3D图片不加载Java

Question

我试着在3D发电机上展示一些发条。但我找不出这个错误：

javax.imageio.IIOException: Can't read input file!
at java.desktop/javax.imageio.ImageIO.read(ImageIO.java:1310)
at Texture.load(Texture.java:20)
at Texture.<init>(Texture.java:15)
at Texture.<clinit>(Texture.java:29)
at Game.<init>(Game.java:45)
at Game.main(Game.java:103)
javax.imageio.IIOException: Can't read input file!

当我启动程序时，整个世界都会出现黑色块：启动程序后的屏幕快照

我真的很想做一个3D引擎，你可以在房间里到处走动。所以这阻止了我的渲染。

这是我的守则：

类别:纹理

import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;

public class Texture {
  public int[] pixels;
  private String loc;
  public final int SIZE;

public Texture(String location, int SIZE) {
    loc = location;
    this.SIZE = SIZE;
    pixels = new int[SIZE * SIZE];
    load();
}

private void load() {
    try {
        BufferedImage image = ImageIO.read(new File(loc));
        int w = image.getWidth();
        int h = image.getHeight();
        image.getRGB(0, 0, w, h, pixels, 0, w);
    } catch (IOException e) {
        e.printStackTrace();
    }
}

public static Texture wood = new Texture("block1.png", 64);
public static Texture brick = new Texture("block2.png", 64);
public static Texture bluestone = new Texture("block3.png", 64);
public static Texture stone = new Texture("block1.png", 64);

}

班级游戏：

import java.awt.Color;
import java.awt.Graphics;
import java.awt.image.BufferStrategy;
import java.awt.image.BufferedImage;
import java.awt.image.DataBufferInt;
import java.util.ArrayList;
import javax.swing.JFrame;

public class Game extends JFrame implements Runnable{

 private static final long serialVersionUID = 1L;
 public int mapWidth = 15;
 public int mapHeight = 15;
 private Thread thread;
 private boolean running;
 private BufferedImage image;
 public int[] pixels;
 public ArrayList<Texture> textures;
 public Camera camera;
 public Screen screen;
 public static int[][] map =
        {
               {1,1,1,1,1,1,1,1,2,2,2,2,2,2,2},
               {1,0,0,0,0,0,0,0,2,0,0,0,0,0,2},
               {1,0,3,3,3,3,3,0,0,0,0,0,0,0,2},
               {1,0,3,0,0,0,3,0,2,0,0,0,0,0,2},
               {1,0,3,0,0,0,3,0,2,2,2,0,2,2,2},
               {1,0,3,0,0,0,3,0,2,0,0,0,0,0,2},
               {1,0,3,3,0,3,3,0,2,0,0,0,0,0,2},
               {1,0,0,0,0,0,0,0,2,0,0,0,0,0,2},
               {1,1,1,1,1,1,1,1,4,4,4,0,4,4,4},
               {1,0,0,0,0,0,1,4,0,0,0,0,0,0,4},
               {1,0,0,0,0,0,1,4,0,0,0,0,0,0,4},
               {1,0,0,0,0,0,1,4,0,3,3,3,3,0,4},
               {1,0,0,0,0,0,1,4,0,3,3,3,3,0,4},
               {1,0,0,0,0,0,0,0,0,0,0,0,0,0,4},
               {1,1,1,1,1,1,1,4,4,4,4,4,4,4,4}

        };
public Game() {
    thread = new Thread(this);
    image = new BufferedImage(640, 480, BufferedImage.TYPE_INT_RGB);
    pixels = ((DataBufferInt)image.getRaster().getDataBuffer()).getData();
    textures = new ArrayList<Texture>();
    textures.add(Texture.wood);
    textures.add(Texture.brick);
    textures.add(Texture.bluestone);
    textures.add(Texture.stone);
    camera = new Camera(4.5, 4.5, 1, 0, 0, -.66);
    screen = new Screen(map, mapWidth, mapHeight, textures, 640, 480);
    addKeyListener(camera);
    setSize(640, 480);
    setResizable(false);
    setTitle("3D Engine");
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setBackground(Color.black);
    setLocationRelativeTo(null);
    setVisible(true);
    start();
}
private synchronized void start() {
    running = true;
    thread.start();
}
public synchronized void stop() {
    running = false;
    try {
        thread.join();
    } catch(InterruptedException e) {
        e.printStackTrace();
    }
}
public void render() {
    BufferStrategy bs = getBufferStrategy();
    if(bs == null) {
        createBufferStrategy(3);
        return;
    }
    Graphics g = bs.getDrawGraphics();
    g.drawImage(image, 0, 0, image.getWidth(), image.getHeight(), null);
    bs.show();
}
public void run() {
    long lastTime = System.nanoTime();
    final double ns = 1000000000.0 / 60.0;//60 times per second
    double delta = 0;
    requestFocus();
    while(running) {
        long now = System.nanoTime();
        delta = delta + ((now-lastTime) / ns);
        lastTime = now;
        while (delta >= 1)//Make sure update is only happening 60 times a second
        {
            //handles all of the logic restricted time
            screen.update(camera, pixels);
            camera.update(map);
            delta--;
        }
        render();//displays to the screen unrestricted time
    }
}
public static void main(String [] args) {
    Game game = new Game();
}

}

Answer 1

加载纹理有问题。评估如何处理根本原因(为什么不能加载图像？)后果(你的世界是黑色的)：

根本原因

要找出无法加载映像的原因，一种方法是知道应用程序试图加载什么图像。修改load()方法如下：

private void load() {
    File file = new File(loc);
    try {
        BufferedImage image = ImageIO.read(file);
        int w = image.getWidth();
        int h = image.getHeight();
        image.getRGB(0, 0, w, h, pixels, 0, w);
    } catch (IOException e) {
        System.out.println("ERROR: Could not load "+file.getAbsolutePath());
        e.printStackTrace();
    }
}

您可能会发现，您只是在错误的目录中搜索。或者访问权限设置不正确。或者文件内容已损坏。或者..。

影响

当加载方法失败时，它不会停止程序。相反，你的游戏一直在运行。然而，像素数组并不包含良好的数据。

确保在方法失败时有有意义的紧急默认值。您可以将“错误图像”加载到像素数组中。这样你至少不应该有一个黑色的窗户。

Answer 2

异常堆栈跟踪非常直观，应该告诉您需要做什么。它指向ImageIO.read(File)代码中的一个异常，其如下所示：

public static BufferedImage read(File input) throws IOException {
// ... 
    if (!input.canRead()) {
        throw new IIOException("Can't read input file!"); // <-- This is the one
    }
// ... 
}

如您所见，问题在于canRead()返回false，并且根据该方法的API文档，该方法返回"__true当且仅当此抽象路径名指定的文件存在并可由应用程序读取；false否则“。

要么您的文件不存在于您试图读取的位置，要么您的文件具有访问保护，从而禁止应用程序读取它。就这么简单。

我相信在catch块中打印new File(loc).getAbsolutePath()将帮助您调试实际位置以及为什么不工作。最有可能的是，您不应该使用File，而应该在应用程序中使用嵌入式资源。