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+--- Thread: About weather (/thread-479.html)
About weather - cedeel - 06-11-2012
Hello all,
I've been pondering about the weather system in MCS for a few days now.
The current system of changing the weather isn't optimal for a few reasons:
- Causes strain on the server by checking weather every tick
- Is a little too random
- Almost guarantees a thunderstorm will happen
As a matter of fact, a feature request was opened in the bug tracker and I could keep the discussion there, but I feel more people will read it here and possibly come with suggestions.
I've been reading the bukkit source (around line #1773) to figure out how they were doing it, but this only describes some of the logic that needs to be implemented.
I've seen a comment in the MCS source questioning whether each world should have its own thread, which seems like a reasonable start.
My current thoughts on improving the weather system are as follows:
1.
- Implement an observable weather management class, which would run in its own thread.
- Make the world respond to the weather management.
In this scenario with the current world implementation, all worlds would have the same weather.
Discuss
RE: About weather - xoft - 06-11-2012
I'm not sure I'm following what you're suggesting. What exactly does "observable" in this context mean? Why would you need a weather management class, why not add just a member or two to the cWorld class?
I've already mind-designed a system for weather that would be, I believe, adequate. Doesn't require any new classes, doesn't require any changes to the threading model, it's pretty and simple:
1. Each world starts with Sunny
2. An interval is selected, depending on the weather type, how long the current weather lasts.
3. When the interval runs out, a new weather and according interval are selected.
So, this change would require:
1. Add the interval member to cWorld
2. Add or modify cWorld::ChangeWeather() function to change weather and set a new interval
3. cWorld's TickWeather should only check the interval and once it elapses, call the ChangeWeather() function with weather.
4. Make cWorld::ChangeWeather accessible from Lua.
I don't think adding a thread just for weather is a good idea. A thread consumes quite a few resources that we cannot spare on some small-footprint platforms (stack RAM) and brings synchronization issues with it (critical sections with possible deadlocks).
However, I'm totally for the idea of each world having a separate tick thread. This is out of the scope of this post, though (not that it would be that difficult to implement that).
Optional configuration: world may have no weather changes (think Nether) -> ChangeWeather checks if a change is allowed. Even more comfortable - allow the kinds of weathers and their interval lengths to be ini-adjusted.
RE: About weather - cedeel - 06-12-2012
Your proposal sounds nice, but in my understanding we would still be making a check each tick, now whether the interval was reached.
(06-11-2012, 11:59 PM)xoft Wrote: Optional configuration: world may have no weather changes (think Nether) -> ChangeWeather checks if a change is allowed. Even more comfortable - allow the kinds of weathers and their interval lengths to be ini-adjusted.
Better yet, make worlds without weather skip weather altogether (small change to world.ini)
RE: About weather - xoft - 06-12-2012
(06-12-2012, 12:10 AM)cedeel Wrote: Your proposal sounds nice, but in my understanding we would still be making a check each tick, now whether the interval was reached.Yes, but the check is much less strain than an extra thread. The check is a simple substraction and then comparison, about four CPU instructions. An extra thread means extra thread context switching and synchronization.
(06-12-2012, 12:10 AM)cedeel Wrote: Better yet, make worlds without weather skip weather altogether (small change to world.ini)Implementation details, of course.
RE: About weather - Taugeshtu - 06-12-2012
Just give me OnWeatherChanged() hook to start thunderstorms with lightning strike at 0,0 in case you'll remove that feature one day >:-D
RE: About weather - cedeel - 06-12-2012
Lightning strike at 0,0,0 will probably go away completely as part of this undertaking.
I suppose a method to strike a given position could be made and exported.
RE: About weather - Taugeshtu - 06-12-2012
It is made
Called cWorld::CastThunderbolt