From 0d31a4afb600e1ad9b911ad4d024699073f9f067 Mon Sep 17 00:00:00 2001
From: Felipe Jorge <felipe.jorge.pereira@gmail.com>
Date: Mon, 14 Jul 2025 00:03:38 -0300
Subject: [PATCH] Win32: Make wait events timeout more consistent

---
 src/win32_init.c     | 10 ++++++++++
 src/win32_platform.h |  8 ++++++++
 2 files changed, 18 insertions(+)

diff --git a/src/win32_init.c b/src/win32_init.c
index 6b6e9d08..8a09495c 100644
--- a/src/win32_init.c
+++ b/src/win32_init.c
@@ -163,6 +163,13 @@ static GLFWbool loadLibraries(void)
             _glfwPlatformGetModuleSymbol(_glfw.win32.ntdll.instance, "RtlVerifyVersionInfo");
     }
 
+    _glfw.win32.winmm.instance = _glfwPlatformLoadModule("winmm.dll");
+    if (_glfw.win32.winmm.instance)
+    {
+        _glfw.win32.winmm.timeBeginPeriod_ = (PFN_timeBeginPeriod) _glfwPlatformGetModuleSymbol(_glfw.win32.winmm.instance, "timeBeginPeriod");
+        _glfw.win32.winmm.timeBeginPeriod_(1);
+    }
+
     return GLFW_TRUE;
 }
 
@@ -187,6 +194,9 @@ static void freeLibraries(void)
 
     if (_glfw.win32.ntdll.instance)
         _glfwPlatformFreeModule(_glfw.win32.ntdll.instance);
+
+    if (_glfw.win32.winmm.instance)
+        _glfwPlatformFreeModule(_glfw.win32.winmm.instance);
 }
 
 // Create key code translation tables
diff --git a/src/win32_platform.h b/src/win32_platform.h
index 49cceba6..d2612e20 100644
--- a/src/win32_platform.h
+++ b/src/win32_platform.h
@@ -258,6 +258,9 @@ typedef HRESULT (WINAPI * PFN_GetDpiForMonitor)(HMONITOR,MONITOR_DPI_TYPE,UINT*,
 typedef LONG (WINAPI * PFN_RtlVerifyVersionInfo)(OSVERSIONINFOEXW*,ULONG,ULONGLONG);
 #define RtlVerifyVersionInfo _glfw.win32.ntdll.RtlVerifyVersionInfo_
 
+// winmm.dll function pointer typedefs
+typedef UINT (WINAPI * PFN_timeBeginPeriod)(UINT);
+
 // WGL extension pointer typedefs
 typedef BOOL (WINAPI * PFNWGLSWAPINTERVALEXTPROC)(int);
 typedef BOOL (WINAPI * PFNWGLGETPIXELFORMATATTRIBIVARBPROC)(HDC,int,int,UINT,const int*,int*);
@@ -442,6 +445,11 @@ typedef struct _GLFWlibraryWin32
         HINSTANCE                       instance;
         PFN_RtlVerifyVersionInfo        RtlVerifyVersionInfo_;
     } ntdll;
+    
+    struct {
+        HINSTANCE                       instance;
+        PFN_timeBeginPeriod             timeBeginPeriod_;
+    } winmm;
 } _GLFWlibraryWin32;
 
 // Win32-specific per-monitor data