Work around a calling convention mismatch between MinGW and VC++

[libs/vr.git] / source / openvr / openvrdevice.cpp

diff --git a/source/openvr/openvrdevice.cpp b/source/openvr/openvrdevice.cpp
index 1081a04937767ee68cb09521522fa00cfc32ab32..f6f0bf1cf796cd18c1781e26100c9d68bfe601ba 100644 (file)
--- a/source/openvr/openvrdevice.cpp
+++ b/source/openvr/openvrdevice.cpp
@@ -1,8 +1,23 @@
 #include <openvr.h>
+#include <msp/vr/stereoview.h>
 #include "openvrdevice.h"
 
 using namespace std;
 
+namespace {
+
+Msp::GL::Matrix convert_matrix(const vr::HmdMatrix34_t &m)
+{
+       Msp::GL::Matrix result;
+       for(unsigned i=0; i<3; ++i)
+               for(unsigned j=0; j<4; ++j)
+                       result(i, j) = m.m[i][j];
+       return result;
+}
+
+}
+
+
 namespace Msp {
 namespace VR {
 
@@ -32,6 +47,28 @@ OpenVRDevice::~OpenVRDevice()
                vr::VR_Shutdown();
 }
 
+void OpenVRDevice::configure_view(StereoView &view) const
+{
+       vr::IVRSystem *vr_sys = vr::VRSystem();
+
+#if defined(__GNUC__) && defined(_WIN32)
+       /* Visual C++ passes the return value address as first stack parameter and
+       the this pointer in ecx.  MinGW does the other way around.  This trick
+       forces the function signature to match at machine code level. */
+       typedef void (vr::IVRSystem::*FuncPtr)(vr::HmdMatrix34_t *, vr::EVREye);
+       FuncPtr get_eye_to_head_transform = reinterpret_cast<FuncPtr>(&vr::IVRSystem::GetEyeToHeadTransform);
+
+       vr::HmdMatrix34_t left, right;
+       (vr_sys->*get_eye_to_head_transform)(&left, vr::Eye_Left);
+       (vr_sys->*get_eye_to_head_transform)(&right, vr::Eye_Right);
+#else
+       vr::HmdMatrix34_t left = vr_sys->GetEyeToHeadTransform(vr::Eye_Left);
+       vr::HmdMatrix34_t right = vr_sys->GetEyeToHeadTransform(vr::Eye_Right);
+#endif
+       
+       view.set_eye_matrices(convert_matrix(left), convert_matrix(right));
+}
+
 OpenVRCamera *OpenVRDevice::create_camera(const GL::Camera &bc)
 {
        return new OpenVRCamera(*this, bc);
@@ -50,11 +87,7 @@ void OpenVRDevice::update_pose_matrices()
 
        vr::TrackedDevicePose_t &hmd_pose = poses[vr::k_unTrackedDeviceIndex_Hmd];
        if(hmd_pose.bPoseIsValid)
-       {
-               for(unsigned i=0; i<3; ++i)
-                       for(unsigned j=0; j<4; ++j)
-                               hmd_matrix(i, j) = hmd_pose.mDeviceToAbsoluteTracking.m[i][j];
-       }
+               hmd_matrix = convert_matrix(hmd_pose.mDeviceToAbsoluteTracking);
 }
 
 } // namespace VR