Snap Gizmo Refactor: Implement options for the gizmo behavior

The Snap Gizmo now has options for occlusion, selection filter and edit
geometry.

It will be useful to implement in current tools.

4 files changed, 43 insertions, 16 deletions

diff --git a/source/blender/editors/gizmo_library/gizmo_types/snap3d_gizmo.c b/source/blender/editors/gizmo_library/gizmo_types/snap3d_gizmo.c
index 6c274a0fbf9..79462f1cdf3 100644
--- a/source/blender/editors/gizmo_library/gizmo_types/snap3d_gizmo.c
+++ b/source/blender/editors/gizmo_library/gizmo_types/snap3d_gizmo.c
@@ -368,25 +368,39 @@ short ED_gizmotypes_snap_3d_update(wmGizmo *gz,
       snap_elements &= ~SCE_SNAP_MODE_EDGE_PERPENDICULAR;
     }
 
+    eSnapSelect snap_select = (snap_gizmo->flag & ED_SNAPGIZMO_SNAP_ONLY_ACTIVE) ?
+                                  SNAP_ONLY_ACTIVE :
+                                  SNAP_ALL;
+
+    eSnapEditType edit_mode_type = (snap_gizmo->flag & ED_SNAPGIZMO_SNAP_EDIT_GEOM_FINAL) ?
+                                       SNAP_GEOM_FINAL :
+                                   (snap_gizmo->flag & ED_SNAPGIZMO_SNAP_EDIT_GEOM_CAGE) ?
+                                       SNAP_GEOM_CAGE :
+                                       SNAP_GEOM_EDIT;
+
+    bool use_occlusion_test = (snap_gizmo->flag & ED_SNAPGIZMO_OCCLUSION_ALWAYS_TRUE) ? false :
+                                                                                        true;
+
     float dist_px = 12.0f * U.pixelsize;
 
     ED_gizmotypes_snap_3d_context_ensure(scene, region, v3d, gz);
-    snap_elem = ED_transform_snap_object_project_view3d_ex(snap_gizmo->snap_context_v3d,
-                                                           depsgraph,
-                                                           snap_elements,
-                                                           &(const struct SnapObjectParams){
-                                                               .snap_select = SNAP_ALL,
-                                                               .edit_mode_type = SNAP_GEOM_EDIT,
-                                                               .use_occlusion_test = true,
-                                                           },
-                                                           mval_fl,
-                                                           prev_co,
-                                                           &dist_px,
-                                                           co,
-                                                           no,
-                                                           &index,
-                                                           NULL,
-                                                           NULL);
+    snap_elem = ED_transform_snap_object_project_view3d_ex(
+        snap_gizmo->snap_context_v3d,
+        depsgraph,
+        snap_elements,
+        &(const struct SnapObjectParams){
+            .snap_select = snap_select,
+            .edit_mode_type = edit_mode_type,
+            .use_occlusion_test = use_occlusion_test,
+        },
+        mval_fl,
+        prev_co,
+        &dist_px,
+        co,
+        no,
+        &index,
+        NULL,
+        NULL);
   }
 
   if (snap_elem == 0) {
diff --git a/source/blender/editors/include/ED_gizmo_library.h b/source/blender/editors/include/ED_gizmo_library.h
index 58b2cb80bbe..571519e52f7 100644
--- a/source/blender/editors/include/ED_gizmo_library.h
+++ b/source/blender/editors/include/ED_gizmo_library.h
@@ -263,6 +263,11 @@ struct SnapObjectContext *ED_gizmotypes_snap_3d_context_ensure(struct Scene *sce
 
 typedef enum {
   ED_SNAPGIZMO_TOGGLE_ALWAYS_TRUE = 1 << 0,
+  ED_SNAPGIZMO_OCCLUSION_ALWAYS_TRUE = 1 << 1,
+  ED_SNAPGIZMO_OCCLUSION_ALWAYS_FALSE = 1 << 2, /* TODO. */
+  ED_SNAPGIZMO_SNAP_ONLY_ACTIVE = 1 << 3,
+  ED_SNAPGIZMO_SNAP_EDIT_GEOM_FINAL = 1 << 4,
+  ED_SNAPGIZMO_SNAP_EDIT_GEOM_CAGE = 1 << 5,
 } eSnapGizmo;
 
 void ED_gizmotypes_snap_3d_flag_set(struct wmGizmo *gz, eSnapGizmo flag);
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 a63c1e86a50..bba41d677c8 100644
--- a/source/blender/editors/include/ED_transform_snap_object_context.h
+++ b/source/blender/editors/include/ED_transform_snap_object_context.h
@@ -43,6 +43,7 @@ typedef enum {
   SNAP_ALL = 0,
   SNAP_NOT_SELECTED = 1,
   SNAP_NOT_ACTIVE = 2,
+  SNAP_ONLY_ACTIVE = 3,
 } eSnapSelect;
 
 typedef enum {
diff --git a/source/blender/editors/transform/transform_snap_object.c b/source/blender/editors/transform/transform_snap_object.c
index fcb4d46358b..7fd7e2675d3 100644
--- a/source/blender/editors/transform/transform_snap_object.c
+++ b/source/blender/editors/transform/transform_snap_object.c
@@ -418,6 +418,13 @@ static void iter_snap_objects(SnapObjectContext *sctx,
   const bool use_backface_culling = params->use_backface_culling;
 
   Base *base_act = view_layer->basact;
+  if (snap_select == SNAP_ONLY_ACTIVE) {
+    Object *obj_eval = DEG_get_evaluated_object(depsgraph, base_act->object);
+    sob_callback(
+        sctx, obj_eval, obj_eval->obmat, edit_mode_type, use_backface_culling, true, data);
+    return;
+  }
+
   for (Base *base = view_layer->object_bases.first; base != NULL; base = base->next) {
     if (!BASE_VISIBLE(v3d, base)) {
       continue;