Fix T84520: Make the different weight paint code paths exclusive to each other

Before this change, you could have the new sculpt symmetry code and the
older weight paint symmetry code active at the same time. This would
lead to users easily trashing their weigh paint data if they were not
careful when switching between modes.

Now the specific weight paint symmetry code is an exclusive toggle so
the user can't accidentally mirror strokes and vertex groups at the same
time. This also paves the way of supporting Y and Z symmetry in the
future for weight groups mirroring if we decide to add it in the future.

Reviewed By: Sybren

Differential Revision: http://developer.blender.org/D10426

1 files changed, 13 insertions, 6 deletions

diff --git a/source/blender/editors/sculpt_paint/paint_vertex.c b/source/blender/editors/sculpt_paint/paint_vertex.c
index fc52f6fea7c..f634e6ad026 100644
--- a/source/blender/editors/sculpt_paint/paint_vertex.c
+++ b/source/blender/editors/sculpt_paint/paint_vertex.c
@@ -769,8 +769,8 @@ static void do_weight_paint_vertex_single(
   MDeformVert *dv_mirr;
   MDeformWeight *dw_mirr;
 
-  /* from now on we can check if mirrors enabled if this var is -1 and not bother with the flag */
-  if (me->editflag & ME_EDIT_VERTEX_GROUPS_X_SYMMETRY) {
+  /* Check if we should mirror vertex groups (X-axis). */
+  if (ME_USING_MIRROR_X_VERTEX_GROUPS(me)) {
     index_mirr = mesh_get_x_mirror_vert(ob, NULL, index, topology);
     vgroup_mirr = wpi->mirror.index;
 
@@ -979,8 +979,8 @@ static void do_weight_paint_vertex_multi(
   float curw, curw_real, oldw, neww, change, curw_mirr, change_mirr;
   float dw_rel_free, dw_rel_locked;
 
-  /* from now on we can check if mirrors enabled if this var is -1 and not bother with the flag */
-  if (me->editflag & ME_EDIT_VERTEX_GROUPS_X_SYMMETRY) {
+  /* Check if we should mirror vertex groups (X-axis). */
+  if (ME_USING_MIRROR_X_VERTEX_GROUPS(me)) {
     index_mirr = mesh_get_x_mirror_vert(ob, NULL, index, topology);
 
     if (!ELEM(index_mirr, -1, index)) {
@@ -1629,7 +1629,7 @@ static bool wpaint_stroke_test_start(bContext *C, wmOperator *op, const float mo
     int i;
     bDeformGroup *dg;
 
-    if (me->editflag & ME_EDIT_VERTEX_GROUPS_X_SYMMETRY) {
+    if (ME_USING_MIRROR_X_VERTEX_GROUPS(me)) {
       BKE_object_defgroup_mirror_selection(
           ob, defbase_tot, defbase_sel, defbase_sel, &defbase_tot_sel);
     }
@@ -2191,7 +2191,7 @@ static void wpaint_paint_leaves(bContext *C,
 
   /* NOTE: current mirroring code cannot be run in parallel */
   TaskParallelSettings settings;
-  const bool use_threading = ((me->editflag & ME_EDIT_VERTEX_GROUPS_X_SYMMETRY) == 0);
+  const bool use_threading = !ME_USING_MIRROR_X_VERTEX_GROUPS(me);
   BKE_pbvh_parallel_range_settings(&settings, use_threading, totnode);
 
   switch ((eBrushWeightPaintTool)brush->weightpaint_tool) {
@@ -2322,6 +2322,13 @@ static void wpaint_do_symmetrical_brush_actions(
 
   cache->symmetry = symm;
 
+  if (me->editflag & ME_EDIT_MIRROR_VERTEX_GROUPS) {
+    /* We don't do any symmetry strokes when mirroing vertex groups. */
+    copy_v3_v3(cache->true_last_location, cache->true_location);
+    cache->is_last_valid = true;
+    return;
+  }
+
   /* symm is a bit combination of XYZ - 1 is mirror
    * X; 2 is Y; 3 is XY; 4 is Z; 5 is XZ; 6 is YZ; 7 is XYZ */
   for (i = 1; i <= symm; i++) {