From 6ec59f8654e6dd34f5f6d18f1fd4cb4c0abad5ba Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E6=9D=8E=E9=80=9A=E6=B4=B2?= <zhangsongcui3371@sina.com>
Date: Thu, 19 Mar 2026 00:56:02 +0800
Subject: [PATCH] Brightness (Windows): fixes detection of external monitors

---
 .../brightness/brightness_windows.cpp         | 68 ++++++++++++++-----
 .../displayserver/displayserver_windows.c     | 11 +--
 2 files changed, 51 insertions(+), 28 deletions(-)

diff --git a/src/detection/brightness/brightness_windows.cpp b/src/detection/brightness/brightness_windows.cpp
index a7b4332a2..c90195972 100644
--- a/src/detection/brightness/brightness_windows.cpp
+++ b/src/detection/brightness/brightness_windows.cpp
@@ -7,8 +7,31 @@ extern "C"
 #include "common/windows/wmi.hpp"
 #include "common/windows/unicode.hpp"
 
-#include <highlevelmonitorconfigurationapi.h>
-#include <physicalmonitorenumerationapi.h>
+#include <winternl.h>
+
+NTSYSAPI NTSTATUS WINAPI GetPhysicalMonitors(
+  _In_  UNICODE_STRING *pstrDeviceName,
+  _In_  DWORD          dwPhysicalMonitorArraySize,
+  _Out_ DWORD          *pdwNumPhysicalMonitorHandlesInArray,
+  _Out_ HANDLE         *phPhysicalMonitorArray
+);
+
+typedef enum _MC_VCP_CODE_TYPE {
+  MC_MOMENTARY,
+  MC_SET_PARAMETER
+} MC_VCP_CODE_TYPE, *LPMC_VCP_CODE_TYPE;
+
+NTSYSAPI NTSTATUS WINAPI DDCCIGetVCPFeature(
+  _In_      HANDLE             hMonitor,
+  _In_      DWORD              dwVCPCode,
+  _Out_opt_ LPMC_VCP_CODE_TYPE pvct,
+  _Out_     DWORD              *pdwCurrentValue,
+  _Out_opt_ DWORD              *pdwMaximumValue
+);
+
+NTSYSAPI NTSTATUS WINAPI DestroyPhysicalMonitorInternal(
+  _In_ HANDLE hMonitor
+);
 
 static const char* detectWithWmi(FFlist* result)
 {
@@ -40,33 +63,42 @@ static const char* detectWithWmi(FFlist* result)
 
 static const char* detectWithDdcci(const FFDisplayServerResult* displayServer, FFlist* result)
 {
-    FF_LIBRARY_LOAD_MESSAGE(dxva2, "dxva2" FF_LIBRARY_EXTENSION, 1)
-    FF_LIBRARY_LOAD_SYMBOL_MESSAGE(dxva2, GetPhysicalMonitorsFromHMONITOR)
-    FF_LIBRARY_LOAD_SYMBOL_MESSAGE(dxva2, GetMonitorBrightness)
-    FF_LIBRARY_LOAD_SYMBOL_MESSAGE(dxva2, DestroyPhysicalMonitor)
+    HMODULE gdi32 = GetModuleHandleW(L"gdi32.dll");
+    if (!gdi32) return "GetModuleHandleW(gdi32.dll) failed";
+    FF_LIBRARY_LOAD_SYMBOL_MESSAGE(gdi32, GetPhysicalMonitors)
+    FF_LIBRARY_LOAD_SYMBOL_MESSAGE(gdi32, DDCCIGetVCPFeature)
+    FF_LIBRARY_LOAD_SYMBOL_MESSAGE(gdi32, DestroyPhysicalMonitorInternal)
 
     FF_LIST_FOR_EACH(FFDisplayResult, display, displayServer->displays)
     {
-        PHYSICAL_MONITOR physicalMonitor;
-        if (ffGetPhysicalMonitorsFromHMONITOR((HMONITOR)(uintptr_t) display->id, 1, &physicalMonitor))
+        if (display->type == FF_DISPLAY_TYPE_BUILTIN) continue;
+
+        MONITORINFOEXW mi;
+        mi.cbSize = sizeof(mi);
+        if (!GetMonitorInfoW((HMONITOR)(uintptr_t) display->id, (LPMONITORINFO) &mi))
+            continue;
+
+        UNICODE_STRING deviceName = {
+            .Length = (USHORT) (wcslen(mi.szDevice) * sizeof(wchar_t)),
+            .MaximumLength = 0,
+            .Buffer = mi.szDevice,
+        };
+        HANDLE physicalMonitor;
+        DWORD monitorCount = 0;
+        if (NT_SUCCESS(ffGetPhysicalMonitors(&deviceName, 1, &monitorCount, &physicalMonitor)) && monitorCount >= 1)
         {
-            DWORD min = 0, curr = 0, max = 0;
-            if (ffGetMonitorBrightness(physicalMonitor.hPhysicalMonitor, &min, &curr, &max))
+            DWORD curr = 0, max = 0;
+            if (NT_SUCCESS(ffDDCCIGetVCPFeature(physicalMonitor, 0x10 /* luminance */, NULL, &curr, &max)))
             {
                 FFBrightnessResult* brightness = (FFBrightnessResult*) ffListAdd(result);
-
-                if (display->name.length)
-                    ffStrbufInitCopy(&brightness->name, &display->name);
-                else
-                    ffStrbufInitWS(&brightness->name, physicalMonitor.szPhysicalMonitorDescription);
-
+                ffStrbufInitCopy(&brightness->name, &display->name);
                 brightness->max = max;
-                brightness->min = min;
+                brightness->min = 0;
                 brightness->current = curr;
                 brightness->builtin = false;
             }
 
-            ffDestroyPhysicalMonitor(physicalMonitor.hPhysicalMonitor);
+            ffDestroyPhysicalMonitorInternal(physicalMonitor);
         }
     }
     return NULL;
diff --git a/src/detection/displayserver/displayserver_windows.c b/src/detection/displayserver/displayserver_windows.c
index 4351ebc0f..c26fd596c 100644
--- a/src/detection/displayserver/displayserver_windows.c
+++ b/src/detection/displayserver/displayserver_windows.c
@@ -30,15 +30,6 @@ static void detectDisplays(FFDisplayServerResult* ds)
             const DISPLAYCONFIG_PATH_INFO* path = &paths[i];
             const DISPLAYCONFIG_SOURCE_MODE* sourceMode = &modes[path->sourceInfo.modeInfoIdx].sourceMode;
 
-            DISPLAYCONFIG_SOURCE_DEVICE_NAME sourceName = {
-                .header = {
-                    .type = DISPLAYCONFIG_DEVICE_INFO_GET_SOURCE_NAME,
-                    .size = sizeof(sourceName),
-                    .adapterId = path->sourceInfo.adapterId,
-                    .id = path->sourceInfo.id,
-                },
-            };
-
             FF_STRBUF_AUTO_DESTROY name = ffStrbufCreate();
             uint32_t physicalWidth = 0, physicalHeight = 0;
 
@@ -157,7 +148,7 @@ static void detectDisplays(FFDisplayServerResult* ds)
                     path->targetInfo.outputTechnology == DISPLAYCONFIG_OUTPUT_TECHNOLOGY_UDI_EMBEDDED
                     ? FF_DISPLAY_TYPE_BUILTIN : FF_DISPLAY_TYPE_EXTERNAL,
                 sourceMode->position.x == 0 && sourceMode->position.y == 0,
-                path->sourceInfo.id,
+                (uintptr_t) hMonitor,
                 physicalWidth,
                 physicalHeight,
                 "GDI"