Initial open sourcing of MuJoCo.

PiperOrigin-RevId: 450374687
Change-Id: Ie3225a46ce095fc28ae8e63c326a640261f562bb

src/xml/xml_urdf.h

@@ -0,0 +1,60 @@
+// Copyright 2021 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 THIRD_PARTY_MUJOCO_SRC_XML_XML_URDF_
+#define THIRD_PARTY_MUJOCO_SRC_XML_XML_URDF_
+
+#include <string>
+#include <vector>
+
+#include "user/user_model.h"
+#include "xml/xml_base.h"
+#include "tinyxml2.h"
+
+// rgb data
+typedef struct _mjRGBA {
+  float val[4];
+} mjRGBA;
+
+// XML parser for URDF files
+class mjXURDF : public mjXBase {
+ public:
+  mjXURDF();                                          // constructor
+  virtual ~mjXURDF();                                 // destructor
+
+  void Parse(tinyxml2::XMLElement* root);             // main parser
+
+ private:
+  int FindName(std::string name, std::vector<std::string>& list);  // find name in list
+  void AddName(std::string name, std::vector<std::string>& list);  // add name to list
+  void AddBody(std::string name);                                  // add body to local table
+  void AddToTree(int n);                                           // add body to mjCModel tree
+  void Body(tinyxml2::XMLElement* body_elem);                      // parse body
+  void Joint(tinyxml2::XMLElement* joint_elem);                    // parse joint
+  mjCGeom* Geom(tinyxml2::XMLElement* geom_elem,
+                mjCBody* pbody, bool collision);      // parse origin and geometry of geom
+  void Origin(tinyxml2::XMLElement* origin_elem, double* pos, double* quat); // parse origin element
+
+  void MakeMaterials(tinyxml2::XMLElement* elem);     // find all materials recursively
+  void Clear(void);                                   // clear local objects
+
+  // URDF parser variables
+  std::vector<std::string> urName;             // body name
+  std::vector<int> urParent;                   // body parent (index in name vector)
+  std::vector<std::vector<int> > urChildren;   // body children (index in name vector)
+  std::vector<std::string> urMat;              // material name
+  std::vector<mjRGBA> urRGBA;                  // material RBG value
+};
+
+#endif  // THIRD_PARTY_MUJOCO_SRC_XML_XML_URDF_