BMesh: avoid incorrect/invalid matrix calculation

- `BKE_object_scale_to_mat3` was used to get the worldspace scale,
  without taking constraints, parenting etc into account.
- Don't pass object's into BMesh API, (prefer matrices instead).
- Avoid matrix invert for each edge-angle calculation.
- Avoid 2x matrix multiplies when looping over edge pairs.

4 files changed, 21 insertions, 35 deletions

diff --git a/source/blender/bmesh/intern/bmesh_polygon.c b/source/blender/bmesh/intern/bmesh_polygon.c
index 8374fd8f51f..9baae8e8a93 100644
--- a/source/blender/bmesh/intern/bmesh_polygon.c
+++ b/source/blender/bmesh/intern/bmesh_polygon.c
@@ -30,7 +30,6 @@
 
 #include "DNA_listBase.h"
 #include "DNA_modifier_types.h"
-#include "DNA_object_types.h"
 
 #include "MEM_guardedalloc.h"
 
@@ -243,23 +242,21 @@ float BM_face_calc_area(const BMFace *f)
 /**
  * Get the area of the face in world space.
  */
-float BM_face_calc_area_worldspace(Object *ob, const BMFace *f)
+float BM_face_calc_area_with_mat3(const BMFace *f, const float mat3[3][3])
 {
 	/* inline 'area_poly_v3' logic, avoid creating a temp array */
 	const BMLoop *l_iter, *l_first;
+	float co[3];
 	float n[3];
 
 	zero_v3(n);
 	l_iter = l_first = BM_FACE_FIRST_LOOP(f);
-	float rsmat[3][3];
-	copy_m3_m4(rsmat, ob->obmat);
+	mul_v3_m3v3(co, mat3, l_iter->v->co);
 	do {
-		float co[3], co_next[3];
-		copy_v3_v3(co, l_iter->v->co);
-		copy_v3_v3(co_next, l_iter->next->v->co);
-		mul_m3_v3(rsmat, co);
-		mul_m3_v3(rsmat, co_next);
+		float co_next[3];
+		mul_v3_m3v3(co_next, mat3, l_iter->next->v->co);
 		add_newell_cross_v3_v3v3(n, co, co_next);
+		copy_v3_v3(co, co_next);
 	} while ((l_iter = l_iter->next) != l_first);
 	return len_v3(n) * 0.5f;
 }
@@ -283,21 +280,19 @@ float BM_face_calc_perimeter(const BMFace *f)
 /**
  * Calculate the perimeter of a ngon in world space.
  */
-float BM_face_calc_perimeter_worldspace(Object *ob, const BMFace *f)
+float BM_face_calc_perimeter_with_mat3(const BMFace *f, const float mat3[3][3])
 {
 	const BMLoop *l_iter, *l_first;
+	float co[3];
 	float perimeter = 0.0f;
 
 	l_iter = l_first = BM_FACE_FIRST_LOOP(f);
-	float rsmat[3][3];
-	copy_m3_m4(rsmat, ob->obmat);
+	mul_v3_m3v3(co, mat3, l_iter->v->co);
 	do {
-		float co[3], co_next[3];
-		copy_v3_v3(co, l_iter->v->co);
-		copy_v3_v3(co_next, l_iter->next->v->co);
-		mul_m3_v3(rsmat, co);
-		mul_m3_v3(rsmat, co_next);
+		float co_next[3];
+		mul_v3_m3v3(co_next, mat3, l_iter->next->v->co);
 		perimeter += len_v3v3(co, co_next);
+		copy_v3_v3(co, co_next);
 	} while ((l_iter = l_iter->next) != l_first);
 
 	return perimeter;
diff --git a/source/blender/bmesh/intern/bmesh_polygon.h b/source/blender/bmesh/intern/bmesh_polygon.h
index 29bb49a8e40..2edfdaa8c03 100644
--- a/source/blender/bmesh/intern/bmesh_polygon.h
+++ b/source/blender/bmesh/intern/bmesh_polygon.h
@@ -28,7 +28,6 @@
  */
 
 struct Heap;
-struct Object;
 
 #include "BLI_compiler_attrs.h"
 
@@ -45,9 +44,9 @@ float BM_face_calc_normal_vcos(
         float const (*vertexCos)[3]) ATTR_NONNULL();
 float BM_face_calc_normal_subset(const BMLoop *l_first, const BMLoop *l_last, float r_no[3]) ATTR_NONNULL();
 float BM_face_calc_area(const BMFace *f) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
-float BM_face_calc_area_worldspace(struct Object *ob, const BMFace *f) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
+float BM_face_calc_area_with_mat3(const BMFace *f, const float mat3[3][3]) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
 float BM_face_calc_perimeter(const BMFace *f) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
-float BM_face_calc_perimeter_worldspace(struct Object *ob, const BMFace *f) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
+float BM_face_calc_perimeter_with_mat3(const BMFace *f, const float mat3[3][3]) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
 void  BM_face_calc_tangent_edge(const BMFace *f, float r_plane[3]) ATTR_NONNULL();
 void  BM_face_calc_tangent_edge_pair(const BMFace *f, float r_plane[3]) ATTR_NONNULL();
 void  BM_face_calc_tangent_edge_diagonal(const BMFace *f, float r_plane[3]) ATTR_NONNULL();
diff --git a/source/blender/bmesh/intern/bmesh_query.c b/source/blender/bmesh/intern/bmesh_query.c
index c51c6322136..59711670334 100644
--- a/source/blender/bmesh/intern/bmesh_query.c
+++ b/source/blender/bmesh/intern/bmesh_query.c
@@ -31,8 +31,6 @@
  * of inspecting the mesh structure directly.
  */
 
-#include "DNA_object_types.h"
-
 #include "MEM_guardedalloc.h"
 
 #include "BLI_math.h"
@@ -41,7 +39,6 @@
 #include "BLI_utildefines_stack.h"
 
 #include "BKE_customdata.h"
-#include "BKE_object.h"
 
 #include "bmesh.h"
 #include "intern/bmesh_private.h"
@@ -1688,7 +1685,7 @@ float BM_edge_calc_face_angle(const BMEdge *e)
 *
 * \return angle in radians
 */
-float BM_edge_calc_face_angle_worldspace_ex(Object *ob, const BMEdge *e, const float fallback)
+float BM_edge_calc_face_angle_with_imat3_ex(const BMEdge *e, const float imat3[3][3], const float fallback)
 {
 	if (BM_edge_is_manifold(e)) {
 		const BMLoop *l1 = e->l;
@@ -1697,12 +1694,9 @@ float BM_edge_calc_face_angle_worldspace_ex(Object *ob, const BMEdge *e, const f
 		copy_v3_v3(no1, l1->f->no);
 		copy_v3_v3(no2, l2->f->no);
 
-		float smat[3][3];
-		BKE_object_scale_to_mat3(ob, smat);
-		invert_m3(smat);
+		mul_transposed_m3_v3(imat3, no1);
+		mul_transposed_m3_v3(imat3, no2);
 
-		mul_m3_v3(smat, no1);
-		mul_m3_v3(smat, no2);
 		normalize_v3(no1);
 		normalize_v3(no2);
 
@@ -1712,9 +1706,9 @@ float BM_edge_calc_face_angle_worldspace_ex(Object *ob, const BMEdge *e, const f
 		return fallback;
 	}
 }
-float BM_edge_calc_face_angle_worldspace(Object *ob, const BMEdge *e)
+float BM_edge_calc_face_angle_with_imat3(const BMEdge *e, const float imat3[3][3])
 {
-	return BM_edge_calc_face_angle_worldspace_ex(ob, e, DEG2RADF(90.0f));
+	return BM_edge_calc_face_angle_with_imat3_ex(e, imat3, DEG2RADF(90.0f));
 }
 
 /**
diff --git a/source/blender/bmesh/intern/bmesh_query.h b/source/blender/bmesh/intern/bmesh_query.h
index 1cfd6cc07a3..7c087a5150f 100644
--- a/source/blender/bmesh/intern/bmesh_query.h
+++ b/source/blender/bmesh/intern/bmesh_query.h
@@ -27,8 +27,6 @@
  *  \ingroup bmesh
  */
 
-struct Object;
-
 bool    BM_vert_in_face(BMVert *v, BMFace *f) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
 int     BM_verts_in_face_count(BMVert **varr, int len, BMFace *f) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
 bool    BM_verts_in_face(BMVert **varr, int len, BMFace *f) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
@@ -125,8 +123,8 @@ void    BM_loop_calc_face_tangent(const BMLoop *l, float r_tangent[3]);
 float   BM_edge_calc_face_angle_ex(const BMEdge *e, const float fallback) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
 float   BM_edge_calc_face_angle(const BMEdge *e) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
 float   BM_edge_calc_face_angle_signed_ex(const BMEdge *e, const float fallback) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
-float   BM_edge_calc_face_angle_worldspace_ex(struct Object *ob, const BMEdge *e, const float fallback) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
-float   BM_edge_calc_face_angle_worldspace(struct Object *ob, const BMEdge *e) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
+float   BM_edge_calc_face_angle_with_imat3_ex(const BMEdge *e, const float imat3[3][3], const float fallback) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
+float   BM_edge_calc_face_angle_with_imat3(const BMEdge *e, const float imat3[3][3]) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
 float   BM_edge_calc_face_angle_signed(const BMEdge *e) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
 void    BM_edge_calc_face_tangent(const BMEdge *e, const BMLoop *e_loop, float r_tangent[3]) ATTR_NONNULL();