Question

我有关于glBufferData和glVertexAttribPointer的问题。出于某种原因，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);

然而，这完美地运作：

    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

我发现了问题，这不是我的代码，但它有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;

JOGL glBufferData与glVertexAttribPointer无法正常工作

1 个答案: