Class WindowsDxgi

java.lang.Object

oshi.jna.platform.windows.WindowsDxgi

public final class WindowsDxgi
extends Object

Minimal JNA binding to dxgi.dll for enumerating display adapters and reading DXGI_ADAPTER_DESC.DedicatedVideoMemory.

DXGI is the authoritative Windows API for dedicated GPU memory. It is not subject to the 2 GiB cap that affects the 32-bit registry value HardwareInformation.MemorySize.

COM vtable layout used here:

IUnknown   (vtable slots 0-2):  QueryInterface, AddRef, Release
IDXGIObject (slots 3-6):        SetPrivateData, SetPrivateDataInterface, GetPrivateData, GetParent
IDXGIFactory (slots 7-13):      EnumAdapters, MakeWindowAssociation, GetWindowAssociation,
                                 CreateSwapChain, CreateSoftwareAdapter, (IDXGIFactory1 adds 2 more)
IDXGIAdapter (slots 3-5 on adapter): EnumOutputs, GetDesc, CheckInterfaceSupport

This class should be considered non-API as it may be removed if/when its code is incorporated into the JNA project.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	WindowsDxgi.DXGI_ADAPTER_DESC	Maps to the Windows DXGI_ADAPTER_DESC structure.

Method Summary

Modifier and Type	Method	Description
static DxgiAdapterInfo	findMatch(List<DxgiAdapterInfo> adapters, int vendorId, int deviceId, String adapterName)	Finds the best-matching DXGI adapter for a given vendor ID, device ID, and adapter name.
static String	normalizeName(String name)	Normalizes an adapter name for fuzzy matching: lower-case, strips (R)/(TM), collapses whitespace.
static List<DxgiAdapterInfo>	queryAdapters()	Enumerates all DXGI display adapters and returns their identity and dedicated video memory.
static long	registryValueToVram(Object value)	Converts a registry value (REG_QWORD as Long, REG_DWORD as Integer, or REG_BINARY as byte[]) to a VRAM size in bytes.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

queryAdapters

public static List<DxgiAdapterInfo> queryAdapters()

Enumerates all DXGI display adapters and returns their identity and dedicated video memory.

Fails gracefully: if dxgi.dll is unavailable or any COM call fails, returns an empty list so callers can fall back to registry-based detection.

Returns:

list of DxgiAdapterInfo, one per adapter; empty if DXGI is unavailable

findMatch

public static DxgiAdapterInfo findMatch(List<DxgiAdapterInfo> adapters,
 int vendorId,
 int deviceId,
 String adapterName)

Finds the best-matching DXGI adapter for a given vendor ID, device ID, and adapter name.

Matching priority:

1. Vendor ID + Device ID (exact, both non-zero)
2. Normalized name match (case-insensitive, ignoring (R), (TM), extra spaces)

If multiple adapters share the same vendor+device ID (e.g. multi-GPU), the first one is returned. If no confident match is found, returns null.

Parameters:

adapters - list from queryAdapters()

vendorId - PCI vendor ID parsed from the registry key (0 if unknown)

deviceId - PCI device ID parsed from the registry key (0 if unknown)

adapterName - adapter name from the registry DriverDesc value

Returns:

best-matching adapter, or null

registryValueToVram

public static long registryValueToVram(Object value)

Converts a registry value (REG_QWORD as Long, REG_DWORD as Integer, or REG_BINARY as byte[]) to a VRAM size in bytes. REG_BINARY is interpreted as little-endian.

Exposed as public for testing.

Parameters:

value - the registry value object

Returns:

the VRAM size in bytes, or 0 if the value type is unrecognised

normalizeName

public static String normalizeName(String name)

Normalizes an adapter name for fuzzy matching: lower-case, strips (R)/(TM), collapses whitespace.

Parameters:

name - the raw adapter name, may be null

Returns:

normalized name, never null