Extract memory allocation functions and core utilities

PiperOrigin-RevId: 801745499
Change-Id: Iaf05c3430769d3115743d8ab020d13148cb2eb59

src/engine/engine_core_util.h

@@ -0,0 +1,139 @@
+// 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_CORE_UTIL_H_
+#define MUJOCO_SRC_ENGINE_ENGINE_CORE_UTIL_H_
+
+#include <mujoco/mjdata.h>
+#include <mujoco/mjexport.h>
+#include <mujoco/mjmodel.h>
+#include "engine/engine_memory.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// determine type of friction cone
+MJAPI int mj_isPyramidal(const mjModel* m);
+
+// determine type of constraint Jacobian
+MJAPI int mj_isSparse(const mjModel* m);
+
+
+//-------------------------- sparse chains ---------------------------------------------------------
+
+// merge dof chains for two bodies
+int mj_mergeChain(const mjModel* m, int* chain, int b1, int b2);
+
+// merge dof chains for two simple bodies
+int mj_mergeChainSimple(const mjModel* m, int* chain, int b1, int b2);
+
+// get body chain
+int mj_bodyChain(const mjModel* m, int body, int* chain);
+
+
+//-------------------------- Jacobians -------------------------------------------------------------
+
+// compute 3/6-by-nv Jacobian of global point attached to given body
+MJAPI void mj_jac(const mjModel* m, const mjData* d,
+                  mjtNum* jacp, mjtNum* jacr, const mjtNum point[3], int body);
+
+// compute body frame Jacobian
+MJAPI void mj_jacBody(const mjModel* m, const mjData* d,
+                      mjtNum* jacp, mjtNum* jacr, int body);
+
+// compute body center-of-mass Jacobian
+MJAPI void mj_jacBodyCom(const mjModel* m, const mjData* d,
+                         mjtNum* jacp, mjtNum* jacr, int body);
+
+// compute subtree center-of-mass Jacobian
+MJAPI void mj_jacSubtreeCom(const mjModel* m, mjData* d, mjtNum* jacp, int body);
+
+// compute geom Jacobian
+MJAPI void mj_jacGeom(const mjModel* m, const mjData* d,
+                      mjtNum* jacp, mjtNum* jacr, int geom);
+
+// compute site Jacobian
+MJAPI void mj_jacSite(const mjModel* m, const mjData* d,
+                      mjtNum* jacp, mjtNum* jacr, int site);
+
+// compute translation Jacobian of point, and rotation Jacobian of axis
+MJAPI void mj_jacPointAxis(const mjModel* m, mjData* d,
+                           mjtNum* jacPoint, mjtNum* jacAxis,
+                           const mjtNum point[3], const mjtNum axis[3], int body);
+
+// compute 3/6-by-nv sparse Jacobian of global point attached to given body
+void mj_jacSparse(const mjModel* m, const mjData* d,
+                  mjtNum* jacp, mjtNum* jacr, const mjtNum* point, int body,
+                  int NV, const int* chain);
+
+// sparse Jacobian difference for simple body contacts
+void mj_jacSparseSimple(const mjModel* m, const mjData* d,
+                        mjtNum* jacdifp, mjtNum* jacdifr, const mjtNum* point,
+                        int body, int flg_second, int NV, int start);
+
+// dense or sparse Jacobian difference for two body points: pos2 - pos1, global
+MJAPI int mj_jacDifPair(const mjModel* m, const mjData* d, int* chain,
+                        int b1, int b2, const mjtNum pos1[3], const mjtNum pos2[3],
+                        mjtNum* jac1p, mjtNum* jac2p, mjtNum* jacdifp,
+                        mjtNum* jac1r, mjtNum* jac2r, mjtNum* jacdifr);
+
+// dense or sparse weighted sum of multiple body Jacobians at same point
+int mj_jacSum(const mjModel* m, mjData* d, int* chain,
+              int n, const int* body, const mjtNum* weight,
+              const mjtNum point[3], mjtNum* jac, int flg_rot);
+
+// compute 3/6-by-nv Jacobian time derivative of global point attached to given body
+MJAPI void mj_jacDot(const mjModel* m, const mjData* d,
+                     mjtNum* jacp, mjtNum* jacr, const mjtNum point[3], int body);
+
+// compute subtree angular momentum matrix
+MJAPI void mj_angmomMat(const mjModel* m, mjData* d, mjtNum* mat, int body);
+
+
+//-------------------------- coordinate transformation ---------------------------------------------
+
+// compute object 6D velocity in object-centered frame, world/local orientation
+MJAPI void mj_objectVelocity(const mjModel* m, const mjData* d,
+                             int objtype, int objid, mjtNum res[6], int flg_local);
+
+// compute object 6D acceleration in object-centered frame, world/local orientation
+MJAPI void mj_objectAcceleration(const mjModel* m, const mjData* d,
+                                 int objtype, int objid, mjtNum res[6], int flg_local);
+
+
+//-------------------------- miscellaneous ---------------------------------------------------------
+
+// map from body local to global Cartesian coordinates
+MJAPI void mj_local2Global(mjData* d, mjtNum xpos[3], mjtNum xmat[9],
+                           const mjtNum pos[3], const mjtNum quat[4],
+                           int body, mjtByte sameframe);
+
+// extract 6D force:torque for one contact, in contact frame
+MJAPI void mj_contactForce(const mjModel* m, const mjData* d, int id, mjtNum result[6]);
+
+// high-level warning function: count warnings in mjData, print only the first time
+MJAPI void mj_warning(mjData* d, int warning, int info);
+
+// extract 6D force:torque for one contact, in contact frame
+MJAPI void mj_contactForce(const mjModel* m, const mjData* d, int id, mjtNum result[6]);
+
+// set default solver parameters
+MJAPI void mj_defaultSolRefImp(mjtNum* solref, mjtNum* solimp);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  // MUJOCO_SRC_ENGINE_ENGINE_CORE_UTIL_H_