光滑的PNGDecoder错误——java.lang。UnsupportedOperationException:此图像不受支持的格式。

I'm making a simple little Galaga clone in Java with the Slick library. Unfortunately, I've run into an issue in which I get this error, followed by the game closing:

我正在用Java做一个简单的Galaga克隆，用光滑的库。不幸的是，我遇到了一个问题，我犯了这个错误，然后游戏结束:

Mon May 12 08:54:32 EDT 2014 WARN:class org.newdawn.slick.opengl.PNGImageData failed to
read the data
java.lang.UnsupportedOperationException: Unsupported format for this image
at org.newdawn.slick.opengl.PNGDecoder.decode(PNGDecoder.java:272)
at org.newdawn.slick.opengl.PNGImageData.loadImage(PNGImageData.java:97)
    at org.newdawn.slick.opengl.CompositeImageData.loadImage(CompositeImageData.
    java:62)
    at org.newdawn.slick.opengl.CompositeImageData.loadImage(CompositeImageData.
    java:43)
    at org.newdawn.slick.opengl.InternalTextureLoader.getTexture(InternalTextureLoader.
    java:292)
    at org.newdawn.slick.opengl.InternalTextureLoader.getTexture(InternalTextureLoader.
    java:254)
at org.newdawn.slick.opengl.InternalTextureLoader.getTexture(InternalTextureLoader.
    java:187)
at org.newdawn.slick.Image.<init>(Image.java:192)
at org.newdawn.slick.Image.<init>(Image.java:166)
at org.newdawn.slick.Image.<init>(Image.java:154)
at org.newdawn.slick.Image.<init>(Image.java:132)
at com.othinolis.danmaku.Play.init(Play.java:21)
at com.othinolis.danmaku.Game.initStatesList(Game.java:20)
at org.newdawn.slick.state.StateBasedGame.init(StateBasedGame.java:164)
at org.newdawn.slick.AppGameContainer.setup(AppGameContainer.java:393)
at org.newdawn.slick.AppGameContainer.start(AppGameContainer.java:317)
at com.othinolis.danmaku.Game.main(Game.java:29)
Mon May 12 08:54:35 EDT 2014 ERROR:null
java.lang.NullPointerException
at com.othinolis.danmaku.Play.render(Play.java:32)
at org.newdawn.slick.state.StateBasedGame.render(StateBasedGame.java:199)
at org.newdawn.slick.GameContainer.updateAndRender(GameContainer.java:688)
at org.newdawn.slick.AppGameContainer.gameLoop(AppGameContainer.java:411)
at org.newdawn.slick.AppGameContainer.start(AppGameContainer.java:321)
at com.othinolis.danmaku.Game.main(Game.java:29)
Mon May 12 08:54:35 EDT 2014 ERROR:Game.render() failure - check the game code.
org.newdawn.slick.SlickException: Game.render() failure - check the game code.
at org.newdawn.slick.GameContainer.updateAndRender(GameContainer.java:691)
at org.newdawn.slick.AppGameContainer.gameLoop(AppGameContainer.java:411)
at org.newdawn.slick.AppGameContainer.start(AppGameContainer.java:321)
at com.othinolis.danmaku.Game.main(Game.java:29)

This happens after I attempt to move states from the main menu and into the game proper, when PNGs are first loaded. All of my resources are PNGs. Here's my other class files:

这发生在我尝试将状态从主菜单移动到游戏本身之后，当PNGs首次加载时。我所有的资源都是PNGs。这是我的其他类文件:

Game.java:

Game.java:

package com.othinolis.danmaku;

import org.newdawn.slick.*;
import org.newdawn.slick.state.*;

public class Game extends StateBasedGame{

   public static final String gamename = "Danmaku Courage";
   public static final int menu = 0;
   public static final int play = 1;

   public Game(String gamename){
      super(gamename);
      this.addState(new Menu(menu));
      this.addState(new Play(play));
   }

   public void initStatesList(GameContainer gc) throws SlickException{
      this.getState(menu).init(gc, this);
      this.getState(play).init(gc, this);
      this.enterState(menu);
   }

   public static void main(String[] args) {
      AppGameContainer appgc;
      try{
         appgc = new AppGameContainer(new Game(gamename));
         appgc.setDisplayMode(600, 600, false);
         appgc.start();
      }catch(SlickException e){
         e.printStackTrace();
      }
   }

}

Menu.java (state 0, runs with no issues):

菜单。java(状态0，运行无问题):

package com.othinolis.danmaku;

import org.lwjgl.input.Mouse;
import org.newdawn.slick.*;
import org.newdawn.slick.state.*;

public class Menu extends BasicGameState{

   Image playNow;
   Image exitGame;

   public Menu(int state){
   }

   public void init(GameContainer gc, StateBasedGame sbg) throws SlickException{
      playNow = new Image("res/playButton.png");
      exitGame = new Image("res/exitGame.png");
   }

   public void render(GameContainer gc, StateBasedGame sbg, Graphics g) throws SlickException{
      g.drawString("Danmaku Courage", 230, 50);
      g.drawString("mousex: " + Mouse.getX() + " mousey: " + Mouse.getY(), 300, 400);
      playNow.draw(200,100);
      exitGame.draw(200,200);
   }

   public void update(GameContainer gc, StateBasedGame sbg, int delta) throws SlickException{
      int posX = Mouse.getX();
      int posY = Mouse.getY();
      //play now button
      if((posX>237 && posX<364)&&(posY>425 && posY<460)){
         if(Mouse.isButtonDown(0)){
            sbg.enterState(1);
         }
      }

      //exit game
      if((posX>254 && posX<335)&&(posY>338 && posY<361)){
         if(Mouse.isButtonDown(0)){
            System.exit(0);
         }
      }
   }

   public int getID(){
      return 0;
   }
}

and Play.java (moving between Menu and Play is where the issue hits. The numbers for collisions with the side of the screen and what have you may not be exact.):

和玩耍。java(在菜单和游戏之间移动是问题所在。与屏幕一侧发生碰撞的数字以及你所拥有的数字可能并不准确。

package com.othinolis.danmaku;

import org.newdawn.slick.*;
import org.newdawn.slick.state.*;

public class Play extends BasicGameState{

   Animation player, movingLeft, movingRight; //2 animations, player will be set to one
   Image worldMap;
   boolean quit = false;
   int[] duration = {200,200}; //length of the frame
   float playerPositionX = 0; //player will start at coordinates 0,0
   float playerPositionY = 0;
   float shiftX = buckyPositionX + 320; //this will shift the screen so bucky appears in middle
   float shiftY = buckyPositionY + 160; //half the length and half the width of the screen

   public Play(int state){
   }

   public void init(GameContainer gc, StateBasedGame sbg) throws SlickException{
      worldMap = new Image("res/background.png");
      Image[] walkLeft = {new Image("res/player.png"), new Image("res/player.png")};
      Image[] walkRight = {new Image("res/player.png"), new Image("res/player.png")};

      movingLeft = new Animation(walkLeft, duration, false);
      movingRight = new Animation(walkRight, duration, false);
      player = movingDown; //by default as soon as game loads, player will be facing down
   }

   public void render(GameContainer gc, StateBasedGame sbg, Graphics g) throws SlickException{
      worldMap.draw(buckyPositionX,buckyPositionY); //draw the map at 0,0 to start
      player.draw(shiftX,shiftY); //draw player at 320, 160 (center of the screen)
      g.drawString("player's X: "+playerPositionX+"\nplayer's Y: "+playerPositionY, 400, 20); //indicator to see where player is

      //when they press escape
      if(quit==true){
         g.drawString("Resume (R)", 250, 100);
         g.drawString("Main Menu (M)", 250, 150);
         g.drawString("Quit Game (Q)", 250, 200);
         if(quit==false){
            g.clear();
         }
      }
   }

   public void update(GameContainer gc, StateBasedGame sbg, int delta) throws SlickException{
      Input input = gc.getInput();
      if(input.isKeyDown(Input.KEY_LEFT)){
         player = movingLeft;
         playerPositionX += delta * .1f;
         if(playerPositionX>324){
            playerPositionX -= delta * .1f;
         }
      }
      if(input.isKeyDown(Input.KEY_RIGHT)){
         player = movingRight;
         playerPositionX -= delta * .1f;
         if(playerPositionX<-840){
            playerPositionX += delta * .1f;
         }
      }

      //escape
      if(input.isKeyDown(Input.KEY_ESCAPE)){
         quit = true;
      }      

      //when they hit escape
      if(quit==true){
         if(input.isKeyDown(Input.KEY_R)){
            quit = false;
         }
         if(input.isKeyDown(Input.KEY_M)){
            sbg.enterState(0);
            try{
               Thread.sleep(250);
            }catch(InterruptedException e){
               e.printStackTrace();
            }
         }
         if(input.isKeyDown(Input.KEY_Q)){
            System.exit(0);
         }
      }
   }

   public int getID(){
      return 1;
   }
}

What I know of slick has come from the several Forum posts I've read about issues like this one, (none of them had the exact issue nor the solution, of course) and Bucky's Slick tutorials that are here. If you'd like to download the project so you can import it and see if you can help me, I've thrown it onto Dropbox here.

我所知道的关于slick的内容来自于我在论坛上读过的一些关于此类问题的文章，(当然，这些文章都没有确切的问题，也没有解决方案)以及Bucky在这里发布的巧妙的教程。如果你想下载这个项目，你可以导入它，看看你能不能帮我，我把它扔到Dropbox这里。

2 个解决方案

#1

That's way too much code for anyone to read or debug. But regarding the actual problem: AFAIK, the Slick PNG loader only supports very few PNG file types (somehow related to performance when reading them, but that may be a myth...). It should be possible to load the image with something like

对于任何人来说，这都是太多的代码了。但是关于实际的问题:AFAIK，光滑的PNG加载程序只支持很少的PNG文件类型(在读取时与性能有关，但这可能是一个神话…)应该可以用类似的东西加载图像

// "Image" here refers to a Slick Image, and NOT to java.awt.Image!
private static Image loadImage(String path) throws IOException
{
    BufferedImage bufferedImage = ImageIO.read(new File(path));
    Texture texture = BufferedImageUtil.getTexture("", bufferedImage);
    Image image = new Img(texture.getImageWidth(), texture.getImageHeight());
    image.setTexture(texture); 
    return image;
}

#2

I had the same error when loading PNG Image using Slick-util library. The only thing I did was opening PNG file to Paint (Yes, Windows image editor) and saving as new PNG image. The problem was probably connected with type of PNG image (PNG Basics) and Paint saves it as some other type.

我在使用Slick-util库加载PNG图像时也有相同的错误。我所做的唯一一件事就是打开PNG文件进行绘图(是的，Windows图像编辑器)并将其保存为新的PNG图像。这个问题可能与PNG图像的类型有关(PNG基础)，而油漆将其保存为其他类型。

My function looked like below (took from Loading Images for LWJGL):

我的函数如下(从加载LWJGL图像中获取):

public int loadTexture(String fileName) {
Texture texture = null;
try {                
    texture = TextureLoader.getTexture("PNG", ResourceLoader.getResourceAsStream("res/" + fileName + ".png"));

    GL30.glGenerateMipmap(GL11.GL_TEXTURE_2D);
    GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MIN_FILTER,
                        GL11.GL_LINEAR_MIPMAP_LINEAR);
    GL11.glTexParameterf(GL11.GL_TEXTURE_2D, GL14.GL_TEXTURE_LOD_BIAS, 0f);
} catch (Exception e) {
    e.printStackTrace();
    System.err.println("Tried to load texture " + fileName + ".png , didn't work");
    System.exit(-1);
}
    textures.add(texture.getTextureID());
    return texture.getTextureID();
}