I'm experimenting with D3D11 for fun. I can create a device and swap chain, RTV, DSV, and get them all working fine. Now in my D3D9 framework I have the capability to change display modes on the fly, and switch fullscreen etc, so I wanted to replicate this functionality in D3D11. (My laptop is rather old and only DirectX 9.0c capable, but D3D11 works through the feature levels).

Here's the code I use to (try to) enumerate display modes and display them in the console output

// Create DXGI factory, enum display modes
IDXGIFactory* pFactory = NULL;
CreateDXGIFactory(__uuidof(IDXGIFactory), (void**)&pFactory);
IDXGIAdapter* pAdapter;
for (int i = 0; true; i++)
{
HRESULT enumhr = pFactory->EnumAdapters(i, &pAdapter);
if (DXGI_ERROR_NOT_FOUND == enumhr || FAILED(enumhr) || NULL == pAdapter)
{
break;
}
DXGI_ADAPTER_DESC adapterDesc;
pAdapter->GetDesc(&adapterDesc);
if (pAdapter)
{
char data[256] = { 0 };
wcstombs(data, adapterDesc.Description, 256);
std::cout << "Found adapter: " << std::endl;
std::cout << " Name: " << data << std::endl;
std::cout << " System Memory: " << adapterDesc.DedicatedSystemMemory << std::endl;
std::cout << " Dedicated Memory: " << adapterDesc.DedicatedVideoMemory << std::endl;
std::cout << " Shared Memory: " << adapterDesc.SharedSystemMemory << std::endl;
std::cout << std::endl;

IDXGIOutput* pOutput;
HRESULT outputhr = pAdapter->EnumOutputs(0, &pOutput);
if (DXGI_ERROR_NOT_FOUND == outputhr || FAILED(outputhr) || NULL == pAdapter)
{
continue;
}

DXGI_FORMAT format = DXGI_FORMAT_R8G8B8A8_UNORM;
UINT modeCount = 0;
HRESULT modehr = pOutput->GetDisplayModeList(format, 0, &modeCount, NULL);
DXGI_MODE_DESC* displayModes = new DXGI_MODE_DESC[modeCount];
pOutput->GetDisplayModeList(format, 0, NULL, displayModes);
std::cout << " " << modeCount << " Display modes available: " << std::endl;
for (int k = 0; k < modeCount; k++)
{
std::cout << " " << displayModes[k].Width << "x" << displayModes[k].Height
<< " @ " << displayModes[k].RefreshRate.Numerator / displayModes[k].RefreshRate.Denominator
<< " Hz" << std::endl;
}
delete[] displayModes;

pOutput->Release();
pAdapter->Release();
}
}


The problem is, modeCount returns 0, and no display modes are found... Why is this happening?

Looks like our codes are pretty similar, but I copied yours over anyway, and got rid of/refactored some stuff. (Whats wrong with camel casing???)

Here's the new code

void EnumDisplayModes()
{
IDXGIFactory *pFactory = NULL;
IDXGIAdapter *pAdapter = NULL;
IDXGIOutput *pOutput = NULL;

CreateDXGIFactory (__uuidof (IDXGIFactory), (void **) &pFactory);

for (UINT i = 0; pFactory->EnumAdapters (i, &pAdapter) != DXGI_ERROR_NOT_FOUND; i++)
{
DXGI_ADAPTER_DESC adapterDesc;

pAdapter->GetDesc(&adapterDesc);
char data[256];
wcstombs(data, adapterDesc.Description, 256);

std::cout << "Graphics adapter: " << data << std::endl;

for (UINT j = 0; pAdapter->EnumOutputs (j, &pOutput) != DXGI_ERROR_NOT_FOUND; j++)
{
UINT numModes;
DXGI_MODE_DESC* pModes = NULL;

pOutput->GetDisplayModeList (DXGI_FORMAT_R8G8B8A8_UNORM, 0, &numModes, pModes);
pModes = new DXGI_MODE_DESC[numModes];
pOutput->GetDisplayModeList (DXGI_FORMAT_R8G8B8A8_UNORM, 0, &numModes, pModes);

std::cout << "Display modes found: " << numModes << std::endl;
for (int k = 0; k < numModes; k++)
{
std::cout << pModes[k].Width << "x" << pModes[k].Height << " @ " <<
pModes[k].RefreshRate.Numerator / pModes[k].RefreshRate.Denominator << std::endl;
}
delete[] pModes;

pOutput->Release();
pOutput = NULL;
}

pAdapter->Release();
pAdapter = NULL;
}

pFactory->Release();
}


And the output

Graphics adapter : Mobile Intel(R) 965 Express Chipset Family
Display modes found: 0


can't try it on my desktop (ATI RHD 6670) because I didn't bring that with me to uni...

But.. that can't be right, because I can create the device and render out triangles (with D3D_FEATURE_LEVEL_9_3), and exactly the same back buffer format!