started work on multiple Rift support - does not itterate all devices on Linux

cmake @ 2ab8ddba

-Subproject commit 7c0af24a1217acf415769e0ac5d2861a2637e698
+Subproject commit 2ab8ddba5b6c77730193e734bfb63cc45ac93e77

src/ACGL/HardwareSupport/SimpleRiftController.cc

@@ -24,6 +24,7 @@ SimpleRiftController::SimpleRiftController( uint32_t _riftnumber )
 
     if (_riftnumber != 0) {
         error() << "opening any other Rift than ID 0 is not supported yet! Trying to open Rift nr 0" << endl;
+        _riftnumber = 0;
     }
 
 #ifdef ACGL_DEBUG
@@ -38,7 +39,19 @@ SimpleRiftController::SimpleRiftController( uint32_t _riftnumber )
         error() << "could not create a Rift Device Manager" << endl;
         mORDevice = NULL;
     } else {
-        mORDevice = *mORManager->EnumerateDevices<HMDDevice>().CreateDevice();
+        DeviceEnumerator<HMDDevice> hmdEnumerator = mORManager->EnumerateDevices<HMDDevice>();
+
+        bool riftOK = true;
+        for (uint32_t i = 0; i < _riftnumber; ++i) {
+            riftOK = hmdEnumerator.Next();
+        }
+
+        if (riftOK) {
+            mORDevice = *hmdEnumerator.CreateDevice();
+        } else {
+            error() << "Rift number " << _riftnumber << " not found" << endl;
+            mORDevice = NULL;
+        }
     }
 
     mORHMDInfo = new OVR::HMDInfo();