ndk/samples/native-activity/jni/main.c - platform/development - Git at Google

 /*
  * Copyright (C) 2010 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  *
  */

 #include <jni.h>

 #include <errno.h>
 #include <poll.h>
 #include <pthread.h>
 #include <sched.h>
 #include <string.h>
 #include <sys/resource.h>

 #include "glutils.h"

 // --------------------------------------------------------------------
 // Rendering and input engine thread
 // --------------------------------------------------------------------

 struct engine {
     pthread_mutex_t mutex;
     pthread_cond_t cond;

     int msgread;
     int msgwrite;

     ANativeActivity* activity;
     pthread_t thread;

     int running;
     int destroyed;
     AInputQueue* inputQueue;
     ANativeWindow* window;
     AInputQueue* pendingInputQueue;
     ANativeWindow* pendingWindow;

     // private to engine thread.
     int animating;
     EGLDisplay display;
     EGLSurface surface;
     EGLContext context;
     int32_t width;
     int32_t height;
     float angle;
     int32_t x;
     int32_t y;
 };

 enum {
     ENGINE_CMD_INPUT_CHANGED,
     ENGINE_CMD_WINDOW_CHANGED,
     ENGINE_CMD_GAINED_FOCUS,
     ENGINE_CMD_LOST_FOCUS,
     ENGINE_CMD_DESTROY,
 };

 static int engine_init_display(struct engine* engine) {
     // initialize opengl and egl
     const EGLint attribs[] = {
             EGL_DEPTH_SIZE, 16,
             EGL_NONE
     };
     EGLint w, h, dummy;
     EGLint numConfigs;
     EGLConfig config;
     EGLSurface surface;
     EGLContext context;

     EGLDisplay display = eglGetDisplay(EGL_DEFAULT_DISPLAY);

     eglInitialize(display, 0, 0);
     selectConfigForNativeWindow(display, attribs, engine->window, &config);
     surface = eglCreateWindowSurface(display, config, engine->window, NULL);
     context = eglCreateContext(display, config, NULL, NULL);
     eglQuerySurface(display, surface, EGL_WIDTH, &w);
     eglQuerySurface(display, surface, EGL_HEIGHT, &h);

     if (eglMakeCurrent(display, surface, surface, context) == EGL_FALSE) {
         LOGW("Unable to eglMakeCurrent");
         return -1;
     }

     engine->display = display;
     engine->context = context;
     engine->surface = surface;
     engine->width = w;
     engine->height = h;
     engine->angle = 0;

     // Initialize GL state.
     glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_FASTEST);
     glEnable(GL_CULL_FACE);
     glShadeModel(GL_SMOOTH);
     glEnable(GL_DEPTH_TEST);

     return 0;
 }

 static void engine_draw_frame(struct engine* engine) {
     if (engine->display == NULL) {
         // No display.
         return;
     }

     glClearColor(((float)engine->x)/engine->width, engine->angle,
             ((float)engine->y)/engine->height, 1);
     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

 #if 0
     glMatrixMode(GL_MODELVIEW);
     glLoadIdentity();
     glTranslatef(0, 0, -3.0f);
     glRotatef(engine->angle,        0, 1, 0);
     glRotatef(engine->angle*0.25f,  1, 0, 0);

     glEnableClientState(GL_VERTEX_ARRAY);
     glEnableClientState(GL_COLOR_ARRAY);

     //mCube.draw(gl);

     glRotatef(engine->angle*2.0f, 0, 1, 1);
     glTranslatef(0.5f, 0.5f, 0.5f);

     //mCube.draw(gl);
 #endif

     eglSwapBuffers(engine->display, engine->surface);

     //engine->angle += 1.2f;
 }

 static int engine_term_display(struct engine* engine) {
     if (engine->display != EGL_NO_DISPLAY) {
         eglMakeCurrent(engine->display, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);
         if (engine->context != EGL_NO_CONTEXT) {
             eglDestroyContext(engine->display, engine->context);
         }
         if (engine->surface != EGL_NO_SURFACE) {
             eglDestroySurface(engine->display, engine->surface);
         }
         eglTerminate(engine->display);
     }
     engine->animating = 0;
     engine->display = EGL_NO_DISPLAY;
     engine->context = EGL_NO_CONTEXT;
     engine->surface = EGL_NO_SURFACE;
 }

 static void* engine_entry(void* param) {
     struct engine* engine = (struct engine*)param;
     struct pollfd pfd[2];
     int numfd;

     pthread_mutex_lock(&engine->mutex);
     engine->running = 1;
     pthread_cond_broadcast(&engine->cond);
     pthread_mutex_unlock(&engine->mutex);

     // loop waiting for stuff to do.  we wait for input events or
     // commands from the main thread.

     pfd[0].fd = engine->msgread;
     pfd[0].events = POLLIN;
     pfd[0].revents = 0;

     while (1) {
         if (engine->inputQueue != NULL) {
             numfd = 2;
             pfd[1].fd = AInputQueue_getFd(engine->inputQueue);
             pfd[1].events = POLLIN;
         } else {
             numfd = 1;
         }

         pfd[0].revents = 0;
         pfd[1].revents = 0;
         int nfd = poll(pfd, numfd, engine->animating ? 0 : -1);
         if (nfd == 0 && engine->animating) {
             // There is no work to do -- step next animation.
             engine->angle += .01f;
             if (engine->angle > 1) {
                 engine->angle = 0;
             }
             engine_draw_frame(engine);
         }
         if (nfd < 0) {
             LOGI("Engine error in poll: %s\n", strerror(errno));
             // Should cleanly exit!
             continue;
         }

         if (pfd[0].revents == POLLIN) {
             int8_t cmd;
             if (read(engine->msgread, &cmd, sizeof(cmd)) == sizeof(cmd)) {
                 switch (cmd) {
                     case ENGINE_CMD_INPUT_CHANGED:
                         LOGI("Engine: ENGINE_CMD_INPUT_CHANGED\n");
                         pthread_mutex_lock(&engine->mutex);
                         engine->inputQueue = engine->pendingInputQueue;
                         pthread_cond_broadcast(&engine->cond);
                         pthread_mutex_unlock(&engine->mutex);
                         break;
                     case ENGINE_CMD_WINDOW_CHANGED:
                         LOGI("Engine: ENGINE_CMD_WINDOW_CHANGED\n");
                         pthread_mutex_lock(&engine->mutex);
                         engine_term_display(engine);
                         engine->window = engine->pendingWindow;
                         if (engine->window != NULL) {
                             engine_init_display(engine);
                             engine_draw_frame(engine);
                         }
                         pthread_cond_broadcast(&engine->cond);
                         pthread_mutex_unlock(&engine->mutex);
                         break;
                     case ENGINE_CMD_LOST_FOCUS:
                         engine->animating = 0;
                         engine_draw_frame(engine);
                         break;
                     case ENGINE_CMD_DESTROY:
                         LOGI("Engine: ENGINE_CMD_DESTROY\n");
                         pthread_mutex_lock(&engine->mutex);
                         engine_term_display(engine);
                         engine->destroyed = 1;
                         pthread_cond_broadcast(&engine->cond);
                         pthread_mutex_unlock(&engine->mutex);
                         // Can't touch engine object after this.
                         return NULL;   // EXIT THREAD
                 }
             } else {
                 LOGI("Failure reading engine cmd: %s\n", strerror(errno));
             }

         } else if (engine->inputQueue != NULL && pfd[1].revents == POLLIN) {
             AInputEvent* event = NULL;
             if (AInputQueue_getEvent(engine->inputQueue, &event) >= 0) {
                 LOGI("New input event: type=%d\n", AInputEvent_getType(event));
                 if (AInputEvent_getType(event) == INPUT_EVENT_TYPE_MOTION) {
                     engine->animating = 1;
                     engine->x = AMotionEvent_getX(event, 0);
                     engine->y = AMotionEvent_getY(event, 0);
                     engine_draw_frame(engine);
                 }
                 AInputQueue_finishEvent(engine->inputQueue, event, 0);
             } else {
                 LOGI("Failure reading next input event: %s\n", strerror(errno));
             }
         }
     }
 }

 static struct engine* engine_create(ANativeActivity* activity) {
     struct engine* engine = (struct engine*)malloc(sizeof(struct engine));
     memset(engine, 0, sizeof(struct engine));
     engine->activity = activity;

     pthread_mutex_init(&engine->mutex, NULL);
     pthread_cond_init(&engine->cond, NULL);

     int msgpipe[2];
     if (pipe(msgpipe)) {
         LOGI("could not create pipe: %s", strerror(errno));
     }
     engine->msgread = msgpipe[0];
     engine->msgwrite = msgpipe[1];

     pthread_attr_t attr;
     pthread_attr_init(&attr);
     pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
     pthread_create(&engine->thread, &attr, engine_entry, engine);

     // Wait for thread to start.
     pthread_mutex_lock(&engine->mutex);
     while (!engine->running) {
         pthread_cond_wait(&engine->cond, &engine->mutex);
     }
     pthread_mutex_unlock(&engine->mutex);

     return engine;
 }

 static void engine_write_cmd(struct engine* engine, int8_t cmd) {
     if (write(engine->msgwrite, &cmd, sizeof(cmd)) != sizeof(cmd)) {
         LOGI("Failure writing engine cmd: %s\n", strerror(errno));
     }
 }

 static void engine_set_input(struct engine* engine, AInputQueue* inputQueue) {
     pthread_mutex_lock(&engine->mutex);
     engine->pendingInputQueue = inputQueue;
     engine_write_cmd(engine, ENGINE_CMD_INPUT_CHANGED);
     while (engine->inputQueue != engine->pendingInputQueue) {
         pthread_cond_wait(&engine->cond, &engine->mutex);
     }
     pthread_mutex_unlock(&engine->mutex);
 }

 static void engine_set_window(struct engine* engine, ANativeWindow* window) {
     pthread_mutex_lock(&engine->mutex);
     engine->pendingWindow = window;
     engine_write_cmd(engine, ENGINE_CMD_WINDOW_CHANGED);
     while (engine->window != engine->pendingWindow) {
         pthread_cond_wait(&engine->cond, &engine->mutex);
     }
     pthread_mutex_unlock(&engine->mutex);
 }

 static void engine_destroy(struct engine* engine) {
     pthread_mutex_lock(&engine->mutex);
     engine_write_cmd(engine, ENGINE_CMD_DESTROY);
     while (!engine->destroyed) {
         pthread_cond_wait(&engine->cond, &engine->mutex);
     }
     pthread_mutex_unlock(&engine->mutex);

     close(engine->msgread);
     close(engine->msgwrite);
     pthread_cond_destroy(&engine->cond);
     pthread_mutex_destroy(&engine->mutex);
 }

 // --------------------------------------------------------------------
 // Native activity interaction (called from main thread)
 // --------------------------------------------------------------------

 static void onDestroy(ANativeActivity* activity)
 {
     LOGI("Destroy: %p\n", activity);
     engine_destroy((struct engine*)activity->instance);
 }

 static void onStart(ANativeActivity* activity)
 {
     LOGI("Start: %p\n", activity);
 }

 static void onResume(ANativeActivity* activity)
 {
     LOGI("Resume: %p\n", activity);
 }

 static void* onSaveInstanceState(ANativeActivity* activity, size_t* outLen)
 {
     LOGI("SaveInstanceState: %p\n", activity);
     return NULL;
 }

 static void onPause(ANativeActivity* activity)
 {
     LOGI("Pause: %p\n", activity);
 }

 static void onStop(ANativeActivity* activity)
 {
     LOGI("Stop: %p\n", activity);
 }

 static void onLowMemory(ANativeActivity* activity)
 {
     LOGI("LowMemory: %p\n", activity);
 }

 static void onWindowFocusChanged(ANativeActivity* activity, int focused)
 {
     LOGI("WindowFocusChanged: %p -- %d\n", activity, focused);
     engine_write_cmd((struct engine*)activity->instance,
             focused ? ENGINE_CMD_GAINED_FOCUS : ENGINE_CMD_LOST_FOCUS);
 }

 static void onNativeWindowCreated(ANativeActivity* activity, ANativeWindow* window)
 {
     LOGI("NativeWindowCreated: %p -- %p\n", activity, window);
     engine_set_window((struct engine*)activity->instance, window);
 }

 static void onNativeWindowDestroyed(ANativeActivity* activity, ANativeWindow* window)
 {
     LOGI("NativeWindowDestroyed: %p -- %p\n", activity, window);
     engine_set_window((struct engine*)activity->instance, NULL);
 }

 static void onInputQueueCreated(ANativeActivity* activity, AInputQueue* queue)
 {
     LOGI("InputQueueCreated: %p -- %p\n", activity, queue);
     engine_set_input((struct engine*)activity->instance, queue);
 }

 static void onInputQueueDestroyed(ANativeActivity* activity, AInputQueue* queue)
 {
     LOGI("InputQueueDestroyed: %p -- %p\n", activity, queue);
     engine_set_input((struct engine*)activity->instance, NULL);
 }

 void ANativeActivity_onCreate(ANativeActivity* activity,
         void* savedState, size_t savedStateSize)
 {
     LOGI("Creating: %p\n", activity);
     activity->callbacks->onDestroy = onDestroy;
     activity->callbacks->onStart = onStart;
     activity->callbacks->onResume = onResume;
     activity->callbacks->onSaveInstanceState = onSaveInstanceState;
     activity->callbacks->onPause = onPause;
     activity->callbacks->onStop = onStop;
     activity->callbacks->onLowMemory = onLowMemory;
     activity->callbacks->onWindowFocusChanged = onWindowFocusChanged;
     activity->callbacks->onNativeWindowCreated = onNativeWindowCreated;
     activity->callbacks->onNativeWindowDestroyed = onNativeWindowDestroyed;
     activity->callbacks->onInputQueueCreated = onInputQueueCreated;
     activity->callbacks->onInputQueueDestroyed = onInputQueueDestroyed;

     activity->instance = engine_create(activity);
 }
	/*
	* Copyright (C) 2010 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*
	*/

	#include <jni.h>

	#include <errno.h>
	#include <poll.h>
	#include <pthread.h>
	#include <sched.h>
	#include <string.h>
	#include <sys/resource.h>

	#include "glutils.h"

	// --------------------------------------------------------------------
	// Rendering and input engine thread
	// --------------------------------------------------------------------

	struct engine {
	pthread_mutex_t mutex;
	pthread_cond_t cond;

	int msgread;
	int msgwrite;

	ANativeActivity* activity;
	pthread_t thread;

	int running;
	int destroyed;
	AInputQueue* inputQueue;
	ANativeWindow* window;
	AInputQueue* pendingInputQueue;
	ANativeWindow* pendingWindow;

	// private to engine thread.
	int animating;
	EGLDisplay display;
	EGLSurface surface;
	EGLContext context;
	int32_t width;
	int32_t height;
	float angle;
	int32_t x;
	int32_t y;
	};

	enum {
	ENGINE_CMD_INPUT_CHANGED,
	ENGINE_CMD_WINDOW_CHANGED,
	ENGINE_CMD_GAINED_FOCUS,
	ENGINE_CMD_LOST_FOCUS,
	ENGINE_CMD_DESTROY,
	};

	static int engine_init_display(struct engine* engine) {
	// initialize opengl and egl
	const EGLint attribs[] = {
	EGL_DEPTH_SIZE, 16,
	EGL_NONE
	};
	EGLint w, h, dummy;
	EGLint numConfigs;
	EGLConfig config;
	EGLSurface surface;
	EGLContext context;

	EGLDisplay display = eglGetDisplay(EGL_DEFAULT_DISPLAY);

	eglInitialize(display, 0, 0);
	selectConfigForNativeWindow(display, attribs, engine->window, &config);
	surface = eglCreateWindowSurface(display, config, engine->window, NULL);
	context = eglCreateContext(display, config, NULL, NULL);
	eglQuerySurface(display, surface, EGL_WIDTH, &w);
	eglQuerySurface(display, surface, EGL_HEIGHT, &h);

	if (eglMakeCurrent(display, surface, surface, context) == EGL_FALSE) {
	LOGW("Unable to eglMakeCurrent");
	return -1;
	}

	engine->display = display;
	engine->context = context;
	engine->surface = surface;
	engine->width = w;
	engine->height = h;
	engine->angle = 0;

	// Initialize GL state.
	glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_FASTEST);
	glEnable(GL_CULL_FACE);
	glShadeModel(GL_SMOOTH);
	glEnable(GL_DEPTH_TEST);

	return 0;
	}

	static void engine_draw_frame(struct engine* engine) {
	if (engine->display == NULL) {
	// No display.
	return;
	}

	glClearColor(((float)engine->x)/engine->width, engine->angle,
	((float)engine->y)/engine->height, 1);
	glClear(GL_COLOR_BUFFER_BIT \| GL_DEPTH_BUFFER_BIT);

	#if 0
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
	glTranslatef(0, 0, -3.0f);
	glRotatef(engine->angle, 0, 1, 0);
	glRotatef(engine->angle*0.25f, 1, 0, 0);

	glEnableClientState(GL_VERTEX_ARRAY);
	glEnableClientState(GL_COLOR_ARRAY);

	//mCube.draw(gl);

	glRotatef(engine->angle*2.0f, 0, 1, 1);
	glTranslatef(0.5f, 0.5f, 0.5f);

	//mCube.draw(gl);
	#endif

	eglSwapBuffers(engine->display, engine->surface);

	//engine->angle += 1.2f;
	}

	static int engine_term_display(struct engine* engine) {
	if (engine->display != EGL_NO_DISPLAY) {
	eglMakeCurrent(engine->display, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);
	if (engine->context != EGL_NO_CONTEXT) {
	eglDestroyContext(engine->display, engine->context);
	}
	if (engine->surface != EGL_NO_SURFACE) {
	eglDestroySurface(engine->display, engine->surface);
	}
	eglTerminate(engine->display);
	}
	engine->animating = 0;
	engine->display = EGL_NO_DISPLAY;
	engine->context = EGL_NO_CONTEXT;
	engine->surface = EGL_NO_SURFACE;
	}

	static void* engine_entry(void* param) {
	struct engine* engine = (struct engine*)param;
	struct pollfd pfd[2];
	int numfd;

	pthread_mutex_lock(&engine->mutex);
	engine->running = 1;
	pthread_cond_broadcast(&engine->cond);
	pthread_mutex_unlock(&engine->mutex);

	// loop waiting for stuff to do. we wait for input events or
	// commands from the main thread.

	pfd[0].fd = engine->msgread;
	pfd[0].events = POLLIN;
	pfd[0].revents = 0;

	while (1) {
	if (engine->inputQueue != NULL) {
	numfd = 2;
	pfd[1].fd = AInputQueue_getFd(engine->inputQueue);
	pfd[1].events = POLLIN;
	} else {
	numfd = 1;
	}

	pfd[0].revents = 0;
	pfd[1].revents = 0;
	int nfd = poll(pfd, numfd, engine->animating ? 0 : -1);
	if (nfd == 0 && engine->animating) {
	// There is no work to do -- step next animation.
	engine->angle += .01f;
	if (engine->angle > 1) {
	engine->angle = 0;
	}
	engine_draw_frame(engine);
	}
	if (nfd < 0) {
	LOGI("Engine error in poll: %s\n", strerror(errno));
	// Should cleanly exit!
	continue;
	}

	if (pfd[0].revents == POLLIN) {
	int8_t cmd;
	if (read(engine->msgread, &cmd, sizeof(cmd)) == sizeof(cmd)) {
	switch (cmd) {
	case ENGINE_CMD_INPUT_CHANGED:
	LOGI("Engine: ENGINE_CMD_INPUT_CHANGED\n");
	pthread_mutex_lock(&engine->mutex);
	engine->inputQueue = engine->pendingInputQueue;
	pthread_cond_broadcast(&engine->cond);
	pthread_mutex_unlock(&engine->mutex);
	break;
	case ENGINE_CMD_WINDOW_CHANGED:
	LOGI("Engine: ENGINE_CMD_WINDOW_CHANGED\n");
	pthread_mutex_lock(&engine->mutex);
	engine_term_display(engine);
	engine->window = engine->pendingWindow;
	if (engine->window != NULL) {
	engine_init_display(engine);
	engine_draw_frame(engine);
	}
	pthread_cond_broadcast(&engine->cond);
	pthread_mutex_unlock(&engine->mutex);
	break;
	case ENGINE_CMD_LOST_FOCUS:
	engine->animating = 0;
	engine_draw_frame(engine);
	break;
	case ENGINE_CMD_DESTROY:
	LOGI("Engine: ENGINE_CMD_DESTROY\n");
	pthread_mutex_lock(&engine->mutex);
	engine_term_display(engine);
	engine->destroyed = 1;
	pthread_cond_broadcast(&engine->cond);
	pthread_mutex_unlock(&engine->mutex);
	// Can't touch engine object after this.
	return NULL; // EXIT THREAD
	}
	} else {
	LOGI("Failure reading engine cmd: %s\n", strerror(errno));
	}

	} else if (engine->inputQueue != NULL && pfd[1].revents == POLLIN) {
	AInputEvent* event = NULL;
	if (AInputQueue_getEvent(engine->inputQueue, &event) >= 0) {
	LOGI("New input event: type=%d\n", AInputEvent_getType(event));
	if (AInputEvent_getType(event) == INPUT_EVENT_TYPE_MOTION) {
	engine->animating = 1;
	engine->x = AMotionEvent_getX(event, 0);
	engine->y = AMotionEvent_getY(event, 0);
	engine_draw_frame(engine);
	}
	AInputQueue_finishEvent(engine->inputQueue, event, 0);
	} else {
	LOGI("Failure reading next input event: %s\n", strerror(errno));
	}
	}
	}
	}

	static struct engine* engine_create(ANativeActivity* activity) {
	struct engine* engine = (struct engine*)malloc(sizeof(struct engine));
	memset(engine, 0, sizeof(struct engine));
	engine->activity = activity;

	pthread_mutex_init(&engine->mutex, NULL);
	pthread_cond_init(&engine->cond, NULL);

	int msgpipe[2];
	if (pipe(msgpipe)) {
	LOGI("could not create pipe: %s", strerror(errno));
	}
	engine->msgread = msgpipe[0];
	engine->msgwrite = msgpipe[1];

	pthread_attr_t attr;
	pthread_attr_init(&attr);
	pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
	pthread_create(&engine->thread, &attr, engine_entry, engine);

	// Wait for thread to start.
	pthread_mutex_lock(&engine->mutex);
	while (!engine->running) {
	pthread_cond_wait(&engine->cond, &engine->mutex);
	}
	pthread_mutex_unlock(&engine->mutex);

	return engine;
	}

	static void engine_write_cmd(struct engine* engine, int8_t cmd) {
	if (write(engine->msgwrite, &cmd, sizeof(cmd)) != sizeof(cmd)) {
	LOGI("Failure writing engine cmd: %s\n", strerror(errno));
	}
	}

	static void engine_set_input(struct engine* engine, AInputQueue* inputQueue) {
	pthread_mutex_lock(&engine->mutex);
	engine->pendingInputQueue = inputQueue;
	engine_write_cmd(engine, ENGINE_CMD_INPUT_CHANGED);
	while (engine->inputQueue != engine->pendingInputQueue) {
	pthread_cond_wait(&engine->cond, &engine->mutex);
	}
	pthread_mutex_unlock(&engine->mutex);
	}

	static void engine_set_window(struct engine* engine, ANativeWindow* window) {
	pthread_mutex_lock(&engine->mutex);
	engine->pendingWindow = window;
	engine_write_cmd(engine, ENGINE_CMD_WINDOW_CHANGED);
	while (engine->window != engine->pendingWindow) {
	pthread_cond_wait(&engine->cond, &engine->mutex);
	}
	pthread_mutex_unlock(&engine->mutex);
	}

	static void engine_destroy(struct engine* engine) {
	pthread_mutex_lock(&engine->mutex);
	engine_write_cmd(engine, ENGINE_CMD_DESTROY);
	while (!engine->destroyed) {
	pthread_cond_wait(&engine->cond, &engine->mutex);
	}
	pthread_mutex_unlock(&engine->mutex);

	close(engine->msgread);
	close(engine->msgwrite);
	pthread_cond_destroy(&engine->cond);
	pthread_mutex_destroy(&engine->mutex);
	}

	// --------------------------------------------------------------------
	// Native activity interaction (called from main thread)
	// --------------------------------------------------------------------

	static void onDestroy(ANativeActivity* activity)
	{
	LOGI("Destroy: %p\n", activity);
	engine_destroy((struct engine*)activity->instance);
	}

	static void onStart(ANativeActivity* activity)
	{
	LOGI("Start: %p\n", activity);
	}

	static void onResume(ANativeActivity* activity)
	{
	LOGI("Resume: %p\n", activity);
	}

	static void* onSaveInstanceState(ANativeActivity* activity, size_t* outLen)
	{
	LOGI("SaveInstanceState: %p\n", activity);
	return NULL;
	}

	static void onPause(ANativeActivity* activity)
	{
	LOGI("Pause: %p\n", activity);
	}

	static void onStop(ANativeActivity* activity)
	{
	LOGI("Stop: %p\n", activity);
	}

	static void onLowMemory(ANativeActivity* activity)
	{
	LOGI("LowMemory: %p\n", activity);
	}

	static void onWindowFocusChanged(ANativeActivity* activity, int focused)
	{
	LOGI("WindowFocusChanged: %p -- %d\n", activity, focused);
	engine_write_cmd((struct engine*)activity->instance,
	focused ? ENGINE_CMD_GAINED_FOCUS : ENGINE_CMD_LOST_FOCUS);
	}

	static void onNativeWindowCreated(ANativeActivity* activity, ANativeWindow* window)
	{
	LOGI("NativeWindowCreated: %p -- %p\n", activity, window);
	engine_set_window((struct engine*)activity->instance, window);
	}

	static void onNativeWindowDestroyed(ANativeActivity* activity, ANativeWindow* window)
	{
	LOGI("NativeWindowDestroyed: %p -- %p\n", activity, window);
	engine_set_window((struct engine*)activity->instance, NULL);
	}

	static void onInputQueueCreated(ANativeActivity* activity, AInputQueue* queue)
	{
	LOGI("InputQueueCreated: %p -- %p\n", activity, queue);
	engine_set_input((struct engine*)activity->instance, queue);
	}

	static void onInputQueueDestroyed(ANativeActivity* activity, AInputQueue* queue)
	{
	LOGI("InputQueueDestroyed: %p -- %p\n", activity, queue);
	engine_set_input((struct engine*)activity->instance, NULL);
	}

	void ANativeActivity_onCreate(ANativeActivity* activity,
	void* savedState, size_t savedStateSize)
	{
	LOGI("Creating: %p\n", activity);
	activity->callbacks->onDestroy = onDestroy;
	activity->callbacks->onStart = onStart;
	activity->callbacks->onResume = onResume;
	activity->callbacks->onSaveInstanceState = onSaveInstanceState;
	activity->callbacks->onPause = onPause;
	activity->callbacks->onStop = onStop;
	activity->callbacks->onLowMemory = onLowMemory;
	activity->callbacks->onWindowFocusChanged = onWindowFocusChanged;
	activity->callbacks->onNativeWindowCreated = onNativeWindowCreated;
	activity->callbacks->onNativeWindowDestroyed = onNativeWindowDestroyed;
	activity->callbacks->onInputQueueCreated = onInputQueueCreated;
	activity->callbacks->onInputQueueDestroyed = onInputQueueDestroyed;

	activity->instance = engine_create(activity);
	}