Method DoFrame

endless-tunnel/app/src/main/cpp/native_engine.cpp:511–566

}

void NativeEngine::DoFrame() {
  // prepare to render (create context, surfaces, etc, if needed)
  if (!PrepareToRender()) {
    // not ready
    VLOGD("NativeEngine: preparation to render failed.");
    return;
  }

  SceneManager* mgr = SceneManager::GetInstance();

  // how big is the surface? We query every frame because it's cheap, and some
  // strange devices out there change the surface size without calling any
  // callbacks...
  int width, height;
  eglQuerySurface(mEglDisplay, mEglSurface, EGL_WIDTH, &width);
  eglQuerySurface(mEglDisplay, mEglSurface, EGL_HEIGHT, &height);

  if (width != mSurfWidth || height != mSurfHeight) {
    // notify scene manager that the surface has changed size
    LOGD("NativeEngine: surface changed size %dx%d --> %dx%d", mSurfWidth,
         mSurfHeight, width, height);
    mSurfWidth = width;
    mSurfHeight = height;
    mgr->SetScreenSize(mSurfWidth, mSurfHeight);
    glViewport(0, 0, mSurfWidth, mSurfHeight);
  }

  // if this is the first frame, install the welcome scene
  if (mIsFirstFrame) {
    mIsFirstFrame = false;
    mgr->RequestNewScene(new WelcomeScene());
  }

  // render!
  mgr->DoFrame();

  // swap buffers
  if (EGL_FALSE == eglSwapBuffers(mEglDisplay, mEglSurface)) {
    // failed to swap buffers...
    LOGW("NativeEngine: eglSwapBuffers failed, EGL error %d", eglGetError());
    HandleEglError(eglGetError());
  }

  // print out GL errors, if any
  GLenum e;
  static int errorsPrinted = 0;
  while ((e = glGetError()) != GL_NO_ERROR) {
    if (errorsPrinted < MAX_GL_ERRORS) {
      _log_opengl_error(e);
      ++errorsPrinted;
      if (errorsPrinted >= MAX_GL_ERRORS) {
        LOGE("*** NativeEngine: TOO MANY OPENGL ERRORS. NO LONGER PRINTING.");
      }
    }
  }
}

android_app* NativeEngine::GetAndroidApp() { return mApp; }