added sdl window.visible support

libs/sdl/sdl.c

@@ -409,6 +409,12 @@ HL_PRIM void HL_NAME(win_resize)(SDL_Window *win, int mode) {
 	case 2:
 		SDL_RestoreWindow(win);
 		break;
+	case 3:
+		SDL_ShowWindow(win);
+		break;
+	case 4:
+		SDL_HideWindow(win);
+		break;
 	default:
 		break;
 	}

libs/sdl/sdl/Window.hx

@@ -26,6 +26,7 @@ class Window {
 	public var width(get, never) : Int;
 	public var height(get, never) : Int;
 	public var displayMode(default, set) : DisplayMode;
+	public var visible(default, set) : Bool = true;
 
 	public function new( title : String, width : Int, height : Int ) {
 		while( true ) {
@@ -93,6 +94,13 @@ class Window {
 		return displayMode;
 	}
 
+	function set_visible(b) {
+		if( visible == b )
+			return b;
+		winResize(win, b ? 3 : 4);
+		return visible = b;
+	}
+
 	public function resize( width : Int, height : Int ) {
 		winSetSize(win, width, height);
 	}