Add user_data field for Timer
This is used by 32blit-lua to store the Lua state and callback function reference.
@@ -11,6 +11,7 @@ namespace blit {
// uint32_t callback; // reference to Lua callback function (can be obtained via `ref = _G['function_name']`)
TimerCallback callback = nullptr;
+ void *user_data = nullptr;
uint32_t duration = 0; // how many milliseconds between callbacks
uint32_t started = 0; // system time when timer started in milliseconds
