[libgdx游戏开发教程]使用Libgdx进行游戏开发(2)-游戏框架搭建

</pre>让我们抛开理论开始code吧。<p></p><p style="margin: 10px auto; padding-top: 0px; padding-bottom: 0px; font-family: Verdana, Arial, Helvetica, sans-serif; line-height: 18px; background-color: rgb(204, 232, 207);">入口类CanyonBunnyMain的代码：</p><p style="margin: 10px auto; padding-top: 0px; padding-bottom: 0px; font-family: Verdana, Arial, Helvetica, sans-serif; line-height: 18px; background-color: rgb(204, 232, 207);"></p><p style="margin: 10px auto; padding-top: 0px; padding-bottom: 0px; font-family: Verdana, Arial, Helvetica, sans-serif; line-height: 18px; background-color: rgb(204, 232, 207);"></p><pre name="code" class="java">package com.packtpub.libgdx.canyonbunny;import com.badlogic.gdx.ApplicationListener;import com.packtpub.libgdx.canyonbunny.game.WorldController;import com.packtpub.libgdx.canyonbunny.game.WorldRenderer;public class CanyonBunnyMain implements ApplicationListener {    private static final String TAG = CanyonBunnyMain.class.getName();    private WorldController worldController;    private WorldRenderer worldRenderer;    @Override    public void create() {    }    @Override    public void render() {    }    @Override    public void resize(int width, int height) {    }    @Override    public void pause() {    }    @Override    public void resume() {    }    @Override    public void dispose() {    }}

WorldController

package com.packtpub.libgdx.canyonbunny.game;public class WorldController {    private static final String TAG = WorldController.class.getName();    public WorldController() {    }    private void init() {    }    public void update(float deltaTime) {    }}

WorldRenderer

package com.packtpub.libgdx.canyonbunny.game;import com.badlogic.gdx.graphics.OrthographicCamera;import com.badlogic.gdx.graphics.g2d.SpriteBatch;import com.badlogic.gdx.utils.Disposable;import com.packtpub.libgdx.canyonbunny.util.Constants;public class WorldRenderer implements Disposable {    private OrthographicCamera camera;    private SpriteBatch batch;    private WorldController worldController;    public WorldRenderer(WorldController worldController) {    }    private void init() {    }    public void render() {    }    public void resize(int width, int height) {    }    @Override    public void dispose() {    }}

我们完成了CanyonBunnyMain, WorldController, WorldRenderer的第一个基本版本（骨架）。

有必要回顾一下我们框架的核心点：游戏主循环是在CanyonBunnyMain类的render()方法中。

要把三者联系起来，首先在create()中添加：

@Override    public void create() {        // Set Libgdx log level to DEBUG        Gdx.app.setLogLevel(Application.LOG_DEBUG);        // Initialize controller and renderer        worldController = new WorldController();        worldRenderer = new WorldRenderer(worldController);    }

然后在render里调用

@Override    public void render() {        // Update game world by the time that has passed        // since last rendered frame.        worldController.update(Gdx.graphics.getDeltaTime());        // Sets the clear screen color to: Cornflower Blue        Gdx.gl.glClearColor(0x64 / 255.0f, 0x95 / 255.0f, 0xed / 255.0f,0xff / 255.0f);//or Gdx.gl.glClearColor(100/255.0f, 149/255.0f, 237/255.0f, 255/255.0f);自定义的颜色        // Clears the screen        Gdx.gl.glClear(GL10.GL_COLOR_BUFFER_BIT);        // Render game world to screen        worldRenderer.render();    }

顺便修改下resize():（在游戏开始和改变窗口大小的时候会触发）

 @Override    public void resize(int width, int height) {        worldRenderer.resize(width, height);    }

之后是dispose

@Overridepublic void dispose() {worldRenderer.dispose();}

【在Android下，可以做个小改进】

在Android上进行暂停的时候：我们让游戏别渲染了。

 加个标志位

private boolean paused;

create()和render()这么改：

@Override    public void create() {        // Set Libgdx log level to DEBUG        Gdx.app.setLogLevel(Application.LOG_DEBUG);        // Initialize controller and renderer        worldController = new WorldController();        worldRenderer = new WorldRenderer(worldController);        // Game world is active on start        paused = false;    }    @Override    public void render() {        // Do not update game world when paused.        if (!paused) {            // Update game world by the time that has passed            // since last rendered frame.            worldController.update(Gdx.graphics.getDeltaTime());        }        // Sets the clear screen color to: Cornflower Blue        Gdx.gl.glClearColor(0x64 / 255.0f, 0x95 / 255.0f, 0xed / 255.0f,                0xff / 255.0f);        // Clears the screen        Gdx.gl.glClear(GL10.GL_COLOR_BUFFER_BIT);        // Render game world to screen        worldRenderer.render();    }

加上切换的代码：

@Override    public void pause() {        paused = true;    }    @Override    public void resume() {        paused = false;    }

OK。整合在一起了。运行看看效果。

太棒了。（你应该猜到了这里使用的设计模式就是MVC模式）

接下来，我们需要一个常量类来保存所有用到的常量。

package com.packtpub.libgdx.canyonbunny.util;public class Constants {// Visible game world is 5 meters widepublic static final float VIEWPORT_WIDTH = 5.0f;// Visible game world is 5 meters tallpublic static final float VIEWPORT_HEIGHT = 5.0f;}

现在需要在屏幕上加点东东了。我们现在在屏幕上画5个箱子。有人已经开始在准备箱子的图片了，这里我们不用图片，自己画。

（画一个矩形填上色，画两个对角线，再画个矩形边框，不就是个箱子吗？哈哈）像素画是不会美工的程序员的最爱，除了比较简单，还因为可以用程序画出来。

当然，用图片也是一样的。
首先要在脑子里想清楚，箱子对象归谁管理？画箱子这个职责是谁的？

箱子对象自然是由控制器来管理：为了方便识别，我们让其中一个箱子作为当前选中的箱子，并且让它自转。

public Sprite[] testSprites;    public int selectedSprite;    public WorldController() {        init();    }    private void init() {        initTestObjects();    }    private void initTestObjects() {        // Create new array for 5 sprites        testSprites = new Sprite[5];        // Create empty POT-sized Pixmap with 8 bit RGBA pixel data        int width = 32;        int height = 32;        Pixmap pixmap = createProceduralPixmap(width, height);        // Create a new texture from pixmap data        Texture texture = new Texture(pixmap);        // Create new sprites using the just created texture        for (int i = 0; i < testSprites.length; i++) {            Sprite spr = new Sprite(texture);            // Define sprite size to be 1m x 1m in game world            spr.setSize(1, 1);            // Set origin to sprite's center            spr.setOrigin(spr.getWidth() / 2.0f, spr.getHeight() / 2.0f);            // Calculate random position for sprite            float randomX = MathUtils.random(-2.0f, 2.0f);            float randomY = MathUtils.random(-2.0f, 2.0f);            spr.setPosition(randomX, randomY);            // Put new sprite into array            testSprites[i] = spr;        }        // Set first sprite as selected one        selectedSprite = 0;    }    private Pixmap createProceduralPixmap(int width, int height) {        Pixmap pixmap = new Pixmap(width, height, Format.RGBA8888);        // Fill square with red color at 50% opacity        pixmap.setColor(1, 0, 0, 0.5f);        pixmap.fill();        // Draw a yellow-colored X shape on square        pixmap.setColor(1, 1, 0, 1);        pixmap.drawLine(0, 0, width, height);        pixmap.drawLine(width, 0, 0, height);        // Draw a cyan-colored border around square        pixmap.setColor(0, 1, 1, 1);        pixmap.drawRectangle(0, 0, width, height);        return pixmap;    }    public void update(float deltaTime) {        updateTestObjects(deltaTime);    }    private void updateTestObjects(float deltaTime) {        // Get current rotation from selected sprite        float rotation = testSprites[selectedSprite].getRotation();        // Rotate sprite by 90 degrees per second        rotation += 90 * deltaTime;        // Wrap around at 360 degrees        rotation %= 360;        // Set new rotation value to selected sprite        testSprites[selectedSprite].setRotation(rotation);    }

注意：这里并没有任何涉及画箱子的部分(这里只是用代码生成了一副像素画，还没有显示)。不要和render搞混淆了。
接下来WorldRender负责把它画出来。

public WorldRenderer(WorldController worldController) {        this.worldController = worldController;        init();    }    private void init() {        batch = new SpriteBatch();        camera = new OrthographicCamera(Constants.VIEWPORT_WIDTH,                Constants.VIEWPORT_HEIGHT);        camera.position.set(0, 0, 0);        camera.update();    }    public void render() {        renderTestObjects();    }    private void renderTestObjects() {        batch.setProjectionMatrix(camera.combined);        batch.begin();        for (Sprite sprite : worldController.testSprites) {            sprite.draw(batch);        }        batch.end();    }    public void resize(int width, int height) {        camera.viewportWidth = (Constants.VIEWPORT_HEIGHT / height) * width;        camera.update();    }    @Override    public void dispose() {        batch.dispose();    }

看看效果

 至此，MVC模式的基本框架完成了。

接下来，我们需要开发一些Debug的控制功能来方便我们的开发。

比如

按上下左右，当前选中的箱子就开始上下左右移动。

按R键，游戏场景重新初始化。

按空格键，下一个箱子被选中。

再比如摄像机跟随当前箱子,视角放大缩小。

不用急着看下一章的代码实现，自己先试试用代码实现这些功能。

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PS:欢迎各路游戏爱好者入群426950359，暗号:Mignet