Add consistent monotonic day counter - get_day_count()

I've written several experimental bits of code that revolve around the
need for a consistent calendar, but implementing one is extremely hard
in mods due to time changes and mods overriding core.get_timeofday(),
which will conflict.

The second part of the problem is that doing this from a mod requires
constant maintenance of a settings file.

An implementation in core is trivial, however, and solves all of
these problems at virtually no cost: No extra branches in server
steps, and a single branch when minetest.set_time_of_day(), which is
entirely reasonable.

We store the day_count value in env_meta.txt.

The use case is obvious: This change allows mods to create an actual
virtual calendar, or properly account for seasonal changes, etc..

We add a "/days" chatcommand that displays the current day count. No
permissions are needed. It can only retrieve the day count, not
modify it.
This commit is contained in:
Auke Kok 2016-03-06 12:02:21 -08:00 committed by est31
parent 3ce6642a26
commit 4e59fcf5c1
6 changed files with 46 additions and 1 deletions

View File

@ -785,6 +785,13 @@ core.register_chatcommand("time", {
end,
})
core.register_chatcommand("days", {
description = "Display day count",
func = function(name, param)
return true, "Current day is " .. core.get_day_count()
end
})
core.register_chatcommand("shutdown", {
description = "shutdown server",
privs = {server=true},

View File

@ -1998,6 +1998,8 @@ and `minetest.auth_reload` call the authetification handler.
* `val` is between `0` and `1`; `0` for midnight, `0.5` for midday
* `minetest.get_timeofday()`
* `minetest.get_gametime()`: returns the time, in seconds, since the world was created
* `minetest.get_day_count()`: returns number days elapsed since world was created,
* accounting for time changes.
* `minetest.find_node_near(pos, radius, nodenames)`: returns pos or `nil`
* `radius`: using a maximum metric
* `nodenames`: e.g. `{"ignore", "group:tree"}` or `"default:dirt"`

View File

@ -208,6 +208,8 @@ void Environment::setDayNightRatioOverride(bool enable, u32 value)
void Environment::setTimeOfDay(u32 time)
{
MutexAutoLock lock(this->m_time_lock);
if (m_time_of_day > time)
m_day_count++;
m_time_of_day = time;
m_time_of_day_f = (float)time / 24000.0;
}
@ -238,8 +240,10 @@ void Environment::stepTimeOfDay(float dtime)
bool sync_f = false;
if (units > 0) {
// Sync at overflow
if (m_time_of_day + units >= 24000)
if (m_time_of_day + units >= 24000) {
sync_f = true;
m_day_count++;
}
m_time_of_day = (m_time_of_day + units) % 24000;
if (sync_f)
m_time_of_day_f = (float)m_time_of_day / 24000.0;
@ -256,6 +260,13 @@ void Environment::stepTimeOfDay(float dtime)
}
}
u32 Environment::getDayCount()
{
// Atomic<u32> counter
return m_day_count;
}
/*
ABMWithState
*/
@ -727,6 +738,7 @@ void ServerEnvironment::saveMeta()
args.setU64("lbm_introduction_times_version", 1);
args.set("lbm_introduction_times",
m_lbm_mgr.createIntroductionTimesString());
args.setU64("day_count", m_day_count);
args.writeLines(ss);
ss<<"EnvArgsEnd\n";
@ -792,6 +804,12 @@ void ServerEnvironment::loadMeta()
}
m_lbm_mgr.loadIntroductionTimes(lbm_introduction_times, m_gamedef, m_game_time);
try {
m_day_count = args.getU64("day_count");
} catch (SettingNotFoundException &e) {
// If missing, start the day counter
m_day_count = 0;
}
}
void ServerEnvironment::loadDefaultMeta()

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@ -95,6 +95,8 @@ public:
void setDayNightRatioOverride(bool enable, u32 value);
u32 getDayCount();
// counter used internally when triggering ABMs
u32 m_added_objects;
@ -117,6 +119,9 @@ protected:
// Overriding the day-night ratio is useful for custom sky visuals
bool m_enable_day_night_ratio_override;
u32 m_day_night_ratio_override;
// Days from the server start, accounts for time shift
// in game (e.g. /time or bed usage)
Atomic<u32> m_day_count;
/*
* Above: values managed by m_time_lock
*/

View File

@ -561,6 +561,15 @@ int ModApiEnvMod::l_get_timeofday(lua_State *L)
return 1;
}
// get_day_count() -> int
int ModApiEnvMod::l_get_day_count(lua_State *L)
{
GET_ENV_PTR;
lua_pushnumber(L, env->getDayCount());
return 1;
}
// get_gametime()
int ModApiEnvMod::l_get_gametime(lua_State *L)
{
@ -1055,6 +1064,7 @@ void ModApiEnvMod::Initialize(lua_State *L, int top)
API_FCT(set_timeofday);
API_FCT(get_timeofday);
API_FCT(get_gametime);
API_FCT(get_day_count);
API_FCT(find_node_near);
API_FCT(find_nodes_in_area);
API_FCT(find_nodes_in_area_under_air);

View File

@ -113,6 +113,9 @@ private:
// get_gametime()
static int l_get_gametime(lua_State *L);
// get_day_count() -> int
static int l_get_day_count(lua_State *L);
// find_node_near(pos, radius, nodenames) -> pos or nil
// nodenames: eg. {"ignore", "group:tree"} or "default:dirt"
static int l_find_node_near(lua_State *L);