我有3个FloatBuffers
- 顶点,法线和颜色,其中包含了名称所暗示的内容。我还有一个IntBuffer
来跟踪索引。
数据看起来正确,但我在显示时遇到问题。我只看到一块空白画布。我不确定我做错了什么。我在init()
,display()
,reshape()
和dispose()
中猜测某些内容被忽略了。任何人都可以告诉我,如果你在下面的代码中发现了一些明显的错误,为什么你认为什么都没有显示?
@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) {
}
答案 0 :(得分:2)
一个明显的问题在于平局调用:
gl.glDrawElements(GL2.GL_TRIANGLES, sd.indices.capacity(), GL2.GL_INT, 0);
GL_INT
对glDrawElements()
的类型参数无效。唯一有效的值为GL_UNSIGNED_BYTE
,GL_UNSIGNED_SHORT
和GL_UNSIGNED_INT
。所以电话需要是:
gl.glDrawElements(GL2.GL_TRIANGLES, sd.indices.capacity(), GL2.GL_UNSIGNED_INT, 0);
如果您遇到OpenGL代码无法正常工作的问题,请务必致电glGetError()
。通过代码调用,您应立即收到GL_INVALID_ENUM
错误。
此外,您的透视设置代码看起来有点可疑。我不完全明白你在那里做的是什么,但即使只是命名也暗示了一个可能的误解:
glu.gluPerspective(camdist, w / (float) h, 0.1f, 1000.0);
gluPerspective()
的第一个参数是视野角度(以度为单位),而不是距离。