JOGL 和帧缓冲区渲染到纹理的问题：无效的帧缓冲区操作错误

Question

好的，我尝试将场景渲染为小型 32x32 纹理，但遇到了问题。当我尝试将任何内容实际绘制到纹理时，出现“无效的帧缓冲区操作”错误。我简化了下面的代码，以便它只是尝试将四边形渲染到纹理，然后将该四边形绑定为渲染到屏幕上的另一个四边形的纹理。所以我的问题是......错误在哪里？这是使用 JOGL 1.1.1。错误发生在代码中的Checkpoint2处。

import java.awt.event.*;

import javax.media.opengl.*;
import javax.media.opengl.glu.*;
import javax.swing.JFrame;
import java.nio.*;

public class Main extends JFrame implements GLEventListener, KeyListener, MouseListener, MouseMotionListener, ActionListener{


/* GL related variables */
private final GLCanvas canvas;
private GL gl;
private GLU glu;

private int winW = 600, winH = 600;

private int texRender_FBO;
private int texRender_RB;
private int texRender_32x32;

public static void main(String args[]) {
    new Main();
}

/* creates OpenGL window */
public Main() {
    super("Problem Child");
    canvas = new GLCanvas();
    canvas.addGLEventListener(this);
    canvas.addKeyListener(this);
    canvas.addMouseListener(this);
    canvas.addMouseMotionListener(this);
    getContentPane().add(canvas);
    setSize(winW, winH);
    setLocationRelativeTo(null);
    setDefaultCloseOperation(EXIT_ON_CLOSE);
    setVisible(true);
    canvas.requestFocus();
}

/* gl display function */
public void display(GLAutoDrawable drawable) {
    gl.glBindFramebufferEXT(GL.GL_FRAMEBUFFER_EXT, this.texRender_FBO);
    gl.glPushAttrib(GL.GL_VIEWPORT_BIT);
    gl.glViewport(0, 0, 32, 32);
    gl.glClearColor(1.f, 0.f, 0.f, 1.f);
    System.out.print("Checkpoint1: "); outputError();
    gl.glBegin(GL.GL_QUADS);
    {
        //gl.glTexCoord2f(0.0f, 0.0f);
        gl.glColor3f(1.f, 0.f, 0.f);
        gl.glVertex3f(0.0f, 1.0f, 1.0f);
        //gl.glTexCoord2f(1.0f, 0.0f);
        gl.glColor3f(1.f, 1.f, 0.f);
        gl.glVertex3f(1.0f, 1.0f, 1.0f);
        //gl.glTexCoord2f(1.0f, 1.0f);
        gl.glColor3f(1.f, 1.f, 1.f);
        gl.glVertex3f(1.0f, 0.0f, 1.0f);
        //gl.glTexCoord2f(0.0f, 1.0f);
        gl.glColor3f(1.f, 0.f, 1.f);
        gl.glVertex3f(0.0f, 0.0f, 1.0f);
    }
    gl.glEnd(); System.out.print("Checkpoint2: "); outputError(); //Here I get an invalid framebuffer operation

    gl.glPopAttrib();
    gl.glBindFramebufferEXT(GL.GL_FRAMEBUFFER_EXT, 0);
    gl.glClearColor(0.f, 0.f, 0.f, 1.f);
    gl.glClear(GL.GL_COLOR_BUFFER_BIT);


    gl.glColor3f(1.f, 1.f, 1.f);
    gl.glBindTexture(GL.GL_TEXTURE_1D, this.texRender_32x32);
    gl.glBegin(GL.GL_QUADS);
    {
        gl.glTexCoord2f(0.0f, 0.0f);
        //gl.glColor3f(1.f, 0.f, 0.f);
        gl.glVertex3f(0.0f, 1.0f, 1.0f);
        gl.glTexCoord2f(1.0f, 0.0f);
        //gl.glColor3f(1.f, 1.f, 0.f);
        gl.glVertex3f(1.0f, 1.0f, 1.0f);
        gl.glTexCoord2f(1.0f, 1.0f);
        //gl.glColor3f(1.f, 1.f, 1.f);
        gl.glVertex3f(1.0f, 0.0f, 1.0f);
        gl.glTexCoord2f(0.0f, 1.0f);
        //gl.glColor3f(1.f, 0.f, 1.f);
        gl.glVertex3f(0.0f, 0.0f, 1.0f);
    }
    gl.glEnd();
}

/* initialize GL */
public void init(GLAutoDrawable drawable) {
    gl = drawable.getGL();
    glu = new GLU();

    gl.glClearColor(.3f, .3f, .3f, 1f);
    gl.glClearDepth(1.0f);

    gl.glMatrixMode(GL.GL_PROJECTION);
    gl.glLoadIdentity();
    gl.glOrtho(0, 1, 0, 1, -10, 10);
    gl.glMatrixMode(GL.GL_MODELVIEW);

    //Set up the 32x32 texture
    this.texRender_FBO = genFBO(gl);
    gl.glBindFramebufferEXT(GL.GL_FRAMEBUFFER_EXT, this.texRender_FBO);

    this.texRender_32x32 = genTexture(gl);
    gl.glBindTexture(GL.GL_TEXTURE_2D, this.texRender_32x32);
    gl.glTexImage2D(GL.GL_TEXTURE_2D, 0, GL.GL_RGB_FLOAT32_ATI, 32, 32, 0, GL.GL_RGB, GL.GL_FLOAT, null);
    gl.glFramebufferTexture2DEXT(GL.GL_FRAMEBUFFER_EXT, GL.GL_COLOR_ATTACHMENT0_EXT, GL.GL_TEXTURE_2D, this.texRender_32x32, 0);
    //gl.glDrawBuffer(GL.GL_COLOR_ATTACHMENT0_EXT);

    this.texRender_RB = genRB(gl);
    gl.glBindRenderbufferEXT(GL.GL_RENDERBUFFER_EXT, this.texRender_RB);
    gl.glRenderbufferStorageEXT(GL.GL_RENDERBUFFER_EXT, GL.GL_DEPTH_COMPONENT24, 32, 32);
    gl.glFramebufferRenderbufferEXT(GL.GL_FRAMEBUFFER_EXT, GL.GL_DEPTH_ATTACHMENT_EXT, GL.GL_RENDERBUFFER_EXT, this.texRender_RB);

    gl.glBindFramebufferEXT(GL.GL_FRAMEBUFFER_EXT, 0);
    gl.glBindRenderbufferEXT(GL.GL_RENDERBUFFER_EXT, 0);
    outputError();
}

private void outputError() {
    int c;
    if ((c = gl.glGetError()) != GL.GL_NO_ERROR)
        System.out.println(glu.gluErrorString(c));
}

private int genRB(GL gl) {
    int[] array = new int[1];
    IntBuffer ib = IntBuffer.wrap(array);
    gl.glGenRenderbuffersEXT(1, ib);
    return ib.get(0);
}

private int genFBO(GL gl) {
    int[] array = new int[1];
    IntBuffer ib = IntBuffer.wrap(array);
    gl.glGenFramebuffersEXT(1, ib);
    return ib.get(0);
}

private int genTexture(GL gl) {
    final int[] tmp = new int[1];
    gl.glGenTextures(1, tmp, 0);
    return tmp[0];
}

/* mouse and keyboard callback functions */
public void reshape(GLAutoDrawable drawable, int x, int y, int width, int height) {
    winW = width;
    winH = height;

    gl.glViewport(0, 0, width, height);
}

//Sorry about these, I just had to delete massive amounts of code to boil this thing down and these are hangers-on
public void mousePressed(MouseEvent e) {}
public void mouseDragged(MouseEvent e) {}
public void mouseReleased(MouseEvent e) {}
public void keyPressed(KeyEvent e) {}
public void displayChanged(GLAutoDrawable drawable, boolean modeChanged, boolean deviceChanged) { }
public void keyTyped(KeyEvent e) { }
public void keyReleased(KeyEvent e) { }
public void mouseMoved(MouseEvent e) { }
public void actionPerformed(ActionEvent e) { }
public void mouseClicked(MouseEvent e) { }
public void mouseEntered(MouseEvent e) { }
public void mouseExited(MouseEvent e) { }

}

Answer 1

为 texRender_32x32 尝试不同的内部格式。我认为这必须是某种 RGBA 格式而不仅仅是 RGB。

编辑：
好吧，我想我找到了。您正在对纹理使用默认的最小过滤器，这意味着 mipmap。创建 & 之后添加此行绑定纹理，一切都应该正常：

gl.glTexParameteri(GL.GL_TEXTURE_2D, GL.GL_TEXTURE_MIN_FILTER, GL.GL_LINEAR);

Answer 2

我对这个例子也有问题。错误

gl.glBindTexture(GL.GL_TEXTURE_1D, this.texRender_32x32);

应该是

gl.glBindTexture(GL.GL_TEXTURE_2D, this.texRender_32x32);