Add sleep related data structures

PiperOrigin-RevId: 829055431
Change-Id: I1ccbd77a57044a754ae7db611b4c2c0010fbda53

src/engine/engine_sleep.h

@@ -0,0 +1,36 @@
+// Copyright 2025 DeepMind Technologies Limited
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef MUJOCO_SRC_ENGINE_ENGINE_SLEEP_H_
+#define MUJOCO_SRC_ENGINE_ENGINE_SLEEP_H_
+
+#include <mujoco/mjdata.h>
+#include <mujoco/mjexport.h>
+#include <mujoco/mjmodel.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// compute sleeping arrays from tree_asleep, if flg_staticawake is set, treat static bodies as awake
+MJAPI void mj_updateSleepInit(const mjModel* m, mjData* d, int flg_staticawake);
+
+// compute {ntree,nbody,nv}_awake, {tree,body}_awake, {body,dof}_awake_ind from tree_asleep
+MJAPI void mj_updateSleep(const mjModel* m, mjData* d);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  // MUJOCO_SRC_ENGINE_ENGINE_SLEEP_H_