lower framerate when not focused

src/au.zig

@@ -427,6 +427,10 @@ pub const Window = struct {
     pub fn should_close(self: Self) bool {
         return c.glfwWindowShouldClose(self.handle) == c.GLFW_TRUE;
     }
+
+    pub fn focused(self: Self) bool {
+        return c.glfwGetWindowAttrib(self.handle, c.GLFW_FOCUSED) == c.GLFW_TRUE;
+    }
 };
 
 pub fn wait_events() []const Bus.Event {