View3D Snap Cursor: don't limit the number of states

The benefit of a flat array in this case is small and limiting, so use a linklist.

1 files changed, 18 insertions, 46 deletions

diff --git a/source/blender/editors/space_view3d/view3d_cursor_snap.c b/source/blender/editors/space_view3d/view3d_cursor_snap.c
index 9c45a89c3ff..5db9dd5d0a7 100644
--- a/source/blender/editors/space_view3d/view3d_cursor_snap.c
+++ b/source/blender/editors/space_view3d/view3d_cursor_snap.c
@@ -54,22 +54,19 @@
 
 #include "WM_api.h"
 
-#define STATE_LEN 8
+#define STATE_INTERN_GET(state) \
+  (SnapStateIntern *)((char *)state - offsetof(SnapStateIntern, snap_state))
 
 typedef struct SnapStateIntern {
+  struct SnapStateIntern *next, *prev;
   V3DSnapCursorState snap_state;
-  int state_active_prev;
-  bool is_active;
 } SnapStateIntern;
 
 typedef struct SnapCursorDataIntern {
   V3DSnapCursorState state_default;
-  SnapStateIntern state_intern[STATE_LEN];
+  ListBase state_intern;
   V3DSnapCursorData snap_data;
 
-  int state_active_len;
-  int state_active;
-
   struct SnapObjectContext *snap_context_v3d;
   const Scene *scene;
   short snap_elem_hidden;
@@ -852,10 +849,11 @@ static void v3d_cursor_snap_draw_fn(bContext *C, int x, int y, void *UNUSED(cust
 
 V3DSnapCursorState *ED_view3d_cursor_snap_state_get(void)
 {
-  if (!g_data_intern.state_active_len) {
+  SnapCursorDataIntern *data_intern = &g_data_intern;
+  if (BLI_listbase_is_empty(&data_intern->state_intern)) {
     return &g_data_intern.state_default;
   }
-  return (V3DSnapCursorState *)&g_data_intern.state_intern[g_data_intern.state_active];
+  return &((SnapStateIntern *)data_intern->state_intern.last)->snap_state;
 }
 
 static void v3d_cursor_snap_activate(void)
@@ -894,11 +892,7 @@ static void v3d_cursor_snap_free(void)
     data_intern->snap_context_v3d = NULL;
   }
 
-  for (SnapStateIntern *state_intern = data_intern->state_intern;
-       state_intern < &data_intern->state_intern[STATE_LEN];
-       state_intern++) {
-    state_intern->is_active = false;
-  }
+  BLI_freelistN(&data_intern->state_intern);
 }
 
 void ED_view3d_cursor_snap_state_default_set(V3DSnapCursorState *state)
@@ -909,51 +903,29 @@ void ED_view3d_cursor_snap_state_default_set(V3DSnapCursorState *state)
 V3DSnapCursorState *ED_view3d_cursor_snap_active(void)
 {
   SnapCursorDataIntern *data_intern = &g_data_intern;
-  if (!data_intern->state_active_len) {
+  if (!data_intern->handle) {
     v3d_cursor_snap_activate();
   }
 
-  data_intern->state_active_len++;
-  for (int i = 0; i < STATE_LEN; i++) {
-    SnapStateIntern *state_intern = &g_data_intern.state_intern[i];
-    if (!state_intern->is_active) {
-      state_intern->snap_state = g_data_intern.state_default;
-      state_intern->is_active = true;
-      state_intern->state_active_prev = data_intern->state_active;
-      data_intern->state_active = i;
-      return (V3DSnapCursorState *)state_intern;
-    }
-  }
+  SnapStateIntern *state_intern = MEM_mallocN(sizeof(*state_intern), __func__);
+  state_intern->snap_state = g_data_intern.state_default;
+  BLI_addtail(&g_data_intern.state_intern, state_intern);
 
-  data_intern->state_active_len--;
-  return NULL;
+  return (V3DSnapCursorState *)&state_intern->snap_state;
 }
 
 void ED_view3d_cursor_snap_deactive(V3DSnapCursorState *state)
 {
   SnapCursorDataIntern *data_intern = &g_data_intern;
-  if (!data_intern->state_active_len) {
-    BLI_assert(false);
+  if (BLI_listbase_is_empty(&data_intern->state_intern)) {
     return;
   }
 
-  if (!state) {
-    return;
-  }
-
-  SnapStateIntern *state_intern = (SnapStateIntern *)state;
-  if (!state_intern->is_active) {
-    return;
-  }
-
-  state_intern->is_active = false;
-  data_intern->state_active_len--;
-  if (!data_intern->state_active_len) {
+  SnapStateIntern *state_intern = STATE_INTERN_GET(state);
+  BLI_remlink(&data_intern->state_intern, state_intern);
+  if (BLI_listbase_is_empty(&data_intern->state_intern)) {
     v3d_cursor_snap_free();
   }
-  else {
-    data_intern->state_active = state_intern->state_active_prev;
-  }
 }
 
 void ED_view3d_cursor_snap_prevpoint_set(V3DSnapCursorState *state, const float prev_point[3])
@@ -977,7 +949,7 @@ V3DSnapCursorData *ED_view3d_cursor_snap_data_get(V3DSnapCursorState *state,
                                                   const int y)
 {
   SnapCursorDataIntern *data_intern = &g_data_intern;
-  if (C && data_intern->state_active_len) {
+  if (C) {
     wmWindowManager *wm = CTX_wm_manager(C);
     if (v3d_cursor_eventstate_has_changed(data_intern, state, wm, x, y)) {
       Depsgraph *depsgraph = CTX_data_ensure_evaluated_depsgraph(C);