Commit | Line | Data |
---|---|---|
cf76e892 JPM |
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 | */ |