仅绘制帧缓冲区，而在OpenGL中没有其他内容

Question

所以我正在将所有内容绘制到可调整大小的帧缓冲区中。
这是我的代码：

int main(int argc, char* argv[])
{
    RUNNING = 1;

    GLuint renderBuffer;
    GLuint frameBuffer;
    GLuint depthRenderBuffer;

    // https://community.khronos.org/t/render-to-renderbuffer-with-depth-test/63793/3

    glGenRenderbuffers( 1, &renderBuffer );
    glBindRenderbuffer( GL_RENDERBUFFER, renderBuffer );
    glRenderbufferStorage( GL_RENDERBUFFER, GL_RGB32F, RES_WIDTH, RES_HEIGHT );
    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, renderBuffer);
    // TODO: check for errors here

    glGenRenderbuffers( 1, &depthRenderBuffer );
    glBindRenderbuffer( GL_RENDERBUFFER, depthRenderBuffer );
    glRenderbufferStorage( GL_RENDERBUFFER, GL_DEPTH_COMPONENT, RES_WIDTH, RES_HEIGHT );
    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depthRenderBuffer);
    // TODO: check for errors here

    while(RUNNING)
    {
        glfwPollEvents();

        glViewport(0, 0, RES_WIDTH, RES_HEIGHT);
        glBindFramebuffer(GL_FRAMEBUFFER, frameBuffer);
        glClearColor(255, 255, 255, 1.0f);
        glEnable(GL_DEPTH_TEST);
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

        // drawing on screen
        draw();

        glBindFramebuffer(GL_READ_FRAMEBUFFER, frameBuffer);
        glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
        glBlitFramebuffer(
        0, 0, RES_WIDTH, RES_HEIGHT,
        0, 0, window_width / 2, window_height / 2,
        GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT, GL_NEAREST);

        glfwSwapBuffers(window);
    }

    return 0;
}

现在，问题在于它似乎正在绘制默认的绘制缓冲区和我的帧缓冲区。 这使所有内容看起来都很奇怪，这是屏幕截图：

因此，好像在默认渲染缓冲区上方绘制了我的帧缓冲区。

我的问题是：

如何使它仅绘制帧缓冲区，而不绘制其底下的内容？