java - JOGL glBufferData 与 glVertexAttribPointer 不起作用

Question

我有一个关于 glBufferData 和 glVertexAttribPointer 的问题。由于某种原因，他们只是不能一起工作。这是代码:

    float[] triangleArray = {
            -1.0f, -1.0f, 0.0f,
            1.0f, -1.0f, 0.0f,
            0.0f, 1.0f, 0.0f    
    };

    IntBuffer vacantNameBuffer = IntBuffer.allocate(2);
    gl.glGenBuffers(1, vacantNameBuffer);
    int bufferIndex = vacantNameBuffer.get();

    FloatBuffer triangleVertexBuffer = Buffers.newDirectFloatBuffer(triangleArray);
    gl.glBindBuffer(GL2.GL_ARRAY_BUFFER, bufferIndex);
    IntBuffer paramBuffer = IntBuffer.allocate(2);
    gl.glGetBufferParameteriv(GL2.GL_ARRAY_BUFFER, GL2.GL_BUFFER_SIZE, paramBuffer);
    System.out.println(paramBuffer.get());
    int triangleBufferSize = triangleVertexBuffer.capacity() * Buffers.SIZEOF_FLOAT;
    gl.glBufferData(
            GL2.GL_ARRAY_BUFFER, 
            triangleBufferSize,
            triangleVertexBuffer, 
            GL2.GL_STATIC_DRAW);
    gl.glGetBufferParameteriv(GL2.GL_ARRAY_BUFFER, GL2.GL_BUFFER_SIZE, paramBuffer);
    System.out.println(paramBuffer.get());
    gl.glEnableVertexAttribArray(0);
    gl.glVertexAttribPointer(
            0, 
            3, 
            GL2.GL_FLOAT, 
            false, 
            0, 
            0);
    gl.glDrawArrays(GL2.GL_TRIANGLES, 0, 3);
    gl.glDisableVertexAttribArray(0);

但是，这非常有效:

    float[] triangleArray = {
            -1.0f, -1.0f, 0.0f,
            1.0f, -1.0f, 0.0f,
            0.0f, 1.0f, 0.0f    
    };

    FloatBuffer triangleVertexBuffer = Buffers.newDirectFloatBuffer(triangleArray);
    /*
    IntBuffer vacantNameBuffer = IntBuffer.allocate(2);
    gl.glGenBuffers(1, vacantNameBuffer);
    int bufferIndex = vacantNameBuffer.get();
    gl.glBindBuffer(GL2.GL_ARRAY_BUFFER, bufferIndex);
    IntBuffer paramBuffer = IntBuffer.allocate(2);
    gl.glGetBufferParameteriv(GL2.GL_ARRAY_BUFFER, GL2.GL_BUFFER_SIZE, paramBuffer);
    System.out.println(paramBuffer.get());
    int triangleBufferSize = triangleVertexBuffer.capacity() * Buffers.SIZEOF_FLOAT;
    gl.glBufferData(
            GL2.GL_ARRAY_BUFFER, 
            triangleBufferSize,
            triangleVertexBuffer, 
            GL2.GL_STATIC_DRAW);
    gl.glGetBufferParameteriv(GL2.GL_ARRAY_BUFFER, GL2.GL_BUFFER_SIZE, paramBuffer);
    System.out.println(paramBuffer.get());
    */
    gl.glEnableVertexAttribArray(0);
    gl.glVertexAttribPointer(
            0, 
            3, 
            GL2.GL_FLOAT, 
            false, 
            0, 
            triangleVertexBuffer);
    gl.glDrawArrays(GL2.GL_TRIANGLES, 0, 3);
    gl.glDisableVertexAttribArray(0);

如果有人愿意指出为什么我的代码不起作用。我将非常感激。

Answer 1

我发现了这个问题，问题不在于我的代码，而是由于 jogl 的限制，需要使用 gl 着色器程序。在这篇文章中找到答案:glDrawArrays() behaving weirdly on Mac OS X ;