BMesh: backport minor changes from 2.8

1 files changed, 44 insertions, 1 deletions

diff --git a/source/blender/bmesh/intern/bmesh_polygon.c b/source/blender/bmesh/intern/bmesh_polygon.c
index 3137725d6e7..5e3f5958a32 100644
--- a/source/blender/bmesh/intern/bmesh_polygon.c
+++ b/source/blender/bmesh/intern/bmesh_polygon.c
@@ -240,6 +240,28 @@ float BM_face_calc_area(const BMFace *f)
 }
 
 /**
+ * Get the area of the face in world space.
+ */
+float BM_face_calc_area_with_mat3(const BMFace *f, 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);
+	mul_v3_m3v3(co, mat3, l_iter->v->co);
+	do {
+		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;
+}
+
+/**
  * compute the perimeter of an ngon
  */
 float BM_face_calc_perimeter(const BMFace *f)
@@ -256,6 +278,27 @@ float BM_face_calc_perimeter(const BMFace *f)
 }
 
 /**
+ * Calculate the perimeter of a ngon in world space.
+ */
+float BM_face_calc_perimeter_with_mat3(const BMFace *f, 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);
+	mul_v3_m3v3(co, mat3, l_iter->v->co);
+	do {
+		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;
+}
+
+/**
  * Utility function to calculate the edge which is most different from the other two.
  *
  * \return The first edge index, where the second vertex is ``(index + 1) % 3``.
@@ -487,7 +530,7 @@ void  BM_face_calc_tangent_vert_diagonal(const BMFace *f, float r_tangent[3])
 }
 
 /**
- * Compute a meaningful direction along the face (use for manipulator axis).
+ * Compute a meaningful direction along the face (use for gizmo axis).
  *
  * \note Callers shouldn't depend on the *exact* method used here.
  */