| 1 | // |
| 2 | // System time handlers |
| 3 | // |
| 4 | // by James Hammons |
| 5 | // (C) 2010 Underground Software |
| 6 | // |
| 7 | // JLH = James Hammons <jlhamm@acm.org> |
| 8 | // |
| 9 | // Who When What |
| 10 | // --- ---------- ------------------------------------------------------------- |
| 11 | // JLH 01/16/2010 Created this log ;-) |
| 12 | // |
| 13 | |
| 14 | // |
| 15 | // STILL TO DO: |
| 16 | // |
| 17 | // - Handling for an event that occurs NOW |
| 18 | // |
| 19 | |
| 20 | #include "event.h" |
| 21 | |
| 22 | #include <stdint.h> |
| 23 | #include "log.h" |
| 24 | |
| 25 | |
| 26 | //#define EVENT_LIST_SIZE 512 |
| 27 | #define EVENT_LIST_SIZE 32 |
| 28 | |
| 29 | |
| 30 | // Now, a bit of weirdness: It seems that the number of lines displayed on the screen |
| 31 | // makes the effective refresh rate either 30 or 25 Hz! |
| 32 | |
| 33 | // NOTE ABOUT TIMING SYSTEM DATA STRUCTURES: |
| 34 | |
| 35 | // A queue won't work for this system because we can't guarantee that an event will go |
| 36 | // in with a time that is later than the ones already queued up. So we just use a simple |
| 37 | // list. |
| 38 | |
| 39 | // Although if we used an insertion sort we could, but it wouldn't work for adjusting |
| 40 | // times... (For that, you would have to remove the event then reinsert it.) |
| 41 | |
| 42 | struct Event |
| 43 | { |
| 44 | bool valid; |
| 45 | int eventType; |
| 46 | double eventTime; |
| 47 | void (* timerCallback)(void); |
| 48 | }; |
| 49 | |
| 50 | |
| 51 | static Event eventList[EVENT_LIST_SIZE]; |
| 52 | static Event eventListJERRY[EVENT_LIST_SIZE]; |
| 53 | static uint32_t nextEvent; |
| 54 | static uint32_t nextEventJERRY; |
| 55 | static uint32_t numberOfEvents; |
| 56 | |
| 57 | |
| 58 | void InitializeEventList(void) |
| 59 | { |
| 60 | for(uint32_t i=0; i<EVENT_LIST_SIZE; i++) |
| 61 | { |
| 62 | eventList[i].valid = false; |
| 63 | eventListJERRY[i].valid = false; |
| 64 | } |
| 65 | |
| 66 | numberOfEvents = 0; |
| 67 | WriteLog("EVENT: Cleared event list.\n"); |
| 68 | } |
| 69 | |
| 70 | |
| 71 | // Set callback time in µs. This is fairly arbitrary, but works well enough for our purposes. |
| 72 | //We just slap the next event into the list in the first available slot, no checking, no nada... |
| 73 | void SetCallbackTime(void (* callback)(void), double time, int type/*= EVENT_MAIN*/) |
| 74 | { |
| 75 | if (type == EVENT_MAIN) |
| 76 | { |
| 77 | for(uint32_t i=0; i<EVENT_LIST_SIZE; i++) |
| 78 | { |
| 79 | if (!eventList[i].valid) |
| 80 | { |
| 81 | //WriteLog("EVENT: Found callback slot #%u...\n", i); |
| 82 | eventList[i].timerCallback = callback; |
| 83 | eventList[i].eventTime = time; |
| 84 | eventList[i].eventType = type; |
| 85 | eventList[i].valid = true; |
| 86 | numberOfEvents++; |
| 87 | |
| 88 | return; |
| 89 | } |
| 90 | } |
| 91 | |
| 92 | WriteLog("EVENT: SetCallbackTime() failed to find an empty slot in the main list (%u events)!\n", numberOfEvents); |
| 93 | } |
| 94 | else |
| 95 | { |
| 96 | for(uint32_t i=0; i<EVENT_LIST_SIZE; i++) |
| 97 | { |
| 98 | if (!eventListJERRY[i].valid) |
| 99 | { |
| 100 | //WriteLog("EVENT: Found callback slot #%u...\n", i); |
| 101 | eventListJERRY[i].timerCallback = callback; |
| 102 | eventListJERRY[i].eventTime = time; |
| 103 | eventListJERRY[i].eventType = type; |
| 104 | eventListJERRY[i].valid = true; |
| 105 | numberOfEvents++; |
| 106 | |
| 107 | return; |
| 108 | } |
| 109 | } |
| 110 | |
| 111 | WriteLog("EVENT: SetCallbackTime() failed to find an empty slot in the main list (%u events)!\n", numberOfEvents); |
| 112 | } |
| 113 | } |
| 114 | |
| 115 | |
| 116 | void RemoveCallback(void (* callback)(void)) |
| 117 | { |
| 118 | for(uint32_t i=0; i<EVENT_LIST_SIZE; i++) |
| 119 | { |
| 120 | if (eventList[i].valid && eventList[i].timerCallback == callback) |
| 121 | { |
| 122 | eventList[i].valid = false; |
| 123 | numberOfEvents--; |
| 124 | |
| 125 | return; |
| 126 | } |
| 127 | else if (eventListJERRY[i].valid && eventListJERRY[i].timerCallback == callback) |
| 128 | { |
| 129 | eventListJERRY[i].valid = false; |
| 130 | numberOfEvents--; |
| 131 | |
| 132 | return; |
| 133 | } |
| 134 | } |
| 135 | } |
| 136 | |
| 137 | |
| 138 | void AdjustCallbackTime(void (* callback)(void), double time) |
| 139 | { |
| 140 | for(uint32_t i=0; i<EVENT_LIST_SIZE; i++) |
| 141 | { |
| 142 | if (eventList[i].valid && eventList[i].timerCallback == callback) |
| 143 | { |
| 144 | eventList[i].eventTime = time; |
| 145 | |
| 146 | return; |
| 147 | } |
| 148 | else if (eventListJERRY[i].valid && eventListJERRY[i].timerCallback == callback) |
| 149 | { |
| 150 | eventListJERRY[i].eventTime = time; |
| 151 | |
| 152 | return; |
| 153 | } |
| 154 | } |
| 155 | } |
| 156 | |
| 157 | |
| 158 | // |
| 159 | // Since our list is unordered WRT time, we have to search it to find the next event |
| 160 | // Returns time to next event & sets nextEvent to that event |
| 161 | // |
| 162 | double GetTimeToNextEvent(int type/*= EVENT_MAIN*/) |
| 163 | { |
| 164 | #if 0 |
| 165 | double time = 0; |
| 166 | bool firstTime = true; |
| 167 | |
| 168 | for(uint32 i=0; i<EVENT_LIST_SIZE; i++) |
| 169 | { |
| 170 | if (eventList[i].valid) |
| 171 | { |
| 172 | if (firstTime) |
| 173 | time = eventList[i].eventTime, nextEvent = i, firstTime = false; |
| 174 | else |
| 175 | { |
| 176 | if (eventList[i].eventTime < time) |
| 177 | time = eventList[i].eventTime, nextEvent = i; |
| 178 | } |
| 179 | } |
| 180 | } |
| 181 | #else |
| 182 | if (type == EVENT_MAIN) |
| 183 | { |
| 184 | double time = eventList[0].eventTime; |
| 185 | nextEvent = 0; |
| 186 | |
| 187 | for(uint32_t i=1; i<EVENT_LIST_SIZE; i++) |
| 188 | { |
| 189 | if (eventList[i].valid && (eventList[i].eventTime < time)) |
| 190 | { |
| 191 | time = eventList[i].eventTime; |
| 192 | nextEvent = i; |
| 193 | } |
| 194 | } |
| 195 | |
| 196 | return time; |
| 197 | } |
| 198 | else |
| 199 | { |
| 200 | double time = eventListJERRY[0].eventTime; |
| 201 | nextEventJERRY = 0; |
| 202 | |
| 203 | for(uint32_t i=1; i<EVENT_LIST_SIZE; i++) |
| 204 | { |
| 205 | if (eventListJERRY[i].valid && (eventListJERRY[i].eventTime < time)) |
| 206 | { |
| 207 | time = eventListJERRY[i].eventTime; |
| 208 | nextEventJERRY = i; |
| 209 | } |
| 210 | } |
| 211 | |
| 212 | return time; |
| 213 | } |
| 214 | #endif |
| 215 | } |
| 216 | |
| 217 | |
| 218 | void HandleNextEvent(int type/*= EVENT_MAIN*/) |
| 219 | { |
| 220 | if (type == EVENT_MAIN) |
| 221 | { |
| 222 | double elapsedTime = eventList[nextEvent].eventTime; |
| 223 | void (* event)(void) = eventList[nextEvent].timerCallback; |
| 224 | |
| 225 | for(uint32_t i=0; i<EVENT_LIST_SIZE; i++) |
| 226 | { |
| 227 | //We can skip the check & just subtract from everything, since the check is probably |
| 228 | //just as heavy as the code after and we won't use the elapsed time from an invalid event anyway. |
| 229 | // if (eventList[i].valid) |
| 230 | eventList[i].eventTime -= elapsedTime; |
| 231 | } |
| 232 | |
| 233 | eventList[nextEvent].valid = false; // Remove event from list... |
| 234 | numberOfEvents--; |
| 235 | |
| 236 | (*event)(); |
| 237 | } |
| 238 | else |
| 239 | { |
| 240 | double elapsedTime = eventListJERRY[nextEventJERRY].eventTime; |
| 241 | void (* event)(void) = eventListJERRY[nextEventJERRY].timerCallback; |
| 242 | |
| 243 | for(uint32_t i=0; i<EVENT_LIST_SIZE; i++) |
| 244 | { |
| 245 | //We can skip the check & just subtract from everything, since the check is probably |
| 246 | //just as heavy as the code after and we won't use the elapsed time from an invalid event anyway. |
| 247 | // if (eventList[i].valid) |
| 248 | eventListJERRY[i].eventTime -= elapsedTime; |
| 249 | } |
| 250 | |
| 251 | eventListJERRY[nextEventJERRY].valid = false; // Remove event from list... |
| 252 | numberOfEvents--; |
| 253 | |
| 254 | (*event)(); |
| 255 | } |
| 256 | } |
| 257 | |
| 258 | |
| 259 | /* |
| 260 | void OPCallback(void) |
| 261 | { |
| 262 | DoFunkyOPStuffHere(); |
| 263 | |
| 264 | SetCallbackTime(OPCallback, HORIZ_PERIOD_IN_USEC); |
| 265 | } |
| 266 | |
| 267 | void VICallback(void) |
| 268 | { |
| 269 | double oneFrameInUsec = 16666.66666666; |
| 270 | SetCallbackTime(VICallback, oneFrameInUsec / numberOfLines); |
| 271 | } |
| 272 | |
| 273 | void JaguarInit(void) |
| 274 | { |
| 275 | double oneFrameInUsec = 16666.66666666; |
| 276 | SetCallbackTime(VICallback, oneFrameInUsec / numberOfLines); |
| 277 | SetCallbackTime(OPCallback, ); |
| 278 | } |
| 279 | |
| 280 | void JaguarExec(void) |
| 281 | { |
| 282 | while (true) |
| 283 | { |
| 284 | double timeToNextEvent = GetTimeToNextEvent(); |
| 285 | |
| 286 | m68k_execute(USEC_TO_M68K_CYCLES(timeToNextEvent)); |
| 287 | GPUExec(USEC_TO_RISC_CYCLES(timeToNextEvent)); |
| 288 | DSPExec(USEC_TO_RISC_CYCLES(timeToNextEvent)); |
| 289 | |
| 290 | if (!HandleNextEvent()) |
| 291 | break; |
| 292 | } |
| 293 | } |
| 294 | |
| 295 | // NOTES: The timers count RISC cycles, and when the dividers count down to zero they can interrupt either the DSP and/or CPU. |
| 296 | |
| 297 | // NEW: |
| 298 | // TOM Programmable Interrupt Timer handler |
| 299 | // NOTE: TOM's PIT is only enabled if the prescaler is != 0 |
| 300 | // The PIT only generates an interrupt when it counts down to zero, not when loaded! |
| 301 | |
| 302 | void TOMResetPIT() |
| 303 | { |
| 304 | // Need to remove previous timer from the queue, if it exists... |
| 305 | RemoveCallback(TOMPITCallback); |
| 306 | |
| 307 | if (TOMPITPrescaler) |
| 308 | { |
| 309 | double usecs = (TOMPITPrescaler + 1) * (TOMPITDivider + 1) * RISC_CYCLE_IN_USEC; |
| 310 | SetCallbackTime(TOMPITCallback, usecs); |
| 311 | } |
| 312 | } |
| 313 | |
| 314 | void TOMPITCallback(void) |
| 315 | { |
| 316 | INT1_RREG |= 0x08; // Set TOM PIT interrupt pending |
| 317 | GPUSetIRQLine(GPUIRQ_TIMER, ASSERT_LINE); // It does the 'IRQ enabled' checking |
| 318 | |
| 319 | if (INT1_WREG & 0x08) |
| 320 | m68k_set_irq(2); // Generate 68K NMI |
| 321 | |
| 322 | TOMResetPIT(); |
| 323 | } |
| 324 | |
| 325 | // Small problem with this approach: If a timer interrupt is already pending, |
| 326 | // the pending timer needs to be replaced with the new one! (Taken care of above, BTW...) |
| 327 | |
| 328 | TOMWriteWord(uint32 address, uint16 data) |
| 329 | { |
| 330 | if (address == PIT0) |
| 331 | { |
| 332 | TOMPITPrescaler = data; |
| 333 | TOMResetPIT(); |
| 334 | } |
| 335 | else if (address == PIT1) |
| 336 | { |
| 337 | TOMPITDivider = data; |
| 338 | TOMResetPIT(); |
| 339 | } |
| 340 | } |
| 341 | |
| 342 | */ |