Use width instead of height of screen for hmd fov, re #43

--HG--
branch : multipass-stereo

code/nel/src/3d/stereo_ovr.cpp

@@ -320,7 +320,7 @@ void CStereoOVR::getScreenResolution(uint &width, uint &height)
 void CStereoOVR::initCamera(uint cid, const NL3D::UCamera *camera)
 {
 	float ar = (float)m_DevicePtr->HMDInfo.HResolution / ((float)m_DevicePtr->HMDInfo.VResolution * 2.0f);
-	float fov = 2.0f * atanf((m_DevicePtr->HMDInfo.VScreenSize / 2.0f) / m_DevicePtr->HMDInfo.EyeToScreenDistance); //(float)NLMISC::Pi/2.f; // 2.0f * atanf(m_DevicePtr->HMDInfo.VScreenSize / 2.0f * m_DevicePtr->HMDInfo.EyeToScreenDistance);
+	float fov = 2.0f * atanf((m_DevicePtr->HMDInfo.HScreenSize * 0.5f * 0.5f) / (m_DevicePtr->HMDInfo.EyeToScreenDistance)); //(float)NLMISC::Pi/2.f; // 2.0f * atanf(m_DevicePtr->HMDInfo.VScreenSize / 2.0f * m_DevicePtr->HMDInfo.EyeToScreenDistance);
 	m_LeftFrustum[cid].initPerspective(fov, ar, camera->getFrustum().Near, camera->getFrustum().Far);
 	m_RightFrustum[cid] = m_LeftFrustum[cid];