View3D Snap Cursor: sanitize and increase the maximum amount of states

3 is a small amount as each viewport creates a gizmo that creates its own state

Now if the state is not created, the gizmos use the last state.

4 files changed, 56 insertions, 42 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 33532bd0549..93ee6ec2d81 100644
--- a/source/blender/editors/gizmo_library/gizmo_types/snap3d_gizmo.c
+++ b/source/blender/editors/gizmo_library/gizmo_types/snap3d_gizmo.c
@@ -225,8 +225,10 @@ static void snap_gizmo_setup(wmGizmo *gz)
   gz->flag |= WM_GIZMO_NO_TOOLTIP;
   SnapGizmo3D *snap_gizmo = (SnapGizmo3D *)gz;
   snap_gizmo->snap_state = ED_view3d_cursor_snap_active();
-  snap_gizmo->snap_state->draw_point = true;
-  snap_gizmo->snap_state->draw_plane = false;
+  if (snap_gizmo->snap_state) {
+    snap_gizmo->snap_state->draw_point = true;
+    snap_gizmo->snap_state->draw_plane = false;
+  }
 
   rgba_float_to_uchar(snap_gizmo->snap_state->color_point, gz->color);
 }
@@ -284,7 +286,9 @@ static int snap_gizmo_invoke(bContext *UNUSED(C),
 static void snap_gizmo_free(wmGizmo *gz)
 {
   SnapGizmo3D *snap_gizmo = (SnapGizmo3D *)gz;
-  ED_view3d_cursor_snap_deactive(snap_gizmo->snap_state);
+  if (snap_gizmo->snap_state) {
+    ED_view3d_cursor_snap_deactive(snap_gizmo->snap_state);
+  }
 }
 
 static void GIZMO_GT_snap_3d(wmGizmoType *gzt)
diff --git a/source/blender/editors/space_view3d/space_view3d.c b/source/blender/editors/space_view3d/space_view3d.c
index eaf90aabe8c..d20a07d3517 100644
--- a/source/blender/editors/space_view3d/space_view3d.c
+++ b/source/blender/editors/space_view3d/space_view3d.c
@@ -522,9 +522,12 @@ static void view3d_ob_drop_draw_activate(struct wmDropBox *drop, wmDrag *drag)
   if (state) {
     return;
   }
+
   state = drop->draw_data = ED_view3d_cursor_snap_active();
-  state->draw_point = true;
-  state->draw_plane = true;
+  if (!state) {
+    /* The maximum snap status stack value has been reached. */
+    return;
+  }
 
   float dimensions[3] = {0.0f};
   if (drag->type == WM_DRAG_ID) {
@@ -549,10 +552,8 @@ static void view3d_ob_drop_draw_activate(struct wmDropBox *drop, wmDrag *drag)
 static void view3d_ob_drop_draw_deactivate(struct wmDropBox *drop, wmDrag *UNUSED(drag))
 {
   V3DSnapCursorState *state = drop->draw_data;
-  if (state) {
-    ED_view3d_cursor_snap_deactive(state);
-    drop->draw_data = NULL;
-  }
+  ED_view3d_cursor_snap_deactive(state);
+  drop->draw_data = NULL;
 }
 
 static bool view3d_ob_drop_poll(bContext *C, wmDrag *drag, const wmEvent *event)
@@ -680,30 +681,28 @@ static void view3d_ob_drop_copy(wmDrag *drag, wmDropBox *drop)
   const bool is_imported_id = drag->type == WM_DRAG_ASSET;
   RNA_boolean_set(drop->ptr, "duplicate", !is_imported_id);
 
-  V3DSnapCursorState *snap_state = drop->draw_data;
-  if (snap_state) {
-    Object *ob = (Object *)id;
-    float obmat_final[4][4];
-
-    V3DSnapCursorData *snap_data;
-    snap_data = ED_view3d_cursor_snap_data_get(snap_state, NULL, 0, 0);
-    copy_m4_m3(obmat_final, snap_data->plane_omat);
-    copy_v3_v3(obmat_final[3], snap_data->loc);
-
-    float scale[3];
-    mat4_to_size(scale, ob->obmat);
-    rescale_m4(obmat_final, scale);
-
-    BoundBox *bb = BKE_object_boundbox_get(ob);
-    if (bb) {
-      float offset[3];
-      BKE_boundbox_calc_center_aabb(bb, offset);
-      offset[2] = bb->vec[0][2];
-      mul_mat3_m4_v3(obmat_final, offset);
-      sub_v3_v3(obmat_final[3], offset);
-    }
-    RNA_float_set_array(drop->ptr, "matrix", &obmat_final[0][0]);
+  V3DSnapCursorState *snap_state = ED_view3d_cursor_snap_state_get();
+  Object *ob = (Object *)id;
+  float obmat_final[4][4];
+
+  V3DSnapCursorData *snap_data;
+  snap_data = ED_view3d_cursor_snap_data_get(snap_state, NULL, 0, 0);
+  copy_m4_m3(obmat_final, snap_data->plane_omat);
+  copy_v3_v3(obmat_final[3], snap_data->loc);
+
+  float scale[3];
+  mat4_to_size(scale, ob->obmat);
+  rescale_m4(obmat_final, scale);
+
+  BoundBox *bb = BKE_object_boundbox_get(ob);
+  if (bb) {
+    float offset[3];
+    BKE_boundbox_calc_center_aabb(bb, offset);
+    offset[2] = bb->vec[0][2];
+    mul_mat3_m4_v3(obmat_final, offset);
+    sub_v3_v3(obmat_final[3], offset);
   }
+  RNA_float_set_array(drop->ptr, "matrix", &obmat_final[0][0]);
 }
 
 static void view3d_collection_drop_copy(wmDrag *drag, wmDropBox *drop)
diff --git a/source/blender/editors/space_view3d/view3d_cursor_snap.c b/source/blender/editors/space_view3d/view3d_cursor_snap.c
index 5eb9ec3625c..9c45a89c3ff 100644
--- a/source/blender/editors/space_view3d/view3d_cursor_snap.c
+++ b/source/blender/editors/space_view3d/view3d_cursor_snap.c
@@ -54,7 +54,7 @@
 
 #include "WM_api.h"
 
-#define STATE_LEN 3
+#define STATE_LEN 8
 
 typedef struct SnapStateIntern {
   V3DSnapCursorState snap_state;
@@ -925,7 +925,6 @@ V3DSnapCursorState *ED_view3d_cursor_snap_active(void)
     }
   }
 
-  BLI_assert(false);
   data_intern->state_active_len--;
   return NULL;
 }
@@ -938,6 +937,10 @@ void ED_view3d_cursor_snap_deactive(V3DSnapCursorState *state)
     return;
   }
 
+  if (!state) {
+    return;
+  }
+
   SnapStateIntern *state_intern = (SnapStateIntern *)state;
   if (!state_intern->is_active) {
     return;
@@ -956,6 +959,9 @@ void ED_view3d_cursor_snap_deactive(V3DSnapCursorState *state)
 void ED_view3d_cursor_snap_prevpoint_set(V3DSnapCursorState *state, const float prev_point[3])
 {
   SnapCursorDataIntern *data_intern = &g_data_intern;
+  if (!state) {
+    state = ED_view3d_cursor_snap_state_get();
+  }
   if (prev_point) {
     copy_v3_v3(data_intern->prevpoint_stack, prev_point);
     state->prevpoint = data_intern->prevpoint_stack;
diff --git a/source/blender/editors/space_view3d/view3d_placement.c b/source/blender/editors/space_view3d/view3d_placement.c
index 7fe97705765..572fc8e3156 100644
--- a/source/blender/editors/space_view3d/view3d_placement.c
+++ b/source/blender/editors/space_view3d/view3d_placement.c
@@ -742,16 +742,19 @@ static void view3d_interactive_add_begin(bContext *C, wmOperator *op, const wmEv
 
   ipd->launch_event = WM_userdef_event_type_from_keymap_type(event->type);
 
-  ipd->snap_state = ED_view3d_cursor_snap_active();
-  ipd->snap_state->draw_point = true;
-  ipd->snap_state->draw_plane = true;
+  V3DSnapCursorState *snap_state_new = ED_view3d_cursor_snap_active();
+  if (snap_state_new) {
+    ipd->snap_state = snap_state = snap_state_new;
+  }
 
+  snap_state->draw_point = true;
+  snap_state->draw_plane = true;
   ipd->is_snap_found =
       view3d_interactive_add_calc_snap(
           C, event, ipd->co_src, ipd->matrix_orient, &ipd->use_snap, &ipd->is_snap_invert) != 0;
 
-  ipd->snap_state->draw_plane = false;
-  ED_view3d_cursor_snap_prevpoint_set(ipd->snap_state, ipd->co_src);
+  snap_state->draw_plane = false;
+  ED_view3d_cursor_snap_prevpoint_set(snap_state, ipd->co_src);
 
   ipd->orient_axis = plane_axis;
   for (int i = 0; i < 2; i++) {
@@ -1515,10 +1518,12 @@ static void preview_plane_free_fn(void *customdata)
 static void WIDGETGROUP_placement_setup(const bContext *UNUSED(C), wmGizmoGroup *gzgroup)
 {
   V3DSnapCursorState *snap_state = ED_view3d_cursor_snap_active();
-  snap_state->draw_plane = true;
+  if (snap_state) {
+    snap_state->draw_plane = true;
 
-  gzgroup->customdata = snap_state;
-  gzgroup->customdata_free = preview_plane_free_fn;
+    gzgroup->customdata = snap_state;
+    gzgroup->customdata_free = preview_plane_free_fn;
+  }
 }
 
 void VIEW3D_GGT_placement(wmGizmoGroupType *gzgt)