aboutsummaryrefslogtreecommitdiff
path: root/source/srtc.c
blob: 3f4f2576718dbf2328d10d34f8c4bf1d158b5c48 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
#include "../copyright"

#include <string.h>
#include "snes9x.h"
#include "srtc.h"
#include "memmap.h"

/***   The format of the rtc_data structure is:

Index Description     Range (nibble)
----- --------------  ---------------------------------------

  0   Seconds low     0-9
  1   Seconds high    0-5

  2   Minutes low     0-9
  3   Minutes high    0-5

  4   Hour low        0-9
  5   Hour high       0-2

  6   Day low         0-9
  7   Day high        0-3

  8   Month           1-C (0xC is December, 12th month)

  9   Year ones       0-9
  A   Year tens       0-9
  B   Year High       9-B  (9=19xx, A=20xx, B=21xx)

  C   Day of week     0-6  (0=Sunday, 1=Monday,...,6=Saturday)

***/

SRTC_DATA           rtc;

static int32_t month_keys[12] = { 1, 4, 4, 0, 2, 5, 0, 3, 6, 1, 4, 6 };


/*********************************************************************************************
 * Note, if you are doing a save state for this game:
 *
 * On save:
 *
 * Call S9xUpdateSrtcTime and save the rtc data structure.
 *
 * On load:
 *
 * restore the rtc data structure
 *      rtc.system_timestamp = time (NULL);
 *********************************************************************************************/


void S9xResetSRTC(void)
{
   rtc.index = -1;
   rtc.mode = MODE_READ;
}

void S9xHardResetSRTC(void)
{
   memset(&rtc, 0, sizeof(rtc));
   rtc.index = -1;
   rtc.mode = MODE_READ;
   rtc.count_enable = false;
   rtc.needs_init = true;
   rtc.system_timestamp = time(NULL); /* Get system timestamp */
}

/**********************************************************************************************/
/* S9xSRTCComputeDayOfWeek(void)                                                              */
/* Return 0-6 for Sunday-Saturday                                                             */
/**********************************************************************************************/
uint32_t S9xSRTCComputeDayOfWeek(void)
{
   uint32_t year = rtc.data[10] * 10 + rtc.data[9];
   uint32_t month = rtc.data[8];
   uint32_t day = rtc.data[7] * 10 + rtc.data[6];
   uint32_t day_of_week;
   year += (rtc.data[11] - 9) * 100;

   /* Range check the month for valid array indices */
   if (month > 12)
      month = 1;

   day_of_week = year + (year / 4) + month_keys[month - 1] + day - 1;

   if ((year % 4 == 0) && (month <= 2))
      day_of_week--;

   day_of_week %= 7;

   return day_of_week;
}


/**********************************************************************************************/
/* S9xSRTCDaysInMonth()                                                                       */
/* Return the number of days in a specific month for a certain year                           */
/**********************************************************************************************/
int32_t S9xSRTCDaysInMmonth(int32_t month, int32_t year)
{
   switch(month)
   {
      case 2:
         if((year % 4 == 0)) /* DKJM2 only uses 199x - 22xx */
            return 29;
         return 28;
      case 4:
      case 6:
      case 9:
      case 11:
         return 30;
      default:
         return 31;
   }
}

#define MINUTETICKS  60
#define HOURTICKS   (60 * MINUTETICKS)
#define DAYTICKS    (24 * HOURTICKS)


/**********************************************************************************************/
/* S9xUpdateSrtcTime()                                                                        */
/* Advance the  S-RTC time if counting is enabled                                             */
/**********************************************************************************************/
void S9xUpdateSrtcTime(void)
{
   time_t  cur_systime;
   int32_t time_diff;

   /* Keep track of game time by computing the number of seconds that pass on the system */
   /* clock and adding the same number of seconds to the S-RTC clock structure. */
   /* Note: Dai Kaijyu Monogatari II only allows dates in the range 1996-21xx. */

   if (rtc.count_enable && !rtc.needs_init)
   {
      cur_systime = time(NULL);
      time_diff = (int32_t)(cur_systime - rtc.system_timestamp);
      rtc.system_timestamp = cur_systime;

      if (time_diff > 0)
      {
         int32_t seconds;
         int32_t minutes;
         int32_t hours;
         int32_t days;
         int32_t month;
         int32_t year;
         int32_t temp_days;
         int32_t year_hundreds;
         int32_t year_tens;
         int32_t year_ones;

         if (time_diff > DAYTICKS)
         {
            days = time_diff / DAYTICKS;
            time_diff = time_diff - days * DAYTICKS;
         }
         else
            days = 0;

         if (time_diff > HOURTICKS)
         {
            hours = time_diff / HOURTICKS;
            time_diff = time_diff - hours * HOURTICKS;
         }
         else
            hours = 0;

         if (time_diff > MINUTETICKS)
         {
            minutes = time_diff / MINUTETICKS;
            time_diff = time_diff - minutes * MINUTETICKS;
         }
         else
            minutes = 0;

         if (time_diff > 0)
            seconds = time_diff;
         else
            seconds = 0;


         seconds += (rtc.data[1] * 10 + rtc.data[0]);
         if (seconds >= 60)
         {
            seconds -= 60;
            minutes += 1;
         }

         minutes += (rtc.data[3] * 10 + rtc.data[2]);
         if (minutes >= 60)
         {
            minutes -= 60;
            hours += 1;
         }

         hours += (rtc.data[5] * 10 + rtc.data[4]);
         if (hours >= 24)
         {
            hours -= 24;
            days += 1;
         }

         if (days > 0)
         {
            year =  rtc.data[10] * 10 + rtc.data[9];
            year += (1000 + rtc.data[11] * 100);
            month = rtc.data[8];
            days += (rtc.data[7] * 10 + rtc.data[6]);
            while (days > (temp_days = S9xSRTCDaysInMmonth(month, year)))
            {
               days -= temp_days;
               month += 1;
               if (month > 12)
               {
                  year += 1;
                  month = 1;
               }
            }

            year_tens = year % 100;
            year_ones = year_tens % 10;
            year_tens /= 10;
            year_hundreds = (year - 1000) / 100;
            rtc.data[6] = days % 10;
            rtc.data[7] = days / 10;
            rtc.data[8] = month;
            rtc.data[9] = year_ones;
            rtc.data[10] = year_tens;
            rtc.data[11] = year_hundreds;
            rtc.data[12] = S9xSRTCComputeDayOfWeek();
         }

         rtc.data[0] = seconds % 10;
         rtc.data[1] = seconds / 10;
         rtc.data[2] = minutes % 10;
         rtc.data[3] = minutes / 10;
         rtc.data[4] = hours % 10;
         rtc.data[5] = hours / 10;
         return;
      }
   }
}

/**********************************************************************************************/
/* S9xSetSRTC(void)                                                                           */
/* This function sends data to the S-RTC used in Dai Kaijyu Monogatari II                     */
/**********************************************************************************************/
void S9xSetSRTC(uint8_t data, uint16_t Address)
{
   (void) Address;
   data &= 0x0F; /* Data is only 4-bits, mask out unused bits. */

   if (data >= 0xD) /* It's an RTC command */
   {
      switch (data)
      {
      case 0xD:
         rtc.mode = MODE_READ;
         rtc.index = -1;
         break;
      case 0xE:
         rtc.mode = MODE_COMMAND;
         break;
      default:
         break;
      }

      return;
   }

   if (rtc.mode == MODE_LOAD_RTC)
   {
      if ((rtc.index >= 0) || (rtc.index < MAX_RTC_INDEX))
      {
         rtc.data[rtc.index++] = data;

         if (rtc.index == MAX_RTC_INDEX) /* We have all the data for the RTC load */
         {
            rtc.system_timestamp = time(NULL); /* Get local system time */
            rtc.data[rtc.index++] = S9xSRTCComputeDayOfWeek(); /* Get the day of the week */

            /* Start RTC counting again */
            rtc.count_enable = true;
            rtc.needs_init = false;
         }

         return;
      }
   }
   else if (rtc.mode == MODE_COMMAND)
   {
      switch (data)
      {
      case COMMAND_CLEAR_RTC:
         rtc.count_enable = false; /* Disable RTC counter */
         memset(rtc.data, 0, MAX_RTC_INDEX + 1);
         rtc.index = -1;
         rtc.mode = MODE_COMMAND_DONE;
         break;
      case COMMAND_LOAD_RTC:
         rtc.count_enable = false; /* Disable RTC counter */
         rtc.index = 0;  /* Setup for writing */
         rtc.mode = MODE_LOAD_RTC;
         break;
      default:
         rtc.mode = MODE_COMMAND_DONE; /* unrecognized command - need to implement. */
      }

      return;
   }
}

/**********************************************************************************************/
/* S9xGetSRTC()                                                                               */
/* This function retrieves data from the S-RTC                                                */
/**********************************************************************************************/
uint8_t S9xGetSRTC(uint16_t Address)
{
   (void) Address;
   if (rtc.mode == MODE_READ)
   {
      if (rtc.index < 0)
      {
         S9xUpdateSrtcTime(); /* Only update it if the game reads it */
         rtc.index++;
         return 0x0f; /* Send start marker. */
      }
      else if (rtc.index > MAX_RTC_INDEX)
      {
         rtc.index = -1; /* Setup for next set of reads */
         return 0x0f; /* Data done marker. */
      }
      else
         return rtc.data[rtc.index++]; /* Feed out the data */
   }
   else
      return 0x0;
}

void S9xSRTCPreSaveState()
{
   if (Settings.SRTC)
   {
      int32_t s;

      S9xUpdateSrtcTime();
      s = Memory.SRAMSize ? (1 << (Memory.SRAMSize + 3)) * 128 : 0;

      if (s > 0x20000)
         s = 0x20000;

      Memory.SRAM [s + 0] = rtc.needs_init;
      Memory.SRAM [s + 1] = rtc.count_enable;
      /* memmove converted: Different mallocs [Neb] */
      memcpy(&Memory.SRAM [s + 2], rtc.data, MAX_RTC_INDEX + 1);
      Memory.SRAM [s + 3 + MAX_RTC_INDEX] = rtc.index;
      Memory.SRAM [s + 4 + MAX_RTC_INDEX] = rtc.mode;

#ifdef MSB_FIRST
      Memory.SRAM [s + 5  + MAX_RTC_INDEX] = (uint8_t)(rtc.system_timestamp >>  0);
      Memory.SRAM [s + 6  + MAX_RTC_INDEX] = (uint8_t)(rtc.system_timestamp >>  8);
      Memory.SRAM [s + 7  + MAX_RTC_INDEX] = (uint8_t)(rtc.system_timestamp >> 16);
      Memory.SRAM [s + 8  + MAX_RTC_INDEX] = (uint8_t)(rtc.system_timestamp >> 24);
      Memory.SRAM [s + 9  + MAX_RTC_INDEX] = (uint8_t)(rtc.system_timestamp >> 32);
      Memory.SRAM [s + 10 + MAX_RTC_INDEX] = (uint8_t)(rtc.system_timestamp >> 40);
      Memory.SRAM [s + 11 + MAX_RTC_INDEX] = (uint8_t)(rtc.system_timestamp >> 48);
      Memory.SRAM [s + 12 + MAX_RTC_INDEX] = (uint8_t)(rtc.system_timestamp >> 56);
#else
      /* memmove converted: Different mallocs [Neb] */
      memcpy(&Memory.SRAM [s + 5 + MAX_RTC_INDEX], &rtc.system_timestamp, sizeof(time_t));
#endif
   }
}

void S9xSRTCPostLoadState()
{
   if (Settings.SRTC)
   {
      int32_t s = Memory.SRAMSize ? (1 << (Memory.SRAMSize + 3)) * 128 : 0;
      if (s > 0x20000)
         s = 0x20000;

      rtc.needs_init = Memory.SRAM [s + 0];
      rtc.count_enable = Memory.SRAM [s + 1];
      /* memmove converted: Different mallocs [Neb] */
      memcpy(rtc.data, &Memory.SRAM [s + 2], MAX_RTC_INDEX + 1);
      rtc.index = Memory.SRAM [s + 3 + MAX_RTC_INDEX];
      rtc.mode = Memory.SRAM [s + 4 + MAX_RTC_INDEX];

#ifdef MSB_FIRST
      rtc.system_timestamp |= (Memory.SRAM [s +  5 + MAX_RTC_INDEX] <<  0);
      rtc.system_timestamp |= (Memory.SRAM [s +  6 + MAX_RTC_INDEX] <<  8);
      rtc.system_timestamp |= (Memory.SRAM [s +  7 + MAX_RTC_INDEX] << 16);
      rtc.system_timestamp |= (Memory.SRAM [s +  8 + MAX_RTC_INDEX] << 24);
      rtc.system_timestamp |= (Memory.SRAM [s +  9 + MAX_RTC_INDEX] << 32);
      rtc.system_timestamp |= (Memory.SRAM [s + 10 + MAX_RTC_INDEX] << 40);
      rtc.system_timestamp |= (Memory.SRAM [s + 11 + MAX_RTC_INDEX] << 48);
      rtc.system_timestamp |= (Memory.SRAM [s + 12 + MAX_RTC_INDEX] << 56);
#else
      /* memmove converted: Different mallocs [Neb] */
      memcpy(&rtc.system_timestamp, &Memory.SRAM [s + 5 + MAX_RTC_INDEX], sizeof(time_t));
#endif
      S9xUpdateSrtcTime();
   }
}