Do not define TINYOBJLOADER_IMPLEMENTATION when building with CMake

src/user/CMakeLists.txt

@@ -25,3 +25,4 @@ set(MUJOCO_USER_SRCS
 )
 
 target_sources(mujoco PRIVATE ${MUJOCO_USER_SRCS})
+target_compile_definitions(mujoco PRIVATE MUJOCO_DO_NOT_DEFINE_TINYOBJLOADER_IMPLEMENTATION)

src/user/user_mesh.cc

@@ -25,7 +25,11 @@
 #include <string>
 #include <vector>
 
+// This macro is defined when MuJoCo is built with CMake,
+// not defined when MuJoCo is built with other build systems
+#ifndef MUJOCO_DO_NOT_DEFINE_TINYOBJLOADER_IMPLEMENTATION
 #define TINYOBJLOADER_IMPLEMENTATION
+#endif
 
 #include <mujoco/mjmodel.h>
 #include "cc/array_safety.h"