JOGL显示使用缓冲区

Question

我有3 FloatBuffers - 顶点，法线和颜色，其中包含名称的建议。我也有一个IntBuffer来跟踪索引。

数据看起来正确，但我在显示时遇到问题。我只看到一张空白的画布。我不知道我做错了什么。我猜在init(),display(),reshape()和dispose()中被忽略了。任何人都可以告诉我，如果你在下面的代码中发现一些明显错误的东西，为什么你觉得没有什么显示？

@Override 
    public void init(GLAutoDrawable drawable) { 
    GL2 gl = drawable.getGL().getGL2(); 
    gl.glClearColor(.0f, .0f, .2f, 0.9f); 
    gl.glEnable(GL2.GL_DEPTH_TEST); 
    gl.glDepthFunc(GL2.GL_LESS); 
    gl.glEnable(GL2.GL_CULL_FACE); 
    gl.glEnable(GL2.GL_LIGHTING); 
    gl.glEnable(GL2.GL_LIGHT0); 
    gl.glEnable(GL2.GL_AUTO_NORMAL); 
    gl.glEnable(GL2.GL_NORMALIZE); 
    gl.glFrontFace(GL2.GL_CCW); 
    gl.glCullFace(GL2.GL_BACK); 
    gl.glHint(GL2.GL_PERSPECTIVE_CORRECTION_HINT, GL2.GL_NICEST); 
    gl.glShadeModel(GL2.GL_SMOOTH); 
    if (viewMesh) { 
     gl.glPolygonMode(GL2.GL_FRONT_AND_BACK, GL2.GL_LINE); 
    } else { 
     gl.glPolygonMode(GL2.GL_FRONT_AND_BACK, GL2.GL_FILL); 
    } 

    glu = new GLU(); 

    // Build the VBOs 
    VBO = IntBuffer.allocate(4); 
    gl.glGenBuffers(4, VBO); 
    vertVBOID = VBO.get(0); 
    normalVBOID = VBO.get(1); 
    colorVBOID = VBO.get(2); 
    indexVBOID = VBO.get(3); 

    // vertices 
    int vsize = sd.verts.capacity() * BufferUtil.SIZEOF_FLOAT; 
    gl.glBindBuffer(GL2.GL_ARRAY_BUFFER, vertVBOID); // get a valid name 
    gl.glBufferData(GL2.GL_ARRAY_BUFFER, vsize, sd.verts, GL2.GL_STATIC_DRAW); 
    gl.glBindBuffer(GL2.GL_ARRAY_BUFFER, 0); // reset 

    // normals 
    int nsize = sd.normals.capacity() * BufferUtil.SIZEOF_FLOAT; 
    gl.glBindBuffer(GL2.GL_ARRAY_BUFFER, normalVBOID); 
    gl.glBufferData(GL2.GL_ARRAY_BUFFER, nsize, sd.normals, GL2.GL_STATIC_DRAW); 
    gl.glBindBuffer(GL2.GL_ARRAY_BUFFER, 0); 

    // colors 
    int csize = sd.colors.capacity() * BufferUtil.SIZEOF_FLOAT; 
    gl.glBindBuffer(GL2.GL_ARRAY_BUFFER, colorVBOID); 
    gl.glBufferData(GL2.GL_ARRAY_BUFFER, csize, sd.colors, GL2.GL_STATIC_DRAW); 
    gl.glBindBuffer(GL2.GL_ARRAY_BUFFER, 0); 

    int isize = sd.indices.capacity() * BufferUtil.SIZEOF_INT; 
    gl.glBindBuffer(GL2.GL_ELEMENT_ARRAY_BUFFER, indexVBOID); 
    gl.glBufferData(GL2.GL_ELEMENT_ARRAY_BUFFER, isize, sd.indices, GL2.GL_STATIC_DRAW); 
    gl.glBindBuffer(GL2.GL_ELEMENT_ARRAY_BUFFER, 0); 

    // sd.verts = null; // copy of data is no longer necessary, it is in the graphics card now. 
    // sd.colors = null; 
    // sd.normals = null; 
    // sd.indices = null; 
} 

@Override 
public void display(GLAutoDrawable drawable) { 
    GL2 gl = drawable.getGL().getGL2(); 
    gl.glMatrixMode(GL2.GL_MODELVIEW); 
    gl.glLoadIdentity(); 
    glu.gluLookAt(45, 0, 0, 0, 0, 0, 0.0, 1.0, 0.0); 

    gl.glScalef(scale, scale, scale); 
    gl.glRotatef(rot, 0, 1, 0); 
    gl.glTranslatef(-sd.tr_x, -sd.tr_y, -sd.tr_z); 

     gl.glEnableClientState(GLPointerFunc.GL_VERTEX_ARRAY); 
    gl.glEnableClientState(GLPointerFunc.GL_NORMAL_ARRAY); 
    gl.glEnableClientState(GLPointerFunc.GL_COLOR_ARRAY); 

    gl.glBindBuffer(GL2.GL_ARRAY_BUFFER, normalVBOID); 
    gl.glNormalPointer(GL2.GL_FLOAT, 0, 0); 
    gl.glBindBuffer(GL2.GL_ARRAY_BUFFER, colorVBOID); 
    gl.glColorPointer(3, GL2.GL_FLOAT, 0, 0); 
    gl.glBindBuffer(GL2.GL_ARRAY_BUFFER, vertVBOID); 
    gl.glVertexPointer(3, GL2.GL_FLOAT, 0, 0); 

    gl.glBindBuffer(GL2.GL_ELEMENT_ARRAY_BUFFER, indexVBOID); 
    gl.glDrawElements(GL2.GL_TRIANGLES, sd.indices.capacity(), GL2.GL_INT, 0); 
    gl.glBindBuffer(GL2.GL_ELEMENT_ARRAY_BUFFER, 0); // unbind it 

    gl.glDisableClientState(GLPointerFunc.GL_VERTEX_ARRAY); 
    gl.glDisableClientState(GLPointerFunc.GL_NORMAL_ARRAY); 
    gl.glDisableClientState(GLPointerFunc.GL_COLOR_ARRAY); 

} 

    @Override 
public void reshape(GLAutoDrawable drawable, int x, int y, int w, int h) { 
    GL2 gl = drawable.getGL().getGL2(); 
    double fov = (Math.PI/4.0); 
    double zmm = Math.abs(sd.min_z - sd.max_z); 
    camdist = (zmm/2.0)/Math.tan(fov/2.0); 

    h = (h == 0) ? 1 : h; 

    gl.glViewport(0, 0, w, h); 
    gl.glMatrixMode(GL2.GL_PROJECTION); 
    gl.glLoadIdentity(); 
    glu.gluPerspective(camdist, w/(float) h, 0.1f, 1000.0); 
} 




    /** 
* Initilaize graphics 
*/ 
public void initOGL() { 
    profile = GLProfile.get(GLProfile.GL2); 
    caps = new GLCapabilities(profile); 
    caps.setHardwareAccelerated(true); 
    canvas = new GLCanvas(caps); 
    canvas.addGLEventListener(this); 
    canvas.requestFocusInWindow(); 
    getContentPane().add(canvas); // add to the frame 
} 


    @Override 
public void dispose(GLAutoDrawable drawable) { 
} 

Answer 1

一个明显的问题是引入呼叫：

gl.glDrawElements(GL2.GL_TRIANGLES, sd.indices.capacity(), GL2.GL_INT, 0); 

GL_INT无效的glDrawElements()的型说法。唯一有效的值是GL_UNSIGNED_BYTE,GL_UNSIGNED_SHORT和GL_UNSIGNED_INT。因此，需要将电话：你有不按预期工作的OpenGL代码中的问题

gl.glDrawElements(GL2.GL_TRIANGLES, sd.indices.capacity(), GL2.GL_UNSIGNED_INT, 0); 

任何时候，请确保您拨打glGetError()。随着你的代码的呼叫，你应该立即得到一个GL_INVALID_ENUM错误。

此外，您的透视设置代码看起来有点可疑。我不完全理解你正在试图做什么有，但哪怕只是命名提出了一种可能的误解：

glu.gluPerspective(camdist, w/(float) h, 0.1f, 1000.0); 

的gluPerspective()第一个参数是场的视角度（度），而不是距离。