Java lwjgl fps图纸发布
我在尝试使用LWJGL跟踪屏幕上的FPS时遇到了一些问题。我的代码出了什么问题 我一直都有这个:Java lwjgl fps图纸发布,java,opengl,lwjgl,slick2d,Java,Opengl,Lwjgl,Slick2d,我在尝试使用LWJGL跟踪屏幕上的FPS时遇到了一些问题。我的代码出了什么问题 我一直都有这个: Exception in thread "main" java.lang.NullPointerException at TheGame.renderFont(TheGame.java:66) at TheGame.start(TheGame.java:48) at TheGame.main(TheGame.java:88) at sun.reflect.Native
Exception in thread "main" java.lang.NullPointerException
at TheGame.renderFont(TheGame.java:66)
at TheGame.start(TheGame.java:48)
at TheGame.main(TheGame.java:88)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at com.intellij.rt.execution.application.AppMain.main(AppMain.java:120)
Process finished with exit code 1
代码在这里,非常简单-它基本上打开窗口并计算FPS,如果跟踪到标题,FPS是可以的,但是如何绘制字符串而不出错
import java.awt.Font;
import org.lwjgl.LWJGLException;
import org.lwjgl.opengl.Display;
import org.lwjgl.opengl.DisplayMode;
import org.lwjgl.Sys;
import org.newdawn.slick.Color;
import org.newdawn.slick.TrueTypeFont;
import org.newdawn.slick.util.ResourceLoader;
public class TheGame
{
int fps;
long lastFPS;
TrueTypeFont font;
boolean antiAlias = true;
public void start()
{
try
{
Display.setDisplayMode(new DisplayMode(800,600));
Display.create();
initFont();
} catch (LWJGLException e) {
e.printStackTrace();
System.exit(0);
}
// init OpenGL here
lastFPS = getTime(); // call before loop to initialise fps timer
while (!Display.isCloseRequested())
{
// render OpenGL here
updateFPS();
Display.update();
}
Display.destroy();
}
public void initFont()
{
Font awtFont = new Font("Times New Roman", Font.BOLD, 24);
TrueTypeFont font = new TrueTypeFont(awtFont, antiAlias);
}
public void updateFPS()
{
if (getTime() - lastFPS > 1000)
{
font.drawString(100, 50, "THE LIGHTWEIGHT JAVA GAMES LIBRARY", Color.yellow);
fps = 0; //reset the FPS counter
lastFPS += 1000; //add one second
}
fps++;
}
public long getTime()
{
return (Sys.getTime() * 1000) / Sys.getTimerResolution();
}
public static void main(String[] argv)
{
TheGame displayExample = new TheGame();
displayExample.start();
}
}
问题是您正在initFont方法中重新声明字体。将initFont更改为:
public void initFont()
{
Font awtFont = new Font("Times New Roman", Font.BOLD, 24);
font = new TrueTypeFont(awtFont, antiAlias);
}
我不知道这是否是您的NPE的原因,但根据JavaDoc,TrueTypeFont已被弃用:改用UnicodeFont。仍然没有解决问题:|它基本上可以处理错误,但屏幕上没有发生任何事情:(我建议实现游戏界面:并使用GameContainer的setShowFPS方法:是。这正是我想要的。非常感谢!