Transform: New Snap Option: Edge Perpendicular

Part of T66420

Option for snapping to the nearest point of a reference coordinate.
The patch also adds Edge Center and Perpendicular snaps to the ruler.

{F7675906}

Reviewers: campbellbarton, brecht

Reviewed By: campbellbarton

Differential Revision: https://developer.blender.org/D5543

11 files changed, 89 insertions, 16 deletions

diff --git a/source/blender/editors/curve/editcurve.c b/source/blender/editors/curve/editcurve.c
index eebc8893112..d7650db546d 100644
--- a/source/blender/editors/curve/editcurve.c
+++ b/source/blender/editors/curve/editcurve.c
@@ -5680,6 +5680,7 @@ static int add_vertex_invoke(bContext *C, wmOperator *op, const wmEvent *event)
           },
           mval,
           NULL,
+          NULL,
           location,
           NULL);
 
diff --git a/source/blender/editors/gizmo_library/gizmo_types/move3d_gizmo.c b/source/blender/editors/gizmo_library/gizmo_types/move3d_gizmo.c
index 21f779b72b1..37ee95d5058 100644
--- a/source/blender/editors/gizmo_library/gizmo_types/move3d_gizmo.c
+++ b/source/blender/editors/gizmo_library/gizmo_types/move3d_gizmo.c
@@ -283,6 +283,7 @@ static int gizmo_move_modal(bContext *C,
                   .use_occlusion_test = true,
               },
               mval_fl,
+              NULL,
               &dist_px,
               co,
               NULL)) {
diff --git a/source/blender/editors/include/ED_transform_snap_object_context.h b/source/blender/editors/include/ED_transform_snap_object_context.h
index f27523bb1f8..97bef25dee8 100644
--- a/source/blender/editors/include/ED_transform_snap_object_context.h
+++ b/source/blender/editors/include/ED_transform_snap_object_context.h
@@ -125,6 +125,7 @@ short ED_transform_snap_object_project_view3d_ex(struct SnapObjectContext *sctx,
                                                  const unsigned short snap_to,
                                                  const struct SnapObjectParams *params,
                                                  const float mval[2],
+                                                 const float prev_co[3],
                                                  float *dist_px,
                                                  float r_loc[3],
                                                  float r_no[3],
@@ -135,6 +136,7 @@ bool ED_transform_snap_object_project_view3d(struct SnapObjectContext *sctx,
                                              const unsigned short snap_to,
                                              const struct SnapObjectParams *params,
                                              const float mval[2],
+                                             const float prev_co[3],
                                              float *dist_px,
                                              /* return args */
                                              float r_loc[3],
diff --git a/source/blender/editors/include/UI_icons.h b/source/blender/editors/include/UI_icons.h
index bca0d8984c8..d615ea34bb1 100644
--- a/source/blender/editors/include/UI_icons.h
+++ b/source/blender/editors/include/UI_icons.h
@@ -667,7 +667,7 @@ DEF_ICON(PARTICLE_PATH)
 /* EDITING */
 DEF_ICON_BLANK(669)
 DEF_ICON_BLANK(670)
-DEF_ICON_BLANK(671)
+DEF_ICON(SNAP_PERPENDICULAR)
 DEF_ICON(SNAP_MIDPOINT)
 DEF_ICON(SNAP_OFF)
 DEF_ICON(SNAP_ON)
diff --git a/source/blender/editors/mesh/editmesh_tools.c b/source/blender/editors/mesh/editmesh_tools.c
index 4e58fee61a2..2b0213dc1ef 100644
--- a/source/blender/editors/mesh/editmesh_tools.c
+++ b/source/blender/editors/mesh/editmesh_tools.c
@@ -437,6 +437,7 @@ void EDBM_project_snap_verts(bContext *C, Depsgraph *depsgraph, ARegion *ar, BME
                                                     },
                                                     mval,
                                                     NULL,
+                                                    NULL,
                                                     co_proj,
                                                     NULL)) {
           mul_v3_m4v3(eve->co, obedit->imat, co_proj);
diff --git a/source/blender/editors/space_view3d/view3d_edit.c b/source/blender/editors/space_view3d/view3d_edit.c
index b9adde6f60e..13001058fed 100644
--- a/source/blender/editors/space_view3d/view3d_edit.c
+++ b/source/blender/editors/space_view3d/view3d_edit.c
@@ -4944,6 +4944,7 @@ void ED_view3d_cursor3d_position_rotation(bContext *C,
                                                        .use_object_edit_cage = false,
                                                    },
                                                    mval_fl,
+                                                   NULL,
                                                    &dist_px,
                                                    ray_co,
                                                    ray_no,
diff --git a/source/blender/editors/space_view3d/view3d_gizmo_ruler.c b/source/blender/editors/space_view3d/view3d_gizmo_ruler.c
index 97a12c7100e..f4e3dc85447 100644
--- a/source/blender/editors/space_view3d/view3d_gizmo_ruler.c
+++ b/source/blender/editors/space_view3d/view3d_gizmo_ruler.c
@@ -343,6 +343,7 @@ static bool view3d_ruler_item_mousemove(RulerInfo *ruler_info,
                                                       .use_object_edit_cage = true,
                                                   },
                                                   mval_fl,
+                                                  NULL,
                                                   &dist_px,
                                                   co,
                                                   ray_normal)) {
@@ -363,16 +364,31 @@ static bool view3d_ruler_item_mousemove(RulerInfo *ruler_info,
     }
     else if (do_snap) {
       const float mval_fl[2] = {UNPACK2(mval)};
+      float *prev_point = NULL;
+
+      if (inter->co_index != 1) {
+        if (ruler_item->flag & RULERITEM_USE_ANGLE) {
+          prev_point = ruler_item->co[1];
+        }
+        else if (inter->co_index == 0) {
+          prev_point = ruler_item->co[2];
+        }
+        else {
+          prev_point = ruler_item->co[0];
+        }
+      }
 
       if (ED_transform_snap_object_project_view3d(
               ruler_info->snap_context,
-              (SCE_SNAP_MODE_VERTEX | SCE_SNAP_MODE_EDGE | SCE_SNAP_MODE_FACE),
+              (SCE_SNAP_MODE_VERTEX | SCE_SNAP_MODE_EDGE | SCE_SNAP_MODE_FACE |
+               SCE_SNAP_MODE_EDGE_MIDPOINT | SCE_SNAP_MODE_EDGE_PERPENDICULAR),
               &(const struct SnapObjectParams){
                   .snap_select = SNAP_ALL,
                   .use_object_edit_cage = true,
                   .use_occlusion_test = true,
               },
               mval_fl,
+              prev_point,
               &dist_px,
               co,
               NULL)) {
diff --git a/source/blender/editors/transform/transform_snap.c b/source/blender/editors/transform/transform_snap.c
index 9d107527833..feaef9a17a1 100644
--- a/source/blender/editors/transform/transform_snap.c
+++ b/source/blender/editors/transform/transform_snap.c
@@ -328,6 +328,7 @@ void applyProject(TransInfo *t)
                       .use_occlusion_test = false,
                   },
                   mval_fl,
+                  NULL,
                   0,
                   loc,
                   no)) {
@@ -999,7 +1000,7 @@ static void CalcSnapGeometry(TransInfo *t, float *UNUSED(vec))
     mval[1] = t->mval[1];
 
     if (t->tsnap.mode & (SCE_SNAP_MODE_VERTEX | SCE_SNAP_MODE_EDGE | SCE_SNAP_MODE_FACE |
-                         SCE_SNAP_MODE_EDGE_MIDPOINT)) {
+                         SCE_SNAP_MODE_EDGE_MIDPOINT | SCE_SNAP_MODE_EDGE_PERPENDICULAR)) {
       zero_v3(no); /* objects won't set this */
       found = snapObjectsTransform(t, mval, &dist_px, loc, no);
     }
@@ -1272,6 +1273,7 @@ bool snapObjectsTransform(
           .use_occlusion_test = t->scene->toolsettings->snap_mode != SCE_SNAP_MODE_FACE,
       },
       mval,
+      t->center_global,
       dist_px,
       r_loc,
       r_no);
diff --git a/source/blender/editors/transform/transform_snap_object.c b/source/blender/editors/transform/transform_snap_object.c
index 4943e538590..761a13c1538 100644
--- a/source/blender/editors/transform/transform_snap_object.c
+++ b/source/blender/editors/transform/transform_snap_object.c
@@ -1260,7 +1260,8 @@ static short snap_mesh_polygon(SnapObjectContext *sctx,
 
     const MPoly *mp = &((SnapObjectData_Mesh *)sod)->poly[*r_index];
     const MLoop *ml = &treedata->loop[mp->loopstart];
-    if (snapdata->snap_to_flag & (SCE_SNAP_MODE_EDGE | SCE_SNAP_MODE_EDGE_MIDPOINT)) {
+    if (snapdata->snap_to_flag &
+        (SCE_SNAP_MODE_EDGE | SCE_SNAP_MODE_EDGE_MIDPOINT | SCE_SNAP_MODE_EDGE_PERPENDICULAR)) {
       elem = SCE_SNAP_MODE_EDGE;
       BLI_assert(treedata->edge != NULL);
       for (int i = mp->totloop; i--; ml++) {
@@ -1297,7 +1298,8 @@ static short snap_mesh_polygon(SnapObjectContext *sctx,
     BMFace *f = BM_face_at_index(em->bm, *r_index);
     BMLoop *l_iter, *l_first;
     l_iter = l_first = BM_FACE_FIRST_LOOP(f);
-    if (snapdata->snap_to_flag & (SCE_SNAP_MODE_EDGE | SCE_SNAP_MODE_EDGE_MIDPOINT)) {
+    if (snapdata->snap_to_flag &
+        (SCE_SNAP_MODE_EDGE | SCE_SNAP_MODE_EDGE_MIDPOINT | SCE_SNAP_MODE_EDGE_PERPENDICULAR)) {
       elem = SCE_SNAP_MODE_EDGE;
       BM_mesh_elem_index_ensure(em->bm, BM_EDGE);
       BM_mesh_elem_table_ensure(em->bm, BM_VERT | BM_EDGE);
@@ -1352,6 +1354,7 @@ static short snap_mesh_edge_verts_mixed(SnapObjectContext *sctx,
                                         Object *ob,
                                         float obmat[4][4],
                                         float original_dist_px,
+                                        const float prev_co[3],
                                         /* read/write args */
                                         float *dist_px,
                                         /* return args */
@@ -1460,13 +1463,43 @@ static short snap_mesh_edge_verts_mixed(SnapObjectContext *sctx,
         }
       }
     }
+
+    if (prev_co && (snapdata->snap_to_flag & SCE_SNAP_MODE_EDGE_PERPENDICULAR)) {
+      float v_near[3], va_g[3], vb_g[3];
+
+      mul_v3_m4v3(va_g, obmat, v_pair[0]);
+      mul_v3_m4v3(vb_g, obmat, v_pair[1]);
+      lambda = line_point_factor_v3(prev_co, va_g, vb_g);
+
+      if (IN_RANGE(lambda, 0.0f, 1.0f)) {
+        interp_v3_v3v3(v_near, va_g, vb_g, lambda);
+
+        if (test_projected_vert_dist(&neasrest_precalc,
+                                     NULL,
+                                     0,
+                                     nearest2d.is_persp,
+                                     v_near,
+                                     &nearest.dist_sq,
+                                     nearest.co)) {
+          float v_nor[2][3];
+          nearest2d.copy_vert_no(vindex[0], v_nor[0], nearest2d.userdata);
+          nearest2d.copy_vert_no(vindex[1], v_nor[1], nearest2d.userdata);
+          mid_v3_v3v3(nearest.no, v_nor[0], v_nor[1]);
+
+          nearest.index = *r_index;
+          elem = SCE_SNAP_MODE_EDGE_PERPENDICULAR;
+        }
+      }
+    }
   }
 
   if (nearest.index != -1) {
     *dist_px = sqrtf(nearest.dist_sq);
 
     copy_v3_v3(r_loc, nearest.co);
-    mul_m4_v3(obmat, r_loc);
+    if (elem != SCE_SNAP_MODE_EDGE_PERPENDICULAR) {
+      mul_m4_v3(obmat, r_loc);
+    }
 
     if (r_no) {
       float imat[4][4];
@@ -2092,7 +2125,8 @@ static short snapMesh(SnapObjectContext *sctx,
     last_index = nearest.index;
   }
 
-  if (snapdata->snap_to_flag & (SCE_SNAP_MODE_EDGE | SCE_SNAP_MODE_EDGE_MIDPOINT)) {
+  if (snapdata->snap_to_flag &
+      (SCE_SNAP_MODE_EDGE | SCE_SNAP_MODE_EDGE_MIDPOINT | SCE_SNAP_MODE_EDGE_PERPENDICULAR)) {
     if (bvhtree[0]) {
       /* snap to loose edges */
       BLI_bvhtree_find_nearest_projected(bvhtree[0],
@@ -2258,7 +2292,8 @@ static short snapEditMesh(SnapObjectContext *sctx,
     }
   }
 
-  if (snapdata->snap_to_flag & (SCE_SNAP_MODE_EDGE | SCE_SNAP_MODE_EDGE_MIDPOINT)) {
+  if (snapdata->snap_to_flag &
+      (SCE_SNAP_MODE_EDGE | SCE_SNAP_MODE_EDGE_MIDPOINT | SCE_SNAP_MODE_EDGE_PERPENDICULAR)) {
     if (sod->bvh_trees[1] == NULL) {
       sod->bvh_trees[1] = BLI_memarena_calloc(sctx->cache.mem_arena, sizeof(**sod->bvh_trees));
     }
@@ -2330,8 +2365,8 @@ static short snapEditMesh(SnapObjectContext *sctx,
     last_index = nearest.index;
   }
 
-  if (treedata_edge &&
-      snapdata->snap_to_flag & (SCE_SNAP_MODE_EDGE | SCE_SNAP_MODE_EDGE_MIDPOINT)) {
+  if (treedata_edge && snapdata->snap_to_flag & (SCE_SNAP_MODE_EDGE | SCE_SNAP_MODE_EDGE_MIDPOINT |
+                                                 SCE_SNAP_MODE_EDGE_PERPENDICULAR)) {
     BM_mesh_elem_table_ensure(em->bm, BM_EDGE | BM_VERT);
     BLI_bvhtree_find_nearest_projected(treedata_edge->tree,
                                        lpmat,
@@ -2727,6 +2762,7 @@ static short transform_snap_context_project_view3d_mixed_impl(
     const unsigned short snap_to_flag,
     const struct SnapObjectParams *params,
     const float mval[2],
+    const float prev_co[3],
     float *dist_px,
     float r_loc[3],
     float r_no[3],
@@ -2735,7 +2771,8 @@ static short transform_snap_context_project_view3d_mixed_impl(
     float r_obmat[4][4])
 {
   BLI_assert((snap_to_flag & (SCE_SNAP_MODE_VERTEX | SCE_SNAP_MODE_EDGE | SCE_SNAP_MODE_FACE |
-                              SCE_SNAP_MODE_EDGE_MIDPOINT)) != 0);
+                              SCE_SNAP_MODE_EDGE_MIDPOINT | SCE_SNAP_MODE_EDGE_PERPENDICULAR)) !=
+             0);
 
   short retval = 0;
   bool has_hit = false;
@@ -2773,7 +2810,8 @@ static short transform_snap_context_project_view3d_mixed_impl(
     }
   }
 
-  if (snap_to_flag & (SCE_SNAP_MODE_VERTEX | SCE_SNAP_MODE_EDGE | SCE_SNAP_MODE_EDGE_MIDPOINT)) {
+  if (snap_to_flag & (SCE_SNAP_MODE_VERTEX | SCE_SNAP_MODE_EDGE | SCE_SNAP_MODE_EDGE_MIDPOINT |
+                      SCE_SNAP_MODE_EDGE_PERPENDICULAR)) {
     short elem;
     float dist_px_tmp = *dist_px;
 
@@ -2827,9 +2865,10 @@ static short transform_snap_context_project_view3d_mixed_impl(
     }
 
     if ((retval == SCE_SNAP_MODE_EDGE) &&
-        (snap_to_flag & (SCE_SNAP_MODE_VERTEX | SCE_SNAP_MODE_EDGE_MIDPOINT))) {
+        (snap_to_flag & (SCE_SNAP_MODE_VERTEX | SCE_SNAP_MODE_EDGE_MIDPOINT |
+                         SCE_SNAP_MODE_EDGE_PERPENDICULAR))) {
       elem = snap_mesh_edge_verts_mixed(
-          sctx, &snapdata, ob, obmat, *dist_px, &dist_px_tmp, loc, no, &index);
+          sctx, &snapdata, ob, obmat, *dist_px, prev_co, &dist_px_tmp, loc, no, &index);
     }
 
     if (elem) {
@@ -2864,6 +2903,7 @@ short ED_transform_snap_object_project_view3d_ex(SnapObjectContext *sctx,
                                                  const unsigned short snap_to,
                                                  const struct SnapObjectParams *params,
                                                  const float mval[2],
+                                                 const float prev_co[3],
                                                  float *dist_px,
                                                  float r_loc[3],
                                                  float r_no[3],
@@ -2872,7 +2912,8 @@ short ED_transform_snap_object_project_view3d_ex(SnapObjectContext *sctx,
                                                  float r_obmat[4][4])
 {
   return transform_snap_context_project_view3d_mixed_impl(
-             sctx, snap_to, params, mval, dist_px, r_loc, r_no, r_index, r_ob, r_obmat) != 0;
+             sctx, snap_to, params, mval, prev_co, dist_px, r_loc, r_no, r_index, r_ob, r_obmat) !=
+         0;
 }
 
 /**
@@ -2882,6 +2923,7 @@ short ED_transform_snap_object_project_view3d_ex(SnapObjectContext *sctx,
  *
  * \param sctx: Snap context.
  * \param mval: Screenspace coordinate.
+ * \param prev_co: Coordinate for perpendicular point calculation (optional).
  * \param dist_px: Maximum distance to snap (in pixels).
  * \param r_co: hit location.
  * \param r_no: hit normal (optional).
@@ -2891,12 +2933,13 @@ bool ED_transform_snap_object_project_view3d(SnapObjectContext *sctx,
                                              const unsigned short snap_to,
                                              const struct SnapObjectParams *params,
                                              const float mval[2],
+                                             const float prev_co[3],
                                              float *dist_px,
                                              float r_loc[3],
                                              float r_no[3])
 {
   return ED_transform_snap_object_project_view3d_ex(
-             sctx, snap_to, params, mval, dist_px, r_loc, r_no, NULL, NULL, NULL) != 0;
+             sctx, snap_to, params, mval, prev_co, dist_px, r_loc, r_no, NULL, NULL, NULL) != 0;
 }
 
 /**
diff --git a/source/blender/makesdna/DNA_scene_types.h b/source/blender/makesdna/DNA_scene_types.h
index 8cf7b82e1ca..9ab9a0b650a 100644
--- a/source/blender/makesdna/DNA_scene_types.h
+++ b/source/blender/makesdna/DNA_scene_types.h
@@ -2048,6 +2048,7 @@ enum {
 #define SCE_SNAP_MODE_VOLUME (1 << 3)
 #define SCE_SNAP_MODE_INCREMENT (1 << 4)
 #define SCE_SNAP_MODE_EDGE_MIDPOINT (1 << 5)
+#define SCE_SNAP_MODE_EDGE_PERPENDICULAR (1 << 6)
 
 /* ToolSettings.snap_node_mode */
 #define SCE_SNAP_MODE_GRID (1 << 5)
diff --git a/source/blender/makesrna/intern/rna_scene.c b/source/blender/makesrna/intern/rna_scene.c
index 0da96a895a9..b1661e9a0eb 100644
--- a/source/blender/makesrna/intern/rna_scene.c
+++ b/source/blender/makesrna/intern/rna_scene.c
@@ -172,6 +172,11 @@ const EnumPropertyItem rna_enum_snap_element_items[] = {
      ICON_SNAP_MIDPOINT,
      "Edge Center",
      "Snap to the middle of edges"},
+    {SCE_SNAP_MODE_EDGE_PERPENDICULAR,
+     "EDGE_PERPENDICULAR",
+     ICON_SNAP_PERPENDICULAR,
+     "Edge Perpendicular",
+     "Snap to the nearest point on an edge"},
     {0, NULL, 0, NULL, NULL},
 };