat3(struct Object *ob, float r_mat[3][3]);
+void BKE_object_to_mat4(struct Object *ob, float r_mat[4][4]);
 void BKE_object_apply_mat4(struct Object *ob,
-                           float mat[4][4],
+                           const float mat[4][4],
                            const bool use_compat,
                            const bool use_parent);
 void BKE_object_apply_mat4_ex(struct Object *ob,
-                              float mat[4][4],
+                              const float mat[4][4],
                               struct Object *parent,
-                              float parentinv[4][4],
+                              const float parentinv[4][4],
                               const bool use_compat);
-void BKE_object_matrix_local_get(struct Object *ob, float mat[4][4]);
+void BKE_object_matrix_local_get(struct Object *ob, float r_mat[4][4]);
 
 bool BKE_object_pose_context_check(const struct Object *ob);
 struct Object *BKE_object_pose_armature_get(struct Object *ob);
@@ -188,7 +188,7 @@ struct Base **BKE_object_pose_base_array_get(struct ViewLayer *view_layer,
                                              struct View3D *v3d,
                                              unsigned int *r_bases_len);
 
-void BKE_object_get_parent_matrix(struct Object *ob, struct Object *par, float parentmat[4][4]);
+void BKE_object_get_parent_matrix(struct Object *ob, struct Object *par, float r_parentmat[4][4]);
 void BKE_object_where_is_calc(struct Depsgraph *depsgraph, struct Scene *scene, struct Object *ob);
 void BKE_object_where_is_calc_ex(struct Depsgraph *depsgraph,
                                  struct Scene *scene,
@@ -199,7 +199,7 @@ void BKE_object_where_is_calc_time(struct Depsgraph *depsgraph,
                                    struct Scene *scene,
                                    struct Object *ob,
                                    float ctime);
-void BKE_object_where_is_calc_mat4(struct Object *ob, float obmat[4][4]);
+void BKE_object_where_is_calc_mat4(struct Object *ob, float r_obmat[4][4]);
 
 /* possibly belong in own moduke? */
 struct BoundBox *BKE_boundbox_alloc_unit(void);
@@ -207,12 +207,12 @@ void BKE_boundbox_init_from_minmax(struct BoundBox *bb, const float min[3], cons
 void BKE_boundbox_calc_center_aabb(const struct BoundBox *bb, float r_cent[3]);
 void BKE_boundbox_calc_size_aabb(const struct BoundBox *bb, float r_size[3]);
 void BKE_boundbox_minmax(const struct BoundBox *bb,
-                         float obmat[4][4],
+                         const float obmat[4][4],
                          float r_min[3],
                          float r_max[3]);
 
 struct BoundBox *BKE_object_boundbox_get(struct Object *ob);
-void BKE_object_dimensions_get(struct Object *ob, float vec[3]);
+void BKE_object_dimensions_get(struct Object *ob, float r_vec[3]);
 void BKE_object_dimensions_set_ex(struct Object *ob,
                                   const float value[3],
                                   int axis_mask,
@@ -233,7 +233,7 @@ bool BKE_object_minmax_dupli(struct Depsgraph *depsgraph,
 
 /* sometimes min-max isn't enough, we need to loop over each point */
 void BKE_object_foreach_display_point(struct Object *ob,
-                                      float obmat[4][4],
+                                      const float obmat[4][4],
                                       void (*func_cb)(const float[3], void *),
                                       void *user_data);
 void BKE_scene_foreach_display_point(struct Depsgraph *depsgraph,
diff --git a/source/blender/blenkernel/intern/armature.c b/source/blender/blenkernel/intern/armature.c
index d1d6cc63174..c977ebe4ae2 100644
--- a/source/blender/blenkernel/intern/armature.c
+++ b/source/blender/blenkernel/intern/armature.c
@@ -1382,7 +1382,7 @@ void get_objectspace_bone_matrix(struct Bone *bone,
 }
 
 /* Convert World-Space Matrix to Pose-Space Matrix */
-void BKE_armature_mat_world_to_pose(Object *ob, float inmat[4][4], float outmat[4][4])
+void BKE_armature_mat_world_to_pose(Object *ob, const float inmat[4][4], float outmat[4][4])
 {
   float obmat[4][4];
 
@@ -1674,7 +1674,9 @@ void BKE_bone_parent_transform_apply(const struct BoneParentTransform *bpt,
 /* Convert Pose-Space Matrix to Bone-Space Matrix.
  * NOTE: this cannot be used to convert to pose-space transforms of the supplied
  *       pose-channel into its local space (i.e. 'visual'-keyframing) */
-void BKE_armature_mat_pose_to_bone(bPoseChannel *pchan, float inmat[4][4], float outmat[4][4])
+void BKE_armature_mat_pose_to_bone(bPoseChannel *pchan,
+                                   const float inmat[4][4],
+                                   float outmat[4][4])
 {
   BoneParentTransform bpt;
 
@@ -1684,7 +1686,9 @@ void BKE_armature_mat_pose_to_bone(bPoseChannel *pchan, float inmat[4][4], float
 }
 
 /* Convert Bone-Space Matrix to Pose-Space Matrix. */
-void BKE_armature_mat_bone_to_pose(bPoseChannel *pchan, float inmat[4][4], float outmat[4][4])
+void BKE_armature_mat_bone_to_pose(bPoseChannel *pchan,
+                                   const float inmat[4][4],
+                                   float outmat[4][4])
 {
   BoneParentTransform bpt;
 
@@ -1720,7 +1724,7 @@ void BKE_armature_loc_pose_to_bone(bPoseChannel *pchan, const float inloc[3], fl
 void BKE_armature_mat_pose_to_bone_ex(struct Depsgraph *depsgraph,
                                       Object *ob,
                                       bPoseChannel *pchan,
-                                      float inmat[4][4],
+                                      const float inmat[4][4],
                                       float outmat[4][4])
 {
   bPoseChannel work_pchan = *pchan;
@@ -1741,7 +1745,7 @@ void BKE_armature_mat_pose_to_bone_ex(struct Depsgraph *depsgraph,
 /**
  * Same as #BKE_object_mat3_to_rot().
  */
-void BKE_pchan_mat3_to_rot(bPoseChannel *pchan, float mat[3][3], bool use_compat)
+void BKE_pchan_mat3_to_rot(bPoseChannel *pchan, const float mat[3][3], bool use_compat)
 {
   BLI_ASSERT_UNIT_M3(mat);
 
@@ -1766,17 +1770,17 @@ void BKE_pchan_mat3_to_rot(bPoseChannel *pchan, float mat[3][3], bool use_compat
 /**
  * Same as #BKE_object_rot_to_mat3().
  */
-void BKE_pchan_rot_to_mat3(const bPoseChannel *pchan, float mat[3][3])
+void BKE_pchan_rot_to_mat3(const bPoseChannel *pchan, float r_mat[3][3])
 {
   /* rotations may either be quats, eulers (with various rotation orders), or axis-angle */
   if (pchan->rotmode > 0) {
     /* euler rotations (will cause gimble lock,
      * but this can be alleviated a bit with rotation orders) */
-    eulO_to_mat3(mat, pchan->eul, pchan->rotmode);
+    eulO_to_mat3(r_mat, pchan->eul, pchan->rotmode);
   }
   else if (pchan->rotmode == ROT_MODE_AXISANGLE) {
     /* axis-angle - not really that great for 3D-changing orientations */
-    axis_angle_to_mat3(mat, pchan->rotAxis, pchan->rotAngle);
+    axis_angle_to_mat3(r_mat, pchan->rotAxis, pchan->rotAngle);
   }
   else {
     /* quats are normalized before use to eliminate scaling issues */
@@ -1786,7 +1790,7 @@ void BKE_pchan_rot_to_mat3(const bPoseChannel *pchan, float mat[3][3])
      * since this was kindof evil in some cases but if this proves to be too problematic,
      * switch back to the old system of operating directly on the stored copy. */
     normalize_qt_qt(quat, pchan->quat);
-    quat_to_mat3(mat, quat);
+    quat_to_mat3(r_mat, quat);
   }
 }
 
@@ -1794,7 +1798,7 @@ void BKE_pchan_rot_to_mat3(const bPoseChannel *pchan, float mat[3][3])
  * Apply a 4x4 matrix to the pose bone,
  * similar to #BKE_object_apply_mat4().
  */
-void BKE_pchan_apply_mat4(bPoseChannel *pchan, float mat[4][4], bool use_compat)
+void BKE_pchan_apply_mat4(bPoseChannel *pchan, const float mat[4][4], bool use_compat)
 {
   float rot[3][3];
   mat4_to_loc_rot_size(pchan->loc, rot, pchan->size, mat);
@@ -1998,7 +2002,7 @@ void mat3_vec_to_roll(const float mat[3][3], const float vec[3], float *r_roll)
  *                        └ -2 * x * z,   x^2 - z^2 ┘
  * </pre>
  */
-void vec_roll_to_mat3_normalized(const float nor[3], const float roll, float mat[3][3])
+void vec_roll_to_mat3_normalized(const float nor[3], const float roll, float r_mat[3][3])
 {
 #define THETA_THRESHOLD_NEGY 1.0e-9f
 #define THETA_THRESHOLD_NEGY_CLOSE 1.0e-5f
@@ -2052,18 +2056,18 @@ void vec_roll_to_mat3_normalized(const float nor[3], const float roll, float mat
   axis_angle_normalized_to_mat3(rMatrix, nor, roll);
 
   /* Combine and output result */
-  mul_m3_m3m3(mat, rMatrix, bMatrix);
+  mul_m3_m3m3(r_mat, rMatrix, bMatrix);
 
 #undef THETA_THRESHOLD_NEGY
 #undef THETA_THRESHOLD_NEGY_CLOSE
 }
 
-void vec_roll_to_mat3(const float vec[3], const float roll, float mat[3][3])
+void vec_roll_to_mat3(const float vec[3], const float roll, float r_mat[3][3])
 {
   float nor[3];
 
   normalize_v3_v3(nor, vec);
-  vec_roll_to_mat3_normalized(nor, roll, mat);
+  vec_roll_to_mat3_normalized(nor, roll, r_mat);
 }
 
 /** \} */
@@ -2418,8 +2422,10 @@ void BKE_pose_rebuild(Main *bmain, Object *ob, bArmature *arm, const bool do_id_
 /** \name Pose Solver
  * \{ */
 
-/* loc/rot/size to given mat4 */
-void BKE_pchan_to_mat4(const bPoseChannel *pchan, float chan_mat[4][4])
+/**
+ * Convert the loc/rot/size to \a r_chanmat (typically #bPoseChannel.chan_mat).
+ */
+void BKE_pchan_to_mat4(const bPoseChannel *pchan, float r_chanmat[4][4])
 {
   float smat[3][3];
   float rmat[3][3];
@@ -2433,12 +2439,12 @@ void BKE_pchan_to_mat4(const bPoseChannel *pchan, float chan_mat[4][4])
 
   /* calculate matrix of bone (as 3x3 matrix, but then copy the 4x4) */
   mul_m3_m3m3(tmat, rmat, smat);
-  copy_m4_m3(chan_mat, tmat);
+  copy_m4_m3(r_chanmat, tmat);
 
   /* prevent action channels breaking chains */
   /* need to check for bone here, CONSTRAINT_TYPE_ACTION uses this call */
   if ((pchan->bone == NULL) || !(pchan->bone->flag & BONE_CONNECTED)) {
-    copy_v3_v3(chan_mat[3], pchan->loc);
+    copy_v3_v3(r_chanmat[3], pchan->loc);
   }
 }
 
diff --git a/source/blender/blenkernel/intern/curve.c b/source/blender/blenkernel/intern/curve.c
index acc3c52c08c..e126fb7f632 100644
--- a/source/blender/blenkernel/intern/curve.c
+++ b/source/blender/blenkernel/intern/curve.c
@@ -5110,8 +5110,11 @@ bool BKE_curve_center_bounds(Curve *cu, float cent[3])
   return false;
 }
 
-void BKE_curve_transform_ex(
-    Curve *cu, float mat[4][4], const bool do_keys, const bool do_props, const float unit_scale)
+void BKE_curve_transform_ex(Curve *cu,
+                            const float mat[4][4],
+                            const bool do_keys,
+                            const bool do_props,
+                            const float unit_scale)
 {
   Nurb *nu;
   BPoint *bp;
@@ -5174,13 +5177,13 @@ void BKE_curve_transform_ex(
   }
 }
 
-void BKE_curve_transform(Curve *cu, float mat[4][4], const bool do_keys, const bool do_props)
+void BKE_curve_transform(Curve *cu, const float mat[4][4], const bool do_keys, const bool do_props)
 {
   float unit_scale = mat4_to_scale(mat);
   BKE_curve_transform_ex(cu, mat, do_keys, do_props, unit_scale);
 }
 
-void BKE_curve_translate(Curve *cu, float offset[3], const bool do_keys)
+void BKE_curve_translate(Curve *cu, const float offset[3], const bool do_keys)
 {
   ListBase *nurb_lb = BKE_curve_nurbs_get(cu);
   Nurb *nu;
diff --git a/source/blender/blenkernel/intern/gpencil_geom.c b/source/blender/blenkernel/intern/gpencil_geom.c
index 53bfd3aa8ff..14eb6bb4f4c 100644
--- a/source/blender/blenkernel/intern/gpencil_geom.c
+++ b/source/blender/blenkernel/intern/gpencil_geom.c
@@ -2427,7 +2427,7 @@ void BKE_gpencil_convert_mesh(Main *bmain,
  * \param gpd: Grease pencil data-block
  * \param mat: Transformation matrix
  */
-void BKE_gpencil_transform(bGPdata *gpd, float mat[4][4])
+void BKE_gpencil_transform(bGPdata *gpd, const float mat[4][4])
 {
   if (gpd == NULL) {
     return;
diff --git a/source/blender/blenkernel/intern/lattice.c b/source/blender/blenkernel/intern/lattice.c
index 8820434cbcf..4d523ffa2e0 100644
--- a/source/blender/blenkernel/intern/lattice.c
+++ b/source/blender/blenkernel/intern/lattice.c
@@ -672,7 +672,7 @@ void BKE_lattice_center_bounds(Lattice *lt, float cent[3])
   mid_v3_v3v3(cent, min, max);
 }
 
-void BKE_lattice_transform(Lattice *lt, float mat[4][4], bool do_keys)
+void BKE_lattice_transform(Lattice *lt, const float mat[4][4], bool do_keys)
 {
   BPoint *bp = lt->def;
   int i = lt->pntsu * lt->pntsv * lt->pntsw;
@@ -694,7 +694,7 @@ void BKE_lattice_transform(Lattice *lt, float mat[4][4], bool do_keys)
   }
 }
 
-void BKE_lattice_translate(Lattice *lt, float offset[3], bool do_keys)
+void BKE_lattice_translate(Lattice *lt, const float offset[3], bool do_keys)
 {
   int i, numVerts;
 
diff --git a/source/blender/blenkernel/intern/mball_tessellate.c b/source/blender/blenkernel/intern/mball_tessellate.c
index ad178e76ef6..72b99bea0f4 100644
--- a/source/blender/blenkernel/intern/mball_tessellate.c
+++ b/source/blender/blenkernel/intern/mball_tessellate.c
@@ -315,7 +315,7 @@ static float densfunc(const MetaElem *ball, float x, float y, float z)
   float dist2;
   float dvec[3] = {x, y, z};
 
-  mul_m4_v3((float(*)[4])ball->imat, dvec);
+  mul_m4_v3((const float(*)[4])ball->imat, dvec);
 
   switch (ball->type) {
     case MB_BALL:
diff --git a/source/blender/blenkernel/intern/mesh.c b/source/blender/blenkernel/intern/mesh.c
index 48baedadd73..048af022adb 100644
--- a/source/blender/blenkernel/intern/mesh.c
+++ b/source/blender/blenkernel/intern/mesh.c
@@ -1305,7 +1305,7 @@ bool BKE_mesh_minmax(const Mesh *me, float r_min[3], float r_max[3])
   return (me->totvert != 0);
 }
 
-void BKE_mesh_transform(Mesh *me, float mat[4][4], bool do_keys)
+void BKE_mesh_transform(Mesh *me, const float mat[4][4], bool do_keys)
 {
   int i;
   MVert *mvert = me->mvert;
diff --git a/source/blender/blenkernel/intern/object.c b/source/blender/blenkernel/intern/object.c
index f77c79a2be7..fe559d2a44e 100644
--- a/source/blender/blenkernel/intern/object.c
+++ b/source/blender/blenkernel/intern/object.c
@@ -2344,7 +2344,7 @@ void BKE_object_tfm_copy(Object *object_dst, const Object *object_src)
 #undef TFMCPY4D
 }
 
-void BKE_object_to_mat3(Object *ob, float mat[3][3]) /* no parent */
+void BKE_object_to_mat3(Object *ob, float r_mat[3][3]) /* no parent */
 {
   float smat[3][3];
   float rmat[3][3];
@@ -2355,38 +2355,38 @@ void BKE_object_to_mat3(Object *ob, float mat[3][3]) /* no parent */
 
   /* rot */
   BKE_object_rot_to_mat3(ob, rmat, true);
-  mul_m3_m3m3(mat, rmat, smat);
+  mul_m3_m3m3(r_mat, rmat, smat);
 }
 
-void BKE_object_to_mat4(Object *ob, float mat[4][4])
+void BKE_object_to_mat4(Object *ob, float r_mat[4][4])
 {
   float tmat[3][3];
 
   BKE_object_to_mat3(ob, tmat);
 
-  copy_m4_m3(mat, tmat);
+  copy_m4_m3(r_mat, tmat);
 
-  add_v3_v3v3(mat[3], ob->loc, ob->dloc);
+  add_v3_v3v3(r_mat[3], ob->loc, ob->dloc);
 }
 
-void BKE_object_matrix_local_get(struct Object *ob, float mat[4][4])
+void BKE_object_matrix_local_get(struct Object *ob, float r_mat[4][4])
 {
   if (ob->parent) {
     float par_imat[4][4];
 
     BKE_object_get_parent_matrix(ob, ob->parent, par_imat);
     invert_m4(par_imat);
-    mul_m4_m4m4(mat, par_imat, ob->obmat);
+    mul_m4_m4m4(r_mat, par_imat, ob->obmat);
   }
   else {
-    copy_m4_m4(mat, ob->obmat);
+    copy_m4_m4(r_mat, ob->obmat);
   }
 }
 
 /**
  * \return success if \a mat is set.
  */
-static bool ob_parcurve(Object *ob, Object *par, float mat[4][4])
+static bool ob_parcurve(Object *ob, Object *par, float r_mat[4][4])
 {
   Curve *cu = par->data;
   float vec[4], dir[3], quat[4], radius, ctime;
@@ -2420,34 +2420,34 @@ static bool ob_parcurve(Object *ob, Object *par, float mat[4][4])
   }
   CLAMP(ctime, 0.0f, 1.0f);
 
-  unit_m4(mat);
+  unit_m4(r_mat);
 
   /* vec: 4 items! */
   if (where_on_path(par, ctime, vec, dir, (cu->flag & CU_FOLLOW) ? quat : NULL, &radius, NULL)) {
     if (cu->flag & CU_FOLLOW) {
       quat_apply_track(quat, ob->trackflag, ob->upflag);
       normalize_qt(quat);
-      quat_to_mat4(mat, quat);
+      quat_to_mat4(r_mat, quat);
     }
     if (cu->flag & CU_PATH_RADIUS) {
       float tmat[4][4], rmat[4][4];
       scale_m4_fl(tmat, radius);
-      mul_m4_m4m4(rmat, tmat, mat);
-      copy_m4_m4(mat, rmat);
+      mul_m4_m4m4(rmat, tmat, r_mat);
+      copy_m4_m4(r_mat, rmat);
     }
-    copy_v3_v3(mat[3], vec);
+    copy_v3_v3(r_mat[3], vec);
   }
 
   return true;
 }
 
-static void ob_parbone(Object *ob, Object *par, float mat[4][4])
+static void ob_parbone(Object *ob, Object *par, float r_mat[4][4])
 {
   bPoseChannel *pchan;
   float vec[3];
 
   if (par->type != OB_ARMATURE) {
-    unit_m4(mat);
+    unit_m4(r_mat);
     return;
   }
 
@@ -2456,7 +2456,7 @@ static void ob_parbone(Object *ob, Object *par, float mat[4][4])
   if (!pchan || !pchan->bone) {
     CLOG_ERROR(
         &LOG, "Object %s with Bone parent: bone %s doesn't exist", ob->id.name + 2, ob->parsubstr);
-    unit_m4(mat);
+    unit_m4(r_mat);
     return;
   }
 
@@ -2464,15 +2464,15 @@ static void ob_parbone(Object *ob, Object *par, float mat[4][4])
   if (pchan->bone->flag & BONE_RELATIVE_PARENTING) {
     /* the new option uses the root - expected behavior, but differs from old... */
     /* XXX check on version patching? */
-    copy_m4_m4(mat, pchan->chan_mat);
+    copy_m4_m4(r_mat, pchan->chan_mat);
   }
   else {
-    copy_m4_m4(mat, pchan->pose_mat);
+    copy_m4_m4(r_mat, pchan->pose_mat);
 
     /* but for backwards compatibility, the child has to move to the tail */
-    copy_v3_v3(vec, mat[1]);
+    copy_v3_v3(vec, r_mat[1]);
     mul_v3_fl(vec, pchan->bone->length);
-    add_v3_v3(mat[3], vec);
+    add_v3_v3(r_mat[3], vec);
   }
 }
 
@@ -2594,7 +2594,7 @@ static void give_parvert(Object *par, int nr, float vec[3])
   }
 }
 
-static void ob_parvert3(Object *ob, Object *par, float mat[4][4])
+static void ob_parvert3(Object *ob, Object *par, float r_mat[4][4])
 {
 
   /* in local ob space */
@@ -2607,16 +2607,16 @@ static void ob_parvert3(Object *ob, Object *par, float mat[4][4])
 
     tri_to_quat(q, v1, v2, v3);
     quat_to_mat3(cmat, q);
-    copy_m4_m3(mat, cmat);
+    copy_m4_m3(r_mat, cmat);
 
-    mid_v3_v3v3v3(mat[3], v1, v2, v3);
+    mid_v3_v3v3v3(r_mat[3], v1, v2, v3);
   }
   else {
-    unit_m4(mat);
+    unit_m4(r_mat);
   }
 }
 
-void BKE_object_get_parent_matrix(Object *ob, Object *par, float parentmat[4][4])
+void BKE_object_get_parent_matrix(Object *ob, Object *par, float r_parentmat[4][4])
 {
   float tmat[4][4];
   float vec[3];
@@ -2632,31 +2632,31 @@ void BKE_object_get_parent_matrix(Object *ob, Object *par, float parentmat[4][4]
       }
 
       if (ok) {
-        mul_m4_m4m4(parentmat, par->obmat, tmat);
+        mul_m4_m4m4(r_parentmat, par->obmat, tmat);
       }
       else {
-        copy_m4_m4(parentmat, par->obmat);
+        copy_m4_m4(r_parentmat, par->obmat);
       }
 
       break;
     case PARBONE:
       ob_parbone(ob, par, tmat);
-      mul_m4_m4m4(parentmat, par->obmat, tmat);
+      mul_m4_m4m4(r_parentmat, par->obmat, tmat);
       break;
 
     case PARVERT1:
-      unit_m4(parentmat);
+      unit_m4(r_parentmat);
       give_parvert(par, ob->par1, vec);
-      mul_v3_m4v3(parentmat[3], par->obmat, vec);
+      mul_v3_m4v3(r_parentmat[3], par->obmat, vec);
       break;
     case PARVERT3:
       ob_parvert3(ob, par, tmat);
 
-      mul_m4_m4m4(parentmat, par->obmat, tmat);
+      mul_m4_m4m4(r_parentmat, par->obmat, tmat);
       break;
 
     case PARSKEL:
-      copy_m4_m4(parentmat, par->obmat);
+      copy_m4_m4(r_parentmat, par->obmat);
       break;
   }
 }
@@ -2672,7 +2672,7 @@ void BKE_object_get_parent_matrix(Object *ob, Object *par, float parentmat[4][4]
  * (without its own matrix applied)
  */
 static void solve_parenting(
-    Object *ob, Object *par, float obmat[4][4], float r_originmat[3][3], const bool set_origin)
+    Object *ob, Object *par, const bool set_origin, float r_obmat[4][4], float r_originmat[3][3])
 {
   float totmat[4][4];
   float tmat[4][4];
@@ -2684,7 +2684,7 @@ static void solve_parenting(
 
   /* total */
   mul_m4_m4m4(tmat, totmat, ob->parentinv);
-  mul_m4_m4m4(obmat, tmat, locmat);
+  mul_m4_m4m4(r_obmat, tmat, locmat);
 
   if (r_originmat) {
     /* usable originmat */
@@ -2714,7 +2714,7 @@ static void object_where_is_calc_ex(Depsgraph *depsgraph,
     Object *par = ob->parent;
 
     /* calculate parent matrix */
-    solve_parenting(ob, par, ob->obmat, r_originmat, true);
+    solve_parenting(ob, par, true, ob->obmat, r_originmat);
   }
   else {
     BKE_object_to_mat4(ob, ob->obmat);
@@ -2757,14 +2757,14 @@ void BKE_object_where_is_calc_time(Depsgraph *depsgraph, Scene *scene, Object *o
  * constraints -- assume dependencies are already solved by depsgraph.
  * no changes to object and it's parent would be done.
  * used for bundles orientation in 3d space relative to parented blender camera */
-void BKE_object_where_is_calc_mat4(Object *ob, float obmat[4][4])
+void BKE_object_where_is_calc_mat4(Object *ob, float r_obmat[4][4])
 {
   if (ob->parent) {
     Object *par = ob->parent;
-    solve_parenting(ob, par, obmat, NULL, false);
+    solve_parenting(ob, par, false, r_obmat, NULL);
   }
   else {
-    BKE_object_to_mat4(ob, obmat);
+    BKE_object_to_mat4(ob, r_obmat);
   }
 }
 
@@ -2825,8 +2825,11 @@ void BKE_object_workob_calc_parent(Depsgraph *depsgraph, Scene *scene, Object *o
  * \param use_compat: true to ensure that rotations are set using the
  * min difference between the old and new orientation.
  */
-void BKE_object_apply_mat4_ex(
-    Object *ob, float mat[4][4], Object *parent, float parentinv[4][4], const bool use_compat)
+void BKE_object_apply_mat4_ex(Object *ob,
+                              const float mat[4][4],
+                              Object *parent,
+                              const float parentinv[4][4],
+                              const bool use_compat)
 {
   /* see BKE_pchan_apply_mat4() for the equivalent 'pchan' function */
 
@@ -2867,7 +2870,7 @@ void BKE_object_apply_mat4_ex(
 
 /* XXX: should be removed after COW operators port to use BKE_object_apply_mat4_ex directly */
 void BKE_object_apply_mat4(Object *ob,
-                           float mat[4][4],
+                           const float mat[4][4],
                            const bool use_compat,
                            const bool use_parent)
 {
@@ -2917,7 +2920,10 @@ void BKE_boundbox_calc_size_aabb(const BoundBox *bb, float r_size[3])
   r_size[2] = 0.5f * fabsf(bb->vec[0][2] - bb->vec[1][2]);
 }
 
-void BKE_boundbox_minmax(const BoundBox *bb, float obmat[4][4], float r_min[3], float r_max[3])
+void BKE_boundbox_minmax(const BoundBox *bb,
+                         const float obmat[4][4],
+                         float r_min[3],
+                         float r_max[3])
 {
   int i;
   for (i = 0; i < 8; i++) {
@@ -3009,7 +3015,7 @@ void BKE_object_boundbox_calc_from_mesh(struct Object *ob, struct Mesh *me_eval)
  * \warning Setting dimensions is prone to feedback loops in evaluation.
  * \{ */
 
-void BKE_object_dimensions_get(Object *ob, float vec[3])
+void BKE_object_dimensions_get(Object *ob, float r_vec[3])
 {
   BoundBox *bb = NULL;
 
@@ -3019,12 +3025,12 @@ void BKE_object_dimensions_get(Object *ob, float vec[3])
 
     mat4_to_size(scale, ob->obmat);
 
-    vec[0] = fabsf(scale[0]) * (bb->vec[4][0] - bb->vec[0][0]);
-    vec[1] = fabsf(scale[1]) * (bb->vec[2][1] - bb->vec[0][1]);
-    vec[2] = fabsf(scale[2]) * (bb->vec[1][2] - bb->vec[0][2]);
+    r_vec[0] = fabsf(scale[0]) * (bb->vec[4][0] - bb->vec[0][0]);
+    r_vec[1] = fabsf(scale[1]) * (bb->vec[2][1] - bb->vec[0][1]);
+    r_vec[2] = fabsf(scale[2]) * (bb->vec[1][2] - bb->vec[0][2]);
   }
   else {
-    zero_v3(vec);
+    zero_v3(r_vec);
   }
 }
 
@@ -3293,7 +3299,7 @@ bool BKE_object_minmax_dupli(Depsgraph *depsgraph,
 }
 
 void BKE_object_foreach_display_point(Object *ob,
-                                      float obmat[4][4],
+                                      const float obmat[4][4],
                                       void (*func_cb)(const float[3], void *),
                                       void *user_data)
 {
diff --git a/source/blender/blenlib/BLI_uvproject.h b/source/blender/blenlib/BLI_uvproject.h
index 8a33ea6961c..4bfa1601b16 100644
--- a/source/blender/blenlib/BLI_uvproject.h
+++ b/source/blender/blenlib/BLI_uvproject.h
@@ -45,7 +45,7 @@ void BLI_uvproject_from_view(float target[2],
                              float winy);
 
 /* apply ortho uv's */
-void BLI_uvproject_from_view_ortho(float target[2], float source[3], float rotmat[4][4]);
+void BLI_uvproject_from_view_ortho(float target[2], float source[3], const float rotmat[4][4]);
 
 /* so we can adjust scale with keeping the struct private */
 void BLI_uvproject_camera_info_scale(struct ProjCameraInfo *uci, float scale_x, float scale_y);
diff --git a/source/blender/blenlib/intern/uvproject.c b/source/blender/blenlib/intern/uvproject.c
index a34c551767a..00fef29587c 100644
--- a/source/blender/blenlib/intern/uvproject.c
+++ b/source/blender/blenlib/intern/uvproject.c
@@ -183,7 +183,7 @@ ProjCameraInfo *BLI_uvproject_camera_info(Object *ob, float (*rotmat)[4], float
   return NULL;
 }
 
-void BLI_uvproject_from_view_ortho(float target[2], float source[3], float rotmat[4][4])
+void BLI_uvproject_from_view_ortho(float target[2], float source[3], const float rotmat[4][4])
 {
   float pv[3];
 
diff --git a/source/blender/draw/engines/eevee/eevee_render.c b/source/blender/draw/engines/eevee/eevee_render.c
index 787fc16a7da..e8619701365 100644
--- a/source/blender/draw/engines/eevee/eevee_render.c
+++ b/source/blender/draw/engines/eevee/eevee_render.c
@@ -160,7 +160,7 @@ void EEVEE_render_view_sync(EEVEE_Data *vedata, RenderEngine *engine, struct Dep
   struct Object *ob_camera_eval = DEG_get_evaluated_object(depsgraph, RE_GetCamera(engine->re));
 
   RE_GetCameraWindow(engine->re, ob_camera_eval, winmat);
-  RE_GetCameraWindowWithOverscan(engine->re, winmat, g_data->overscan);
+  RE_GetCameraWindowWithOverscan(engine->re, g_data->overscan, winmat);
   RE_GetCameraModelMatrix(engine->re, ob_camera_eval, viewinv);
 
   invert_m4_m4(viewmat, viewinv);
diff --git a/source/blender/editors/armature/armature_utils.c b/source/blender/editors/armature/armature_utils.c
index b2e329deee7..04c1ec97841 100644
--- a/source/blender/editors/armature/armature_utils.c
+++ b/source/blender/editors/armature/armature_utils.c
@@ -229,7 +229,7 @@ EditBone *ED_armature_ebone_find_shared_parent(EditBone *ebone_child[], const ui
   return NULL;
 }
 
-void ED_armature_ebone_to_mat3(EditBone *ebone, float mat[3][3])
+void ED_armature_ebone_to_mat3(EditBone *ebone, float r_mat[3][3])
 {
   float delta[3], roll;
 
@@ -246,20 +246,20 @@ void ED_armature_ebone_to_mat3(EditBone *ebone, float mat[3][3])
     }
   }
 
-  vec_roll_to_mat3_normalized(delta, roll, mat);
+  vec_roll_to_mat3_normalized(delta, roll, r_mat);
 }
 
-void ED_armature_ebone_to_mat4(EditBone *ebone, float mat[4][4])
+void ED_armature_ebone_to_mat4(EditBone *ebone, float r_mat[4][4])
 {
   float m3[3][3];
 
   ED_armature_ebone_to_mat3(ebone, m3);
 
-  copy_m4_m3(mat, m3);
-  copy_v3_v3(mat[3], ebone->head);
+  copy_m4_m3(r_mat, m3);
+  copy_v3_v3(r_mat[3], ebone->head);
 }
 
-void ED_armature_ebone_from_mat3(EditBone *ebone, float mat[3][3])
+void ED_armature_ebone_from_mat3(EditBone *ebone, const float mat[3][3])
 {
   float vec[3], roll;
   const float len = len_v3v3(ebone->head, ebone->tail);
@@ -270,7 +270,7 @@ void ED_armature_ebone_from_mat3(EditBone *ebone, float mat[3][3])
   ebone->roll = roll;
 }
 
-void ED_armature_ebone_from_mat4(EditBone *ebone, float mat[4][4])
+void ED_armature_ebone_from_mat4(EditBone *ebone, const float mat[4][4])
 {
   float mat3[3][3];
 
diff --git a/source/blender/editors/include/ED_armature.h b/source/blender/editors/include/ED_armature.h
index d82c7126cf2..6749adb2ea0 100644
--- a/source/blender/editors/include/ED_armature.h
+++ b/source/blender/editors/include/ED_armature.h
@@ -225,10 +225,10 @@ void ED_armature_ebone_remove(struct bArmature *arm, EditBone *exBone);
 bool ED_armature_ebone_is_child_recursive(EditBone *ebone_parent, EditBone *ebone_child);
 EditBone *ED_armature_ebone_find_shared_parent(EditBone *ebone_child[],
                                                const unsigned int ebone_child_tot);
-void ED_armature_ebone_to_mat3(EditBone *ebone, float mat[3][3]);
-void ED_armature_ebone_to_mat4(EditBone *ebone, float mat[4][4]);
-void ED_armature_ebone_from_mat3(EditBone *ebone, float mat[3][3]);
-void ED_armature_ebone_from_mat4(EditBone *ebone, float mat[4][4]);
+void ED_armature_ebone_to_mat3(EditBone *ebone, float r_mat[3][3]);
+void ED_armature_ebone_to_mat4(EditBone *ebone, float r_mat[4][4]);
+void ED_armature_ebone_from_mat3(EditBone *ebone, const float mat[3][3]);
+void ED_armature_ebone_from_mat4(EditBone *ebone, const float mat[4][4]);
 EditBone *ED_armature_ebone_find_name(const struct ListBase *edbo, const char *name);
 EditBone *ED_armature_ebone_get_mirrored(const struct ListBase *edbo, EditBone *ebo);
 void ED_armature_ebone_transform_mirror_update(struct bArmature *arm,
diff --git a/source/blender/editors/include/ED_view3d.h b/source/blender/editors/include/ED_view3d.h
index f44b099f42e..4060efbda92 100644
--- a/source/blender/editors/include/ED_view3d.h
+++ b/source/blender/editors/include/ED_view3d.h
@@ -135,13 +135,13 @@ bool ED_view3d_has_workbench_in_texture_color(const struct Scene *scene,
 void ED_view3d_cursor3d_position(struct bContext *C,
                                  const int mval[2],
                                  const bool use_depth,
-                                 float cursor_co[3]);
+                                 float r_cursor_co[3]);
 void ED_view3d_cursor3d_position_rotation(struct bContext *C,
                                           const int mval[2],
                                           const bool use_depth,
                                           enum eV3DCursorOrient orientation,
-                                          float cursor_co[3],
-                                          float cursor_quat[4]);
+                                          float r_cursor_co[3],
+                                          float r_cursor_quat[4]);
 void ED_view3d_cursor3d_update(struct bContext *C,
                                const int mval[2],
                                const bool use_depth,
@@ -403,10 +403,10 @@ bool ED_view3d_win_to_segment_clipped(struct Depsgraph *depsgraph,
                                       const bool do_clip);
 void ED_view3d_ob_project_mat_get(const struct RegionView3D *v3d,
                                   struct Object *ob,
-                                  float pmat[4][4]);
+                                  float r_pmat[4][4]);
 void ED_view3d_ob_project_mat_get_from_obmat(const struct RegionView3D *rv3d,
-                                             float obmat[4][4],
-                                             float pmat[4][4]);
+                                             const float obmat[4][4],
+                                             float r_pmat[4][4]);
 
 void ED_view3d_project(const struct ARegion *region, const float world[3], float r_region_co[3]);
 bool ED_view3d_unproject(
@@ -460,7 +460,7 @@ void ED_view3d_clipping_calc(struct BoundBox *bb,
                              const struct ARegion *region,
                              const struct Object *ob,
                              const struct rcti *rect);
-void ED_view3d_clipping_local(struct RegionView3D *rv3d, float mat[4][4]);
+void ED_view3d_clipping_local(struct RegionView3D *rv3d, const float mat[4][4]);
 bool ED_view3d_clipping_test(const struct RegionView3D *rv3d,
                              const float co[3],
                              const bool is_local);
@@ -601,8 +601,8 @@ void ED_view3d_draw_setup_view(const struct wmWindowManager *wm,
                                struct Scene *scene,
                                struct ARegion *region,
                                struct View3D *v3d,
-                               float viewmat[4][4],
-                               float winmat[4][4],
+                               const float viewmat[4][4],
+                               const float winmat[4][4],
                                const struct rcti *rect);
 
 struct Base *ED_view3d_give_base_under_cursor(struct bContext *C, const int mval[2]);
@@ -613,11 +613,11 @@ void ED_view3d_update_viewmat(struct Depsgraph *depsgraph,
                               const struct Scene *scene,
                               struct View3D *v3d,
                               struct ARegion *region,
-                              float viewmat[4][4],
-                              float winmat[4][4],
+                              const float viewmat[4][4],
+                              const float winmat[4][4],
                               const struct rcti *rect,
                               bool offscreen);
-bool ED_view3d_quat_from_axis_view(const char view, const char view_axis_roll, float quat[4]);
+bool ED_view3d_quat_from_axis_view(const char view, const char view_axis_roll, float r_quat[4]);
 bool ED_view3d_quat_to_axis_view(const float viewquat[4],
                                  const float epsilon,
                                  char *r_view,
@@ -676,7 +676,9 @@ void ED_view3d_lock_clear(struct View3D *v3d);
 #define VIEW3D_MARGIN 1.4f
 #define VIEW3D_DIST_FALLBACK 1.0f
 
-float ED_view3d_offset_distance(float mat[4][4], const float ofs[3], const float dist_fallback);
+float ED_view3d_offset_distance(const float mat[4][4],
+                                const float ofs[3],
+                                const float dist_fallback);
 void ED_view3d_distance_set(struct RegionView3D *rv3d, const float dist);
 bool ED_view3d_distance_set_from_location(struct RegionView3D *rv3d,
                                           const float dist_co[3],
diff --git a/source/blender/editors/include/ED_view3d_offscreen.h b/source/blender/editors/include/ED_view3d_offscreen.h
index 11d1aed1e73..846f4d7eabb 100644
--- a/source/blender/editors/include/ED_view3d_offscreen.h
+++ b/source/blender/editors/include/ED_view3d_offscreen.h
@@ -49,8 +49,8 @@ void ED_view3d_draw_offscreen(struct Depsgraph *depsgraph,
                               struct ARegion *region,
                               int winx,
                               int winy,
-                              float viewmat[4][4],
-                              float winmat[4][4],
+                              const float viewmat[4][4],
+                              const float winmat[4][4],
                               bool is_image_render,
                               bool do_sky,
                               bool is_persp,
@@ -65,8 +65,8 @@ void ED_view3d_draw_offscreen_simple(struct Depsgraph *depsgraph,
                                      int winx,
                                      int winy,
                                      unsigned int draw_flags,
-                                     float viewmat[4][4],
-                                     float winmat[4][4],
+                                     const float viewmat[4][4],
+                                     const float winmat[4][4],
                                      float clip_start,
                                      float clip_end,
                                      bool is_image_render,
diff --git a/source/blender/editors/object/object_add.c b/source/blender/editors/object/object_add.c
index f9e6c531b39..4270f1cbc72 100644
--- a/source/blender/editors/object/object_add.c
+++ b/source/blender/editors/object/object_add.c
@@ -255,13 +255,13 @@ void ED_object_base_init_transform_on_add(Object *object, const float loc[3], co
 /* Uses context to figure out transform for primitive.
  * Returns standard diameter. */
 float ED_object_new_primitive_matrix(
-    bContext *C, Object *obedit, const float loc[3], const float rot[3], float primmat[4][4])
+    bContext *C, Object *obedit, const float loc[3], const float rot[3], float r_primmat[4][4])
 {
   Scene *scene = CTX_data_scene(C);
   View3D *v3d = CTX_wm_view3d(C);
   float mat[3][3], rmat[3][3], cmat[3][3], imat[3][3];
 
-  unit_m4(primmat);
+  unit_m4(r_primmat);
 
   eul_to_mat3(rmat, rot);
   invert_m3(rmat);
@@ -270,13 +270,13 @@ float ED_object_new_primitive_matrix(
   copy_m3_m4(mat, obedit->obmat);
   mul_m3_m3m3(cmat, rmat, mat);
   invert_m3_m3(imat, cmat);
-  copy_m4_m3(primmat, imat);
+  copy_m4_m3(r_primmat, imat);
 
   /* center */
-  copy_v3_v3(primmat[3], loc);
-  sub_v3_v3v3(primmat[3], primmat[3], obedit->obmat[3]);
+  copy_v3_v3(r_primmat[3], loc);
+  sub_v3_v3v3(r_primmat[3], r_primmat[3], obedit->obmat[3]);
   invert_m3_m3(imat, mat);
-  mul_m3_v3(imat, primmat[3]);
+  mul_m3_v3(imat, r_primmat[3]);
 
   {
     const float dia = v3d ? ED_view3d_grid_scale(scene, v3d, NULL) :
diff --git a/source/blender/editors/space_view3d/view3d_draw.c b/source/blender/editors/space_view3d/view3d_draw.c
index 411b18717bf..cf132a1a0c0 100644
--- a/source/blender/editors/space_view3d/view3d_draw.c
+++ b/source/blender/editors/space_view3d/view3d_draw.c
@@ -115,8 +115,8 @@ void ED_view3d_update_viewmat(Depsgraph *depsgraph,
                               const Scene *scene,
                               View3D *v3d,
                               ARegion *region,
-                              float viewmat[4][4],
-                              float winmat[4][4],
+                              const float viewmat[4][4],
+                              const float winmat[4][4],
                               const rcti *rect,
                               bool offscreen)
 {
@@ -197,8 +197,8 @@ static void view3d_main_region_setup_view(Depsgraph *depsgraph,
                                           Scene *scene,
                                           View3D *v3d,
                                           ARegion *region,
-                                          float viewmat[4][4],
-                                          float winmat[4][4],
+                                          const float viewmat[4][4],
+                                          const float winmat[4][4],
                                           const rcti *rect)
 {
   RegionView3D *rv3d = region->regiondata;
@@ -214,8 +214,8 @@ static void view3d_main_region_setup_offscreen(Depsgraph *depsgraph,
                                                const Scene *scene,
                                                View3D *v3d,
                                                ARegion *region,
-                                               float viewmat[4][4],
-                                               float winmat[4][4])
+                                               const float viewmat[4][4],
+                                               const float winmat[4][4])
 {
   RegionView3D *rv3d = region->regiondata;
   ED_view3d_update_viewmat(depsgraph, scene, v3d, region, viewmat, winmat, NULL, true);
@@ -353,8 +353,8 @@ void ED_view3d_draw_setup_view(const wmWindowManager *wm,
                                Scene *scene,
                                ARegion *region,
                                View3D *v3d,
-                               float viewmat[4][4],
-                               float winmat[4][4],
+                               const float viewmat[4][4],
+                               const float winmat[4][4],
                                const rcti *rect)
 {
   RegionView3D *rv3d = region->regiondata;
@@ -1640,7 +1640,7 @@ static void view3d_stereo3d_setup_offscreen(Depsgraph *depsgraph,
                                             const Scene *scene,
                                             View3D *v3d,
                                             ARegion *region,
-                                            float winmat[4][4],
+                                            const float winmat[4][4],
                                             const char *viewname)
 {
   /* update the viewport matrices with the new camera */
@@ -1667,8 +1667,8 @@ void ED_view3d_draw_offscreen(Depsgraph *depsgraph,
                               ARegion *region,
                               int winx,
                               int winy,
-                              float viewmat[4][4],
-                              float winmat[4][4],
+                              const float viewmat[4][4],
+                              const float winmat[4][4],
                               bool is_image_render,
                               bool do_sky,
                               bool UNUSED(is_persp),
@@ -1759,8 +1759,8 @@ void ED_view3d_draw_offscreen_simple(Depsgraph *depsgraph,
                                      int winx,
                                      int winy,
                                      uint draw_flags,
-                                     float viewmat[4][4],
-                                     float winmat[4][4],
+                                     const float viewmat[4][4],
+                                     const float winmat[4][4],
                                      float clip_start,
                                      float clip_end,
                                      bool is_image_render,
@@ -2406,7 +2406,7 @@ struct RV3DMatrixStore *ED_view3d_mats_rv3d_backup(struct RegionView3D *rv3d)
   copy_m4_m4(rv3dmat->viewinv, rv3d->viewinv);
   copy_v4_v4(rv3dmat->viewcamtexcofac, rv3d->viewcamtexcofac);
   rv3dmat->pixsize = rv3d->pixsize;
-  return (void *)rv3dmat;
+  return rv3dmat;
 }
 
 void ED_view3d_mats_rv3d_restore(struct RegionView3D *rv3d, struct RV3DMatrixStore *rv3dmat_pt)
diff --git a/source/blender/editors/space_view3d/view3d_edit.c b/source/blender/editors/space_view3d/view3d_edit.c
index bf02845058e..19aa9cb203b 100644
--- a/source/blender/editors/space_view3d/view3d_edit.c
+++ b/source/blender/editors/space_view3d/view3d_edit.c
@@ -4868,7 +4868,9 @@ void VIEW3D_OT_background_image_remove(wmOperatorType *ot)
  * Draw border or toggle off.
  * \{ */
 
-static void calc_local_clipping(float clip_local[6][4], BoundBox *clipbb, float mat[4][4])
+static void calc_local_clipping(float clip_local[6][4],
+                                const BoundBox *clipbb,
+                                const float mat[4][4])
 {
   BoundBox clipbb_local;
   float imat[4][4];
@@ -4883,7 +4885,7 @@ static void calc_local_clipping(float clip_local[6][4], BoundBox *clipbb, float
   ED_view3d_clipping_calc_from_boundbox(clip_local, &clipbb_local, is_negative_m4(mat));
 }
 
-void ED_view3d_clipping_local(RegionView3D *rv3d, float mat[4][4])
+void ED_view3d_clipping_local(RegionView3D *rv3d, const float mat[4][4])
 {
   if (rv3d->rflag & RV3D_CLIPPING) {
     calc_local_clipping(rv3d->clip_local, rv3d->clipbb, mat);
diff --git a/source/blender/editors/space_view3d/view3d_project.c b/source/blender/editors/space_view3d/view3d_project.c
index f4ec9a22520..c10a88af146 100644
--- a/source/blender/editors/space_view3d/view3d_project.c
+++ b/source/blender/editors/space_view3d/view3d_project.c
@@ -303,12 +303,12 @@ eV3DProjStatus ED_view3d_project_float_object(const ARegion *region,
 
 float ED_view3d_pixel_size(const RegionView3D *rv3d, const float co[3])
 {
-  return mul_project_m4_v3_zfac((float(*)[4])rv3d->persmat, co) * rv3d->pixsize * U.pixelsize;
+  return mul_project_m4_v3_zfac(rv3d->persmat, co) * rv3d->pixsize * U.pixelsize;
 }
 
 float ED_view3d_pixel_size_no_ui_scale(const RegionView3D *rv3d, const float co[3])
 {
-  return mul_project_m4_v3_zfac((float(*)[4])rv3d->persmat, co) * rv3d->pixsize;
+  return mul_project_m4_v3_zfac(rv3d->persmat, co) * rv3d->pixsize;
 }
 
 /**
@@ -316,7 +316,7 @@ float ED_view3d_pixel_size_no_ui_scale(const RegionView3D *rv3d, const float co[
  */
 float ED_view3d_calc_zfac(const RegionView3D *rv3d, const float co[3], bool *r_flip)
 {
-  float zfac = mul_project_m4_v3_zfac((float(*)[4])rv3d->persmat, co);
+  float zfac = mul_project_m4_v3_zfac(rv3d->persmat, co);
 
   if (r_flip) {
     *r_flip = (zfac < 0.0f);
@@ -483,11 +483,11 @@ void ED_view3d_global_to_vector(const RegionView3D *rv3d, const float coord[3],
     p1[3] = 1.0f;
     copy_v3_v3(p2, p1);
     p2[3] = 1.0f;
-    mul_m4_v4((float(*)[4])rv3d->viewmat, p2);
+    mul_m4_v4(rv3d->viewmat, p2);
 
     mul_v3_fl(p2, 2.0f);
 
-    mul_m4_v4((float(*)[4])rv3d->viewinv, p2);
+    mul_m4_v4(rv3d->viewinv, p2);
 
     sub_v3_v3v3(vec, p1, p2);
   }
@@ -749,25 +749,26 @@ bool ED_view3d_win_to_segment_clipped(struct Depsgraph *depsgraph,
   return true;
 }
 
-/* Utility functions for projection
- * ******************************** */
+/* -------------------------------------------------------------------- */
+/** \name Utility functions for projection
+ * \{ */
 
-void ED_view3d_ob_project_mat_get(const RegionView3D *rv3d, Object *ob, float pmat[4][4])
+void ED_view3d_ob_project_mat_get(const RegionView3D *rv3d, Object *ob, float r_pmat[4][4])
 {
   float vmat[4][4];
 
-  mul_m4_m4m4(vmat, (float(*)[4])rv3d->viewmat, ob->obmat);
-  mul_m4_m4m4(pmat, (float(*)[4])rv3d->winmat, vmat);
+  mul_m4_m4m4(vmat, rv3d->viewmat, ob->obmat);
+  mul_m4_m4m4(r_pmat, rv3d->winmat, vmat);
 }
 
 void ED_view3d_ob_project_mat_get_from_obmat(const RegionView3D *rv3d,
-                                             float obmat[4][4],
-                                             float pmat[4][4])
+                                             const float obmat[4][4],
+                                             float r_pmat[4][4])
 {
   float vmat[4][4];
 
-  mul_m4_m4m4(vmat, (float(*)[4])rv3d->viewmat, obmat);
-  mul_m4_m4m4(pmat, (float(*)[4])rv3d->winmat, vmat);
+  mul_m4_m4m4(vmat, rv3d->viewmat, obmat);
+  mul_m4_m4m4(r_pmat, rv3d->winmat, vmat);
 }
 
 /**
@@ -791,3 +792,5 @@ bool ED_view3d_unproject(
 
   return GPU_matrix_unproject(region_co, rv3d->viewmat, rv3d->winmat, viewport, world);
 }
+
+/** \} */
diff --git a/source/blender/editors/space_view3d/view3d_utils.c b/source/blender/editors/space_view3d/view3d_utils.c
index bd2323f47f4..4e73a2be17e 100644
--- a/source/blender/editors/space_view3d/view3d_utils.c
+++ b/source/blender/editors/space_view3d/view3d_utils.c
@@ -335,7 +335,7 @@ void ED_view3d_clipping_calc(
  *
  * \{ */
 
-static bool view3d_boundbox_clip_m4(const BoundBox *bb, float persmatob[4][4])
+static bool view3d_boundbox_clip_m4(const BoundBox *bb, const float persmatob[4][4])
 {
   int a, flag = -1, fl;
 
@@ -1243,7 +1243,9 @@ float ED_view3d_radius_to_dist(const View3D *v3d,
  * \param fallback_dist: The distance to use if the object is too near or in front of \a ofs.
  * \returns A newly calculated distance or the fallback.
  */
-float ED_view3d_offset_distance(float mat[4][4], const float ofs[3], const float fallback_dist)
+float ED_view3d_offset_distance(const float mat[4][4],
+                                const float ofs[3],
+                                const float fallback_dist)
 {
   float pos[4] = {0.0f, 0.0f, 0.0f, 1.0f};
   float dir[4] = {0.0f, 0.0f, 1.0f, 0.0f};
@@ -1374,11 +1376,11 @@ static float view3d_quat_axis[6][4][4] = {
 
 };
 
-bool ED_view3d_quat_from_axis_view(const char view, const char view_axis_roll, float quat[4])
+bool ED_view3d_quat_from_axis_view(const char view, const char view_axis_roll, float r_quat[4])
 {
   BLI_assert(view_axis_roll <= RV3D_VIEW_AXIS_ROLL_270);
   if (RV3D_VIEW_IS_AXIS(view)) {
-    copy_qt_qt(quat, view3d_quat_axis[view - RV3D_VIEW_FRONT][view_axis_roll]);
+    copy_qt_qt(r_quat, view3d_quat_axis[view - RV3D_VIEW_FRONT][view_axis_roll]);
     return true;
   }
   return false;
diff --git a/source/blender/makesrna/intern/rna_curve_api.c b/source/blender/makesrna/intern/rna_curve_api.c
index 1207f19b95f..94fdb130026 100644
--- a/source/blender/makesrna/intern/rna_curve_api.c
+++ b/source/blender/makesrna/intern/rna_curve_api.c
@@ -37,7 +37,7 @@
 #ifdef RNA_RUNTIME
 static void rna_Curve_transform(Curve *cu, float *mat, bool shape_keys)
 {
-  BKE_curve_transform(cu, (float(*)[4])mat, shape_keys, true);
+  BKE_curve_transform(cu, (const float(*)[4])mat, shape_keys, true);
 
   DEG_id_tag_update(&cu->id, 0);
 }
diff --git a/source/blender/render/extern/include/RE_pipeline.h b/source/blender/render/extern/include/RE_pipeline.h
index f9d2e915fad..45b5362d40b 100644
--- a/source/blender/render/extern/include/RE_pipeline.h
+++ b/source/blender/render/extern/include/RE_pipeline.h
@@ -367,8 +367,8 @@ struct RenderPass *RE_pass_find_by_type(volatile struct RenderLayer *rl,
 #define RE_BAKE_AO 2
 
 void RE_GetCameraWindow(struct Render *re, struct Object *camera, float mat[4][4]);
-void RE_GetCameraWindowWithOverscan(struct Render *re, float mat[4][4], float overscan);
-void RE_GetCameraModelMatrix(struct Render *re, struct Object *camera, float r_mat[4][4]);
+void RE_GetCameraWindowWithOverscan(struct Render *re, float overscan, float r_winmat[4][4]);
+void RE_GetCameraModelMatrix(struct Render *re, struct Object *camera, float r_modelmat[4][4]);
 struct Scene *RE_GetScene(struct Render *re);
 void RE_SetScene(struct Render *re, struct Scene *sce);
 
diff --git a/source/blender/render/intern/source/initrender.c b/source/blender/render/intern/source/initrender.c
index 2e9f30397db..d631dd1a2ff 100644
--- a/source/blender/render/intern/source/initrender.c
+++ b/source/blender/render/intern/source/initrender.c
@@ -211,14 +211,14 @@ void RE_SetCamera(Render *re, Object *cam_ob)
   re_camera_params_get(re, &params);
 }
 
-void RE_GetCameraWindow(struct Render *re, struct Object *camera, float mat[4][4])
+void RE_GetCameraWindow(struct Render *re, struct Object *camera, float r_winmat[4][4])
 {
   RE_SetCamera(re, camera);
-  copy_m4_m4(mat, re->winmat);
+  copy_m4_m4(r_winmat, re->winmat);
 }
 
 /* Must be called after RE_GetCameraWindow(), does not change re->winmat. */
-void RE_GetCameraWindowWithOverscan(struct Render *re, float mat[4][4], float overscan)
+void RE_GetCameraWindowWithOverscan(struct Render *re, float overscan, float r_winmat[4][4])
 {
   CameraParams params;
   params.is_ortho = re->winmat[3][3] != 0.0f;
@@ -233,12 +233,12 @@ void RE_GetCameraWindowWithOverscan(struct Render *re, float mat[4][4], float ov
   params.viewplane.ymin -= overscan;
   params.viewplane.ymax += overscan;
   BKE_camera_params_compute_matrix(&params);
-  copy_m4_m4(mat, params.winmat);
+  copy_m4_m4(r_winmat, params.winmat);
 }
 
-void RE_GetCameraModelMatrix(Render *re, struct Object *camera, float r_mat[4][4])
+void RE_GetCameraModelMatrix(Render *re, struct Object *camera, float r_modelmat[4][4])
 {
-  BKE_camera_multiview_model_matrix(&re->r, camera, re->viewname, r_mat);
+  BKE_camera_multiview_model_matrix(&re->r, camera, re->viewname, r_modelmat);
 }
 
 /* ~~~~~~~~~~~~~~~~ part (tile) calculus ~~~~~~~~~~~~~~~~~~~~~~ */