[問題] 請高手幫忙OpenGL framebuffer

[popen (Penpineapple-applepen)]

開發平台(Platform): (Ex: Win10, Linux, ...) 
win 7

編譯器(Ex: GCC, clang, VC++...)+目標環境(跟開發平台不同的話需列出)
VC++ 2013

額外使用到的函數庫(Library Used): (Ex: OpenGL, ...) 
OpenCV, OpenGL, OpenVR

問題(Question)：
我用2台IP CAM抓即時影像丟入Htc vive的雙眼虛擬實境裡,每秒30張,
但在VR裡的影像有一點不連續,能否幫我看是不是openGL的frame buffer有寫錯
因為我對OpenGL不太熟,程式也是從網路抓下來修修改改測試的

程式碼(Code)：(請善用置底文網頁, 記得排版) 

int framebufferWidth = 704, framebufferHeight = 480;
int numEyes = 2;  //左右眼
GLuint framebuffer[numEyes];
glGenFramebuffers(numEyes, framebuffer);

//主要while迴圈,在VR裡顯示影像
while (!glfwWindowShouldClose(window)) {
  for (int eye = 0; eye < numEyes; ++eye) {
     glBindFramebuffer(GL_FRAMEBUFFER, framebuffer[eye]);
     glViewport(0, 0, framebufferWidth, framebufferHeight);
     glBindFramebuffer(GL_FRAMEBUFFER, 0);  //(這行是不是不需要)

     glClearColor(0.1f, 0.2f, 0.3f, 0.0f);
     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

     GLuint colorRenderTarget[numEyes];
     if (eye == 0)      //將左眼的OpenCV mat轉成OpenGL texture格式
        colorRenderTarget[eye] = matToTexture(left_image, GL_LINEAR_MIPMAP_LINEAR, GL_LINEAR, GL_CLAMP);
     else if (eye == 1)  //將右眼的OpenCV mat轉成OpenGL texture格式
        colorRenderTarget[eye] = matToTexture(right_image, GL_LINEAR_MIPMAP_LINEAR, GL_LINEAR, GL_CLAMP);

     glEnable(GL_TEXTURE_2D);
     glBindTexture(GL_TEXTURE_2D, colorRenderTarget[eye]);
     glBindFramebuffer(GL_FRAMEBUFFER, framebuffer[eye]);
     glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, colorRenderTarget[eye], 0);
     glBindFramebuffer(GL_FRAMEBUFFER, 0);

     //將雙眼影像丟入Htc vive裡
     const vr::Texture_t tex = { reinterpret_cast<void*>(intptr_t(colorRenderTarget[eye])), vr::API_OpenGL, vr::ColorSpace_Linear };
     vr::VRCompositor()->Submit(vr::EVREye(eye), &tex);

     glDeleteTextures(1, &colorRenderTarget[numEyes]);
     glDisable(GL_TEXTURE_2D);
  }
}

glfwSwapBuffers(window);
glfwPollEvents();


下面是matToTexture函式(從網路抓來修改的):
GLuint matToTexture(cv::Mat &mat, GLenum minFilter, GLenum magFilter, GLenum
wrapFilter)
{
        // Generate a number for our textureID's unique handle
        GLuint textureID;
        glGenTextures(1, &textureID);

        // Bind to our texture handle
        glBindTexture(GL_TEXTURE_2D, textureID);

        // Catch silly-mistake texture interpolation method for magnification
        if (magFilter == GL_LINEAR_MIPMAP_LINEAR ||
                magFilter == GL_LINEAR_MIPMAP_NEAREST ||
                magFilter == GL_NEAREST_MIPMAP_LINEAR ||
                magFilter == GL_NEAREST_MIPMAP_NEAREST)
        {
            cout << "You can't use MIPMAPs for magnification - setting filter to GL_LINEAR" << endl;
            magFilter = GL_LINEAR;
        }

        // Set texture interpolation methods for minification and magnification
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, minFilter);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, magFilter);

        // Set texture clamping method
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, wrapFilter);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, wrapFilter);
        //glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
        //glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);

        // Set incoming texture format to:
        // GL_BGR       for CV_CAP_OPENNI_BGR_IMAGE,
        // GL_LUMINANCE for CV_CAP_OPENNI_DISPARITY_MAP,
        // Work out other mappings as required ( there's a list in comments in
main() )
        GLenum inputColourFormat = GL_BGR;
        if (mat.channels() == 1)
        {
                inputColourFormat = GL_LUMINANCE;
        }

        // Create the texture
        glTexImage2D(GL_TEXTURE_2D,     // Type of texture
                0,                 // Pyramid level (for mip-mapping) - 0 is the top
level
                GL_RGB,            // Internal colour format to convert to
                mat.cols,          // Image width  i.e. 640 for Kinect in standard mode
                mat.rows,          // Image height i.e. 480 for Kinect in standard mode
                0,                 // Border width in pixels (can either be 1 or 0)
                inputColourFormat, // Input image format (i.e. GL_RGB, GL_RGBA, GL_BGR
etc.)
                GL_UNSIGNED_BYTE,  // Image data type
                mat.ptr());        // The actual image data itself

        // If we're using mipmaps then generate them. Note: This requires OpenGL
3.0 or higher
        if (minFilter == GL_LINEAR_MIPMAP_LINEAR ||
                minFilter == GL_LINEAR_MIPMAP_NEAREST ||
                minFilter == GL_NEAREST_MIPMAP_LINEAR ||
                minFilter == GL_NEAREST_MIPMAP_NEAREST)
        {
                glGenerateMipmap(GL_TEXTURE_2D);
        }

        return textureID;
}


補充說明(Supplement)：
matToTexture函式應該還好, 能幫我檢查主要的while迴圈嗎?



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推 ggggggh: 為何有pyramid?
→ popen: 那裡有pyramid?
→ popen: 那個不用管,那是注解啊,那直接用copy來的
推 doom8199: vr 一般要跑在 90fps+ 才會順吧, 30太小了
→ doom8199: 再來你的 code 有幾個問題, 第一個是兩個 FBO 的 state
→ doom8199: 都設完了, 但沒人用它?  叫 GPU做事的指令應該是被埋在
→ doom8199: 'Submit' 裏頭, 可是也沒看到你把 FBO 傳進去
→ doom8199: 第二個是每個 swapbuffer 前都做了兩次 mat to texture
→ doom8199: 等於每個 frame 都做了兩次 memory copy 至 GPU 端
→ doom8199: 這種做法很沒效率; 一般應該是 GL要開 external texture
推 smartclever: windows上有eglimage可以用嗎?
→ popen: doom,請問能否提供範例,要怎麼修改才好