Strange GL frame buffer corruption

I am working on a new app using GL 4.2 core profile from scratch.

This is my init code:

Code :

---

     HDC hDC = ::GetDC(hWnd);
 
 
    PIXELFORMATDESCRIPTOR pfd;
    ::ZeroMemory(&pfd, sizeof(pfd));
    pfd.nSize = sizeof(pfd);
    pfd.nVersion = 1;
    pfd.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL 
        | PFD_GENERIC_ACCELERATED | PFD_DOUBLEBUFFER;
    pfd.iPixelType = PFD_TYPE_RGBA;
    pfd.cColorBits = 32;
    pfd.cAlphaBits = 8;
    pfd.cDepthBits = 24;
    pfd.cStencilBits = 8;
 
 
    int format = ::ChoosePixelFormat(hDC, &pfd);
 
 
    ::SetPixelFormat (hDC, format, &pfd);
 
 
    HGLRC hTempRC = ::wglCreateContext(hDC);
 
 
    ::wglMakeCurrent(hDC, hTempRC);
 
 
    wgl_LoadFunctions(hDC);
 
 
    int attribs[] = 
    {
        WGL_CONTEXT_MAJOR_VERSION_ARB, 4,
        WGL_CONTEXT_MINOR_VERSION_ARB, 2,
        WGL_CONTEXT_PROFILE_MASK_ARB, WGL_CONTEXT_CORE_PROFILE_BIT_ARB,
        0
    };
 
 
    HGLRC hRC = ::wglCreateContextAttribsARB(hDC, nullptr, attribs);    
 
 
    ::wglMakeCurrent(nullptr, nullptr);
 
 
    wglDeleteContext(hTempRC);
 
 
    ::wglMakeCurrent(hDC, hRC);
 
 
 
    ogl_LoadFunctions();

---

I then clear the framebuffer to red:

Code :

---

 
    ::glClearColor(1.0f, 0.0f, 0.0f, 1.0f);
    ::glClearDepthf(1.0f);
    ::glClearStencil(0);
 
 
    ::glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
    SwapBuffers(hDC);

---

This is the result:
http://i.imgur.com/0Nk9D.png

What am I doing wrong?

I am on Windows 7 SP1 64-bit, with AMD Catalyst 12.11 drivers.

How about without PFD_GENERIC_ACCELERATED specified in pfd.dwFlags?
From the MSDN PIXELFORMATDESCRIPTOR docs:

Quote:

---

The generic implementation is the Microsoft GDI software implementation of OpenGL.

---

Asking for a pixel format that supports a software implementation of OpenGL, and then creating an OpenGL 4.2 context may be the cause of the problem.

Quote:

---

Originally Posted by Dan Bartlett

How about without PFD_GENERIC_ACCELERATED specified in pfd.dwFlags?
Asking for a pixel format that supports a software implementation of OpenGL, and then creating an OpenGL 4.2 context may be the cause of the problem.

---

Removing that did not change anything.

Also the MSDN docs say next to PFD_GENERIC_ACCELERATED:

Quote:

---

The pixel format is supported by a device driver that accelerates the generic implementation. If this flag is clear and the PFD_GENERIC_FORMAT flag is set, the pixel format is supported by the generic implementation only.

---

Which indicates that it is the opposite of what you think, it looks for a non-generic implementation.

I discovered the problem.

It looks like it's a bug in AMD's driver.

I am running this on my HP latop which comes with two GPUs - an integrated one in the CPU/APU, and a dedicated GPU. AMD calls this Radeon Dual Graphics.

In the AMD driver control panel I can control whether a program runs in power saving mode - which means it only runs on the APU, or high performance mode - which runs it on both GPUs using CrossFire.

When I run it in high performance I get the corruption, but when I run it in power saving it correctly renders solid red.

So it must be a bug in the CrossFire driver.

EDIT: Just checked the current Catalyst driver versions, I was running Catalyst 12.11 Beta 3, which is about 1 month old, the current version 12.11 Beta 7.

I will test to see if the bug is still in Beta 7 - when it finishes downloading...