OpenGL：帧缓冲区，不完整的纹理附件

Question

我已经搜索了几个小时来解决我的问题。 首先。我有 HD 7800 系列 AMD GPU，最新的驱动程序。

我正在尝试创建具有我需要的所有帧缓冲区功能的帧缓冲区类。看来我可以使用渲染缓冲区，但是绘制到纹理会导致非常奇怪的错误。

FrameBuffer::FrameBuffer(int width, int height)
{
    createFrameBuffer();
//  createDepthBufferAttachment(width, height); //commented out for testing (THIS WORKS)
    createTextureAttachment(width, height);
//  createDepthTextureAttachment(width, height); //commented out for testing
    glBindFramebuffer(GL_FRAMEBUFFER, fbo);
    if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE){
        std::cerr << glCheckFramebufferStatus(GL_FRAMEBUFFER) << "\nFramebuffer failed to generate! 0\n";
    }
    unbindFrameBuffer();


}

FrameBuffer::~FrameBuffer()
{
    if (fbo != NULL)
        glDeleteFramebuffers(1, &fbo);
    if (colorTexture != NULL)
        glDeleteTextures(1, &colorTexture);
    if (depthBuffer != NULL)
        glDeleteRenderbuffers(1, &depthBuffer);
    if (depthTexture != NULL)
        glDeleteTextures(1, &depthTexture);
}

void FrameBuffer::createFrameBuffer(){
    glGenFramebuffers(1, &fbo);

}

void FrameBuffer::createTextureAttachment(int width, int height){
    glGenTextures(1, &colorTexture);
    glBindTexture(GL_TEXTURE_2D, colorTexture);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, GL_RGBA, 0, GL_UNSIGNED_BYTE, NULL);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

    glBindTexture(GL_TEXTURE_2D, 0);
    glBindFramebuffer(GL_FRAMEBUFFER, fbo);
    glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, colorTexture, 0);
    if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE){
        std::cerr << glCheckFramebufferStatus(GL_FRAMEBUFFER) << "\nFramebuffer failed to generate! 1\n";
    }
    glBindFramebuffer(GL_FRAMEBUFFER, 0);

}
void FrameBuffer::createDepthTextureAttachment(int width, int height){
    glGenTextures(1, &depthTexture);
    glBindTexture(GL_TEXTURE_2D, depthTexture);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT32, width, height, GL_DEPTH_COMPONENT, 0, GL_FLOAT, NULL);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);

    glBindTexture(GL_TEXTURE_2D, 0);
    glBindFramebuffer(GL_FRAMEBUFFER, fbo);
    glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, depthTexture, 0);
    if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE){
        std::cerr << glCheckFramebufferStatus(GL_FRAMEBUFFER) << "\nFramebuffer failed to generate! 2\n";
    }
    glBindFramebuffer(GL_FRAMEBUFFER, 0);

}

void FrameBuffer::createDepthBufferAttachment(int width, int height){
    glGenRenderbuffers(1, &depthBuffer);
    glBindRenderbuffer(GL_RENDERBUFFER, depthBuffer);
    glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT, width, height);
    glBindRenderbuffer(GL_RENDERBUFFER, 0);
    glBindFramebuffer(GL_FRAMEBUFFER, fbo);
    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depthBuffer);
    if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE){
        std::cerr << glCheckFramebufferStatus(GL_FRAMEBUFFER) << "\nFramebuffer failed to generate! 3\n";
    }
    glBindFramebuffer(GL_FRAMEBUFFER, 0);
}

void FrameBuffer::bindFrameBuffer( int width, int height){
    glBindTexture(GL_TEXTURE_2D, 0);
    glBindFramebuffer(GL_FRAMEBUFFER, fbo);
    glViewport(0, 0, width, height);
}

void FrameBuffer::unbindFrameBuffer(){
    glBindFramebuffer(GL_FRAMEBUFFER, 0);
    glViewport(0, 0, DisplayManager::getWidth(), DisplayManager::getHeight());
}

glCheckFrameBufferStatus 返回 GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT 在两次检查中。 createDepthTextureAttachment() 也会发生同样的情况 两者似乎都不起作用

createDepthBufferAttachment() 工作正常。

更多信息： 是的，实际上我实际上是在给函数指定宽度和高度，它们都是 1024。 我尝试将 GL_RGBA 更改为 GL_RGB，也尝试了不同大小的 GL_DEPTH_COMPONENT。

目前我打算只使用 1 个纹理，而不是全部 3 个函数。

我不知道这是否重要，但 SDL_GL_SetAttribute(SDL_GL_BUFFER_SIZE, 32);已设置。

我也尝试过 glFramebufferTexture() 函数。

提前谢谢你！

Answer 1

glTexImage2D() 调用中的参数顺序错误。看第一个：

glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, GL_RGBA, 0, GL_UNSIGNED_BYTE, NULL);

与函数定义比较：

void glTexImage2D(
    GLenum target,
    GLint level,
    GLint internalFormat,
    GLsizei width,
    GLsizei height,
    GLint border,
    GLenum format,
    GLenum type,
    const GLvoid* data);

可以看到第6个参数是边框宽度，第7个参数是格式。你有这两个倒置。调用应该是：

glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);

同样的事情也适用于另一个呼叫。

如果您在 OpenGL 代码工作时遇到问题，我强烈建议您致电 glGetError()。它会很快告诉您这些调用存在错误。