概述：要知道，做一个游戏，摄像头是必不可少的。接下来，我将讲解libgdx里面摄像头的移动
2d摄像头OrthographicCamera也叫做正交相机
结果展示：
按上下左右是可以移动的
OrthographicCamera camera的使用：
完整代码：
package com.brentaureli.mariobros.cam;
import com.badlogic.gdx.ApplicationListener;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.Input;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.OrthographicCamera;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.graphics.g2d.Sprite;
import com.badlogic.gdx.graphics.g2d.SpriteBatch;
import com.badlogic.gdx.math.MathUtils;
import static com.badlogic.gdx.Gdx.gl;
public class T1 implements ApplicationListener {
private OrthographicCamera camera;
private float VIEWPORT_WIDTH=100f;
private float VIEWPORT_HEIGHT=100f;
private SpriteBatch batch;
private Sprite sprite;
@Override
public void create() {
sprite=new Sprite(new Texture(Gdx.files.internal("block.png")));
sprite.setSize(VIEWPORT_WIDTH,VIEWPORT_HEIGHT);
sprite.setPosition(0, 0);
float w = Gdx.graphics.getWidth();
float h = Gdx.graphics.getHeight();
camera=new OrthographicCamera(100,100*h/w);
camera.position.set(15f,11.25f,0);
camera.update();
batch=new SpriteBatch();
}
@Override
public void resize(int width, int height) {
//调整窗口，相机位置不变
camera.viewportWidth = 30f;
camera.viewportHeight = 30f * height / width;
camera.update();
}
@Override
public void render() {
handleInput();
resetCamera();
camera.update();
batch.setProjectionMatrix(camera.combined);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
batch.begin();
sprite.draw(batch);
batch.end();
}
private void resetCamera() {
if (Gdx.input.isKeyPressed(Input.Keys.R)) {
camera.position.set(camera.viewportWidth / 2f, camera.viewportHeight / 2f, 0);
camera.zoom = 1;
camera.rotate(0, 0, 0, 1);
}
}
private void handleInput() {
//放大相机
if (Gdx.input.isKeyPressed(Input.Keys.A)) {
camera.zoom += 0.02;
}
//缩小相机
if (Gdx.input.isKeyPressed(Input.Keys.Q)) {
camera.zoom -= 0.02;
}
//左移相机
if (Gdx.input.isKeyPressed(Input.Keys.LEFT)) {
camera.translate(-3, 0, 0);
}
//右移相机
if (Gdx.input.isKeyPressed(Input.Keys.RIGHT)) {
camera.translate(3, 0, 0);
}
//下移相机
if (Gdx.input.isKeyPressed(Input.Keys.DOWN)) {
camera.translate(0, -3, 0);
}
//上移相机
if (Gdx.input.isKeyPressed(Input.Keys.UP)) {
camera.translate(0, 3, 0);
}
}
@Override
public void pause() {
}
@Override
public void resume() {
}
@Override
public void dispose() {
sprite.getTexture().dispose();
batch.dispose();
}
}
主类完整代码：
package com.brentaureli.mariobros.desktop;
import com.badlogic.gdx.backends.lwjgl3.Lwjgl3Application;
import com.badlogic.gdx.backends.lwjgl3.Lwjgl3ApplicationConfiguration;
import com.brentaureli.mariobros.cam.T1;
public class DesktopLauncher {
public static void main (String[] arg) {
Lwjgl3ApplicationConfiguration config = new Lwjgl3ApplicationConfiguration();
config.setForegroundFPS(60);
config.setTitle("camera-example");
new Lwjgl3Application(new T1(), config);
}
}
先设置了一个背景
private Sprite sprite;
sprite=new Sprite(new Texture(Gdx.files.internal("block.png")));
sprite.setSize(VIEWPORT_WIDTH,VIEWPORT_HEIGHT);
sprite.setPosition(0, 0);
设置了背景的图片，背景的大小，背景位置。
接下来的代码：
float w = Gdx.graphics.getWidth();
float h = Gdx.graphics.getHeight();
camera=new OrthographicCamera(100,100*h/w);
camera.position.set(15f,11.25f,0);
camera.update();
batch=new SpriteBatch();
设置了camera的范围，camera的位置 camera.update();这个是每次更新camera的位置呀什么的都要进行一次更新。然后就是new了一个缓冲。
接下来的代码：
//调整窗口，相机位置不变
camera.viewportWidth = 30f;
camera.viewportHeight = 30f * height / width;
camera.update();
就是单纯的再调试了一下窗口。
接下来的代码：
private void handleInput() {
//放大相机
if (Gdx.input.isKeyPressed(Input.Keys.A)) {
camera.zoom += 0.02;
}
//缩小相机
if (Gdx.input.isKeyPressed(Input.Keys.Q)) {
camera.zoom -= 0.02;
}
//左移相机
if (Gdx.input.isKeyPressed(Input.Keys.LEFT)) {
camera.translate(-3, 0, 0);
}
//右移相机
if (Gdx.input.isKeyPressed(Input.Keys.RIGHT)) {
camera.translate(3, 0, 0);
}
//下移相机
if (Gdx.input.isKeyPressed(Input.Keys.DOWN)) {
camera.translate(0, -3, 0);
}
//上移相机
if (Gdx.input.isKeyPressed(Input.Keys.UP)) {
camera.translate(0, 3, 0);
}
}
添加了一下键盘输入的按键，camera.zoom += 0.02;就是将摄像的范围扩大同理camera.zoom -= 0.02;就是减少，而 camera.translate就是移动位置。
接下来的代码：
private void resetCamera() {
if (Gdx.input.isKeyPressed(Input.Keys.R)) {
camera.position.set(camera.viewportWidth / 2f, camera.viewportHeight / 2f, 0);
camera.zoom = 1;
camera.rotate(0, 0, 0, 1);
}
}
就是单纯的按r重置摄像头
然后就是：
camera.update();
batch.setProjectionMatrix(camera.combined);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
batch.begin();
sprite.draw(batch);
batch.end();
将摄像头进行更新，然后 batch.setProjectionMatrix(camera.combined);这个，这个可以说是固定搭配，就是配置一下摄像头。
batch.begin();
sprite.draw(batch);
batch.end();
缓存区打开，然后画图，end方法结尾。这算是固定搭配。
3D摄像头PerspectiveCamera也叫做透视相机
完整代码：
package com.brentaureli.mariobros.cam;
import com.badlogic.gdx.ApplicationListener;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.PerspectiveCamera;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.graphics.VertexAttributes;
import com.badlogic.gdx.graphics.g3d.Material;
import com.badlogic.gdx.graphics.g3d.Model;
import com.badlogic.gdx.graphics.g3d.ModelBatch;
import com.badlogic.gdx.graphics.g3d.ModelInstance;
import com.badlogic.gdx.graphics.g3d.attributes.TextureAttribute;
import com.badlogic.gdx.graphics.g3d.utils.FirstPersonCameraController;
import com.badlogic.gdx.graphics.g3d.utils.ModelBuilder;
import static com.badlogic.gdx.Gdx.gl;
public class T2 implements ApplicationListener {
private PerspectiveCamera camera;
private FirstPersonCameraController cameraController;
private ModelBatch batch;
private ModelBuilder builder;
private Texture texture;
private Model model;
private ModelInstance instance;
@Override
public void create() {
camera=new PerspectiveCamera(70, Gdx.graphics.getWidth(),Gdx.graphics.getHeight());
camera.position.set(0,0,0);
camera.near=0.1f;
camera.far=1000f;
camera.update();
cameraController=new FirstPersonCameraController(camera);
Gdx.input.setInputProcessor(cameraController);
cameraController.update();
batch=new ModelBatch();
builder=new ModelBuilder();
texture=new Texture(Gdx.files.internal("block.png"));
Material material=new Material(new TextureAttribute(TextureAttribute.Diffuse,texture));
int attributes= VertexAttributes.Usage.Position|VertexAttributes.Usage.TextureCoordinates;
model= builder.createBox(3, 3, 3, material, attributes);
instance= new ModelInstance(model);
instance.transform.setToTranslation(0,0,-5);
}
@Override
public void resize(int width, int height) {
camera.viewportWidth=width;
camera.viewportHeight=height;
camera.update();
cameraController.update();
}
@Override
public void render() {
gl.glClear(GL20.GL_COLOR_BUFFER_BIT|GL20.GL_DEPTH_BUFFER_BIT);
camera.update();
cameraController.update();
batch.begin(camera);
batch.render(instance);
batch.end();
}
@Override
public void pause() {
}
@Override
public void resume() {
}
@Override
public void dispose() {
}
}
主类就换个类名就行了，接下来是结果展示图：
按wsad可以上下左右移动。
由于篇幅可能过长，下一章也许会讲。
