le(GL_DEPTH_TEST);
return 0;
}
/**
* Just the current frame in the display.
*/
static void engine_draw_frame(struct engine* engine) {
if (engine->display == NULL) {
// No display.
return;
}
// Just fill the screen with a color.
glClearColor(((float)engine->state.x)/engine->width, engine->state.angle,
((float)engine->state.y)/engine->height, 1);
glClear(GL_COLOR_BUFFER_BIT);
eglSwapBuffers(engine->display, engine->surface);
}
/**
* Tear down the EGL context currently associated with the display.
*/
static void 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;
}
/**
* Process the next input event.
*/
static int32_t engine_handle_input(struct android_app* app, AInputEvent* event) {
struct engine* engine = (struct engine*)app->userData;
if (AInputEvent_getType(event) == AINPUT_EVENT_TYPE_MOTION) {
engine->animating = 1;
engine->state.x = AMotionEvent_getX(event, 0);
engine->state.y = AMotionEvent_getY(event, 0);
return 1;
}
return 0;
}
/**
* Process the next main command.
*/
static void engine_handle_cmd(struct android_app* app, int32_t cmd) {
struct engine* engine = (struct engine*)app->userData;
switch (cmd) {
case APP_CMD_SAVE_STATE:
// The system has asked us to save our current state. Do so.
engine->app->savedState = malloc(sizeof(struct saved_state));
*((struct saved_state*)engine->app->savedState) = engine->state;
engine->app->savedStateSize = sizeof(struct saved_state);
break;
case APP_CMD_INIT_WINDOW:
// The window is being shown, get it ready.
if (engine->app->window != NULL) {
engine_init_display(engine);
engine_draw_frame(engine);
}
break;
case APP_CMD_TERM_WINDOW:
// The window is being hidden or closed, clean it up.
engine_term_display(engine);
break;
case APP_CMD_GAINED_FOCUS:
// When our app gains focus, we start monitoring the accelerometer.
if (engine->accelerometerSensor != NULL) {
ASensorEventQueue_enableSensor(engine->sensorEventQueue,
engine->accelerometerSensor);
// We'd like to get 60 events per second (in us).
ASensorEventQueue_setEventRate(engine->sensorEventQueue,
engine->accelerometerSensor, (1000L/60)*1000);
}
break;
case APP_CMD_LOST_FOCUS:
// When our app loses focus, we stop monitoring the accelerometer.
// This is to avoid consuming battery while not being used.
if (engine->accelerometerSensor != NULL) {