Fix crash when making objects to share same mesh
authorSergey Sharybin <sergey.vfx@gmail.com>
Mon, 4 Jun 2018 13:11:09 +0000 (15:11 +0200)
committerSergey Sharybin <sergey.vfx@gmail.com>
Mon, 4 Jun 2018 13:17:16 +0000 (15:17 +0200)
Make it more reliable and predictable way of getting pointer to
an original mesh which came from copy-on-write engine.

Related change: made it (hopefully) more clear name for flags.

source/blender/blenkernel/intern/DerivedMesh.c
source/blender/blenkernel/intern/lattice.c
source/blender/blenkernel/intern/object.c
source/blender/depsgraph/intern/builder/deg_builder_nodes.cc
source/blender/depsgraph/intern/depsgraph.cc
source/blender/depsgraph/intern/depsgraph_query.cc
source/blender/depsgraph/intern/eval/deg_eval_copy_on_write.cc
source/blender/makesdna/DNA_ID.h
source/blender/makesdna/DNA_object_types.h

index c554d5e..1698946 100644 (file)
@@ -2790,7 +2790,7 @@ static void editbmesh_calc_modifiers(
                        }
                        else {
                                struct Mesh *mesh = ob->data;
-                               if (mesh->id.tag & LIB_TAG_COPY_ON_WRITE) {
+                               if (mesh->id.tag & LIB_TAG_COPIED_ON_WRITE) {
                                        BKE_mesh_runtime_ensure_edit_data(mesh);
                                        mesh->runtime.edit_data->vertexCos = MEM_dupallocN(deformedVerts);
                                }
@@ -2832,7 +2832,7 @@ static void editbmesh_calc_modifiers(
        else {
                /* this is just a copy of the editmesh, no need to calc normals */
                struct Mesh *mesh = ob->data;
-               if (mesh->id.tag & LIB_TAG_COPY_ON_WRITE) {
+               if (mesh->id.tag & LIB_TAG_COPIED_ON_WRITE) {
                        BKE_mesh_runtime_ensure_edit_data(mesh);
                        if (mesh->runtime.edit_data->vertexCos != NULL)
                                MEM_freeN((void *)mesh->runtime.edit_data->vertexCos);
@@ -2943,18 +2943,14 @@ static void mesh_finalize_eval(Object *object)
        if (mesh_eval->mat != NULL) {
                MEM_freeN(mesh_eval->mat);
        }
+       /* Set flag which makes it easier to see what's going on in a debugger. */
+       mesh_eval->id.tag |= LIB_TAG_COPIED_ON_WRITE_EVAL_RESULT;
        mesh_eval->mat = MEM_dupallocN(mesh->mat);
        mesh_eval->totcol = mesh->totcol;
        /* Make evaluated mesh to share same edit mesh pointer as original
         * and copied meshes.
         */
        mesh_eval->edit_btmesh = mesh->edit_btmesh;
-       /* Special flags to help debugging and also to allow copy-on-write core
-        * to understand that on re-evaluation this mesh is to be preserved and
-        * to be remapped back to copied original mesh when used as object data.
-        */
-       mesh_eval->id.tag |= LIB_TAG_COPY_ON_WRITE_EVAL;
-       mesh_eval->id.orig_id = &mesh->id;
        /* Copy autosmooth settings from original mesh.
         * This is not done by BKE_mesh_new_nomain_from_template(), so need to take
         * extra care here.
@@ -2970,7 +2966,7 @@ static void mesh_finalize_eval(Object *object)
 
        /* Object is sometimes not evaluated!
         * TODO(sergey): BAD TEMPORARY HACK FOR UNTIL WE ARE SMARTER */
-       if (object->id.tag & LIB_TAG_COPY_ON_WRITE) {
+       if (object->id.tag & LIB_TAG_COPIED_ON_WRITE) {
                object->data = mesh_eval;
        }
        else {
index 0fa20f0..b5b62de 100644 (file)
@@ -1057,7 +1057,7 @@ void BKE_lattice_modifiers_calc(struct Depsgraph *depsgraph, Scene *scene, Objec
                modifier_deformVerts_DM_deprecated(md, &mectx, NULL, vertexCos, numVerts);
        }
 
-       if (ob->id.tag & LIB_TAG_COPY_ON_WRITE) {
+       if (ob->id.tag & LIB_TAG_COPIED_ON_WRITE) {
                if (vertexCos) {
                        BKE_lattice_vertexcos_apply(ob, vertexCos);
                        MEM_freeN(vertexCos);
index 2eb3590..9c42cc6 100644 (file)
@@ -344,7 +344,9 @@ void BKE_object_free_derived_caches(Object *ob)
        if (ob->runtime.mesh_eval != NULL) {
                Mesh *mesh_eval = ob->runtime.mesh_eval;
                /* Restore initial pointer. */
-               ob->data = mesh_eval->id.orig_id;
+               if (ob->data == mesh_eval) {
+                       ob->data = ob->runtime.mesh_orig;
+               }
                /* Evaluated mesh points to edit mesh, but does not own it. */
                mesh_eval->edit_btmesh = NULL;
                BKE_mesh_free(mesh_eval);
index 5867e27..f01baed 100644 (file)
@@ -311,7 +311,7 @@ ID *DepsgraphNodeBuilder::get_cow_id(const ID *id_orig) const
 
 ID *DepsgraphNodeBuilder::ensure_cow_id(ID *id_orig)
 {
-       if (id_orig->tag & LIB_TAG_COPY_ON_WRITE) {
+       if (id_orig->tag & LIB_TAG_COPIED_ON_WRITE) {
                /* ID is already remapped to copy-on-write. */
                return id_orig;
        }
index b968180..26a23cf 100644 (file)
@@ -310,7 +310,7 @@ IDDepsNode *Depsgraph::find_id_node(const ID *id) const
 
 IDDepsNode *Depsgraph::add_id_node(ID *id, ID *id_cow_hint)
 {
-       BLI_assert((id->tag & LIB_TAG_COPY_ON_WRITE) == 0);
+       BLI_assert((id->tag & LIB_TAG_COPIED_ON_WRITE) == 0);
        IDDepsNode *id_node = find_id_node(id);
        if (!id_node) {
                DepsNodeFactory *factory = deg_type_get_factory(DEG_NODE_TYPE_ID_REF);
@@ -500,7 +500,7 @@ ID *Depsgraph::get_cow_id(const ID *id_orig) const
                 * We try to enforce that in debug builds, for for release we play a bit
                 * safer game here.
                 */
-               if ((id_orig->tag & LIB_TAG_COPY_ON_WRITE) == 0) {
+               if ((id_orig->tag & LIB_TAG_COPIED_ON_WRITE) == 0) {
                        /* TODO(sergey): This is nice sanity check to have, but it fails
                         * in following situations:
                         *
index 06fbe98..ca9f32d 100644 (file)
@@ -240,6 +240,6 @@ ID *DEG_get_original_id(ID *id)
        if (id->orig_id == NULL) {
                return id;
        }
-       BLI_assert((id->tag & LIB_TAG_COPY_ON_WRITE) != 0);
+       BLI_assert((id->tag & LIB_TAG_COPIED_ON_WRITE) != 0);
        return (ID *)id->orig_id;
 }
index 2789f18..858e366 100644 (file)
@@ -542,6 +542,7 @@ void update_special_pointers(const Depsgraph *depsgraph,
                        BLI_assert(object_cow->derivedDeform == NULL);
                        object_cow->mode = object_orig->mode;
                        object_cow->sculpt = object_orig->sculpt;
+                       object_cow->runtime.mesh_orig = (Mesh *)object_cow->data;
                        if (object_cow->type == OB_ARMATURE) {
                                BKE_pose_remap_bone_pointers((bArmature *)object_cow->data,
                                                             object_cow->pose);
@@ -724,12 +725,12 @@ static void deg_backup_object_runtime(
        Mesh *mesh_eval = object->runtime.mesh_eval;
        object_runtime_backup->runtime = object->runtime;
        BKE_object_runtime_reset(object);
-       /* Currently object update will override actual object->data
-        * to an evaluated version. Need to make sure we don't have
-        * data set to evaluated one before free anything.
+       /* Object update will override actual object->data to an evaluated version.
+        * Need to make sure we don't have data set to evaluated one before free
+        * anything.
         */
        if (mesh_eval != NULL && object->data == mesh_eval) {
-               object->data = mesh_eval->id.orig_id;
+               object->data = object->runtime.mesh_orig;
        }
        /* Store curve cache and make sure we don't free it. */
        object_runtime_backup->curve_cache = object->curve_cache;
@@ -742,20 +743,33 @@ static void deg_restore_object_runtime(
         Object *object,
         const ObjectRuntimeBackup *object_runtime_backup)
 {
+       Mesh *mesh_orig = object->runtime.mesh_orig;
        object->runtime = object_runtime_backup->runtime;
+       object->runtime.mesh_orig = mesh_orig;
        if (object->runtime.mesh_eval != NULL) {
-               Mesh *mesh_eval = object->runtime.mesh_eval;
-               /* Do same thing as object update: override actual object data
-                * pointer with evaluated datablock.
-                */
-               if (object->type == OB_MESH) {
-                       object->data = mesh_eval;
-                       /* Evaluated mesh simply copied edit_btmesh pointer from
-                        * original mesh during update, need to make sure no dead
-                        * pointers are left behind.
+               if (object->id.recalc & ID_RECALC_GEOMETRY) {
+                       /* If geometry is tagged for update it means, that part of
+                        * evaluated mesh are not valid anymore. In this case we can not
+                        * have any "persistent" pointers to point to an invalid data.
+                        *
+                        * We restore object's data datablock to an original copy of
+                        * that datablock.
+                        */
+                       object->data = mesh_orig;
+               }
+               else {
+                       Mesh *mesh_eval = object->runtime.mesh_eval;
+                       /* Do same thing as object update: override actual object data
+                        * pointer with evaluated datablock.
                         */
-                       Mesh *mesh = ((Mesh *)mesh_eval->id.orig_id);
-                       mesh_eval->edit_btmesh = mesh->edit_btmesh;
+                       if (object->type == OB_MESH) {
+                               object->data = mesh_eval;
+                               /* Evaluated mesh simply copied edit_btmesh pointer from
+                                * original mesh during update, need to make sure no dead
+                                * pointers are left behind.
+                               */
+                               mesh_eval->edit_btmesh = mesh_orig->edit_btmesh;
+                       }
                }
        }
        if (object_runtime_backup->curve_cache != NULL) {
@@ -995,8 +1009,8 @@ bool deg_validate_copy_on_write_datablock(ID *id_cow)
 void deg_tag_copy_on_write_id(ID *id_cow, const ID *id_orig)
 {
        BLI_assert(id_cow != id_orig);
-       BLI_assert((id_orig->tag & LIB_TAG_COPY_ON_WRITE) == 0);
-       id_cow->tag |= LIB_TAG_COPY_ON_WRITE;
+       BLI_assert((id_orig->tag & LIB_TAG_COPIED_ON_WRITE) == 0);
+       id_cow->tag |= LIB_TAG_COPIED_ON_WRITE;
        id_cow->orig_id = (ID *)id_orig;
 }
 
index 05e39c6..6ce0c94 100644 (file)
@@ -467,8 +467,8 @@ enum {
        LIB_TAG_PRE_EXISTING    = 1 << 11,
 
        /* The datablock is a copy-on-write/localized version. */
-       LIB_TAG_COPY_ON_WRITE   = 1 << 12,
-       LIB_TAG_COPY_ON_WRITE_EVAL = 1 << 13,
+       LIB_TAG_COPIED_ON_WRITE               = 1 << 12,
+       LIB_TAG_COPIED_ON_WRITE_EVAL_RESULT   = 1 << 13,
        LIB_TAG_LOCALIZED = 1 << 14,
 
        /* RESET_NEVER tag datablock for freeing etc. behavior (usually set when copying real one into temp/runtime one). */
index daff6ab..c9db5fb 100644 (file)
@@ -145,6 +145,11 @@ typedef struct ObjectDisplay {
 
 /* Not saved in file! */
 typedef struct Object_Runtime {
+       /* Original mesh pointer, before object->data was changed to point
+        * to mesh_eval.
+        * Is assigned by dependency craph's copy-on-write evaluation.
+        */
+       struct Mesh *mesh_orig;
        /* Mesh structure created during object evaluation.
         * It has all modifiers applied.
         */