Fix T80937: Changing the contrain axis does not return to the scene orientation

This was the behavior in old versions of blender.

During a transformation operation, when pressing a contrain key, the chosen
orientation is that of the scene.

If you press the same key, the orientation changes to Global or Local.

However, if you choose another contrain axis with the orientation changed,
the orientation does not return to the set for the scene.

It remains Global or Local.

Now when changing a contrain axis, no matter what the current orientation is,
it always returns to the scene orientation.

1 files changed, 59 insertions, 51 deletions

diff --git a/source/blender/editors/transform/transform_generics.c b/source/blender/editors/transform/transform_generics.c
index a2e1c50e375..ba87f0bcc38 100644
--- a/source/blender/editors/transform/transform_generics.c
+++ b/source/blender/editors/transform/transform_generics.c
@@ -442,7 +442,10 @@ void initTransInfo(bContext *C, TransInfo *t, wmOperator *op, const wmEvent *eve
   }
 
   BLI_assert(is_zero_v4(t->values_modal_offset));
+
+  bool use_orient_axis = false;
   bool t_values_set_is_array = false;
+
   if (op && (prop = RNA_struct_find_property(op->ptr, "value")) &&
       RNA_property_is_set(op->ptr, prop)) {
     float values[4] = {0}; /* in case value isn't length 4, avoid uninitialized memory  */
@@ -465,19 +468,28 @@ void initTransInfo(bContext *C, TransInfo *t, wmOperator *op, const wmEvent *eve
     }
   }
 
+  if (op && (prop = RNA_struct_find_property(op->ptr, "orient_axis"))) {
+    t->orient_axis = RNA_property_enum_get(op->ptr, prop);
+    use_orient_axis = true;
+  }
+
   if (op && (prop = RNA_struct_find_property(op->ptr, "constraint_axis"))) {
     bool constraint_axis[3] = {false, false, false};
-    if (RNA_property_is_set(op->ptr, prop)) {
-      RNA_property_boolean_get_array(op->ptr, prop, constraint_axis);
-    }
-
-    if (t_values_set_is_array && t->flag & T_INPUT_IS_VALUES_FINAL) {
-      /* For operators whose `t->values` is array, set constraint so that the
-       * orientation is more intuitive in the Redo Panel. */
-      for (int i = 3; i--;) {
-        constraint_axis[i] |= t->values[i] != 0.0f;
+    if (t->flag & T_INPUT_IS_VALUES_FINAL) {
+      if (t_values_set_is_array) {
+        /* For operators whose `t->values` is array, set constraint so that the
+         * orientation is more intuitive in the Redo Panel. */
+        for (int i = 3; i--;) {
+          constraint_axis[i] |= t->values[i] != 0.0f;
+        }
+      }
+      else if (use_orient_axis) {
+        constraint_axis[t->orient_axis] = true;
       }
     }
+    else if (RNA_property_is_set(op->ptr, prop)) {
+      RNA_property_boolean_get_array(op->ptr, prop, constraint_axis);
+    }
 
     if (constraint_axis[0] || constraint_axis[1] || constraint_axis[2]) {
       t->con.mode |= CON_APPLY;
@@ -495,9 +507,13 @@ void initTransInfo(bContext *C, TransInfo *t, wmOperator *op, const wmEvent *eve
   }
 
   {
-    short orient_type_set = -1;
-    short orient_type_matrix_set = -1;
+    short orient_types[3];
+    float custom_matrix[3][3];
+
+    short orient_type_default = V3D_ORIENT_GLOBAL;
     short orient_type_scene = V3D_ORIENT_GLOBAL;
+    short orient_type_set = V3D_ORIENT_GLOBAL;
+    short orient_type_matrix_set = -1;
 
     if ((t->spacetype == SPACE_VIEW3D) && (t->region->regiontype == RGN_TYPE_WINDOW)) {
       TransformOrientationSlot *orient_slot = &t->scene->orientation_slots[SCE_ORIENT_DEFAULT];
@@ -508,14 +524,6 @@ void initTransInfo(bContext *C, TransInfo *t, wmOperator *op, const wmEvent *eve
       }
     }
 
-    short orient_types[3];
-    float custom_matrix[3][3];
-    bool use_orient_axis = false;
-
-    if (op && (prop = RNA_struct_find_property(op->ptr, "orient_axis"))) {
-      t->orient_axis = RNA_property_enum_get(op->ptr, prop);
-      use_orient_axis = true;
-    }
     if (op && (prop = RNA_struct_find_property(op->ptr, "orient_axis_ortho"))) {
       t->orient_axis_ortho = RNA_property_enum_get(op->ptr, prop);
     }
@@ -530,21 +538,21 @@ void initTransInfo(bContext *C, TransInfo *t, wmOperator *op, const wmEvent *eve
       }
 
       /* Change the default orientation to be used when redoing. */
-      orient_types[0] = orient_type_set;
-      orient_types[1] = orient_type_set;
-      orient_types[2] = orient_type_scene;
+      orient_type_default = orient_type_set;
+    }
+    else if (t->con.mode & CON_APPLY) {
+      orient_type_set = orient_type_default = orient_type_scene;
     }
     else {
+      if (orient_type_set == orient_type_scene) {
+        BLI_assert(orient_type_set == V3D_ORIENT_GLOBAL);
+        orient_type_set = V3D_ORIENT_LOCAL;
+      }
+
       if ((t->flag & T_MODAL) && (use_orient_axis || transform_mode_is_changeable(t->mode)) &&
           (t->mode != TFM_ALIGN)) {
-        orient_types[0] = V3D_ORIENT_VIEW;
+        orient_type_default = V3D_ORIENT_VIEW;
       }
-      else {
-        orient_types[0] = orient_type_scene;
-      }
-      orient_types[1] = orient_type_scene;
-      orient_types[2] = orient_type_scene != V3D_ORIENT_GLOBAL ? V3D_ORIENT_GLOBAL :
-                                                                 V3D_ORIENT_LOCAL;
     }
 
     if (op && ((prop = RNA_struct_find_property(op->ptr, "orient_matrix")) &&
@@ -555,39 +563,39 @@ void initTransInfo(bContext *C, TransInfo *t, wmOperator *op, const wmEvent *eve
           RNA_property_is_set(op->ptr, prop)) {
         orient_type_matrix_set = RNA_property_enum_get(op->ptr, prop);
       }
-      else if (orient_type_set != -1) {
-        orient_type_matrix_set = orient_type_set;
-      }
       else {
-        orient_type_matrix_set = orient_type_set = V3D_ORIENT_GLOBAL;
+        orient_type_matrix_set = orient_type_set;
       }
 
       if (orient_type_matrix_set == orient_type_set) {
         /* Constraints are forced to use the custom matrix when redoing. */
-        orient_types[0] = V3D_ORIENT_CUSTOM_MATRIX;
+        orient_type_set = V3D_ORIENT_CUSTOM_MATRIX;
       }
     }
 
-    if (t->con.mode & CON_APPLY) {
-      t->orient_curr = 1;
-    }
+    orient_types[0] = orient_type_default;
+    orient_types[1] = orient_type_scene;
+    orient_types[2] = orient_type_set;
 
-    /* For efficiency, avoid calculating the same orientation twice. */
-    for (int i = 1; i < 3; i++) {
-      t->orient[i].type = transform_orientation_matrix_get(
-          C, t, orient_types[i], custom_matrix, t->orient[i].matrix);
-    }
-
-    if (orient_types[0] != orient_types[1]) {
-      t->orient[0].type = transform_orientation_matrix_get(
-          C, t, orient_types[0], custom_matrix, t->orient[0].matrix);
-    }
-    else {
-      memcpy(&t->orient[0], &t->orient[1], sizeof(t->orient[0]));
+    for (int i = 0; i < 3; i++) {
+      /* For efficiency, avoid calculating the same orientation twice. */
+      int j;
+      for (j = 0; j < i; j++) {
+        if (orient_types[j] == orient_types[i]) {
+          memcpy(&t->orient[i], &t->orient[j], sizeof(*t->orient));
+          break;
+        }
+      }
+      if (j == i) {
+        t->orient[i].type = transform_orientation_matrix_get(
+            C, t, orient_types[i], custom_matrix, t->orient[i].matrix);
+      }
     }
 
-    const char *spacename = transform_orientations_spacename_get(t, orient_types[0]);
-    BLI_strncpy(t->spacename, spacename, sizeof(t->spacename));
+    /* Set orient_curr to -1 in order to force the update in
+     * `transform_orientations_current_set`. */
+    t->orient_curr = -1;
+    transform_orientations_current_set(t, (t->con.mode & CON_APPLY) ? 2 : 0);
   }
 
   if (op && ((prop = RNA_struct_find_property(op->ptr, "release_confirm")) &&