move method
Implementation
void move(RainSnowParams params) {
params.y = params.y + params.speed;
if (WeatherUtil.isSnow(_state.widget.weatherType)) {
double offsetX = sin(params.y / (300 + 50 * params.alpha)) *
(1 + 0.5 * params.alpha) *
params.widthRatio;
params.x += offsetX;
}
if (params.y > params.height / params.scale) {
params.y = -params.height * params.scale;
if (WeatherUtil.isRainy(_state.widget.weatherType) &&
_state._images.isNotEmpty) {
params.y = -_state._images[0].height.toDouble();
}
params.reset();
}
}