使用DXGI获得精确的显存大小

DXGI可以获得显存的精确大小。但因为DXGI是基于WDDM，因此要先判断当前系统的显示驱动模型是不是WDDM。

 

HasWDDMDriver()

{

    LPDIRECT3DCREATE9EX pD3D9Create9Ex = NULL;

    HMODULE             hD3D9          = NULL;



    hD3D9 = LoadLibrary( L"d3d9.dll" );



    if ( NULL == hD3D9 ) {

        return false;

    }



    //

    /*  Try to create IDirect3D9Ex interface (also known as a DX9L interface). This interface can only be created if the driver is a WDDM driver.

     */

    //

    pD3D9Create9Ex = (LPDIRECT3DCREATE9EX) GetProcAddress( hD3D9, "Direct3DCreate9Ex" );



    return pD3D9Create9Ex != NULL;

}

 

然后通过访问Adapter的GetDesc得到一个DXGI_ADAPTER_DESC结构体，其内保存了显卡信息。  

 

IDXGIDevice * pDXGIDevice;
hr = g_pd3dDevice->QueryInterface(__uuidof(IDXGIDevice), (void **)&pDXGIDevice);
IDXGIAdapter * pDXGIAdapter;
pDXGIDevice->GetAdapter(&pDXGIAdapter);
DXGI_ADAPTER_DESC adapterDesc;
pDXGIAdapter->GetDesc(&adapterDesc);