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Linux 使用OpenGL 3.2+；带固定基地运营商

linux opengl

Linux 使用OpenGL 3.2+；带固定基地运营商,linux,opengl,fbo,glx,Linux,Opengl,Fbo,Glx,我有一台ubuntu机器，还有一个用OSX编写的命令行应用程序，它使用FBOs在屏幕外呈现一些东西。这是代码的一部分 this->systemProvider->setupContext(); //be careful with this one. to add thingies to identify if a context is set up or not this->systemProvider->useContext(); gle

我有一台ubuntu机器，还有一个用OSX编写的命令行应用程序，它使用FBOs在屏幕外呈现一些东西。这是代码的一部分

        this->systemProvider->setupContext(); //be careful with this one. to add thingies to identify if a context is set up or not
    this->systemProvider->useContext();
    glewExperimental = GL_TRUE;
    glewInit();


    GLuint framebuffer, renderbuffer, depthRenderBuffer;

    GLuint imageWidth = _viewPortWidth,
            imageHeight = _viewPortHeight;

    //Set up a FBO with one renderbuffer attachment
    glGenFramebuffers(1, &framebuffer);
    glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);

    glGenRenderbuffers(1, &renderbuffer);
    glBindRenderbuffer(GL_RENDERBUFFER, renderbuffer);
    glRenderbufferStorage(GL_RENDERBUFFER, GL_RGB, imageWidth, imageHeight);
    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, renderbuffer);


    //Now bind a depth buffer to the FBO
    glGenRenderbuffers(1, &depthRenderBuffer);
    glBindRenderbuffer(GL_RENDERBUFFER, depthRenderBuffer);
    glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT, _viewPortWidth, _viewPortHeight);
    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depthRenderBuffer);

“系统提供程序”是一个围绕OS X的NSopunLLeVice的C++包装器，它只用于创建渲染上下文并使其处于当前状态，而不将其与窗口关联。所有渲染都在FBO中进行

我试图使用GLX为Linux（Ubuntu）使用相同的方法，但我很难做到这一点，因为我看到GLX需要像素缓冲区

我正在尝试遵循本教程：

最后，它使用一个像素缓冲区使上下文成为当前的，我听说这是不推荐的，我们应该放弃它，转而使用帧缓冲区对象，这是对的（我可能是错的）

有人有更好的方法或想法吗？

我不知道这是否是最好的解决方案，但它确实对我有效

将函数绑定到我们可以使用的局部变量

typedef GLXContext (*glXCreateContextAttribsARBProc)(Display*, GLXFBConfig, GLXContext, Bool, const int*);
typedef Bool (*glXMakeContextCurrentARBProc)(Display*, GLXDrawable, GLXDrawable, GLXContext);
static glXCreateContextAttribsARBProc glXCreateContextAttribsARB = NULL;
static glXMakeContextCurrentARBProc   glXMakeContextCurrentARB   = NULL;
我们的对象作为类属性：

Display *display;
GLXPbuffer pbuffer;
GLXContext openGLContext;

    glXCreateContextAttribsARB = (glXCreateContextAttribsARBProc) glXGetProcAddressARB( (const GLubyte *) "glXCreateContextAttribsARB" );
    glXMakeContextCurrentARB   = (glXMakeContextCurrentARBProc)   glXGetProcAddressARB( (const GLubyte *) "glXMakeContextCurrent");

    display = XOpenDisplay(NULL);
    if (display == NULL){
        std::cout  << "error getting the X display";
    }

    static int visualAttribs[] = {None};
    int numberOfFrameBufferConfigurations;
    GLXFBConfig *fbConfigs = glXChooseFBConfig(display, DefaultScreen(display), visualAttribs, &numberOfFrameBufferConfigurations);

    int context_attribs[] = {
        GLX_CONTEXT_MAJOR_VERSION_ARB ,3,
        GLX_CONTEXT_MINOR_VERSION_ARB, 2,
        GLX_CONTEXT_FLAGS_ARB, GLX_CONTEXT_DEBUG_BIT_ARB,
        GLX_CONTEXT_PROFILE_MASK_ARB, GLX_CONTEXT_CORE_PROFILE_BIT_ARB,
        None
    };

    std::cout << "initialising context...";
    this->openGLContext = glXCreateContextAttribsARB(display, fbConfigs[0], 0, True, context_attribs);

    int pBufferAttribs[] = {
        GLX_PBUFFER_WIDTH, (int)this->initialWidth,
        GLX_PBUFFER_HEIGHT, (int)this->initialHeight,
        None
    };

    this->pbuffer = glXCreatePbuffer(display, fbConfigs[0], pBufferAttribs);
    XFree(fbConfigs);
    XSync(display, False);

if(!glXMakeContextCurrent(display, pbuffer, pbuffer, openGLContext)){
    std::cout << "error with content creation\n";
}else{
    std::cout << "made a context the current context\n";
}
设置上下文：

Display *display;
GLXPbuffer pbuffer;
GLXContext openGLContext;

    glXCreateContextAttribsARB = (glXCreateContextAttribsARBProc) glXGetProcAddressARB( (const GLubyte *) "glXCreateContextAttribsARB" );
    glXMakeContextCurrentARB   = (glXMakeContextCurrentARBProc)   glXGetProcAddressARB( (const GLubyte *) "glXMakeContextCurrent");

    display = XOpenDisplay(NULL);
    if (display == NULL){
        std::cout  << "error getting the X display";
    }

    static int visualAttribs[] = {None};
    int numberOfFrameBufferConfigurations;
    GLXFBConfig *fbConfigs = glXChooseFBConfig(display, DefaultScreen(display), visualAttribs, &numberOfFrameBufferConfigurations);

    int context_attribs[] = {
        GLX_CONTEXT_MAJOR_VERSION_ARB ,3,
        GLX_CONTEXT_MINOR_VERSION_ARB, 2,
        GLX_CONTEXT_FLAGS_ARB, GLX_CONTEXT_DEBUG_BIT_ARB,
        GLX_CONTEXT_PROFILE_MASK_ARB, GLX_CONTEXT_CORE_PROFILE_BIT_ARB,
        None
    };

    std::cout << "initialising context...";
    this->openGLContext = glXCreateContextAttribsARB(display, fbConfigs[0], 0, True, context_attribs);

    int pBufferAttribs[] = {
        GLX_PBUFFER_WIDTH, (int)this->initialWidth,
        GLX_PBUFFER_HEIGHT, (int)this->initialHeight,
        None
    };

    this->pbuffer = glXCreatePbuffer(display, fbConfigs[0], pBufferAttribs);
    XFree(fbConfigs);
    XSync(display, False);

if(!glXMakeContextCurrent(display, pbuffer, pbuffer, openGLContext)){
    std::cout << "error with content creation\n";
}else{
    std::cout << "made a context the current context\n";
}

glXCreateContextAttribsARB=（glXCreateContextAttribsARBProc）glXGetProcAddressARB（（const GLubyte*）“glXCreateContextAttribsARB”）；
glXMakeContextCurrentARB=（glXMakeContextCurrentARBProc）glXGetProcAddressARB（（const GLubyte*）“glXMakeContextCurrent”）；
display=XOpenDisplay（空）；
如果（显示==NULL）{
标准：：cout initialWidth，
GLX_PBUFFER_高度，（int）此->初始高度，
没有一个
};
此->pbuffer=glXCreatePbuffer（显示，fbConfigs[0]，pBufferAttribs）；
XFree（fbConfigs）；
XSync（显示，False）；
使用上下文：

Display *display;
GLXPbuffer pbuffer;
GLXContext openGLContext;

    glXCreateContextAttribsARB = (glXCreateContextAttribsARBProc) glXGetProcAddressARB( (const GLubyte *) "glXCreateContextAttribsARB" );
    glXMakeContextCurrentARB   = (glXMakeContextCurrentARBProc)   glXGetProcAddressARB( (const GLubyte *) "glXMakeContextCurrent");

    display = XOpenDisplay(NULL);
    if (display == NULL){
        std::cout  << "error getting the X display";
    }

    static int visualAttribs[] = {None};
    int numberOfFrameBufferConfigurations;
    GLXFBConfig *fbConfigs = glXChooseFBConfig(display, DefaultScreen(display), visualAttribs, &numberOfFrameBufferConfigurations);

    int context_attribs[] = {
        GLX_CONTEXT_MAJOR_VERSION_ARB ,3,
        GLX_CONTEXT_MINOR_VERSION_ARB, 2,
        GLX_CONTEXT_FLAGS_ARB, GLX_CONTEXT_DEBUG_BIT_ARB,
        GLX_CONTEXT_PROFILE_MASK_ARB, GLX_CONTEXT_CORE_PROFILE_BIT_ARB,
        None
    };

    std::cout << "initialising context...";
    this->openGLContext = glXCreateContextAttribsARB(display, fbConfigs[0], 0, True, context_attribs);

    int pBufferAttribs[] = {
        GLX_PBUFFER_WIDTH, (int)this->initialWidth,
        GLX_PBUFFER_HEIGHT, (int)this->initialHeight,
        None
    };

    this->pbuffer = glXCreatePbuffer(display, fbConfigs[0], pBufferAttribs);
    XFree(fbConfigs);
    XSync(display, False);

if(!glXMakeContextCurrent(display, pbuffer, pbuffer, openGLContext)){
    std::cout << "error with content creation\n";
}else{
    std::cout << "made a context the current context\n";
}

if（！glXMakeContextCurrent（display，pbuffer，pbuffer，openGLContext））{

很好，是的，渲染缓冲区现在没有多大用处。你能详细说明一下吗？渲染缓冲区是什么意思？你有更好的跨平台替代方案吗？我可能说的“渲染缓冲区”是什么意思？你的代码正在使用它们。我希望你能详细说明这些替代方案，为什么你不认为它们不是很有用，因为在一个小型的谷歌搜索中，人们说最好的方法之一是使用fbo，不仅用于屏幕外渲染，还用于渲染到纹理效果。我很想听听你的替代方案。@BartekBanachewicz我相信他说的是像素缓冲区，而不是渲染缓冲区。我正试图在Ubuntu上使用GLX做完全相同的事情。OP提到的链接使用像素缓冲区来生成上下文。但是像素缓冲区不受欢迎，FBO是首选。他问的是如果我们想使用FBO，需要做什么。我的编译器是tellin告诉我“glXCreateContextAttribsARBProc”是一个未知的类型名