3 files changed, 163 insertions, 1 deletions

diff --git a/source/blender/blenkernel/BKE_object.h b/source/blender/blenkernel/BKE_object.h
index 434175624b7..e6e6d621ef3 100644
--- a/source/blender/blenkernel/BKE_object.h
+++ b/source/blender/blenkernel/BKE_object.h
@@ -87,6 +87,14 @@ struct Object *BKE_object_add_only_object(struct Main *bmain, int type, const ch
 struct Object *BKE_object_add(struct Main *bmain, struct Scene *scene, int type);
 void *BKE_object_obdata_add_from_type(struct Main *bmain, int type);
 
+void BKE_object_lod_add(struct Object *ob);
+void BKE_object_lod_sort(struct Object *ob);
+bool BKE_object_lod_remove(struct Object *ob, int level);
+bool BKE_object_lod_update(struct Object *ob, float camera_position[3]);
+bool BKE_object_lod_is_usable(struct Object *ob, struct Scene *scene);
+struct Object *BKE_object_lod_meshob_get(struct Object *ob, struct Scene *scene);
+struct Object *BKE_object_lod_matob_get(struct Object *ob, struct Scene *scene);
+
 struct Object *BKE_object_copy_ex(struct Main *bmain, struct Object *ob, int copy_caches);
 struct Object *BKE_object_copy(struct Object *ob);
 void BKE_object_make_local(struct Object *ob);
diff --git a/source/blender/blenkernel/intern/material.c b/source/blender/blenkernel/intern/material.c
index cf9b838a7c2..9df523a5bfe 100644
--- a/source/blender/blenkernel/intern/material.c
+++ b/source/blender/blenkernel/intern/material.c
@@ -675,7 +675,7 @@ Material *give_current_material(Object *ob, short act)
 {
 	Material ***matarar, *ma;
 	short *totcolp;
-	
+
 	if (ob == NULL) return NULL;
 	
 	/* if object cannot have material, (totcolp == NULL) */
diff --git a/source/blender/blenkernel/intern/object.c b/source/blender/blenkernel/intern/object.c
index 0694bde7b91..70b5fb9d420 100644
--- a/source/blender/blenkernel/intern/object.c
+++ b/source/blender/blenkernel/intern/object.c
@@ -388,6 +388,8 @@ void BKE_object_free(Object *ob)
 
 	if (ob->pc_ids.first) BLI_freelistN(&ob->pc_ids);
 
+	BLI_freelistN(&ob->lodlevels);
+
 	/* Free runtime curves data. */
 	if (ob->curve_cache) {
 		BLI_freelistN(&ob->curve_cache->bev);
@@ -427,6 +429,7 @@ void BKE_object_unlink(Object *ob)
 	ModifierData *md;
 	ARegion *ar;
 	RegionView3D *rv3d;
+	LodLevel *lod;
 	int a, found;
 	
 	unlink_controllers(&ob->controllers);
@@ -608,6 +611,12 @@ void BKE_object_unlink(Object *ob)
 				DAG_id_tag_update(&obt->id, OB_RECALC_DATA);
 		}
 
+		/* levels of detail */
+		for (lod = obt->lodlevels.first; lod; lod = lod->next) {
+			if (lod->source == ob)
+				lod->source = NULL;
+		}
+
 		obt = obt->id.next;
 	}
 	
@@ -1015,6 +1024,138 @@ Object *BKE_object_add(Main *bmain, Scene *scene, int type)
 	return ob;
 }
 
+void BKE_object_lod_add(Object *ob)
+{
+	LodLevel *lod = MEM_callocN(sizeof(LodLevel), "LoD Level");
+	LodLevel *last = ob->lodlevels.last;
+
+	/* If the lod list is empty, initialize it with the base lod level */
+	if (!last) {
+		LodLevel *base = MEM_callocN(sizeof(LodLevel), "Base LoD Level");
+		BLI_addtail(&ob->lodlevels, base);
+		base->flags = OB_LOD_USE_MESH | OB_LOD_USE_MAT;
+		base->source = ob;
+		last = ob->currentlod = base;
+	}
+	
+	lod->distance = last->distance + 25.0f;
+	lod->flags = OB_LOD_USE_MESH | OB_LOD_USE_MAT;
+
+	BLI_addtail(&ob->lodlevels, lod);
+}
+
+static int lod_cmp(void *a, void *b)
+{
+	LodLevel *loda = (LodLevel*)a;
+	LodLevel *lodb = (LodLevel*)b;
+
+	if (loda->distance < lodb->distance) return -1;
+	return loda->distance > lodb->distance;
+}
+
+void BKE_object_lod_sort(Object *ob)
+{
+	BLI_sortlist(&ob->lodlevels, lod_cmp);
+}
+
+bool BKE_object_lod_remove(Object *ob, int level)
+{
+	LodLevel *rem;
+
+	if (level < 1 || level > BLI_countlist(&ob->lodlevels) - 1)
+		return false;
+
+	rem = BLI_findlink(&ob->lodlevels, level);
+
+	if (rem == ob->currentlod) {
+		ob->currentlod = rem->prev;
+	}
+
+	BLI_remlink(&ob->lodlevels, rem);
+	MEM_freeN(rem);
+
+	/* If there are no user defined lods, remove the base lod as well */
+	if (BLI_countlist(&ob->lodlevels) == 1) {
+		LodLevel *base = ob->lodlevels.first;
+		BLI_remlink(&ob->lodlevels, base);
+		MEM_freeN(base);
+		ob->currentlod = NULL;
+	}
+
+	return true;
+}
+
+static LodLevel* lod_level_select(Object *ob, float cam_loc[3])
+{
+	LodLevel *current = ob->currentlod;
+	float ob_loc[3], delta[3];
+	float distance2;
+
+	if (!current) return NULL;
+
+	copy_v3_v3(ob_loc, ob->obmat[3]);
+	sub_v3_v3v3(delta, ob_loc, cam_loc);
+	distance2 = len_squared_v3(delta);
+
+	/* check for higher LoD */
+	if (distance2 < current->distance*current->distance) {
+		while (current->prev && distance2 < current->distance*current->distance) {
+			current = current->prev;
+		}
+	}
+	/* check for lower LoD */
+	else {
+		while (current->next && distance2 > current->next->distance*current->next->distance) {
+			current = current->next;
+		}
+	}
+
+	return current;
+}
+
+bool BKE_object_lod_is_usable(Object *ob, Scene *scene)
+{
+	bool active = (scene) ? ob == OBACT : 0;
+	return (ob->mode == OB_MODE_OBJECT || !active);
+}
+
+bool BKE_object_lod_update(Object *ob, float camera_position[3])
+{
+	LodLevel* cur_level = ob->currentlod;
+	LodLevel* new_level = lod_level_select(ob, camera_position);
+
+	if (new_level != cur_level) {
+		ob->currentlod = new_level;
+		return true;
+	}
+
+	return false;
+}
+
+static Object *lod_ob_get(Object *ob, Scene *scene, int flag)
+{
+	LodLevel *current = ob->currentlod;
+
+	if (!current || !BKE_object_lod_is_usable(ob, scene))
+		return ob;
+
+	while( current->prev && (!(current->flags & flag) || !current->source || current->source->type != OB_MESH)) {
+		current = current->prev;
+	}
+
+	return current->source;
+}
+
+struct Object *BKE_object_lod_meshob_get(Object *ob, Scene *scene)
+{
+	return lod_ob_get(ob, scene, OB_LOD_USE_MESH);
+}
+
+struct Object *BKE_object_lod_matob_get(Object *ob, Scene *scene)
+{
+	return lod_ob_get(ob, scene, OB_LOD_USE_MAT);
+}
+
 SoftBody *copy_softbody(SoftBody *sb, int copy_caches)
 {
 	SoftBody *sbn;
@@ -1226,6 +1367,16 @@ static void copy_object_pose(Object *obn, Object *ob)
 	}
 }
 
+static void copy_object_lod(Object *obn, Object *ob)
+{
+	BLI_duplicatelist(&obn->lodlevels, &ob->lodlevels);
+
+	if (obn->lodlevels.first)
+		((LodLevel*)obn->lodlevels.first)->source = obn;
+
+	obn->currentlod = (LodLevel*) obn->lodlevels.first;
+}
+
 bool BKE_object_pose_context_check(Object *ob)
 {
 	if ((ob) &&
@@ -1346,6 +1497,9 @@ Object *BKE_object_copy_ex(Main *bmain, Object *ob, int copy_caches)
 
 	obn->mpath = NULL;
 
+	copy_object_lod(obn, ob);
+	
+
 	/* Copy runtime surve data. */
 	obn->curve_cache = NULL;