astronomy-357.patch

From 5773820d9cf1c1c1836028f7dd80dfe27669e194 Mon Sep 17 00:00:00 2001
From: Yani <6956790+yani@users.noreply.github.com>
Date: Sat, 10 Aug 2024 18:02:10 +0200
Subject: [PATCH] Check if GetSystemTimePreciseAsFileTime() is available and
 fallback to GetSystemTimeAsFileTime()

---
 source/c/astronomy.c | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/source/c/astronomy.c b/source/c/astronomy.c
index 08ec6c76..8325a764 100644
--- a/source/c/astronomy.c
+++ b/source/c/astronomy.c
@@ -1013,7 +1013,24 @@ astro_time_t Astronomy_CurrentTime(void)
     FILETIME ft;
     ULARGE_INTEGER large;
     /* Get time in 100-nanosecond units from January 1, 1601. */
-    GetSystemTimePreciseAsFileTime(&ft);
+    /* GetSystemTimePreciseAsFileTime is only available since Windows 8 */
+    typedef void (WINAPI *GetSystemTimePreciseAsFileTimeFunc)(LPFILETIME);
+    GetSystemTimePreciseAsFileTimeFunc pGetSystemTimePreciseAsFileTime = NULL;
+    HMODULE hModule = GetModuleHandleA("kernel32.dll");
+    if (hModule) {
+        union {
+            FARPROC proc;
+            GetSystemTimePreciseAsFileTimeFunc func;
+        } converter;
+        converter.proc = GetProcAddress(hModule, "GetSystemTimePreciseAsFileTime");
+        pGetSystemTimePreciseAsFileTime = converter.func;
+    }
+    // Use the function if available, otherwise fallback
+    if (pGetSystemTimePreciseAsFileTime) {
+        pGetSystemTimePreciseAsFileTime(&ft);
+    } else {
+        GetSystemTimeAsFileTime(&ft);
+    }
     large.u.LowPart  = ft.dwLowDateTime;
     large.u.HighPart = ft.dwHighDateTime;
     sec = (large.QuadPart - 116444736000000000ULL) / 1.0e+7;