.gitmodules

@@ -82,3 +82,6 @@
 [submodule "modules/shader_compiler/lib/json-c"]
 	path = modules/shader_compiler/lib/json-c
 	url = https://github.com/json-c/json-c.git
+[submodule "modules/camera/lib/OpenXR-SDK"]
+	path = modules/camera/lib/OpenXR-SDK
+	url = https://github.com/KhronosGroup/OpenXR-SDK.git

modules/camera/CMakeLists.txt

@@ -22,6 +22,9 @@ set(vkcv_camera_sources
 		
 		${vkcv_camera_include}/vkcv/camera/TrackballCameraController.hpp
 		${vkcv_camera_source}/vkcv/camera/TrackballCameraController.cpp
+
+		${vkcv_camera_include}/vkcv/camera/XRCameraController.hpp
+		${vkcv_camera_source}/vkcv/camera/XRCameraController.cpp
 )
 
 filter_headers(vkcv_camera_sources ${vkcv_camera_include} vkcv_camera_headers)
@@ -34,6 +37,9 @@ set_target_properties(vkcv_camera PROPERTIES PUBLIC_HEADER "${vkcv_camera_header
 set(vkcv_camera_lib lib)
 set(vkcv_camera_lib_path ${PROJECT_SOURCE_DIR}/${vkcv_camera_lib})
 
+# Check and load OpenXR-SDK
+include(config/OPEN_XR_SDK.cmake)
+
 target_link_libraries(vkcv_camera PUBLIC
 		${vkcv_camera_libraries}
 		vkcv

modules/camera/config/OPEN_XR_SDK.cmake

+
+use_git_submodule("${vkcv_camera_lib_path}/OpenXR-SDK" open_xr_status)
+
+if (${open_xr_status})
+	list(APPEND vkcv_camera_includes ${vkcv_camera_lib}/OpenXR-SDK/include)
+
+  add_subdirectory(${vkcv_camera_lib}/OpenXR-SDK)
+	
+	list(APPEND vkcv_camera_definitions XR_USE_GRAPHICS_API_VULKAN)
+endif ()

modules/camera/include/vkcv/camera/XRCameraController.hpp

+#pragma once
+/**
+ * @authors Tobias Frisch
+ * @file include/vkcv/camera/XRCameraController.hpp
+ * @brief XRCameraController class of the camera module for the vkcv framework. This class inherits from the base
+ * class @#CameraController and enables camera objects to be orbited around a specific center point.
+ */
+
+#include "CameraController.hpp"
+
+#include <openxr/openxr.h>
+
+namespace vkcv::camera {
+
+    /**
+     * @addtogroup vkcv_camera
+     * @{
+     */
+
+    /**
+     * @brief Used to control the camera via an HMD.
+     */
+    class XRCameraController final : public CameraController {
+    private:
+        XrInstance m_instance;
+        XrSystemId m_system_id;
+        XrSession m_session;
+        XrSpace m_space;
+
+    public:
+
+        /**
+         * @brief The default constructor of the #XRCameraController.
+         */
+        XRCameraController();
+
+        /**
+         * @brief The destructor of the #XRCameraController (default behavior).
+         */
+        ~XRCameraController();
+
+        /**
+         * @brief Updates @p camera in respect to @p deltaTime.
+         * @param[in] deltaTime The time that has passed since last update.
+         * @param[in] camera The camera object
+         */
+        void updateCamera(double deltaTime, Camera &camera) override;
+
+        /**
+         * @brief A callback function for key events. Currently, the trackball camera does not support camera movement.
+         * It can only orbit around its center point.
+         * @param[in] key The keyboard key.
+         * @param[in] scancode The platform-specific scancode.
+         * @param[in] action The key action.
+         * @param[in] mods The modifier bits.
+         * @param[in] camera The camera object.
+         */
+        void keyCallback(int key, int scancode, int action, int mods, Camera &camera) override;
+
+        /**
+         * @brief A callback function for mouse scrolling events. Currently, this leads to changes in the field of view
+         * of the camera object.
+         * @param[in] offsetX The offset in horizontal direction.
+         * @param[in] offsetY The offset in vertical direction.
+         * @param[in] camera The camera object.
+         */
+        void scrollCallback(double offsetX, double offsetY, Camera &camera) override;
+
+        /**
+         * @brief A callback function for mouse movement events. Currently, this leads to panning the view of the
+         * camera, if #mouseButtonCallback(int button, int action, int mods) enabled panning.
+         * @param[in] xoffset The horizontal mouse position.
+         * @param[in] yoffset The vertical mouse position.
+         * @param[in] camera The camera object.
+         */
+        void mouseMoveCallback(double xoffset, double yoffset, Camera &camera) override;
+
+        /**
+         * @brief A callback function for mouse button events. Currently, the right mouse button enables panning the
+         * view of the camera as long as it is pressed.
+         * @param[in] button The mouse button.
+         * @param[in] action The button action.
+         * @param[in] mods The modifier bits.
+         * @param[in] camera The camera object.
+         */
+        void mouseButtonCallback(int button, int action, int mods, Camera &camera) override;
+
+        /**
+         * @brief A callback function for gamepad input events.
+         * @param gamepadIndex The gamepad index.
+         * @param camera The camera object.
+         * @param frametime The current frametime.
+         */
+        void gamepadCallback(int gamepadIndex, Camera &camera, double frametime) override;
+    };
+
+    /** @} */
+
+}
\ No newline at end of file

OpenXR-SDK @ 67cfb6a4

+Subproject commit 67cfb6a4bc5496451efcf5d35af017f4f1761648

modules/camera/src/vkcv/camera/XRCameraController.cpp

+
+#include "vkcv/camera/XRCameraController.hpp"
+
+namespace vkcv::camera {
+
+  XRCameraController::XRCameraController() :
+    m_instance(XR_NULL_HANDLE),
+    m_system_id(XR_NULL_SYSTEM_ID),
+    m_session(XR_NULL_HANDLE),
+    m_space(XR_NULL_HANDLE)
+  {
+    XrInstanceCreateInfo instanceInfo {XR_TYPE_INSTANCE_CREATE_INFO};
+
+    strcpy(instanceInfo.applicationInfo.applicationName, VKCV_FRAMEWORK_NAME);
+
+    if (XR_SUCCESS != xrCreateInstance(&instanceInfo, &m_instance)) {
+      vkcv::log(vkcv::LogLevel::ERROR, "Creating an XR instance failed");
+    }
+
+    XrSystemGetInfo systemInfo {XR_TYPE_SYSTEM_GET_INFO};
+    systemInfo.formFactor = m_options->Parsed.FormFactor;
+    
+    if (XR_SUCCESS != xrGetSystem(m_instance, &systemInfo, &m_system_id)) {
+      vkcv::log(vkcv::LogLevel::ERROR, "Getting an XR system id failed");
+    }
+
+    XrSessionCreateInfo sessionInfo {XR_TYPE_SESSION_CREATE_INFO};
+    sessionInfo.systemId = m_system_id;
+
+    if (XR_SUCCESS != xrCreateSession(m_instance, &sessionInfo, &m_session)) {
+      vkcv::log(vkcv::LogLevel::ERROR, "Creating an XR session failed");
+    }
+
+    XrReferenceSpaceCreateInfo spaceInfo {XR_TYPE_REFERENCE_SPACE_CREATE_INFO};
+    spaceInfo.poseInReferenceSpace.orientation.w = 1.0f;
+    spaceInfo.referenceSpaceType = XR_REFERENCE_SPACE_TYPE_LOCAL;
+
+    if (XR_SUCCESS != xrCreateReferenceSpace(m_session, &spaceInfo, &m_space)) {
+      vkcv::log(vkcv::LogLevel::ERROR, "Creating an XR space failed");
+    }
+  }
+
+  XRCameraController::~XRCameraController() {
+    if (m_space) {
+      xrDestroySpace(m_space);
+    }
+
+    if (m_session) {
+      xrDestroySession(m_session);
+    }
+
+    if (m_instance) {
+      xrDestroyInstance(m_instance);
+    }
+  }
+
+  void XRCameraController::updateCamera(double deltaTime, Camera &camera) {
+    std::vector<XrView> views;
+
+    XrViewState viewState {XR_TYPE_VIEW_STATE};
+    const uint32_t viewCapacity = views.size();
+    uint32_t viewCount;
+
+    XrViewLocateInfo viewInfo {XR_TYPE_VIEW_LOCATE_INFO};
+    viewInfo.viewConfigurationType = XR_VIEW_CONFIGURATION_TYPE_PRIMARY_STEREO;
+    viewInfo.space = m_space;
+
+    XrResult result = xrLocateViews(
+      m_session,
+      &viewInfo,
+      &viewState,
+      &viewCount,
+      views.data()
+    );
+
+    if ((XR_SUCCESS != result) || 
+        ((viewState.viewStateFlags & XR_VIEW_STATE_POSITION_VALID_BIT) == 0) ||
+        ((viewState.viewStateFlags & XR_VIEW_STATE_ORIENTATION_VALID_BIT) == 0)) {
+      vkcv::log(vkcv::LogLevel::WARNING, "Unable to locate XR views");
+      return;
+    }
+
+    // TODO
+  }
+
+  void XRCameraController::keyCallback(int key, int scancode, int action, int mods, Camera &camera) {
+    // TODO
+  }
+
+  void XRCameraController::scrollCallback(double offsetX, double offsetY, Camera &camera) {
+    // TODO
+  }
+
+  void XRCameraController::mouseMoveCallback(double xoffset, double yoffset, Camera &camera) {
+    // TODO
+  }
+
+  void XRCameraController::mouseButtonCallback(int button, int action, int mods, Camera &camera) {
+    // TODO
+  }
+
+  void XRCameraController::gamepadCallback(int gamepadIndex, Camera &camera, double frametime) {
+    // TODO
+  }
+
+}