When I enable the full scene antialiasing in DirectX 9, latest SDK, the program crashes at point where I create the vertex declaration claiming about null pointer access violation. I checked the hardware if it supports the requested FSAA samplers, and it does. What could be the problem?

Well the device is not created when FSAA is set. I tried playing with device type and vertex processing mode, but nothing changed. I got null device, with error code of invalid call. I run the program in debug mode, and using the debug version of libraries.

Actually here's some code may help:


memset(d3dpp, 0, sizeof(D3DPRESENT_PARAMETERS));

// Common attribs
d3dpp->Windowed = m_win.windowed;
d3dpp->hDeviceWindow = m_win.hwnd;
d3dpp->SwapEffect = D3DSWAPEFFECT_DISCARD;
d3dpp->EnableAutoDepthStencil = TRUE;
d3dpp->AutoDepthStencilFormat = D3DFMT_D16;
d3dpp->Flags = D3DPRESENTFLAG_LOCKABLE_BACKBUFFER;

//, D3DDEVTYPE_HAL, m_win.hwnd, D3DCREATE_HARDWARE_VERTEXPROCESSING
if (m_d3d->CheckDeviceMultiSampleType(D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, D3DFMT_A8R8G8B8, TRUE, D3DMULTISAMPLE_4_SAMPLES, NULL) == D3D_OK)
{
d3dpp->MultiSampleType = D3DMULTISAMPLE_4_SAMPLES;
}

// Render dims are the same as the client
// Pixel format is the same as the desktop
if (m_win.windowed) {
// They are already set by the create and resize functions
//m_win.render_width = client area width
//m_win.render_height = client area height
d3dpp->BackBufferWidth = 0; // So that D3D uses the client area dimensions
d3dpp->BackBufferFormat = D3DFMT_UNKNOWN;
} else {
// Render dims are the current dispmode resolution
d3dpp->BackBufferWidth = m_disp.dispmode[m_disp.curmode].xres;
d3dpp->BackBufferHeight = m_disp.dispmode[m_disp.curmode].yres;
d3dpp->FullScreen_RefreshRateInHz = m_disp.dispmode[m_disp.curmode].refresh;
// Pixel format is the display setting format
d3dpp->BackBufferFormat = m_disp.format;
}

....

rslt = m_d3d->CreateDevice(D3DADAPTER_DEFAULT, D3DDEVTYPE_HAL, m_win.hwnd,
D3DCREATE_HARDWARE_VERTEXPROCESSING, &d3dpp, &m_dev);

From: http://msdn.microsoft.com/en-us/library/bb174313(VS.85).aspx

Quote:Back buffers created as part of the device are only lockable if D3DPRESENTFLAG_LOCKABLE_BACKBUFFER is specified in the presentation parameters. (Multisampled back buffers and depth surfaces are never lockable.)

Try setting the flags to 0 instead of D3DPRESENTFLAG_LOCKABLE_BACKBUFFER.