1 files changed, 88 insertions, 0 deletions
diff --git a/gfx/vr/service/openvr/src/envvartools_public.cpp b/gfx/vr/service/openvr/src/envvartools_public.cpp
new file mode 100644
index 0000000000..4fb4817927
--- /dev/null
+++ b/gfx/vr/service/openvr/src/envvartools_public.cpp
@@ -0,0 +1,88 @@
+//========= Copyright Valve Corporation ============//
+#include "envvartools_public.h"
+#include "strtools_public.h"
+#include <stdlib.h>
+#include <string>
+#include <cctype>
+
+#if defined(_WIN32)
+#include <windows.h>
+
+#undef GetEnvironmentVariable
+#undef SetEnvironmentVariable
+#endif
+
+
+std::string GetEnvironmentVariable( const char *pchVarName )
+{
+#if defined(_WIN32)
+	char rchValue[32767]; // max size for an env var on Windows
+	DWORD cChars = GetEnvironmentVariableA( pchVarName, rchValue, sizeof( rchValue ) );
+	if( cChars == 0 )
+		return "";
+	else
+		return rchValue;
+#elif defined(POSIX)
+	char *pchValue = getenv( pchVarName );
+	if( pchValue )
+		return pchValue;
+	else
+		return "";
+#else
+#error "Unsupported Platform"
+#endif
+}
+
+bool GetEnvironmentVariableAsBool( const char *pchVarName, bool bDefault )
+{
+	std::string sValue = GetEnvironmentVariable( pchVarName );
+
+	if ( sValue.empty() )
+	{
+		return bDefault;
+	}
+
+	sValue = StringToLower( sValue );
+	std::string sYesValues[] = { "y", "yes", "true" };
+	std::string sNoValues[] = { "n", "no", "false" };
+
+	for ( std::string &sMatch : sYesValues )
+	{
+		if ( sMatch == sValue )
+		{
+			return true;
+		}
+	}
+
+	for ( std::string &sMatch : sNoValues )
+	{
+		if ( sMatch == sValue )
+		{
+			return false;
+		}
+	}
+
+	if ( std::isdigit( sValue.at(0) ) )
+	{
+		return atoi( sValue.c_str() ) != 0;
+	}
+
+	fprintf( stderr,
+			 "GetEnvironmentVariableAsBool(%s): Unable to parse value '%s', using default %d\n",
+			 pchVarName, sValue.c_str(), bDefault );
+	return bDefault;
+}
+
+bool SetEnvironmentVariable( const char *pchVarName, const char *pchVarValue )
+{
+#if defined(_WIN32)
+	return 0 != SetEnvironmentVariableA( pchVarName, pchVarValue );
+#elif defined(POSIX)
+	if( pchVarValue == NULL )
+		return 0 == unsetenv( pchVarName );
+	else
+		return 0 == setenv( pchVarName, pchVarValue, 1 );
+#else
+#error "Unsupported Platform"
+#endif
+}