GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT 正在尝试创建多重采样帧缓冲区

Question

我正在尝试弄清楚如何创建处理多重采样的帧缓冲区对象。下面是我试图让它工作的尝试，但是每当我检查我的帧缓冲区状态时，我总是收到 GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT 错误。即使我仅附加颜色缓冲区或仅附加 depth/stencil 缓冲区，我也会收到此错误。

我从没有多重采样的旧版本改编了这段代码，它能够创建一个完整的帧缓冲区。我留下了那些旧电话，但将它们注释掉了。

如何正确设置？

void DocumentPanel::setupFramebuffer()
{
    QOpenGLFunctions_3_3_Core *f = QOpenGLContext::currentContext()->versionFunctions<QOpenGLFunctions_3_3_Core>();

    int w = width();
    int h = height();
    int samples = 16;

    if (_frameBufferID == 0)
    {
        f->glGenFramebuffers(1, &_frameBufferID);
        f->glBindFramebuffer(GL_FRAMEBUFFER, _frameBufferID);
    }

    if (_texBufferColor == 0)
    {
        // generate texture
        f->glGenTextures(1, &_texBufferColor);
        f->glBindTexture(GL_TEXTURE_2D, _texBufferColor);
        f->glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
        f->glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
        f->glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
        f->glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
//        f->glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, w, h, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
        f->glTexImage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE, samples, GL_RGBA8, w, h, false);
        f->glBindTexture(GL_TEXTURE_2D, 0);

        // attach it to currently bound framebuffer object
//        f->glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, _texBufferColor, 0);
        f->glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D_MULTISAMPLE, _texBufferColor, 0);
    }

    if (_renderBufferDepthStencilID == 0)
    {
        f->glGenRenderbuffers(1, &_renderBufferDepthStencilID);
        f->glBindRenderbuffer(GL_RENDERBUFFER, _renderBufferDepthStencilID);
//        f->glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, w, h);
        f->glRenderbufferStorageMultisample(GL_RENDERBUFFER, samples, GL_DEPTH24_STENCIL8, w, h);
        f->glBindRenderbuffer(GL_RENDERBUFFER, 0);

        f->glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER, _renderBufferDepthStencilID);
    }

    GLenum status = f->glCheckFramebufferStatus(GL_FRAMEBUFFER);
    if (status != GL_FRAMEBUFFER_COMPLETE)
    {
        //error
        QString err;

        switch (status)
        {
        case GL_FRAMEBUFFER_UNDEFINED:
            err = "GL_FRAMEBUFFER_UNDEFINED";
        break;
        case GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT:
            err = "GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT";
        break;
        case GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT :
            err = "GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT ";
        break;
        case GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER :
            err = "GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER ";
        break;
        case GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER :
            err = "GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER ";
        break;
        case GL_FRAMEBUFFER_UNSUPPORTED :
            err = "GL_FRAMEBUFFER_UNSUPPORTED ";
        break;
        case GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE :
            err = "GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE ";
        break;
        case GL_FRAMEBUFFER_INCOMPLETE_LAYER_TARGETS  :
            err = "GL_FRAMEBUFFER_INCOMPLETE_LAYER_TARGETS  ";
        break;
        }

        f->glBindFramebuffer(GL_FRAMEBUFFER, 0);

        qDebug() << "Error building frambuffer: " << err;
        return;
    }

    //Rendering to window again
    f->glBindFramebuffer(GL_FRAMEBUFFER, 0);
}

Answer 1

GL_TEXTURE_2D 和 GL_TEXTURE_2D_MULTISAMPLE 是不同的纹理目标。您的代码将纹理绑定到 GL_TEXTURE_2D，但随后尝试通过 GL_TEXTURE_2D_MULTISAMPLE 对其进行操作，这是行不通的。

相反，您应该将 ALL 目标更改为 GL_TEXTURE_2D_MULTISAMPLE:

    f->glGenTextures(1, &_texBufferColor);
    f->glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, _texBufferColor);
    f->glTexImage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE, samples, GL_RGBA8, w, h, false);
    f->glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, 0);

GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT 正在尝试创建多重采样帧缓冲区

GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT trying to create multisample framebuffer

opengl

multisampling

framebuffer