AbstractScreen.java

package com.bluebananagames.gametemplate.screen;

import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.InputMultiplexer;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.OrthographicCamera;
import com.badlogic.gdx.graphics.g2d.SpriteBatch;
import com.badlogic.gdx.math.Rectangle;
import com.badlogic.gdx.math.Vector2;
import com.badlogic.gdx.scenes.scene2d.Stage;
import com.bluebananagames.gametemplate.Assets;
import com.bluebananagames.gametemplate.GameTemplateGame;

public abstract class AbstractScreen implements com.badlogic.gdx.Screen {
	protected final GameTemplateGame game;
	protected final OrthographicCamera camera;
	protected final SpriteBatch batch;
	protected final Stage stage;
	protected final InputMultiplexer inputMultiplexer;

	private Rectangle viewport;
	protected Assets assets = new Assets();

	public static final float CANVAS_WIDTH = 1920f;
	public static final float CANVAS_HEIGHT = 1080f;
	private static final float ASPECT_RATIO = CANVAS_WIDTH / CANVAS_HEIGHT;

	public AbstractScreen(GameTemplateGame game) {
		this.game = game;

		this.camera = new OrthographicCamera(CANVAS_WIDTH, CANVAS_HEIGHT);
		this.camera.position.set(CANVAS_WIDTH / 2f, CANVAS_HEIGHT / 2f, 0f);

		this.batch = new SpriteBatch();
		this.stage = new Stage(CANVAS_WIDTH, CANVAS_HEIGHT, true);

		this.inputMultiplexer = new InputMultiplexer(stage);

		Gdx.input.setInputProcessor(inputMultiplexer);
	}

	@Override
	public void render(float delta) {
		// update and draw the stage actors
		stage.act(delta);

		camera.update();

		if (viewport != null) {
			Gdx.gl.glViewport((int) viewport.x, (int) viewport.y, (int) viewport.width, (int) viewport.height);
		}

		// the following code clears the screen with the given RGB color (black)
		Gdx.gl.glClearColor(0f, 0f, 0f, 1f);
		Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);

	}

	@Override
	public void dispose() {
		// dispose the collaborators
		stage.dispose();
		batch.dispose();
		assets.dispose();
	}

	@Override
	public void resize(int width, int height) {
		// calculate new viewport
		float aspectRatio = (float) width / (float) height;
		float scale = 1f;
		Vector2 crop = new Vector2(0f, 0f);

		if (aspectRatio > ASPECT_RATIO) {
			scale = (float) height / (float) CANVAS_HEIGHT;
			crop.x = (width - CANVAS_WIDTH * scale) / 2f;
		} else if (aspectRatio < ASPECT_RATIO) {
			scale = (float) width / (float) CANVAS_WIDTH;
			crop.y = (height - CANVAS_HEIGHT * scale) / 2f;
		} else {
			scale = (float) width / (float) CANVAS_WIDTH;
		}

		float w = (float) CANVAS_WIDTH * scale;
		float h = (float) CANVAS_HEIGHT * scale;
		viewport = new Rectangle(crop.x, crop.y, w, h);

		camera.position.set(CANVAS_WIDTH / 2f, CANVAS_HEIGHT / 2f, 0f);

		// TODO: touch area is not right if using other aspect ratio then 1.6.
		// May not be an issue if depending on controller input alone.

		// stage.getCamera().position.set(CANVAS_WIDTH / 2f, CANVAS_HEIGHT / 2f,
		// 0f);
		// stage.getCamera().update();
	}

	public Assets getAssets() {
		return assets;
	}
}