Fix T57852: Mesh X Mirror option not working

D3869 by @lichtwerk w/ own edits

4 files changed, 64 insertions, 49 deletions

diff --git a/source/blender/editors/transform/transform.c b/source/blender/editors/transform/transform.c
index 055e9744043..c70bfc63b33 100644
--- a/source/blender/editors/transform/transform.c
+++ b/source/blender/editors/transform/transform.c
@@ -2171,7 +2171,7 @@ void saveTransform(bContext *C, TransInfo *t, wmOperator *op)
 	}
 
 	if ((prop = RNA_struct_find_property(op->ptr, "mirror"))) {
-		RNA_property_boolean_set(op->ptr, prop, (t->flag & T_MIRROR) != 0);
+		RNA_property_boolean_set(op->ptr, prop, (t->flag & T_NO_MIRROR) == 0);
 	}
 
 	if ((prop = RNA_struct_find_property(op->ptr, "constraint_axis"))) {
@@ -5980,7 +5980,7 @@ static void slide_origdata_create_data_vert(
 }
 
 static void slide_origdata_create_data(
-        TransInfo *t, TransDataContainer *tc, SlideOrigData *sod,
+        TransDataContainer *tc, SlideOrigData *sod,
         TransDataGenericSlideVert *sv_array, unsigned int v_stride, unsigned int v_num)
 {
 	if (sod->use_origfaces) {
@@ -6015,7 +6015,7 @@ static void slide_origdata_create_data(
 			slide_origdata_create_data_vert(bm, sod, sv);
 		}
 
-		if (t->flag & T_MIRROR) {
+		if (tc->mirror.axis_flag) {
 			TransData *td = tc->data;
 			TransDataGenericSlideVert *sv_mirror;
 
@@ -6995,7 +6995,7 @@ static bool createEdgeSlideVerts_double_side(TransInfo *t, TransDataContainer *t
 	/* create copies of faces for customdata projection */
 	bmesh_edit_begin(bm, BMO_OPTYPE_FLAG_UNTAN_MULTIRES);
 	slide_origdata_init_data(tc, &sld->orig_data);
-	slide_origdata_create_data(t, tc, &sld->orig_data, (TransDataGenericSlideVert *)sld->sv, sizeof(*sld->sv), sld->totsv);
+	slide_origdata_create_data(tc, &sld->orig_data, (TransDataGenericSlideVert *)sld->sv, sizeof(*sld->sv), sld->totsv);
 
 	if (rv3d) {
 		calcEdgeSlide_even(t, tc, sld, mval);
@@ -7190,7 +7190,7 @@ static bool createEdgeSlideVerts_single_side(TransInfo *t, TransDataContainer *t
 	/* create copies of faces for customdata projection */
 	bmesh_edit_begin(bm, BMO_OPTYPE_FLAG_UNTAN_MULTIRES);
 	slide_origdata_init_data(tc, &sld->orig_data);
-	slide_origdata_create_data(t, tc, &sld->orig_data, (TransDataGenericSlideVert *)sld->sv, sizeof(*sld->sv), sld->totsv);
+	slide_origdata_create_data(tc, &sld->orig_data, (TransDataGenericSlideVert *)sld->sv, sizeof(*sld->sv), sld->totsv);
 
 	if (rv3d) {
 		calcEdgeSlide_even(t, tc, sld, mval);
@@ -7806,7 +7806,7 @@ static bool createVertSlideVerts(TransInfo *t, TransDataContainer *tc)
 
 	bmesh_edit_begin(bm, BMO_OPTYPE_FLAG_UNTAN_MULTIRES);
 	slide_origdata_init_data(tc, &sld->orig_data);
-	slide_origdata_create_data(t, tc, &sld->orig_data, (TransDataGenericSlideVert *)sld->sv, sizeof(*sld->sv), sld->totsv);
+	slide_origdata_create_data(tc, &sld->orig_data, (TransDataGenericSlideVert *)sld->sv, sizeof(*sld->sv), sld->totsv);
 
 	sld->em = em;
 
diff --git a/source/blender/editors/transform/transform.h b/source/blender/editors/transform/transform.h
index 115c06317f5..530c03d56f8 100644
--- a/source/blender/editors/transform/transform.h
+++ b/source/blender/editors/transform/transform.h
@@ -514,6 +514,16 @@ typedef struct TransDataContainer {
 	/** Center of transformation (in local-space), Calculated from #TransInfo.center_global. */
 	float center_local[3];
 
+	/**
+	 * Mirror option
+	 */
+	struct {
+		/* Currently for mesh X mirror only. */
+		int axis_flag;
+		/** Set to -1.0f or 1.0 when use_mirror is set. */
+		float sign;
+	} mirror;
+
 	TransCustomDataContainer custom;
 } TransDataContainer;
 
@@ -618,8 +628,6 @@ typedef struct TransInfo {
 
 	short		prop_mode;
 
-	short		mirror;
-
 	float		values[4];
 	/** Offset applied ontop of modal input. */
 	float		values_modal_offset[4];
@@ -710,7 +718,8 @@ enum {
     /** Auto-ik is on. */
 	T_AUTOIK =            1 << 18,
 
-	T_MIRROR =            1 << 19,
+	/** Don't use mirror even if the data-block option is set. */
+	T_NO_MIRROR =         1 << 19,
 
 	T_AUTOVALUES =        1 << 20,
 
diff --git a/source/blender/editors/transform/transform_conversions.c b/source/blender/editors/transform/transform_conversions.c
index 6e4386a4171..cf911a995a1 100644
--- a/source/blender/editors/transform/transform_conversions.c
+++ b/source/blender/editors/transform/transform_conversions.c
@@ -2676,12 +2676,9 @@ static void createTransEditVerts(TransInfo *t)
 		 * Optional, allocate if needed. */
 		int *dists_index = NULL;
 
-		if (t->flag & T_MIRROR) {
-			/* TODO(campbell): xform: We need support for many mirror objects at once! */
-			if (tc->is_active) {
-				EDBM_verts_mirror_cache_begin(em, 0, false, (t->flag & T_PROP_EDIT) == 0, use_topology);
-				mirror = 1;
-			}
+		if (tc->mirror.axis_flag) {
+			EDBM_verts_mirror_cache_begin(em, 0, false, (t->flag & T_PROP_EDIT) == 0, use_topology);
+			mirror = 1;
 		}
 
 		/**
@@ -2791,7 +2788,7 @@ static void createTransEditVerts(TransInfo *t)
 			BM_ITER_MESH (eve, &iter, bm, BM_VERTS_OF_MESH) {
 				if (BM_elem_flag_test(eve, BM_ELEM_SELECT) && eve->co[0] != 0.0f) {
 					if (eve->co[0] < 0.0f) {
-						t->mirror = -1;
+						tc->mirror.sign = -1.0f;
 						mirror = -1;
 					}
 					break;
@@ -2895,7 +2892,7 @@ cleanup:
 		if (dists_index)
 			MEM_freeN(dists_index);
 
-		if (t->flag & T_MIRROR) {
+		if (tc->mirror.axis_flag) {
 			EDBM_verts_mirror_cache_end(em);
 		}
 	}
@@ -6381,7 +6378,7 @@ static void special_aftertrans_update__mesh(bContext *UNUSED(C), TransInfo *t)
 			char hflag;
 			bool has_face_sel = (bm->totfacesel != 0);
 
-			if (t->flag & T_MIRROR) {
+			if (tc->mirror.axis_flag) {
 				TransData *td;
 				int i;
 
diff --git a/source/blender/editors/transform/transform_generics.c b/source/blender/editors/transform/transform_generics.c
index 8ae23737e5e..5f7d3ec5bde 100644
--- a/source/blender/editors/transform/transform_generics.c
+++ b/source/blender/editors/transform/transform_generics.c
@@ -237,27 +237,29 @@ static void clipMirrorModifier(TransInfo *t)
 static void editbmesh_apply_to_mirror(TransInfo *t)
 {
 	FOREACH_TRANS_DATA_CONTAINER (t, tc) {
-		TransData *td = tc->data;
-		BMVert *eve;
-		int i;
+		if (tc->mirror.axis_flag) {
+			TransData *td = tc->data;
+			BMVert *eve;
+			int i;
 
-		for (i = 0; i < tc->data_len; i++, td++) {
-			if (td->flag & TD_NOACTION)
-				break;
-			if (td->loc == NULL)
-				break;
-			if (td->flag & TD_SKIP)
-				continue;
-
-			eve = td->extra;
-			if (eve) {
-				eve->co[0] = -td->loc[0];
-				eve->co[1] = td->loc[1];
-				eve->co[2] = td->loc[2];
-			}
+			for (i = 0; i < tc->data_len; i++, td++) {
+				if (td->flag & TD_NOACTION)
+					break;
+				if (td->loc == NULL)
+					break;
+				if (td->flag & TD_SKIP)
+					continue;
 
-			if (td->flag & TD_MIRROR_EDGE) {
-				td->loc[0] = 0;
+				eve = td->extra;
+				if (eve) {
+					eve->co[0] = -td->loc[0];
+					eve->co[1] = td->loc[1];
+					eve->co[2] = td->loc[2];
+				}
+
+				if (td->flag & TD_MIRROR_EDGE) {
+					td->loc[0] = 0;
+				}
 			}
 		}
 	}
@@ -812,8 +814,11 @@ static void recalcData_objects(TransInfo *t)
 				applyProject(t);
 				clipMirrorModifier(t);
 			}
-			if ((t->options & CTX_NO_MIRROR) == 0 && (t->flag & T_MIRROR))
+			if ((t->flag & T_NO_MIRROR) == 0 &&
+			    (t->options & CTX_NO_MIRROR) == 0)
+			{
 				editbmesh_apply_to_mirror(t);
+			}
 
 			if (t->mode == TFM_EDGE_SLIDE) {
 				projectEdgeSlideData(t, false);
@@ -1227,6 +1232,12 @@ void initTransDataContainers_FromObjectData(TransInfo *t, Object *obact, Object
 
 		for (int i = 0; i < objects_len; i++) {
 			TransDataContainer *tc = &t->data_container[i];
+			/* TODO, multiple axes. */
+			tc->mirror.axis_flag = (
+			        ((t->flag & T_NO_MIRROR) == 0) &&
+			        ((t->options & CTX_NO_MIRROR) == 0) &&
+			        (((Mesh *)objects[i]->data)->editflag & ME_EDIT_MIRROR_X) != 0);
+
 			if (object_mode & OB_MODE_EDIT) {
 				tc->obedit = objects[i];
 				/* Check needed for UV's */
@@ -1548,18 +1559,16 @@ void initTransInfo(bContext *C, TransInfo *t, wmOperator *op, const wmEvent *eve
 	if (op && ((prop = RNA_struct_find_property(op->ptr, "mirror")) &&
 	           RNA_property_is_set(op->ptr, prop)))
 	{
-		if (RNA_property_boolean_get(op->ptr, prop)) {
-			t->flag |= T_MIRROR;
-			t->mirror = 1;
+		if (!RNA_property_boolean_get(op->ptr, prop)) {
+			t->flag |= T_NO_MIRROR;
 		}
 	}
-	// Need stuff to take it from edit mesh or whatnot here
-	else if (t->spacetype == SPACE_VIEW3D) {
-		/* TODO(campbell): xform, get mirror from each object. */
-		if (t->obedit_type == OB_MESH && (((Mesh *)OBACT(t->view_layer)->data)->editflag & ME_EDIT_MIRROR_X)) {
-			t->flag |= T_MIRROR;
-			t->mirror = 1;
-		}
+	else if ((t->spacetype == SPACE_VIEW3D) && (t->obedit_type == OB_MESH)) {
+		/* pass */
+	}
+	else {
+		/* Avoid mirroring for unsupported contexts. */
+		t->options |= CTX_NO_MIRROR;
 	}
 
 	/* setting PET flag only if property exist in operator. Otherwise, assume it's not supported */
@@ -2168,7 +2177,7 @@ void calculatePropRatio(TransInfo *t)
 				if (td->flag & TD_SELECTED) {
 					td->factor = 1.0f;
 				}
-				else if (t->flag & T_MIRROR && td->loc[0] * t->mirror < -0.00001f) {
+				else if (tc->mirror.axis_flag && (td->loc[0] * tc->mirror.sign) < -0.00001f) {
 					td->flag |= TD_SKIP;
 					td->factor = 0.0f;
 					restoreElement(td);