From a41654b4f1fe1d521fa81208394120ed1f3956d6 Mon Sep 17 00:00:00 2001
From: Roman Fomin <rfomin@gmail.com>
Date: Mon, 19 Aug 2024 15:01:06 +0700
Subject: [PATCH] fix building on Win7 (#1849)

---
 CMakeLists.txt | 11 +++++++++++
 config.h.in    |  1 +
 src/i_timer.c  |  4 +++-
 3 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8fb69e8e..b10ba459 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -57,6 +57,17 @@ check_library_exists(m pow "" HAVE_LIBM)
 check_include_file("dirent.h" HAVE_DIRENT_H)
 check_symbol_exists(strcasecmp "strings.h" HAVE_DECL_STRCASECMP)
 check_symbol_exists(strncasecmp "strings.h" HAVE_DECL_STRNCASECMP)
+check_c_source_compiles("
+    #include <windows.h>
+    int main()
+    {
+        CreateWaitableTimerEx(NULL, NULL, CREATE_WAITABLE_TIMER_HIGH_RESOLUTION,
+                              TIMER_ALL_ACCESS);
+        return 0;
+    }
+  "
+  HAVE_HIGH_RES_TIMER
+)
 check_c_source_compiles("
     #include <immintrin.h>
     int main()
diff --git a/config.h.in b/config.h.in
index 088899f3..26e6b2db 100644
--- a/config.h.in
+++ b/config.h.in
@@ -6,6 +6,7 @@
 #cmakedefine HAVE_DIRENT_H
 #cmakedefine01 HAVE_DECL_STRCASECMP
 #cmakedefine01 HAVE_DECL_STRNCASECMP
+#cmakedefine HAVE_HIGH_RES_TIMER
 #cmakedefine HAVE__DIV64
 #cmakedefine HAVE_ALSA
 #cmakedefine HAVE_FLUIDSYNTH
diff --git a/src/i_timer.c b/src/i_timer.c
index ed6101cd..723e96c3 100644
--- a/src/i_timer.c
+++ b/src/i_timer.c
@@ -148,11 +148,13 @@ void I_InitTimer(void)
 
 #ifdef _WIN32
     // Create an unnamed waitable timer.
+    hTimer = NULL;
+  #ifdef HAVE_HIGH_RES_TIMER
     hTimer = CreateWaitableTimerEx(NULL, NULL,
                                    CREATE_WAITABLE_TIMER_MANUAL_RESET
                                    | CREATE_WAITABLE_TIMER_HIGH_RESOLUTION,
                                    TIMER_ALL_ACCESS);
-
+  #endif
     if (hTimer == NULL)
     {
         hTimer = CreateWaitableTimer(NULL, TRUE, NULL);