if define, else ... for headers

Project/Include/Bridge_C_API.h

+#ifndef __BRIDGE_C_API_H__
+#define __BRIDGE_C_API_H__
+
 #include "HMD.h"
 #include "Oculus.h"
 
@@ -14,4 +17,6 @@ extern "C" {
 	unsigned int Oculus_height(Oculus *oculus) { return oculus->getHeight(); }
 	void Oculus_projectionMatrixLeft(Oculus *oculus, const float nearz, const float farz, float *r_matrix[4][4]) { return oculus->getProjectionMatrixLeft(nearz, farz, r_matrix); }
 	void Oculus_projectionMatrixRight(Oculus *oculus, const float nearz, const float farz, float *r_matrix[4][4]) { return oculus->getProjectionMatrixRight(nearz, farz, r_matrix); }
-}
\ No newline at end of file
+}
+
+#endif /* __BRIDGE_C_API_H__ */
\ No newline at end of file