Add support to notify when the headset is (un)mounted

demo/export_presets.cfg

@@ -22,7 +22,7 @@ one_click_deploy/clear_previous_install=true
 custom_template/debug=""
 custom_template/release=""
 custom_template/use_custom_build=true
-custom_template/plugins=""
+custom_template/plugins="OVRMobile"
 command_line/extra_args=""
 version/code=1
 version/name="1.0"

plugin/src/main/cpp/jni/ovr_mobile_plugin_jni.cpp

@@ -0,0 +1,27 @@
+/**
+* Created by Fredia Huya-Kouadio. 
+*/
+
+#include <jni.h>
+
+#include "ovr_mobile_session.h"
+#include "jni_common.h"
+#include "ovr_mobile_plugin_wrapper.h"
+
+#undef JNI_PACKAGE_NAME
+#define JNI_PACKAGE_NAME org_godotengine_plugin_vr_oculus_mobile
+
+#undef JNI_CLASS_NAME
+#define JNI_CLASS_NAME OvrMobilePlugin
+
+extern "C" {
+JNIEXPORT void JNICALL JNI_METHOD(initializeWrapper)(JNIEnv* env,
+                                                     jobject object) {
+  ovrmobile::OvrMobilePluginWrapper::initializeWrapper(env, object);
+}
+
+JNIEXPORT void JNICALL JNI_METHOD(uninitializeWrapper)(JNIEnv* env,
+                                                       jobject object) {
+  ovrmobile::OvrMobilePluginWrapper::uninitializeWrapper(env);
+}
+};

plugin/src/main/cpp/jni/ovr_mobile_plugin_wrapper.cpp

@@ -0,0 +1,60 @@
+/**
+* Created by Fredia Huya-Kouadio. 
+*/
+
+#include "ovr_mobile_plugin_wrapper.h"
+#include "common.h"
+
+namespace ovrmobile {
+
+jobject OvrMobilePluginWrapper::ovr_mobile_plugin_instance = nullptr;
+jmethodID OvrMobilePluginWrapper::on_headset_mounted_id = nullptr;
+jmethodID OvrMobilePluginWrapper::on_headset_unmounted_id = nullptr;
+
+OvrMobilePluginWrapper::OvrMobilePluginWrapper() {}
+
+OvrMobilePluginWrapper::~OvrMobilePluginWrapper() {}
+
+void OvrMobilePluginWrapper::initializeWrapper(JNIEnv* env,
+                                               jobject ovr_mobile_plugin) {
+  ovr_mobile_plugin_instance = env->NewGlobalRef(ovr_mobile_plugin);
+  ALOG_ASSERT(ovr_mobile_plugin_instance != nullptr, "Invalid jobject value.");
+
+  jclass
+      ovr_mobile_plugin_class = env->GetObjectClass(ovr_mobile_plugin_instance);
+  ALOG_ASSERT(ovr_mobile_plugin_class != nullptr, "Invalid jclass value.");
+
+  on_headset_mounted_id =
+      env->GetMethodID(ovr_mobile_plugin_class, "onHeadsetMounted", "()V");
+  ALOG_ASSERT(on_headset_mounted_id != nullptr,
+              "Unable to find onHeadsetMounted");
+
+  on_headset_unmounted_id =
+      env->GetMethodID(ovr_mobile_plugin_class, "onHeadsetUnmounted", "()V");
+  ALOG_ASSERT(on_headset_unmounted_id != nullptr,
+              "Unable to find onHeadsetUnmounted");
+}
+
+void OvrMobilePluginWrapper::uninitializeWrapper(JNIEnv* env) {
+  if (ovr_mobile_plugin_instance) {
+    env->DeleteGlobalRef(ovr_mobile_plugin_instance);
+    ovr_mobile_plugin_instance = nullptr;
+    on_headset_mounted_id = nullptr;
+    on_headset_unmounted_id = nullptr;
+  }
+}
+
+void OvrMobilePluginWrapper::on_headset_mounted() {
+  if (ovr_mobile_plugin_instance && on_headset_mounted_id) {
+    JNIEnv *env = android_api->godot_android_get_env();
+    env->CallVoidMethod(ovr_mobile_plugin_instance, on_headset_mounted_id);
+  }
+}
+
+void OvrMobilePluginWrapper::on_headset_unmounted() {
+  if (ovr_mobile_plugin_instance && on_headset_unmounted_id) {
+    JNIEnv* env = android_api->godot_android_get_env();
+    env->CallVoidMethod(ovr_mobile_plugin_instance, on_headset_unmounted_id);
+  }
+}
+} // namespace ovrmobile

plugin/src/main/cpp/jni/ovr_mobile_plugin_wrapper.h

@@ -0,0 +1,35 @@
+/**
+* Created by Fredia Huya-Kouadio. 
+*/
+
+#ifndef OVRMOBILE_OVR_MOBILE_PLUGIN_WRAPPER_H
+#define OVRMOBILE_OVR_MOBILE_PLUGIN_WRAPPER_H
+
+#include <jni.h>
+
+namespace ovrmobile {
+
+// Provide native access to the org.godotengine.plugin.vr.oculus.mobile.OvrMobilePlugin instance.
+class OvrMobilePluginWrapper {
+ public:
+  static void initializeWrapper(JNIEnv* env, jobject ovr_mobile_plugin);
+
+  static void uninitializeWrapper(JNIEnv* env);
+
+  static void on_headset_mounted();
+
+  static void on_headset_unmounted();
+
+ private:
+  OvrMobilePluginWrapper();
+  ~OvrMobilePluginWrapper();
+
+  static jobject ovr_mobile_plugin_instance;
+  static jmethodID on_headset_mounted_id;
+  static jmethodID on_headset_unmounted_id;
+
+};
+
+} // namespace ovrmobile
+
+#endif // OVRMOBILE_OVR_MOBILE_PLUGIN_WRAPPER_H

plugin/src/main/cpp/ovr_mobile_session.cpp

@@ -5,6 +5,7 @@
 #include "ovr_mobile_session.h"
 #include "common.h"
 #include <unistd.h>
+#include "jni/ovr_mobile_plugin_wrapper.h"
 
 namespace ovrmobile {
 
@@ -231,6 +232,28 @@ void OvrMobileSession::process() {
 
 	// Update the oculus controllers state.
 	ovr_mobile_controller->process(ovr, &java, predicted_display_time);
+
+	// Update the headset_mounted state if necessary
+	bool is_mounted = is_headset_mounted();
+	if (headset_mounted != is_mounted) {
+		if (is_mounted) {
+			// Notify that the headset is mounted.
+			OvrMobilePluginWrapper::on_headset_mounted();
+		} else {
+			// Notify that the headset is unmounted.
+			OvrMobilePluginWrapper::on_headset_unmounted();
+		}
+		headset_mounted = is_mounted;
+	}
+}
+
+bool OvrMobileSession::is_headset_mounted() const {
+	if (!in_vr_mode()) {
+		return false;
+	}
+
+	return vrapi_GetSystemStatusInt(&java, VRAPI_SYS_STATUS_MOUNTED)
+			== VRAPI_TRUE;
 }
 
 bool OvrMobileSession::enter_vr_mode() {

plugin/src/main/cpp/ovr_mobile_session.h

@@ -48,11 +48,11 @@ class OvrMobileSession {
 	// the api functionality.
 	bool initialize();
 
-	bool in_vr_mode() {
+	bool in_vr_mode() const {
 		return initialized && ovr != nullptr;
 	}
 
-	bool is_initialized() { return initialized; }
+	bool is_initialized() const { return initialized; }
 
 	// Notifies that the interface should be paused. For ovrmobile, this means we should leave vr mode if it's active.
 	void on_pause();
@@ -92,6 +92,8 @@ class OvrMobileSession {
 		return godot_eye == /* EYE_RIGHT */ 2 ? static_cast<int>(ovrEye::VRAPI_EYE_RIGHT) : static_cast<int>(ovrEye::VRAPI_EYE_LEFT);
 	}
 
+	bool is_headset_mounted() const;
+
 	static OvrMobileSession* singleton_instance;
 
 	bool initialized = false;
@@ -101,6 +103,7 @@ class OvrMobileSession {
 	unsigned int swap_interval;
 	uint64_t frame_index = 1;
 	double predicted_display_time = 0;
+	bool headset_mounted = true;
 
 	ovrVector4f default_layer_color_scale;
 

plugin/src/main/java/org/godotengine/plugin/vr/oculus/mobile/OvrMobilePlugin.kt

@@ -4,22 +4,84 @@ package org.godotengine.plugin.vr.oculus.mobile
 
 import org.godotengine.godot.Godot
 import org.godotengine.godot.plugin.GodotPlugin
+import java.util.concurrent.ConcurrentLinkedQueue
 
 /**
  * Driver class for the Oculus Mobile Godot plugin.
  */
 class OvrMobilePlugin(godot: Godot) : GodotPlugin(godot) {
 
+    /**
+     * Used to inquire about the headset state.
+     */
+    interface HeadsetStateListener {
+        /**
+         * Notifies when the headset is mounted.
+         */
+        fun onHeadsetMounted()
+
+        /**
+         * Notifies when the headset is unmounted.
+         */
+        fun onHeadsetUnmounted()
+    }
+
     companion object {
         init {
             System.loadLibrary("godot_ovrmobile")
         }
     }
 
+    private val headsetStateListeners = ConcurrentLinkedQueue<HeadsetStateListener>()
+
     override fun getPluginGDNativeLibrariesPaths() =
         setOf("addons/godot_ovrmobile/godot_ovrmobile.gdnlib")
 
     override fun getPluginMethods() = listOf<String>()
 
     override fun getPluginName() = "OVRMobile"
+
+    override fun onGLGodotMainLoopStarted() {
+        super.onGLGodotMainLoopStarted()
+        initializeWrapper()
+    }
+
+    override fun onMainDestroy() {
+        super.onMainDestroy()
+        runOnGLThread {
+            uninitializeWrapper()
+        }
+    }
+
+    fun registerHeadsetStateListener(listener: HeadsetStateListener) {
+        headsetStateListeners.add(listener)
+    }
+
+    fun unregisterHeadsetStateListener(listener: HeadsetStateListener) {
+        headsetStateListeners.remove(listener)
+    }
+
+    /**
+     * Invoked by the native code to signal the headset is mounted.
+     */
+    private fun onHeadsetMounted() {
+        // TODO(m4gr3d): Emit headset mounted signal when https://github.com/godotengine/godot/pull/37305 is submitted.
+        for (listener in headsetStateListeners) {
+            listener.onHeadsetMounted()
+        }
+    }
+
+    /**
+     * Invoked by the native code to signal the headset is unmounted.
+     */
+    private fun onHeadsetUnmounted() {
+        // TODO(m4gr3d): Emit headset unmounted signal when https://github.com/godotengine/godot/pull/37305 is submitted.
+        for (listener in headsetStateListeners) {
+            listener.onHeadsetUnmounted()
+        }
+    }
+
+    private external fun initializeWrapper()
+
+    private external fun uninitializeWrapper()
 }