Initial open sourcing of MuJoCo.

PiperOrigin-RevId: 450374687
Change-Id: Ie3225a46ce095fc28ae8e63c326a640261f562bb

src/engine/engine_crossplatform.h

@@ -0,0 +1,49 @@
+// 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 MUJOCO_SRC_ENGINE_ENGINE_CROSSPLATFORM_H_
+#define MUJOCO_SRC_ENGINE_ENGINE_CROSSPLATFORM_H_
+
+#include <stdlib.h>
+
+// Windows
+#ifdef _WIN32
+//  #define isnan _isnan
+  #define strcasecmp _stricmp
+  #define strncasecmp _strnicmp
+
+  #define mjQUICKSORT(buf, elnum, elsz, func, context) \
+      qsort_s(buf, elnum, elsz, func, context)
+  #define quicksortfunc(name, context, el1, el2) \
+      static int name(void* context, const void* el1, const void* el2)
+
+// Unix-common
+#else
+  // Apple
+  #ifdef __APPLE__
+    #define mjQUICKSORT(buf, elnum, elsz, func, context) \
+        qsort_r(buf, elnum, elsz, context, func)
+    #define quicksortfunc(name, context, el1, el2) \
+        static int name(void* context, const void* el1, const void* el2)
+
+  // non-Apple
+  #else
+    #define mjQUICKSORT(buf, elnum, elsz, func, context) \
+        qsort_r(buf, elnum, elsz, func, context)
+    #define quicksortfunc(name, context, el1, el2) \
+        static int name(const void* el1, const void* el2, void* context)
+  #endif
+#endif
+
+#endif  // MUJOCO_SRC_ENGINE_ENGINE_CROSSPLATFORM_H_