How to call EnumAdapters from IDXGFactory in c?

Question

How to call the EnumAdapters function in c from IDXGFactory

    UINT i = 0; 
    IDXGIFactory* pFactory = NULL;
    IDXGIAdapter * pAdapter; 
    HRESULT hr = CreateDXGIFactory(&IID_IDXGIFactory, (void**)(&pFactory) );

    if (hr != S_OK)
    {
        printf("Failed to create DXIFactory object\n");
    }

using pFactory->EnumAdapters(i, pAdapter) does not work and causes this error

struct "IDXGIFactory" has no field "EnumAdapters"

Answer 1

You are interested in reading up on topic "using COM in plain C", where you can find relevant detailed explanations.

For you very specific question the code might look like:

#include <dxgi.h>

#pragma comment(lib, "dxgi.lib")
#pragma comment(lib, "dxguid.lib")

int main()
{
    IDXGIFactory* pFactory = NULL;
    UINT i = 0; 
    IDXGIAdapter* pAdapter; 
    HRESULT hr;
    hr = CreateDXGIFactory(&IID_IDXGIFactory, (void**)(&pFactory));
    hr = pFactory->lpVtbl->EnumAdapters(pFactory, i, &pAdapter);
    return 0;
}

Or, another way is to take advantage of COBJMACROS in which case you have IDXGIFactory_EnumAdapters available to you.

#define COBJMACROS

#include <dxgi.h>

#pragma comment(lib, "dxgi.lib")
#pragma comment(lib, "dxguid.lib")

int main()
{
    IDXGIFactory* pFactory = NULL;
    UINT i = 0; 
    IDXGIAdapter* pAdapter; 
    HRESULT hr;
    hr = CreateDXGIFactory(&IID_IDXGIFactory, (void**)(&pFactory));
    hr = IDXGIFactory_EnumAdapters(pFactory, i, &pAdapter);
    return 0;
}