[Bf-blender-cvs] [65df2fd] master: bmesh py api: expose BM_face_calc_tangent_*
Campbell Barton
noreply at git.blender.org
Sun Jun 12 07:11:06 CEST 2016
Commit: 65df2fd9976178c98db5401ff4e965047e35afdb
Author: Campbell Barton
Date: Sun Jun 12 12:22:38 2016 +1000
Branches: master
https://developer.blender.org/rB65df2fd9976178c98db5401ff4e965047e35afdb
bmesh py api: expose BM_face_calc_tangent_*
D1988 by @wisaac, with own edits and improvements.
This improves on existing tangent calculation functions too.
- BM_face_calc_tangent_auto: Chooses method based on number of sides, used by manipulator (not exposed to Python).
- BM_face_calc_tangent_edge: from longest edge.
- BM_face_calc_tangent_edge_pair: from longest edge-pair (most useful with quads).
- BM_face_calc_tangent_edge_diagonal: edge farthest from any vertex.
- BM_face_calc_tangent_vert_diagonal: vert farthest from any vertex.
Also optimize BM_vert_tri_calc_tangent_edge* functions to avoid sqrt.
===================================================================
M source/blender/bmesh/intern/bmesh_marking.c
M source/blender/bmesh/intern/bmesh_polygon.c
M source/blender/bmesh/intern/bmesh_polygon.h
M source/blender/editors/transform/transform_orientations.c
M source/blender/python/bmesh/bmesh_py_types.c
===================================================================
diff --git a/source/blender/bmesh/intern/bmesh_marking.c b/source/blender/bmesh/intern/bmesh_marking.c
index 3fe8887..d6ca723 100644
--- a/source/blender/bmesh/intern/bmesh_marking.c
+++ b/source/blender/bmesh/intern/bmesh_marking.c
@@ -904,7 +904,7 @@ void BM_editselection_plane(BMEditSelection *ese, float r_plane[3])
}
else if (ese->htype == BM_FACE) {
BMFace *efa = (BMFace *)ese->ele;
- BM_face_calc_plane(efa, r_plane);
+ BM_face_calc_tangent_auto(efa, r_plane);
}
}
diff --git a/source/blender/bmesh/intern/bmesh_polygon.c b/source/blender/bmesh/intern/bmesh_polygon.c
index 62b29e6..79051a2 100644
--- a/source/blender/bmesh/intern/bmesh_polygon.c
+++ b/source/blender/bmesh/intern/bmesh_polygon.c
@@ -286,64 +286,258 @@ float BM_face_calc_perimeter(const BMFace *f)
return perimeter;
}
-void BM_vert_tri_calc_plane(BMVert *verts[3], float r_plane[3])
+/**
+ * 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``.
+ */
+static int bm_vert_tri_find_unique_edge(BMVert *verts[3])
{
- float lens[3];
+ /* find the most 'unique' loop, (greatest difference to others) */
+#if 1
+ /* optimized version that avoids sqrt */
float difs[3];
- int order[3] = {0, 1, 2};
+ for (int i_prev = 1, i_curr = 2, i_next = 0;
+ i_next < 3;
+ i_prev = i_curr, i_curr = i_next++)
+ {
+ const float *co = verts[i_curr]->co;
+ const float *co_other[2] = {verts[i_prev]->co, verts[i_next]->co};
+ float proj_dir[3];
+ mid_v3_v3v3(proj_dir, co_other[0], co_other[1]);
+ sub_v3_v3(proj_dir, co);
+
+ float proj_pair[2][3];
+ project_v3_v3v3(proj_pair[0], co_other[0], proj_dir);
+ project_v3_v3v3(proj_pair[1], co_other[1], proj_dir);
+ difs[i_next] = len_squared_v3v3(proj_pair[0], proj_pair[1]);
+ }
+#else
+ const float lens[3] = {
+ len_v3v3(verts[0]->co, verts[1]->co),
+ len_v3v3(verts[1]->co, verts[2]->co),
+ len_v3v3(verts[2]->co, verts[0]->co),
+ };
+ const float difs[3] = {
+ fabsf(lens[1] - lens[2]),
+ fabsf(lens[2] - lens[0]),
+ fabsf(lens[0] - lens[1]),
+ };
+#endif
- lens[0] = len_v3v3(verts[0]->co, verts[1]->co);
- lens[1] = len_v3v3(verts[1]->co, verts[2]->co);
- lens[2] = len_v3v3(verts[2]->co, verts[0]->co);
+ int order[3] = {0, 1, 2};
+ axis_sort_v3(difs, order);
- /* find the shortest or the longest loop */
- difs[0] = fabsf(lens[1] - lens[2]);
- difs[1] = fabsf(lens[2] - lens[0]);
- difs[2] = fabsf(lens[0] - lens[1]);
+ return order[0];
+}
- axis_sort_v3(difs, order);
- sub_v3_v3v3(r_plane, verts[order[0]]->co, verts[(order[0] + 1) % 3]->co);
+/**
+ * Calculate a tangent from any 3 vertices.
+ *
+ * The tangent aligns to the most *unique* edge
+ * (the edge most unlike the other two).
+ *
+ * \param r_tangent: Calculated unit length tangent (return value).
+ */
+void BM_vert_tri_calc_tangent_edge(BMVert *verts[3], float r_tangent[3])
+{
+ const int index = bm_vert_tri_find_unique_edge(verts);
+
+ sub_v3_v3v3(r_tangent, verts[index]->co, verts[(index + 1) % 3]->co);
+
+ normalize_v3(r_tangent);
}
/**
- * Compute a meaningful direction along the face (use for manipulator axis).
- * \note result isnt normalized.
+ * Calculate a tangent from any 3 vertices,
+ *
+ * The tangent follows the center-line formed by the most unique edges center
+ * and the opposite vertex.
+ *
+ * \param r_tangent: Calculated unit length tangent (return value).
*/
-void BM_face_calc_plane(const BMFace *f, float r_plane[3])
+void BM_vert_tri_calc_tangent_edge_pair(BMVert *verts[3], float r_tangent[3])
+{
+ const int index = bm_vert_tri_find_unique_edge(verts);
+
+ const float *v_a = verts[index]->co;
+ const float *v_b = verts[(index + 1) % 3]->co;
+ const float *v_other = verts[(index + 2) % 3]->co;
+
+ mid_v3_v3v3(r_tangent, v_a, v_b);
+ sub_v3_v3v3(r_tangent, v_other, r_tangent);
+
+ normalize_v3(r_tangent);
+}
+
+/**
+ * Compute the tanget of the face, using the longest edge.
+ */
+void BM_face_calc_tangent_edge(const BMFace *f, float r_tangent[3])
+{
+ const BMLoop *l_long = BM_face_find_longest_loop((BMFace *)f);
+
+ sub_v3_v3v3(r_tangent, l_long->v->co, l_long->next->v->co);
+
+ normalize_v3(r_tangent);
+
+}
+
+/**
+ * Compute the tanget of the face, using the two longest disconected edges.
+ *
+ * \param r_tangent: Calculated unit length tangent (return value).
+ */
+void BM_face_calc_tangent_edge_pair(const BMFace *f, float r_tangent[3])
{
if (f->len == 3) {
BMVert *verts[3];
BM_face_as_array_vert_tri((BMFace *)f, verts);
- BM_vert_tri_calc_plane(verts, r_plane);
+ BM_vert_tri_calc_tangent_edge_pair(verts, r_tangent);
}
else if (f->len == 4) {
+ /* Use longest edge pair */
BMVert *verts[4];
float vec[3], vec_a[3], vec_b[3];
- // BM_iter_as_array(NULL, BM_VERTS_OF_FACE, efa, (void **)verts, 4);
BM_face_as_array_vert_quad((BMFace *)f, verts);
sub_v3_v3v3(vec_a, verts[3]->co, verts[2]->co);
sub_v3_v3v3(vec_b, verts[0]->co, verts[1]->co);
- add_v3_v3v3(r_plane, vec_a, vec_b);
+ add_v3_v3v3(r_tangent, vec_a, vec_b);
sub_v3_v3v3(vec_a, verts[0]->co, verts[3]->co);
sub_v3_v3v3(vec_b, verts[1]->co, verts[2]->co);
add_v3_v3v3(vec, vec_a, vec_b);
- /* use the biggest edge length */
- if (len_squared_v3(r_plane) < len_squared_v3(vec)) {
- copy_v3_v3(r_plane, vec);
+ /* use the longest edge length */
+ if (len_squared_v3(r_tangent) < len_squared_v3(vec)) {
+ copy_v3_v3(r_tangent, vec);
}
}
else {
- const BMLoop *l_long = BM_face_find_longest_loop((BMFace *)f);
+ /* For ngons use two longest disconnected edges */
+ BMLoop *l_long = BM_face_find_longest_loop((BMFace *)f);
+ BMLoop *l_long_other = NULL;
- sub_v3_v3v3(r_plane, l_long->v->co, l_long->next->v->co);
+ float len_max_sq = 0.0f;
+ float vec_a[3], vec_b[3];
+
+ BMLoop *l_iter = l_long->prev->prev;
+ BMLoop *l_last = l_long->next;
+
+ do {
+ const float len_sq = len_squared_v3v3(l_iter->v->co, l_iter->next->v->co);
+ if (len_sq >= len_max_sq) {
+ l_long_other = l_iter;
+ len_max_sq = len_sq;
+ }
+ } while ((l_iter = l_iter->prev) != l_last);
+
+ sub_v3_v3v3(vec_a, l_long->next->v->co, l_long->v->co);
+ sub_v3_v3v3(vec_b, l_long_other->v->co, l_long_other->next->v->co);
+ add_v3_v3v3(r_tangent, vec_a, vec_b);
+
+ /* Edges may not be opposite side of the ngon,
+ * this could cause problems for ngons with multiple-aligned edges of the same length.
+ * Fallback to longest edge. */
+ if (UNLIKELY(normalize_v3(r_tangent) == 0.0f)) {
+ normalize_v3_v3(r_tangent, vec_a);
+ }
}
+}
- normalize_v3(r_plane);
+/**
+ * Compute the tanget of the face, using the edge farthest away from any vertex in the face.
+ *
+ * \param r_tangent: Calculated unit length tangent (return value).
+ */
+void BM_face_calc_tangent_edge_diagonal(const BMFace *f, float r_tangent[3])
+{
+ BMLoop *l_iter, *l_first;
+
+ l_iter = l_first = BM_FACE_FIRST_LOOP(f);
+
+ /* incase of degenerate faces */
+ zero_v3(r_tangent);
+
+ /* warning: O(n^2) loop here, take care! */
+ float dist_max_sq = 0.0f;
+ do {
+ BMLoop *l_iter_other = l_iter->next;
+ BMLoop *l_iter_last = l_iter->prev;
+ do {
+ BLI_assert(!ELEM(l_iter->v->co, l_iter_other->v->co, l_iter_other->next->v->co));
+ float co_other[3], vec[3];
+ closest_to_line_segment_v3(co_other, l_iter->v->co, l_iter_other->v->co, l_iter_other->next->v->co);
+ sub_v3_v3v3(vec, l_iter->v->co, co_other);
+
+ const float dist_sq = len_squared_v3(vec);
+ if (dist_sq > dist_max_sq) {
+ dist_max_sq = dist_sq;
+ copy_v3_v3(r_tangent, vec);
+ }
+ } while ((l_iter_other = l_iter_other->next) != l_iter_last);
+ } while ((l_iter = l_iter->next) != l_first);
+
+ normalize_v3(r_tangent);
+}
+
+/**
+ * Compute the tanget of the face, using longest distance between vertices on the face.
+ *
+ * \note The logic is almost identical to #BM_face_calc_tangent_edge_diagonal
+ */
+void BM_face_calc_tangent_vert_diagonal(const BMFace *f, float r_tangent[3])
+{
+ BMLoop *l_iter, *l_first;
+
+ l_iter = l_first = BM_FACE_FIRST_LOOP(f);
+
+ /* incase of degenerate faces */
+ zero_v3(r_tangent);
+
+ /* warning: O(n^2) loop here, take care! */
+ float dist_max_sq = 0.0f;
+ do {
+ BMLoop *l_iter_other = l_iter->next;
+ do {
+ float vec[3];
+ sub_v3_v3v3(vec, l_iter->v->co, l_iter_other->v->co);
+
+ const float dist_sq = len_squared_v3(vec);
+ if (dist_sq > dist_max_sq) {
+ dist_max_sq = dist_sq;
+ copy_v3_v3(r_tangent, vec);
+ }
+ } while ((l_iter_other = l_iter_other->next) != l_iter);
+ } while ((l_iter = l_iter->next) != l_first);
+
+ normalize_v3(r_tangent);
+}
+
+/**
+ * Compute a meaningful direction along the face (use for manipulator axis).
+ *
+ * \note Callers shouldn't depend on the *exact* method used here.
+ */
+void BM_face_calc_tangent_auto(const BMFace *f, float r_tangent[3])
+{
+ if (f->len == 3) {
+ /* most 'unique' edge of a triangle */
+ BMVert *verts[3];
+ BM_face_as_array_vert_tri((BMFace *)f, verts);
+ BM_vert_tri_calc_tangent_edge(verts, r_tangent);
+ }
+ else if (f->len == 4) {
+ /* longest edge pair of a quad */
+ BM_face_calc_tangent_edge_pair((BMFace *)f, r_tangent);
+ }
+ else {
+ /* longest edge of an ngon */
+ BM_face_calc_tangent_edge((BMFace *)f, r_tangent);
+ }
}
/**
diff --git a/source/blender/bmesh/intern/bmesh_polygon.h b/source/blender/bmesh/intern/bmesh_polygon.h
index 8f0df81..1e50a50 100644
--- a/source/blender/bmesh/intern/bmesh_polygon.h
+++ b/source/blender/bmesh/intern/bmesh_polygon.h
@@ -45,7 +45,11 @@ float BM_face_calc_normal_vcos(
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_perimeter(const BMFace *f) ATTR_WARN_UNUSED_RESULT ATTR_NONNULL();
-void BM_face_calc_plane(const BMFace *f, float r_plane[3]) 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();
+void BM_face_calc_tangent_vert_diagonal(co
@@ Diff output truncated at 10240 characters. @@
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