samples/game_controller/common/scene.hpp

/*
 * Copyright 2021 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
 *
 *     https://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.
 */

#pragma once

struct PointerCoords;

/* Represents a scene. A scene is an object that knows how to render itself to
 * the screen and knows how to react to input. At any moment in the game,
 * exactly one scene is active, and that scene is the one who decides what gets
 * drawn to the screen and how input is handled. See also: SceneManager */
class Scene {
 public:
  // Called when graphics context is initialized. This is when textures,
  // geometry, etc should be initialized.
  virtual void OnStartGraphics();

  // Called when the graphics context is about to be shut down. Tear down
  // all geometry, textures, etc.
  virtual void OnKillGraphics();

  // Called when this scene has just been installed as the active scene.
  virtual void OnInstall();

  // Called when it's time to draw a frame to the screen.
  virtual void DoFrame();

  // Called when this scene is about to be uninstalled as the active scene.
  virtual void OnUninstall();

  // Called when a pointer goes down (e.g. touch, touchpad, etc)
  virtual void OnPointerDown(int pointerId, const struct PointerCoords *coords);

  // Called when a pointer goes up (e.g. touch, touchpad, etc)
  virtual void OnPointerUp(int pointerId, const struct PointerCoords *coords);

  // Called when a pointer moves (e.g. touch, touchpad, etc)
  virtual void OnPointerMove(int pointerId, const struct PointerCoords *coords);

  // Called when screen gets resized
  virtual void OnScreenResized(int width, int height);

  // Called when game is paused (e.g. onPause())
  virtual void OnPause();

  // Called when game is resumed (e.g. onResumed())
  virtual void OnResume();

  // Destructor
  virtual ~Scene();
};