glDrawArrays doesn't work

OpenGL Development JOGL Development
#1

glDrawArrays doesn’t work, it just shows a window with black background, nothing on it!

I searched this forum and used the “BufferUtil.newFloatBuffer” to generate the ordered floatbuffer, but still can not figure out where the problem is.
Anybody can help me check it and give me a help? Thanks very much!

I’m really screwed and can’t finish it before the deadline :’(

 public void display(GLAutoDrawable drawable) {
        GL gl = drawable.getGL();
        gl.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);
        gl.glLoadIdentity();
        gl.glColor3f(1F, 0F, 0F);

        // create FloatBuffer and store data in it
        float vs[] = {0, -0.1f, -0.1f, 0, -0.1f, 0.1f, 0, 0.1f, 0.1f, 0, 0.1f, -0.1f};
        FloatBuffer vertexBuffer = BufferUtil.newFloatBuffer(vs.length);

        vertexBuffer.clear();      
         vertexBuffer.put(vs);

        vertexBuffer.flip();
        vertexBuffer.rewind();

        // enable vertex array
        gl.glEnableClientState(GL.GL_VERTEX_ARRAY);

        // give pointer to data
        gl.glVertexPointer(3, GL.GL_FLOAT, 0, vertexBuffer);

        gl.glBegin(GL.GL_QUADS);

        // draw
        gl.glDrawArrays(GL.GL_QUADS, 0, 3);
//        gl.glDrawElements(GL.GL_QUADS, 3, GL.GL_QUADS, vertexBuffer);

        gl.glEnd();
    }

another question, when I use the gl.glDrawElements(GL.GL_QUADS, 3, GL.GL_QUADS, vertexBuffer),
I even can not compile it. It says:

“May not call this between glBegin and glEnd”

So, where can I call glDrawElements? Thanks!!!

#2

Remove the glBegin() and glEnd() calls - you don’t use those with glDrawArrays.

Also, I think the last argument to glDrawArrays is the number of items you indexed with glVertexPointer, which is 3 * 4 == 12, not 3, as you had.

#3

Still doesn’t work :-[, I’m really frustrated.

Is there any other suggestions? Thanks very much!!!

Ps. my JDK is 1.4.2_06, does it work?

#4

fixed, thanks!!!