Fix T75793: Mirror modifier UV flip only works on first UDIM Tile

Was flipping around the 0-1 range, now (optionally) flip around each tile.

Also added this option for BMesh bmo_mirror.

Reviewed By: campbellbarton

Maniphest Tasks: T75793

Differential Revision: https://developer.blender.org/D7460

2 files changed, 16 insertions, 2 deletions

diff --git a/source/blender/bmesh/intern/bmesh_opdefines.c b/source/blender/bmesh/intern/bmesh_opdefines.c
index 4fa7bf64834..14e3c57f038 100644
--- a/source/blender/bmesh/intern/bmesh_opdefines.c
+++ b/source/blender/bmesh/intern/bmesh_opdefines.c
@@ -320,6 +320,7 @@ static BMOpDefine bmo_mirror_def = {
    {"axis",            BMO_OP_SLOT_INT, {(int)BMO_OP_SLOT_SUBTYPE_INT_ENUM}, bmo_enum_axis_xyz},   /* the axis to use. */
    {"mirror_u",        BMO_OP_SLOT_BOOL},  /* mirror UVs across the u axis */
    {"mirror_v",        BMO_OP_SLOT_BOOL},  /* mirror UVs across the v axis */
+   {"mirror_udim",     BMO_OP_SLOT_BOOL},  /* mirror UVs in each tile */
    {{'\0'}},
   },
   /* slots_out */
diff --git a/source/blender/bmesh/operators/bmo_mirror.c b/source/blender/bmesh/operators/bmo_mirror.c
index 36297b3f816..b5b56f4432d 100644
--- a/source/blender/bmesh/operators/bmo_mirror.c
+++ b/source/blender/bmesh/operators/bmo_mirror.c
@@ -48,6 +48,7 @@ void bmo_mirror_exec(BMesh *bm, BMOperator *op)
   int axis = BMO_slot_int_get(op->slots_in, "axis");
   bool mirror_u = BMO_slot_bool_get(op->slots_in, "mirror_u");
   bool mirror_v = BMO_slot_bool_get(op->slots_in, "mirror_v");
+  bool mirror_udim = BMO_slot_bool_get(op->slots_in, "mirror_udim");
   BMOpSlot *slot_targetmap;
 
   ototvert = bm->totvert;
@@ -94,10 +95,22 @@ void bmo_mirror_exec(BMesh *bm, BMOperator *op)
         for (i = 0; i < totlayer; i++) {
           luv = CustomData_bmesh_get_n(&bm->ldata, l->head.data, CD_MLOOPUV, i);
           if (mirror_u) {
-            luv->uv[0] = 1.0f - luv->uv[0];
+            float uv_u = luv->uv[0];
+            if (mirror_udim) {
+              luv->uv[0] = ceilf(uv_u) - fmodf(uv_u, 1.0f);
+            }
+            else {
+              luv->uv[0] = 1.0f - uv_u;
+            }
           }
           if (mirror_v) {
-            luv->uv[1] = 1.0f - luv->uv[1];
+            float uv_v = luv->uv[1];
+            if (mirror_udim) {
+              luv->uv[1] = ceilf(uv_v) - fmodf(uv_v, 1.0f);
+            }
+            else {
+              luv->uv[1] = 1.0f - uv_v;
+            }
           }
         }
       }