调用glBufferSubData时会生成GL_INVALID_OPERATION

Question

我想让GLTools在Android设备上启动。（GLTools是一个OpenGL SuperBible库）。这本书只讨论iOS而不是Android。 有一个问题。

void GLBatch::CopyVertexData3f(M3DVector3f *vVerts) 
{
// First time, create the buffer object, allocate the space
if(uiVertexArray == 0) {
    glGenBuffers(1, &uiVertexArray);
    glBindBuffer(GL_ARRAY_BUFFER, uiVertexArray);
    glBufferData(GL_ARRAY_BUFFER, sizeof(GLfloat) * 3 * nNumVerts, vVerts, GL_DYNAMIC_DRAW);
    }
else    { // Just bind to existing object
    glBindBuffer(GL_ARRAY_BUFFER, uiVertexArray);
    __android_log_print(ANDROID_LOG_ERROR, "CopyVertexData3f", "uiVertexArray = %d", 
        glIsBuffer(uiVertexArray));
    // Copy the data in
    glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(GLfloat) * 3 * nNumVerts, vVerts);
    //glBufferData(GL_ARRAY_BUFFER, sizeof(GLfloat) * 3 * nNumVerts, vVerts, GL_DYNAMIC_DRAW);
    pVerts = NULL;
    }
}

如果变量uiVertexArray不为零。代码将在else块中输入并抛出A GL_INVALID_OPERATION，如下所示：

<qgl2DrvAPI_glBufferSubData:769>: GL_INVALID_OPERATION

如果保留的缓冲区对象名称0绑定到目标，则生成GL_INVALID_OPERATION。 但uiVertexArray不是零。为什么代码在调用glBufferSubData？

时抛出GL_INVALID_OPERATION

一旦我将glBufferSubData改为glBufferData，它就可以了。