Unravel the Mystery: How to Get a Monitor’s Actual Identifier/Name from a DXGI_OUTPUT_DESC?

Are you tired of dealing with cryptic DirectX identifiers and wanting to know the actual name of the monitor connected to your system? Today, we’ll embark on a journey to demystify the DXGI_OUTPUT_DESC structure and extract the actual identifier/name of a monitor. Buckle up, folks, and let’s dive into the world of DirectX and Windows programming!

What is DXGI_OUTPUT_DESC?

The DXGI_OUTPUT_DESC structure is part of the DirectX Graphics Infrastructure (DXGI) API, which provides a description of an output (monitor) in a DXGI 1.2 or later device. This structure contains information about the output, such as its size, orientation, and whether it’s a primary monitor.

typedef struct DXGI_OUTPUT_DESC {
    WCHAR DeviceName[32];
    RECT DesktopCoordinates;
    RECT DesktopMode;
    DXGI_MODE_ROTATION Rotation;
    DXGI_DISPLAY_MODE_SCANLINE_ORDERING ScanlineOrdering;
    BOOL ScalingSupportFlags;
} DXGI_OUTPUT_DESC;

As you can see, the DXGI_OUTPUT_DESC structure contains a bunch of useful information, but the actual identifier or name of the monitor is nowhere to be found. Or is it?

The Quest for the Monitor’s Actual Identifier/Name

To get the actual identifier or name of a monitor, we’ll need to use a combination of DXGI and Windows API functions. The process might seem daunting at first, but fear not, dear reader, for we’ll break it down into manageable chunks.

Step 1: Enumerate DXGI Outputs

The first step is to enumerate the DXGI outputs (monitors) connected to the system. We’ll use the IDXGIOutput interface to achieve this.

IDXGIOutput *pOutput;
UINT numOutputs = 0;

// Create a DXGI factory
IDXGIFactory *pFactory;
hr = CreateDXGIFactory(__uuidof(IDXGIFactory), (void **)&pFactory);
if (FAILED(hr)) {
    // Handle error
}

// Enumerate DXGI outputs
hr = pFactory->EnumOutputs(0, &pOutput, &numOutputs);
if (FAILED(hr)) {
    // Handle error
}

In this example, we create a DXGI factory using the CreateDXGIFactory function and then use the IDXGIFactory::EnumOutputs method to get an array of IDXGIOutput interfaces, which represent the connected monitors.

Step 2: Get the DXGI_OUTPUT_DESC Structure

Now that we have the IDXGIOutput interface, we can get the DXGI_OUTPUT_DESC structure using the IDXGIOutput::GetDesc method.

DXGI_OUTPUT_DESC desc;
hr = pOutput->GetDesc(&desc);
if (FAILED(hr)) {
    // Handle error
}

The DXGI_OUTPUT_DESC structure contains the DeviceName member, which is a WCHAR array containing the name of the output device. However, this name is not the actual identifier or name of the monitor, but rather a cryptic identifier like “\\\\.\\DISPLAY1”. We need to decipher this code to get the actual monitor name.

Step 3: Convert the DXGI_OUTPUT_DESC DeviceName to a Monitor Handle

To convert the DeviceName to a monitor handle, we’ll use the Windows API function, EnumDisplayDevices. This function enumerates display devices (monitors) on the system.

DISPLAY_DEVICE dd;
dd.cb = sizeof(DISPLAY_DEVICE);
EnumDisplayDevices(desc.DeviceName, 0, &dd, 0);

In this example, we use the EnumDisplayDevices function to get a DISPLAY_DEVICE structure, which contains information about the monitor, including its handle.

Step 4: Get the Actual Monitor Identifier/Name

Now that we have the monitor handle, we can use the GetMonitorInfo function to get the actual identifier or name of the monitor.

MONITORINFO mi;
mi.cbSize = sizeof(MONITORINFO);
GetMonitorInfo(dd.hMonitor, &mi);

The MONITORINFO structure contains the szDevice member, which is the actual identifier or name of the monitor, such as “Monitor ( Dell U2414H)”.

The Complete Code

Here’s the complete code that puts it all together:

#include <Windows.h>
#include <d3d11.h>

int main() {
    IDXGIFactory *pFactory;
    IDXGIOutput *pOutput;
    UINT numOutputs = 0;

    // Create a DXGI factory
    hr = CreateDXGIFactory(__uuidof(IDXGIFactory), (void **)&pFactory);
    if (FAILED(hr)) {
        // Handle error
    }

    // Enumerate DXGI outputs
    hr = pFactory->EnumOutputs(0, &pOutput, &numOutputs);
    if (FAILED(hr)) {
        // Handle error
    }

    for (UINT i = 0; i < numOutputs; i++) {
        DXGI_OUTPUT_DESC desc;
        hr = pOutput->GetDesc(&desc);
        if (FAILED(hr)) {
            // Handle error
        }

        DISPLAY_DEVICE dd;
        dd.cb = sizeof(DISPLAY_DEVICE);
        EnumDisplayDevices(desc.DeviceName, 0, &dd, 0);

        MONITORINFO mi;
        mi.cbSize = sizeof(MONITORINFO);
        GetMonitorInfo(dd.hMonitor, &mi);

        printf("Monitor %d: %ws\n", i, mi.szDevice);
    }

    return 0;
}

This code enumerates the DXGI outputs, gets the DXGI_OUTPUT_DESC structure, converts the DeviceName to a monitor handle, and finally gets the actual identifier or name of the monitor using the GetMonitorInfo function.

Conclusion

In this article, we’ve successfully unraveled the mystery of getting a monitor’s actual identifier or name from a DXGI_OUTPUT_DESC structure. By combining DXGI and Windows API functions, we’ve bridged the gap between the cryptic DirectX identifiers and the actual monitor names. This knowledge will undoubtedly prove valuable in your DirectX and Windows programming endeavors.

Remember, the key to success lies in understanding the relationships between the various DirectX and Windows API structures and functions. With patience and practice, you’ll become a master of unraveling the mysteries of the DXGI_OUTPUT_DESC and beyond!

FAQs

• What is the purpose of the DXGI_OUTPUT_DESC structure?

  The DXGI_OUTPUT_DESC structure provides a description of an output (monitor) in a DXGI 1.2 or later device.

• How do I get the actual monitor name from the DXGI_OUTPUT_DESC structure?

  You can get the actual monitor name by converting the DeviceName member of the DXGI_OUTPUT_DESC structure to a monitor handle using the EnumDisplayDevices function, and then using the GetMonitorInfo function to get the actual monitor name.

• What is the difference between a DXGI output and a Windows display device?

  A DXGI output refers to a monitor connected to the system, while a Windows display device is a more general term that includes monitors, projectors, and other display devices.

Function	Description
CreateDXGIFactory	Creates a DXGI factory.
EnumOutputs	Enumerates DXGI outputs (monitors) connected to the system.
GetDesc	Gets the DXGI_OUTPUT_DESC structure for a DXGI output.
EnumDisplayDevices	Enumerates display devices (monitors) on the system.
GetMonitorInfo	Gets information about a monitor, including its actual identifier or name.

By mastering the techniques outlined in this article, you’ll be well on your way to unlocking the secrets of the DXGI_OUTPUT_DESC structure and uncovering the actual monitor names that lie within.

Happy coding, and may the DirectX be with you!

Frequently Asked Question

Are you tired of dealing with DXGI_OUTPUT_DESC and wondering how to get a monitor’s actual identifier or name? Worry no more! Here are the answers to your burning questions.