Question

我有以下代码。我正在尝试创建一个具有两个颜色附件和一个深度模板附件的Multisample Framebuffer。

/* Generate Framebuffer and textures & renderbuffers */
glGenFramebuffers(1, &m_framebuffer);
glGenTextures(1, &m_fboColorAttachment);
glGenTextures(1, &m_fboAdditionalInfo);

glGenRenderbuffers(1,&m_fboRenderbufferDepthStencil);

glBindFramebuffer(GL_FRAMEBUFFER, m_framebuffer);

    /* setup color output 0 */
    glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, m_fboColorAttachment);
        glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_NEAREST);
        glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_NEAREST);
        glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_S,GL_CLAMP_TO_EDGE);
        glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_T,GL_CLAMP_TO_EDGE);
        glTexImage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE, 4, GL_RGBA8, renderDimensionsX, renderDimensionsY, GL_FALSE);
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D_MULTISAMPLE, m_fboColorAttachment, 0);
    glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, 0);

    /* setup color output 1 */
    glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, m_fboAdditionalInfo);
        glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_NEAREST);
        glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_NEAREST);
        glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_S,GL_CLAMP_TO_EDGE);
        glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_WRAP_T,GL_CLAMP_TO_EDGE);
        glTexImage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE, 4, GL_R32UI, renderDimensionsX, renderDimensionsY, GL_FALSE);
        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT1, GL_TEXTURE_2D_MULTISAMPLE, m_fboAdditionalInfo, 0);
    glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, 0);

    /* setup depth and stencil */
    glBindRenderbuffer(GL_RENDERBUFFER, m_fboRenderbufferDepthStencil);
    glRenderbufferStorageMultisample(GL_RENDERBUFFER, 4, GL_DEPTH24_STENCIL8, renderDimensionsX, renderDimensionsY);
    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER, m_fboRenderbufferDepthStencil);

    auto status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
    if(status != GL_FRAMEBUFFER_COMPLETE)
    {
        std::wstring statusStr = L"WTF error";
        if(status == GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT)
            statusStr = L"Attachment";
        else if(status == GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT)
            statusStr = L"Missing attachment";
        else if(status == GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER)
            statusStr = L"Draw buffer";
        else if(status == GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER)
            statusStr = L"Read buffer";
        else if(status == GL_FRAMEBUFFER_UNSUPPORTED)
            statusStr = L"Unsupported";
        else if(status == GL_FRAMEBUFFER_UNDEFINED)
            statusStr = L"Undefined";
        else if(status == GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE)
            statusStr = L"Multisample";
        else if(status == GL_FRAMEBUFFER_INCOMPLETE_LAYER_TARGETS)
            statusStr = L"Layer targets";
        drawFuncLog << L"Framebuffer status: " << statusStr << L"\r\n";
    }

glBindFramebuffer(GL_FRAMEBUFFER, 0);

我正在返回GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT状态。据我所知，所有内容都是以多重采样的形式创建的，并且多重采样级别的数量在附件中匹配。附件不完整显然意味着我的附件之一不完整，我认为是深度模板渲染缓冲区。

Answer 1

请参见OpenGL 4.6 API Core Profile Specification; 9.4.2 Whole Framebuffer Completeness; page 326：

如果满足以下所有条件，则绑定到目标的帧缓冲区对象被认为是完整的帧缓冲区：
  ......


所有附加纹理的TEXTURE_FIXED_SAMPLE_LOCATIONS值都相同；并且，如果附加的图像是渲染缓冲区和纹理的混合，则所有附加的纹理的TEXTURE_FIXED_SAMPLE_LOCATIONS的值必须为 TRUE 。

这意味着您必须将两个纹理附件的GL_TRUE传递到glTexImage2DMultisample的最后一个参数，以解决此问题：

glTexImage2DMultisample(
    GL_TEXTURE_2D_MULTISAMPLE, 4, GL_RGBA8, renderDimensionsX, renderDimensionsY, GL_TRUE);

glTexImage2DMultisample(
    GL_TEXTURE_2D_MULTISAMPLE, 4, GL_R32UI, renderDimensionsX, renderDimensionsY, GL_TRUE);

为什么我在这里得到GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT？

1 个答案: