GEEKING

Rendering/LibOVR/Include/Extras/OVR_CAPI_Util.h

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+/********************************************************************************//**
+\file      OVR_CAPI_Util.h
+\brief     This header provides LibOVR utility function declarations
+\copyright Copyright 2015 Oculus VR, LLC All Rights reserved.
+*************************************************************************************/
+
+#ifndef OVR_CAPI_Util_h
+#define OVR_CAPI_Util_h
+
+
+#include "OVR_CAPI.h"
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+/// Enumerates modifications to the projection matrix based on the application's needs.
+///
+/// \see ovrMatrix4f_Projection
+///
+typedef enum ovrProjectionModifier_
+{
+    /// Use for generating a default projection matrix that is:
+    /// * Left-handed.
+    /// * Near depth values stored in the depth buffer are smaller than far depth values.
+    /// * Both near and far are explicitly defined.
+    /// * With a clipping range that is (0 to w).
+    ovrProjection_None = 0x00,
+
+    /// Enable if using right-handed transformations in your application.
+    ovrProjection_RightHanded = 0x01,
+
+    /// After the projection transform is applied, far values stored in the depth buffer will be less than closer depth values.
+    /// NOTE: Enable only if the application is using a floating-point depth buffer for proper precision.
+    ovrProjection_FarLessThanNear = 0x02,
+
+    /// When this flag is used, the zfar value pushed into ovrMatrix4f_Projection() will be ignored
+    /// NOTE: Enable only if ovrProjection_FarLessThanNear is also enabled where the far clipping plane will be pushed to infinity.
+    ovrProjection_FarClipAtInfinity = 0x04,
+
+    /// Enable if the application is rendering with OpenGL and expects a projection matrix with a clipping range of (-w to w).
+    /// Ignore this flag if your application already handles the conversion from D3D range (0 to w) to OpenGL.
+    ovrProjection_ClipRangeOpenGL = 0x08,
+} ovrProjectionModifier;
+
+
+/// Return values for ovr_Detect.
+///
+/// \see ovr_Detect
+///
+typedef struct OVR_ALIGNAS(8) ovrDetectResult_
+{
+    /// Is ovrFalse when the Oculus Service is not running.
+    ///   This means that the Oculus Service is either uninstalled or stopped.
+    ///   IsOculusHMDConnected will be ovrFalse in this case.
+    /// Is ovrTrue when the Oculus Service is running.
+    ///   This means that the Oculus Service is installed and running.
+    ///   IsOculusHMDConnected will reflect the state of the HMD.
+    ovrBool IsOculusServiceRunning;
+
+    /// Is ovrFalse when an Oculus HMD is not detected.
+    ///   If the Oculus Service is not running, this will be ovrFalse.
+    /// Is ovrTrue when an Oculus HMD is detected.
+    ///   This implies that the Oculus Service is also installed and running.
+    ovrBool IsOculusHMDConnected;
+
+    OVR_UNUSED_STRUCT_PAD(pad0, 6) ///< \internal struct padding
+
+} ovrDetectResult;
+
+OVR_STATIC_ASSERT(sizeof(ovrDetectResult) == 8, "ovrDetectResult size mismatch");
+
+
+/// Detects Oculus Runtime and Device Status
+///
+/// Checks for Oculus Runtime and Oculus HMD device status without loading the LibOVRRT
+/// shared library.  This may be called before ovr_Initialize() to help decide whether or
+/// not to initialize LibOVR.
+///
+/// \param[in] timeoutMsec Specifies a timeout to wait for HMD to be attached or 0 to poll.
+///
+/// \return Returns an ovrDetectResult object indicating the result of detection.
+///
+/// \see ovrDetectResult
+///
+OVR_PUBLIC_FUNCTION(ovrDetectResult) ovr_Detect(int timeoutMsec);
+
+// On the Windows platform,
+#ifdef _WIN32
+    /// This is the Windows Named Event name that is used to check for HMD connected state.
+    #define OVR_HMD_CONNECTED_EVENT_NAME L"OculusHMDConnected"
+#endif // _WIN32
+
+
+/// Used to generate projection from ovrEyeDesc::Fov.
+///
+/// \param[in] fov Specifies the ovrFovPort to use.
+/// \param[in] znear Distance to near Z limit.
+/// \param[in] zfar Distance to far Z limit.
+/// \param[in] projectionModFlags A combination of the ovrProjectionModifier flags.
+///
+/// \return Returns the calculated projection matrix.
+/// 
+/// \see ovrProjectionModifier
+///
+OVR_PUBLIC_FUNCTION(ovrMatrix4f) ovrMatrix4f_Projection(ovrFovPort fov, float znear, float zfar, unsigned int projectionModFlags);
+
+
+/// Extracts the required data from the result of ovrMatrix4f_Projection.
+///
+/// \param[in] projection Specifies the project matrix from which to extract ovrTimewarpProjectionDesc.
+/// \param[in] projectionModFlags A combination of the ovrProjectionModifier flags.
+/// \return Returns the extracted ovrTimewarpProjectionDesc.
+/// \see ovrTimewarpProjectionDesc
+///
+OVR_PUBLIC_FUNCTION(ovrTimewarpProjectionDesc) ovrTimewarpProjectionDesc_FromProjection(ovrMatrix4f projection, unsigned int projectionModFlags);
+
+
+/// Generates an orthographic sub-projection.
+///
+/// Used for 2D rendering, Y is down.
+///
+/// \param[in] projection The perspective matrix that the orthographic matrix is derived from.
+/// \param[in] orthoScale Equal to 1.0f / pixelsPerTanAngleAtCenter.
+/// \param[in] orthoDistance Equal to the distance from the camera in meters, such as 0.8m.
+/// \param[in] hmdToEyeViewOffsetX Specifies the offset of the eye from the center.
+///
+/// \return Returns the calculated projection matrix.
+///
+OVR_PUBLIC_FUNCTION(ovrMatrix4f) ovrMatrix4f_OrthoSubProjection(ovrMatrix4f projection, ovrVector2f orthoScale,
+                                                                float orthoDistance, float hmdToEyeViewOffsetX);
+
+
+
+/// Computes offset eye poses based on headPose returned by ovrTrackingState.
+///
+/// \param[in] headPose Indicates the HMD position and orientation to use for the calculation.
+/// \param[in] hmdToEyeViewOffset Can be ovrEyeRenderDesc.HmdToEyeViewOffset returned from 
+///            ovr_GetRenderDesc. For monoscopic rendering, use a vector that is the average 
+///            of the two vectors for both eyes.
+/// \param[out] outEyePoses If outEyePoses are used for rendering, they should be passed to 
+///             ovr_SubmitFrame in ovrLayerEyeFov::RenderPose or ovrLayerEyeFovDepth::RenderPose.
+///
+OVR_PUBLIC_FUNCTION(void) ovr_CalcEyePoses(ovrPosef headPose,
+                                           const ovrVector3f hmdToEyeViewOffset[2],
+                                           ovrPosef outEyePoses[2]);
+
+
+/// Returns the predicted head pose in outHmdTrackingState and offset eye poses in outEyePoses. 
+///
+/// This is a thread-safe function where caller should increment frameIndex with every frame
+/// and pass that index where applicable to functions called on the rendering thread.
+/// Assuming outEyePoses are used for rendering, it should be passed as a part of ovrLayerEyeFov.
+/// The caller does not need to worry about applying HmdToEyeViewOffset to the returned outEyePoses variables.
+///
+/// \param[in]  hmd Specifies an ovrHmd previously returned by ovr_Create.
+/// \param[in]  frameIndex Specifies the targeted frame index, or 0 to refer to one frame after 
+///             the last time ovr_SubmitFrame was called.
+/// \param[in]  hmdToEyeViewOffset Can be ovrEyeRenderDesc.HmdToEyeViewOffset returned from 
+///             ovr_GetRenderDesc. For monoscopic rendering, use a vector that is the average 
+///             of the two vectors for both eyes.
+/// \param[in]  latencyMarker Specifies that this call is the point in time where
+///             the "App-to-Mid-Photon" latency timer starts from. If a given ovrLayer
+///             provides "SensorSampleTimestamp", that will override the value stored here.
+/// \param[out] outEyePoses The predicted eye poses.
+/// \param[out] outHmdTrackingState The predicted ovrTrackingState. May be NULL, in which case it is ignored.
+///
+OVR_PUBLIC_FUNCTION(void) ovr_GetEyePoses(ovrSession session, long long frameIndex, ovrBool latencyMarker,
+                                             const ovrVector3f hmdToEyeViewOffset[2],
+                                             ovrPosef outEyePoses[2],
+                                             ovrTrackingState* outHmdTrackingState);
+
+
+
+
+#ifdef __cplusplus
+} /* extern "C" */
+#endif
+
+
+#endif // Header include guard