我正在尝试初始化GL11，因为我在讨论引用
的方法时遇到了麻烦GL11 gl
作为其论点。我试图在我的渲染器类中初始化它，但它没有工作，所以我认为初始化是弄乱渲染器并创建了一个新类来初始化。
import javax.microedition.khronos.egl.EGL10;
import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.egl.EGLContext;
import javax.microedition.khronos.egl.EGLDisplay;
import javax.microedition.khronos.opengles.GL11;
import android.opengl.GLU;
public class Unproject {
public static float setx;
public static float sety;
public static float posx, posy, posz;
EGLConfig[] configs = new EGLConfig[1];
EGLConfig config = configs[0];
static EGLContext glContext;
public static GL11 gl = (GL11)glContext.getGL();
EGLDisplay dpy = ((EGL10) gl).eglGetDisplay(EGL10.EGL_DEFAULT_DISPLAY);
public Unproject() {
glContext = ((EGL10) gl).eglCreateContext(dpy, config, EGL10.EGL_NO_CONTEXT, null);
}
public static void vector3 (GL11 gl){
int[] viewport = new int[4];
float[] modelview = new float[16];
float[] projection = new float[16];
float winx, winy, winz;
float[] newcoords = new float[3];
gl.glGetIntegerv(GL11.GL_VIEWPORT, viewport, 0);
gl.glGetFloatv(GL11.GL_MODELVIEW_MATRIX, modelview, 0);
gl.glGetFloatv(GL11.GL_PROJECTION_MATRIX, projection, 0);
winx = (float)setx;
winy = (float)viewport[3] - sety;
winz = 0;
GLU.gluUnProject(winx, winy, winz, modelview, 0, projection, 0, viewport, 0, newcoords, 0);
posx = (int)newcoords[1];
posy = (int)newcoords[2];
posz = (int)newcoords[3];
}
}
Vector3是我遇到麻烦的方法。我把它从渲染器移到这个类中。
这是我的渲染器：
import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.opengles.GL10;
import javax.microedition.khronos.opengles.GL11;
import android.opengl.GLU;
import android.opengl.GLSurfaceView.Renderer;
import android.view.MotionEvent;
public class GLSurfaceRenderer implements Renderer{
public float setx, sety;
private float posx, posy, posz;
private double speed;
private static float rotation;
private static float statrotation;
GL11 gl;
private static FlatColoredSquare square;
private static FlatColoredSquare statSquare;
public GLSurfaceRenderer () {
square = new FlatColoredSquare();
statSquare = new FlatColoredSquare();
rotation = (float) Math.floor(Math.random()*361);
speed = 0.1;
}
public synchronized void randomMethod(MotionEvent event){
if (event.getAction() == MotionEvent.ACTION_DOWN){
setx = event.getX();
sety = event.getY();
Unproject.vector3(gl);
}
}
@Override
public void onDrawFrame(GL10 gl) {
gl.glClear(GL10.GL_COLOR_BUFFER_BIT |
GL10.GL_DEPTH_BUFFER_BIT);
gl.glLoadIdentity();
gl.glScalef(10, 10, 0);
gl.glPushMatrix();
gl.glRotatef(rotation, 0, 0, 1);
gl.glTranslatef((float) speed/10, 0, 0);
square.draw(gl);
gl.glPopMatrix();
gl.glPushMatrix();
gl.glTranslatef(posx, posy, posz);
gl.glRotatef(statrotation,0,0,1);
statSquare.draw(gl);
gl.glPopMatrix();
statrotation++;
speed++;
}
@Override
public void onSurfaceChanged(GL10 gl, int width, int height) {
gl.glViewport(0, 0, width, height);
gl.glMatrixMode(GL10.GL_PROJECTION);
gl.glLoadIdentity();
GLU.gluOrtho2D(gl, 0.0f, width, 0.0f, height);
gl.glMatrixMode(GL10.GL_MODELVIEW);
gl.glLoadIdentity();
}
@Override
public void onSurfaceCreated(GL10 gl, EGLConfig config) {
gl.glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
gl.glShadeModel(GL10.GL_SMOOTH);
gl.glClearDepthf(1.0f);
gl.glEnable(GL10.GL_DEPTH_TEST);
gl.glDepthFunc(GL10.GL_LEQUAL);
gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_NICEST);
}
}
不幸的是，这段代码抛出了ExceptionInInitializerError
08-01 17:01:34.672: ERROR/AndroidRuntime(421): Uncaught handler: thread main exiting due to uncaught exception
08-01 17:01:34.762: ERROR/AndroidRuntime(421): java.lang.ExceptionInInitializerError
08-01 17:01:34.762: ERROR/AndroidRuntime(421): at android.app.ui.GLSurfaceRenderer.randomMethod(GLSurfaceRenderer.java:44)
08-01 17:01:34.762: ERROR/AndroidRuntime(421): at android.app.ui.Practice.onTouchEvent(Practice.java:37)
08-01 17:01:34.762: ERROR/AndroidRuntime(421): at android.app.Activity.dispatchTouchEvent(Activity.java:2064)
08-01 17:01:34.762: ERROR/AndroidRuntime(421): at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1643)
08-01 17:01:34.762: ERROR/AndroidRuntime(421): at android.view.ViewRoot.handleMessage(ViewRoot.java:1690)
08-01 17:01:34.762: ERROR/AndroidRuntime(421): at android.os.Handler.dispatchMessage(Handler.java:99)
08-01 17:01:34.762: ERROR/AndroidRuntime(421): at android.os.Looper.loop(Looper.java:123)
08-01 17:01:34.762: ERROR/AndroidRuntime(421): at android.app.ActivityThread.main(ActivityThread.java:4310)
08-01 17:01:34.762: ERROR/AndroidRuntime(421): at java.lang.reflect.Method.invokeNative(Native Method)
08-01 17:01:34.762: ERROR/AndroidRuntime(421): at java.lang.reflect.Method.invoke(Method.java:521)
08-01 17:01:34.762: ERROR/AndroidRuntime(421): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
08-01 17:01:34.762: ERROR/AndroidRuntime(421): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
08-01 17:01:34.762: ERROR/AndroidRuntime(421): at dalvik.system.NativeStart.main(Native Method)
08-01 17:01:34.762: ERROR/AndroidRuntime(421): Caused by: java.lang.NullPointerException
08-01 17:01:34.762: ERROR/AndroidRuntime(421): at android.app.ui.Unproject.<clinit>(Unproject.java:22)
08-01 17:01:34.762: ERROR/AndroidRuntime(421): ... 13 more
我能做些什么来纠正这个问题？我完全错了吗？我认为这可能是我在课堂之间共享变量的方式，有没有更好的方法呢？
答案 0 :(得分：2)
Based on this documentation抛出ExceptionInInitializerError以指示在评估静态初始值设定项或静态变量的初始值设定项期间发生了异常。检查你的代码是否有任何静态初始化逻辑。
答案 1 :(得分：1)
看来你得到的错误是由于类初始化中的NullPointerException。
static EGLContext glContext;
public static GL11 gl = (GL11)glContext.getGL();
您会注意到您正在尝试从未初始化的EGLContext实例调用getGl（）。在使用之前，您需要首先指定glContext。
stacktrace提到<clinit>，如果你不知道它意味着什么，这不是很有用。它引用了类初始化，这是静态成员初始化时发生的情况（如本例所示），但它也可以引用一个如下所示的静态初始化块：
static {
//some static init code
}
抛出ExceptionInInitializerError的原因可能是因为更高级别的东西正在捕获所有异常，并将它们包装在ExceptionInInitializerError中。