1 files changed, 222 insertions, 0 deletions

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 <slouken@libsdl.org>
+
+  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;
+}