load our DLL procs only once

internal/driver/glfw/driver_windows.go

@@ -21,6 +21,15 @@ const (
 	ES_DISPLAY_REQUIRED ES = 0x00000002
 )
 
+var (
+	kernel32 = syscall.NewLazyDLL("kernel32.dll")
+	user32   = syscall.NewLazyDLL("user32.dll")
+
+	executionState     = kernel32.NewProc("SetThreadExecutionState")
+	MessageBox         = user32.NewProc("MessageBoxW")
+	getDoubleClickTime = user32.NewProc("GetDoubleClickTime")
+)
+
 func toNativePtr(s string) *uint16 {
 	pstr, err := syscall.UTF16PtrFromString(s)
 	if err != nil {
@@ -31,8 +40,6 @@ func toNativePtr(s string) *uint16 {
 
 // https://docs.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-messageboxw
 func messageBoxError(text, caption string) {
-	user32 := syscall.NewLazyDLL("user32.dll")
-	MessageBox := user32.NewProc("MessageBoxW")
 
 	uType := MB_OK | MB_ICONERROR
 
@@ -57,9 +64,6 @@ func logError(msg string, err error) {
 }
 
 func setDisableScreenBlank(disable bool) {
-	kernel32 := syscall.NewLazyDLL("kernel32.dll")
-	executionState := kernel32.NewProc("SetThreadExecutionState")
-
 	uType := ES_CONTINUOUS
 	if disable {
 		uType |= ES_DISPLAY_REQUIRED
@@ -72,11 +76,6 @@ const defaultDoubleTapDelay = 300 * time.Millisecond
 
 func (g *gLDriver) DoubleTapDelay() time.Duration {
 	// https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-getdoubleclicktime
-	user32 := syscall.NewLazyDLL("user32.dll")
-	if user32 == nil {
-		return defaultDoubleTapDelay
-	}
-	getDoubleClickTime := user32.NewProc("GetDoubleClickTime")
 	if getDoubleClickTime == nil {
 		return defaultDoubleTapDelay
 	}