[gtk/wip/master.win.egl: 193/193] GDK/Win32: Force GLES if running on ARM64

[Chun-wei Fan <fanchunwei src gnome org>]

commit a481733b400a43d34a9587b2c1d2bb1aa6d8447b
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Tue May 7 00:09:03 2019 -0700

    GDK/Win32: Force GLES if running on ARM64
    
    If GLES support is enabled on Windows, force GLES mode if we are running
    on a ARM64 version of Windows (i.e. Windows 10 for ARM).
    
    This is required as ARM64 versions of Windows only provide a software
    implementation of OpenGL 1.1/1.2, which is not enough for our purposes.
    Thus, we could make instead use the GLES support provided via Google's
    libANGLE (which emulates OpenGL/ES 3 with Direct3D 9/11), so that we
    can run GtkGLArea programs under OpenGL/ES in ARM64 versions of Windows.
    
    Note that eventually we could update the libepoxy build files for Windows
    to not check nor enable WGL when building for ARM64 Windows, as the WGL
    items do not work, although they do build.

 gdk/win32/gdkdisplay-win32.c   | 39 +++++++++++++++++++++++++++++++++++++++
 gdk/win32/gdkdisplay-win32.h   | 11 +++++++++++
 gdk/win32/gdkglcontext-win32.c |  3 ++-
 3 files changed, 52 insertions(+), 1 deletion(-)
---
diff --git a/gdk/win32/gdkdisplay-win32.c b/gdk/win32/gdkdisplay-win32.c
index 4c060437da..a1c0b26e0b 100644
--- a/gdk/win32/gdkdisplay-win32.c
+++ b/gdk/win32/gdkdisplay-win32.c
@@ -43,6 +43,10 @@
 # include <epoxy/egl.h>
 #endif
 
+#ifndef IMAGE_FILE_MACHINE_ARM64
+# define IMAGE_FILE_MACHINE_ARM64 0xAA64
+#endif
+
 static int debug_indent = 0;
 
 /**
@@ -880,6 +884,40 @@ _gdk_win32_enable_hidpi (GdkWin32Display *display)
     }
 }
 
+static void
+_gdk_win32_check_on_arm64 (GdkWin32Display *display)
+{
+  static gsize checked = 0;
+
+  if (g_once_init_enter (&checked))
+    {
+      HMODULE kernel32 = LoadLibraryW (L"kernel32.dll");
+
+      if (kernel32 != NULL)
+        {
+          display->cpu_funcs.isWow64Process2 =
+            (funcIsWow64Process2) GetProcAddress (kernel32, "IsWow64Process2");
+
+          if (display->cpu_funcs.isWow64Process2 != NULL)
+            {
+              USHORT proc_cpu = 0;
+              USHORT native_cpu = 0;
+
+              display->cpu_funcs.isWow64Process2 (GetCurrentProcess (),
+                                                  &proc_cpu,
+                                                  &native_cpu);
+
+              if (native_cpu == IMAGE_FILE_MACHINE_ARM64)
+                display->running_on_arm64 = TRUE;
+            }
+
+          FreeLibrary (kernel32);
+        }
+
+      g_once_init_leave (&checked, 1);
+    }
+}
+
 static void
 gdk_win32_display_init (GdkWin32Display *display)
 {
@@ -888,6 +926,7 @@ gdk_win32_display_init (GdkWin32Display *display)
   display->monitors = G_LIST_MODEL (g_list_store_new (GDK_TYPE_MONITOR));
 
   _gdk_win32_enable_hidpi (display);
+  _gdk_win32_check_on_arm64 (display);
 
   /* if we have DPI awareness, set up fixed scale if set */
   if (display->dpi_aware_type != PROCESS_DPI_UNAWARE &&
diff --git a/gdk/win32/gdkdisplay-win32.h b/gdk/win32/gdkdisplay-win32.h
index 0264ee82cd..b9bfaeb2e1 100644
--- a/gdk/win32/gdkdisplay-win32.h
+++ b/gdk/win32/gdkdisplay-win32.h
@@ -69,6 +69,13 @@ typedef struct _GdkWin32User32DPIFuncs
   funcIsProcessDPIAware isDpiAwareFunc;
 } GdkWin32User32DPIFuncs;
 
+/* Detect running architecture */
+typedef BOOL (WINAPI *funcIsWow64Process2) (HANDLE, USHORT *, USHORT *);
+typedef struct _GdkWin32KernelCPUFuncs
+{
+  funcIsWow64Process2 isWow64Process2;
+} GdkWin32KernelCPUFuncs;
+
 struct _GdkWin32Display
 {
   GdkDisplay display;
@@ -131,6 +138,10 @@ struct _GdkWin32Display
 
   /* Message filters */
   GList *filters;
+
+  /* Running CPU items */
+  guint running_on_arm64 : 1;
+  GdkWin32KernelCPUFuncs cpu_funcs;
 };
 
 struct _GdkWin32DisplayClass
diff --git a/gdk/win32/gdkglcontext-win32.c b/gdk/win32/gdkglcontext-win32.c
index d52c16e2cb..056b651355 100644
--- a/gdk/win32/gdkglcontext-win32.c
+++ b/gdk/win32/gdkglcontext-win32.c
@@ -540,7 +540,8 @@ _gdk_win32_display_init_gl (GdkDisplay *display)
 #ifdef GDK_WIN32_ENABLE_EGL
   EGLDisplay egl_disp;
 
-  disable_wgl = GDK_DISPLAY_DEBUG_CHECK (display, GL_GLES);
+  disable_wgl = GDK_DISPLAY_DEBUG_CHECK (display, GL_GLES) ||
+                display_win32->running_on_arm64;
 #endif
 
   if (display_win32->have_wgl