How to Take Screenshot in Opengl

OpenGL game screen capture

Problem is solved, I just calling GetScreenData(...) before SwapBuffers(...) now it works correctly but there is still a weird thing, on some computers I'v got shifted screens, for example: Screen #1 Don't know why it happens, for sure it happens on Nvidia 5xxx(m) i 7xxx(m) series so far as I know.
Big thanks for @AndonM.Coleman

Regular window screen capture using openGL

What you're asking for is something completely outside the scope of OpenGL. OpenGL is designed to be a platform-agnostic API for applications to talk about drawing stuff into framebuffers in an abstract fashion. OpenGL has no notion of windows*, screens, or a desktop. OpenGL doesn't operate at a level where such concepts exist. Heck, OpenGL doesn't even know what a GPU is. OpenGL is supposed to be initialized through platform-specific mechanisms to establish a context which assigns actual meaning to OpenGL API calls. As far as I know, there is no way to set up an OpenGL context with a framebuffer whose contents would somehow correspond to the desktop on Windows (or any other platform I'm aware of). As far as my understanding goes, this wouldn't really make sense…

To do what you want to do, you'll have to rely on the respective platform-specific APIs. The probably simplest way on Windows is to get an HDC for the entire desktop and BitBlt from there. See, e.g., this question for more on that. A more modern approach would be to use the DXGI Desktop Duplication API.

(*) yes, I know the OpenGL specification technically does talk about "windows" in a few places; but it only really does so when it's talking about all the things it's not responsible for…

Screenshots in OpenGL using python

Read the framebuffer with glReadPixels before the display is updated (before pygame.display.flip() or pygame.display.update()). Use pygame.image.fromstring() to create new Surfaces from the buffer. Finally, save the Surface to a file:

def main(): 
    # [...]
      
    while True: 
        screenshot = False
        for event in pygame.event.get(): 
            if event.type == pygame.QUIT: 
                pygame.quit() 
                quit() 
            if event.type == pygame.KEYDOWN:
                if event.key == pygame.K_s:
                    screenshot = True
        
        glRotatef(1, 12, 0,55115 ) 
        for i in range(8): 
            s=[] 
            for j in verticies[i]: 
                s.append([j]) 
            k=zarb_matris(s,a) 
            verticies[i]=k 

        glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT) 
        Cube() 

        if screenshot:
            screen = pygame.display.get_surface()
            size = screen.get_size()
            buffer = glReadPixels(0, 0, *size, GL_RGBA, GL_UNSIGNED_BYTE)
            screen_surf = pygame.image.fromstring(buffer, size, "RGBA")
            pygame.image.save(screen_surf, "screenshot.jpg")

        pygame.display.flip() 
        pygame.time.wait(10) 

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