From 5a079a2d114f96d4847d1ee305d5b7c16eeec50e Mon Sep 17 00:00:00 2001 From: 3gg <3gg@shellblade.net> Date: Sat, 27 Dec 2025 12:03:39 -0800 Subject: Initial commit --- contrib/SDL-3.2.8/src/time/SDL_time.c | 222 ++++++++++++++++++++++++++++++++++ 1 file changed, 222 insertions(+) create mode 100644 contrib/SDL-3.2.8/src/time/SDL_time.c (limited to 'contrib/SDL-3.2.8/src/time/SDL_time.c') diff --git a/contrib/SDL-3.2.8/src/time/SDL_time.c b/contrib/SDL-3.2.8/src/time/SDL_time.c new file mode 100644 index 0000000..54059de --- /dev/null +++ b/contrib/SDL-3.2.8/src/time/SDL_time.c @@ -0,0 +1,222 @@ +/* + Simple DirectMedia Layer + Copyright (C) 1997-2025 Sam Lantinga + + This software is provided 'as-is', without any express or implied + warranty. In no event will the authors be held liable for any damages + arising from the use of this software. + + Permission is granted to anyone to use this software for any purpose, + including commercial applications, and to alter it and redistribute it + freely, subject to the following restrictions: + + 1. The origin of this software must not be misrepresented; you must not + claim that you wrote the original software. If you use this software + in a product, an acknowledgment in the product documentation would be + appreciated but is not required. + 2. Altered source versions must be plainly marked as such, and must not be + misrepresented as being the original software. + 3. This notice may not be removed or altered from any source distribution. +*/ +#include "SDL_internal.h" + +#include "SDL_time_c.h" + +/* The following algorithms are based on those of Howard Hinnant and are in the public domain. + * + * http://howardhinnant.github.io/date_algorithms.html + */ + +/* Given a calendar date, returns days since Jan 1 1970, and optionally + * the day of the week [0-6, 0 is Sunday] and day of the year [0-365]. + */ +Sint64 SDL_CivilToDays(int year, int month, int day, int *day_of_week, int *day_of_year) +{ + + year -= month <= 2; + const int era = (year >= 0 ? year : year - 399) / 400; + const unsigned yoe = (unsigned)(year - era * 400); // [0, 399] + const unsigned doy = (153 * (month > 2 ? month - 3 : month + 9) + 2) / 5 + day - 1; // [0, 365] + const unsigned doe = yoe * 365 + yoe / 4 - yoe / 100 + doy; // [0, 146096] + const Sint64 z = (Sint64)(era) * 146097 + (Sint64)(doe)-719468; + + if (day_of_week) { + *day_of_week = (int)(z >= -4 ? (z + 4) % 7 : (z + 5) % 7 + 6); + } + if (day_of_year) { + // This algorithm considers March 1 to be the first day of the year, so offset by Jan + Feb. + if (doy > 305) { + // Day 0 is the first day of the year. + *day_of_year = doy - 306; + } else { + const int doy_offset = 59 + (!(year % 4) && ((year % 100) || !(year % 400))); + *day_of_year = doy + doy_offset; + } + } + + return z; +} + +bool SDL_GetDateTimeLocalePreferences(SDL_DateFormat *dateFormat, SDL_TimeFormat *timeFormat) +{ + // Default to ISO 8061 date format, as it is unambiguous, and 24 hour time. + if (dateFormat) { + *dateFormat = SDL_DATE_FORMAT_YYYYMMDD; + } + if (timeFormat) { + *timeFormat = SDL_TIME_FORMAT_24HR; + } + + SDL_GetSystemTimeLocalePreferences(dateFormat, timeFormat); + + return true; +} + +int SDL_GetDaysInMonth(int year, int month) +{ + static const int DAYS_IN_MONTH[] = { + 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 + }; + + if (month < 1 || month > 12) { + SDL_SetError("Month out of range [1-12], requested: %i", month); + return -1; + } + + int days = DAYS_IN_MONTH[month - 1]; + + /* A leap year occurs every 4 years... + * but not every 100 years... + * except for every 400 years. + */ + if (month == 2 && (!(year % 4) && ((year % 100) || !(year % 400)))) { + ++days; + } + + return days; +} + +int SDL_GetDayOfYear(int year, int month, int day) +{ + int dayOfYear; + + if (month < 1 || month > 12) { + SDL_SetError("Month out of range [1-12], requested: %i", month); + return -1; + } + if (day < 1 || day > SDL_GetDaysInMonth(year, month)) { + SDL_SetError("Day out of range [1-%i], requested: %i", SDL_GetDaysInMonth(year, month), month); + return -1; + } + + SDL_CivilToDays(year, month, day, NULL, &dayOfYear); + return dayOfYear; +} + +int SDL_GetDayOfWeek(int year, int month, int day) +{ + int dayOfWeek; + + if (month < 1 || month > 12) { + SDL_SetError("Month out of range [1-12], requested: %i", month); + return -1; + } + if (day < 1 || day > SDL_GetDaysInMonth(year, month)) { + SDL_SetError("Day out of range [1-%i], requested: %i", SDL_GetDaysInMonth(year, month), month); + return -1; + } + + SDL_CivilToDays(year, month, day, &dayOfWeek, NULL); + return dayOfWeek; +} + +static bool SDL_DateTimeIsValid(const SDL_DateTime *dt) +{ + if (dt->month < 1 || dt->month > 12) { + SDL_SetError("Malformed SDL_DateTime: month out of range [1-12], current: %i", dt->month); + return false; + } + + const int daysInMonth = SDL_GetDaysInMonth(dt->year, dt->month); + if (dt->day < 1 || dt->day > daysInMonth) { + SDL_SetError("Malformed SDL_DateTime: day of month out of range [1-%i], current: %i", daysInMonth, dt->month); + return false; + } + if (dt->hour < 0 || dt->hour > 23) { + SDL_SetError("Malformed SDL_DateTime: hour out of range [0-23], current: %i", dt->hour); + return false; + } + if (dt->minute < 0 || dt->minute > 59) { + SDL_SetError("Malformed SDL_DateTime: minute out of range [0-59], current: %i", dt->minute); + return false; + } + if (dt->second < 0 || dt->second > 60) { + SDL_SetError("Malformed SDL_DateTime: second out of range [0-60], current: %i", dt->second); + return false; // 60 accounts for a possible leap second. + } + if (dt->nanosecond < 0 || dt->nanosecond >= SDL_NS_PER_SECOND) { + SDL_SetError("Malformed SDL_DateTime: nanosecond out of range [0-999999999], current: %i", dt->nanosecond); + return false; + } + + return true; +} + +bool SDL_DateTimeToTime(const SDL_DateTime *dt, SDL_Time *ticks) +{ + static const Sint64 max_seconds = SDL_NS_TO_SECONDS(SDL_MAX_TIME) - 1; + static const Sint64 min_seconds = SDL_NS_TO_SECONDS(SDL_MIN_TIME) + 1; + bool result = true; + + if (!dt) { + return SDL_InvalidParamError("dt"); + } + if (!ticks) { + return SDL_InvalidParamError("ticks"); + } + if (!SDL_DateTimeIsValid(dt)) { + // The validation function sets the error string. + return false; + } + + *ticks = SDL_CivilToDays(dt->year, dt->month, dt->day, NULL, NULL) * SDL_SECONDS_PER_DAY; + *ticks += (((dt->hour * 60) + dt->minute) * 60) + dt->second - dt->utc_offset; + if (*ticks > max_seconds || *ticks < min_seconds) { + *ticks = SDL_clamp(*ticks, min_seconds, max_seconds); + result = SDL_SetError("Date out of range for SDL_Time representation; SDL_Time value clamped"); + } + *ticks = SDL_SECONDS_TO_NS(*ticks) + dt->nanosecond; + + return result; +} + +#define DELTA_EPOCH_1601_100NS (11644473600ll * 10000000ll) // [100 ns] (100 ns units between 1601-01-01 and 1970-01-01, 11644473600 seconds) + +void SDL_TimeToWindows(SDL_Time ticks, Uint32 *dwLowDateTime, Uint32 *dwHighDateTime) +{ + /* Convert nanoseconds to Win32 ticks. + * SDL_Time has a range of roughly 292 years, so even SDL_MIN_TIME can't underflow the Win32 epoch. + */ + const Uint64 wtime = (Uint64)((ticks / 100) + DELTA_EPOCH_1601_100NS); + + if (dwLowDateTime) { + *dwLowDateTime = (Uint32)wtime; + } + + if (dwHighDateTime) { + *dwHighDateTime = (Uint32)(wtime >> 32); + } +} + +SDL_Time SDL_TimeFromWindows(Uint32 dwLowDateTime, Uint32 dwHighDateTime) +{ + static const Uint64 wintime_min = (Uint64)((SDL_MIN_TIME / 100) + DELTA_EPOCH_1601_100NS); + static const Uint64 wintime_max = (Uint64)((SDL_MAX_TIME / 100) + DELTA_EPOCH_1601_100NS); + + Uint64 wtime = (((Uint64)dwHighDateTime << 32) | dwLowDateTime); + + // Clamp the windows time range to the SDL_Time min/max + wtime = SDL_clamp(wtime, wintime_min, wintime_max); + + return (SDL_Time)(wtime - DELTA_EPOCH_1601_100NS) * 100; +} -- cgit v1.2.3