From ad0ab2f3961bf58135f24802dd37e0a217e7f738 Mon Sep 17 00:00:00 2001
From: bruvzg <7645683+bruvzg@users.noreply.github.com>
Date: Tue, 30 Jul 2024 10:09:30 +0300
Subject: [PATCH] [Windows] Improve OpenGL/ANGLE switching on ARM64.

---
 platform/windows/display_server_windows.cpp | 36 ++++++++++++++++-----
 1 file changed, 28 insertions(+), 8 deletions(-)

diff --git a/platform/windows/display_server_windows.cpp b/platform/windows/display_server_windows.cpp
index 020ef0c31b3..fa6ed81793f 100644
--- a/platform/windows/display_server_windows.cpp
+++ b/platform/windows/display_server_windows.cpp
@@ -5984,13 +5984,32 @@ DisplayServerWindows::DisplayServerWindows(const String &p_rendering_driver, Win
 // Init context and rendering device
 #if defined(GLES3_ENABLED)
 
-#if defined(__arm__) || defined(__aarch64__) || defined(_M_ARM) || defined(_M_ARM64)
-	// There's no native OpenGL drivers on Windows for ARM, switch to ANGLE over DX.
-	if (rendering_driver == "opengl3") {
-		rendering_driver = "opengl3_angle";
-	}
-#elif defined(EGL_STATIC)
 	bool fallback = GLOBAL_GET("rendering/gl_compatibility/fallback_to_angle");
+	bool show_warning = true;
+
+	if (rendering_driver == "opengl3") {
+		// There's no native OpenGL drivers on Windows for ARM, always enable fallback.
+#if defined(__arm__) || defined(__aarch64__) || defined(_M_ARM) || defined(_M_ARM64)
+		fallback = true;
+		show_warning = false;
+#else
+		typedef BOOL(WINAPI * IsWow64Process2Ptr)(HANDLE, USHORT *, USHORT *);
+
+		IsWow64Process2Ptr IsWow64Process2 = (IsWow64Process2Ptr)GetProcAddress(GetModuleHandle(TEXT("kernel32")), "IsWow64Process2");
+		if (IsWow64Process2) {
+			USHORT process_arch = 0;
+			USHORT machine_arch = 0;
+			if (!IsWow64Process2(GetCurrentProcess(), &process_arch, &machine_arch)) {
+				machine_arch = 0;
+			}
+			if (machine_arch == 0xAA64) {
+				fallback = true;
+				show_warning = false;
+			}
+		}
+#endif
+	}
+
 	if (fallback && (rendering_driver == "opengl3")) {
 		Dictionary gl_info = detect_wgl();
 
@@ -6016,11 +6035,12 @@ DisplayServerWindows::DisplayServerWindows(const String &p_rendering_driver, Win
 		}
 
 		if (force_angle || (gl_info["version"].operator int() < 30003)) {
-			WARN_PRINT("Your video card drivers seem not to support the required OpenGL 3.3 version, switching to ANGLE.");
+			if (show_warning) {
+				WARN_PRINT("Your video card drivers seem not to support the required OpenGL 3.3 version, switching to ANGLE.");
+			}
 			rendering_driver = "opengl3_angle";
 		}
 	}
-#endif
 
 	if (rendering_driver == "opengl3") {
 		gl_manager_native = memnew(GLManagerNative_Windows);