-
Notifications
You must be signed in to change notification settings - Fork 8
/
libretro.c
643 lines (549 loc) · 16.8 KB
/
libretro.c
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
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <stdarg.h>
#include <string.h>
#include "libretro.h"
#include "chip8.h"
#define VALID_EXTENSIONS "ch8|sc8|xo8|hc8"
#ifdef USE_RGB565
typedef unsigned short pixel_t;
#if defined(ABGR1555)
#define vRGB(r,g,b) ((((b) & 0xf8) << 7) | (((g) & 0xf8) << 2) | (((r) & 0xf8) >> 3))
#else
#define vRGB(r,g,b) ((((r) & 0xf8) << 8) | (((g) & 0xfc) << 3) | (((b) & 0xf8) >> 3))
#endif
#else
typedef unsigned int pixel_t;
#define vRGB(r,g,b) (((r) << 16) | ((g) << 8) | (b))
#endif
static pixel_t frame[DISPLAY_WIDTH * DISPLAY_HEIGHT];
static retro_environment_t environ_cb;
static retro_log_printf_t log_cb;
static retro_video_refresh_t video_cb;
static retro_input_poll_t input_poll_cb;
static retro_input_state_t input_state_cb;
static retro_audio_sample_t audio_cb;
static retro_audio_sample_batch_t audio_batch_cb;
static CHIP8 chip8;
static unsigned long cpu_debt = 0;
#define AUDIO_RESAMPLE_RATE 44100
static unsigned int audio_counter_chip8 = 0;
static unsigned int audio_counter_resample = 0;
static unsigned int audio_freq_chip8 = 0;
static int snd_buf_pntr = 0;
static uint8_t sram[NUM_USER_FLAGS];
struct theme {
pixel_t bg, p1, p2, overlap;
const char *name;
};
bool chip8_handle_user_flags(CHIP8 *chip8p, int num_flags, bool save)
{
if (num_flags <= NUM_USER_FLAGS)
{
if (save)
{
memcpy(sram, chip8p->V, num_flags);
}
else
{
memcpy(chip8p->V, sram, num_flags);
}
return true;
}
else
{
return true; // Only return false on file open error.
}
}
#define BG_COLOR_DEFAULT vRGB(0,0,0)
#define P1_COLOR_DEFAULT vRGB(0xFF,0xFF,0xFF)
#define P2_COLOR_DEFAULT vRGB(0xAA,0xAA,0xAA)
#define OVERLAP_COLOR_DEFAULT vRGB(0x55,0x55,0x55)
// Color/Display
// TODO: Add more themes!
static const struct theme color_themes[] = {
{BG_COLOR_DEFAULT, P1_COLOR_DEFAULT, P2_COLOR_DEFAULT, OVERLAP_COLOR_DEFAULT, "Default"},
{vRGB(0,0,0), vRGB(0xFF,0xFF,0xFF), vRGB(0,0,0), vRGB(0,0,0), "Black and white"},
{vRGB(0xFF,0xFF,0xFF), vRGB(0,0,0), vRGB(0,0,0), vRGB(0,0,0), "Inverted black and white"},
{vRGB(0,0,0), vRGB(0xFF,0,0), vRGB(0,0,0), vRGB(0,0,0), "Blood"},
{vRGB(0,0,0), vRGB(0,0xFF,0), vRGB(0,0,0), vRGB(0,0,0), "Hacker"},
{vRGB(0,0,0), vRGB(0,0,0xFF), vRGB(0,0,0), vRGB(0,0,0), "Space" },
{vRGB(0xF0,0x90,0x7C), vRGB(0x96,0x29,0x12), vRGB(0xF4,0x69,0), vRGB(0xFA, 0xA4,0), "Crazy Orange"},
{vRGB(0x10,0,0x19), vRGB(0xFF,0xE1,0xFF), vRGB(0xE7,0,0xEA), vRGB(0xE7,0,0xEA), "Cyberpunk"}
};
static pixel_t bg_color = BG_COLOR_DEFAULT;
static pixel_t p1_color = P1_COLOR_DEFAULT;
static pixel_t p2_color = P2_COLOR_DEFAULT;
static pixel_t overlap_color = OVERLAP_COLOR_DEFAULT;
static void fallback_log(enum retro_log_level level,
const char *fmt, ...) {
va_list args;
(void) level;
va_start(args, fmt);
vfprintf(stderr, fmt, args);
va_end(args);
}
#define FIRST_QUIRK_VARIABLE 0
static struct retro_variable variables[] =
{
{
"jaxe_quirk_0_ram_init",
"Ram init quirk; enabled|disabled",
},
{
"jaxe_quirk_1_8xy6_8xye",
"8xy6/8xyE quirk; enabled|disabled",
},
{
"jaxe_quirk_2_fx55_fx65",
"Fx55/Fx65 quirk; enabled|disabled",
},
{
"jaxe_quirk_3_bnnn",
"Bnnn quirk; enabled|disabled",
},
{
"jaxe_quirk_4_big_sprite_lores",
"Big Sprite LORES quirk; enabled|disabled",
},
{
"jaxe_quirk_5_00fe_00ff",
"00FE/00FF quirk; enabled|disabled",
},
{
"jaxe_quirk_6_sprite_wrapping",
"Sprite Wrapping; enabled|disabled",
},
{
"jaxe_quirk_7_collision_enumeration",
"Collision Enumeration; enabled|disabled",
},
{
"jaxe_quirk_8_collision_bottom_of_screen",
"Collision with Bottom of Screen; enabled|disabled",
},
{
"jaxe_quirk_9_disable_undefined_VF_after_logical_OR_AND_XOR",
"Disable undefined VF after logical OR, AND, XOR; enabled|disabled",
},
{
"jaxe_cpu_requency",
"CPU frequency; 1000|1500|2000|3000|5000|10000|25000|50000|100000|800|750|600|500|400|300",
},
{
"jaxe_theme",
"Theme; Default|Black and white|Inverted black and white|Blood|Hacker|Space|Crazy Orange|Cyberpunk"
},
{ NULL, NULL },
};
// TODO: find a better mapping
static unsigned hexorder[] = {
RETRO_DEVICE_ID_JOYPAD_B,
RETRO_DEVICE_ID_JOYPAD_START,
RETRO_DEVICE_ID_JOYPAD_Y,
RETRO_DEVICE_ID_JOYPAD_SELECT,
RETRO_DEVICE_ID_JOYPAD_L,
RETRO_DEVICE_ID_JOYPAD_UP,
RETRO_DEVICE_ID_JOYPAD_A,
RETRO_DEVICE_ID_JOYPAD_LEFT,
RETRO_DEVICE_ID_JOYPAD_DOWN,
RETRO_DEVICE_ID_JOYPAD_RIGHT,
RETRO_DEVICE_ID_JOYPAD_R,
RETRO_DEVICE_ID_JOYPAD_L2,
RETRO_DEVICE_ID_JOYPAD_X,
RETRO_DEVICE_ID_JOYPAD_R2,
RETRO_DEVICE_ID_JOYPAD_L3,
RETRO_DEVICE_ID_JOYPAD_R3
};
static struct retro_input_descriptor input_desc[] = {
{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_LEFT, "7" },
{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_Y, "2" },
{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_DOWN, "8" },
{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_RIGHT, "9" },
{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_B, "0" },
{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_SELECT,"3" },
{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_X, "C" },
{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_UP, "5" },
{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_A, "6" },
{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_START, "1" },
{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_L, "4" },
{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_R, "A" },
{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_L2, "B" },
{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_R2, "D" },
{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_L3, "E" },
{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_R3, "F" },
{ 0 },
};
void retro_set_environment(retro_environment_t fn)
{
static const struct retro_system_content_info_override content_overrides[] = {
{
VALID_EXTENSIONS, /* extensions */
false, /* need_fullpath */
true /* persistent_data */
},
{ NULL, false, false }
};
environ_cb = fn;
fn(RETRO_ENVIRONMENT_SET_VARIABLES, variables);
struct retro_log_callback log;
if (environ_cb(RETRO_ENVIRONMENT_GET_LOG_INTERFACE, &log))
log_cb = log.log;
else
log_cb = fallback_log;
/* Request a persistent content data buffer */
environ_cb(RETRO_ENVIRONMENT_SET_CONTENT_INFO_OVERRIDE,
(void*)content_overrides);
environ_cb(RETRO_ENVIRONMENT_SET_INPUT_DESCRIPTORS, input_desc);
}
static void load_theme(void)
{
struct retro_variable var;
int theme_number = 0;
var.key = "jaxe_theme";
var.value = NULL;
if (environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var) && var.value) {
for (int i = 0; i < sizeof (color_themes) / sizeof(color_themes[0]); i++) {
if (strcmp(var.value, color_themes[i].name) == 0)
theme_number = i;
}
}
bg_color = color_themes[theme_number].bg;
p1_color = color_themes[theme_number].p1;
p2_color = color_themes[theme_number].p2;
overlap_color = color_themes[theme_number].overlap;
}
static unsigned long get_cpu_freq_var(unsigned long def)
{
struct retro_variable var;
var.key = "jaxe_cpu_requency";
var.value = NULL;
if (!environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var) || !var.value)
return def;
unsigned long cpu_freq = strtoul(var.value, 0, 0);
if (cpu_freq == 0)
return def;
return cpu_freq;
}
static void chip8_init_with_vars(void)
{
bool quirks[NUM_QUIRKS] = {1, 1, 1, 1, 1, 1, 1, 1, 1, 1};
unsigned long cpu_freq = CPU_FREQ_DEFAULT;
unsigned long timer_freq = TIMER_FREQ_DEFAULT;
unsigned long refresh_freq = REFRESH_FREQ_DEFAULT;
uint16_t pc_start_addr = PC_START_ADDR_DEFAULT;
load_theme();
for (int i = 0; i < NUM_QUIRKS; i++) {
struct retro_variable var;
var.key = variables[i + FIRST_QUIRK_VARIABLE].key;
var.value = NULL;
quirks[i] = (!environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var) || !var.value) || strcmp(var.value, "disabled") != 0;
}
cpu_freq = get_cpu_freq_var(CPU_FREQ_DEFAULT);
chip8_init(&chip8, cpu_freq, timer_freq, refresh_freq, pc_start_addr,
quirks);
}
// Makes the physical screen match the emulator display.
void draw_display(void)
{
for (int y = 0; y < DISPLAY_HEIGHT; y++)
{
for (int x = 0; x < DISPLAY_WIDTH; x++)
{
pixel_t color;
if (!chip8.display[y][x] && !chip8.display2[y][x])
{
color = bg_color;
}
else if (chip8.display[y][x] && !chip8.display2[y][x])
{
color = p1_color;
}
else if (!chip8.display[y][x] && chip8.display2[y][x])
{
color = p2_color;
}
else
{
color = overlap_color;
}
frame[x + y * DISPLAY_WIDTH] = color;
}
}
}
void retro_set_video_refresh(retro_video_refresh_t fn) { video_cb = fn; }
void retro_set_audio_sample(retro_audio_sample_t fn) { audio_cb = fn; }
void retro_set_audio_sample_batch(retro_audio_sample_batch_t fn) { audio_batch_cb = fn; }
void retro_set_input_poll(retro_input_poll_t fn) { input_poll_cb = fn; }
void retro_set_input_state(retro_input_state_t fn) { input_state_cb = fn; }
void retro_init(void)
{
}
static void *rom_buf = NULL;
static const void *rom_data = NULL;
static size_t rom_size = 0;
static void load_rom(void) {
cpu_debt = 0;
audio_counter_chip8 = 0;
audio_counter_resample = 0;
audio_freq_chip8 = 0;
snd_buf_pntr = 0;
chip8_init_with_vars();
chip8_load_font(&chip8);
chip8_load_rom_buffer(&chip8, rom_data, rom_size);
}
bool retro_load_game(const struct retro_game_info *info)
{
const struct retro_game_info_ext *info_ext = NULL;
/* We need persistent ROM buffer for resets. */
rom_buf = NULL;
rom_data = NULL;
rom_size = 0;
if (environ_cb(RETRO_ENVIRONMENT_GET_GAME_INFO_EXT, &info_ext) &&
info_ext && info_ext->persistent_data) {
rom_data = (const uint8_t*)info_ext->data;
rom_size = info_ext->size;
}
/* If frontend does not support persistent
* content data, must create a copy */
if (!rom_data) {
if (!info)
return false;
rom_size = info->size;
rom_buf = malloc(rom_size);
if (!rom_buf) {
log_cb(RETRO_LOG_INFO, "Failed to allocate ROM buffer.\n");
return false;
}
memcpy(rom_buf, info->data, rom_size);
rom_data = (const uint8_t*)rom_buf;
}
load_rom();
return true;
}
void retro_unload_game(void)
{
if (rom_buf)
free(rom_buf);
rom_buf = NULL;
rom_data = NULL;
rom_size = 0;
}
int16_t get_audio_sample(void)
{
// Get the byte of the emulator's buffer that the next sample is in.
int16_t x = chip8.RAM[AUDIO_BUF_ADDR + (snd_buf_pntr / 8)];
// Get the actual sample bit.
x <<= (snd_buf_pntr % 8);
x &= 0x80;
// Finally set the buffer to max volume if sample is 1.
x *= 0xFF;
/* Keep track of where we are in the emulator's sound buffer and
wrap back around if necessary. */
snd_buf_pntr++;
if (snd_buf_pntr >= (AUDIO_BUF_SIZE * 8))
{
snd_buf_pntr = 0;
}
return x;
}
static void audio_sample(int16_t sample) {
int16_t buf[200]; // Should be enough to call batch_cb only once
// in most cases
int16_t *bufptr = buf;
while (audio_counter_resample >= ONE_SEC / AUDIO_RESAMPLE_RATE) {
*bufptr++ = sample;
*bufptr++ = sample;
if (bufptr >= buf + sizeof(buf) / sizeof(buf[0])) {
audio_batch_cb(buf, (bufptr - buf) / 2);
bufptr = buf;
}
audio_counter_resample -= ONE_SEC / AUDIO_RESAMPLE_RATE;
}
if (bufptr != buf) {
audio_batch_cb(buf, (bufptr - buf) / 2);
}
}
void retro_run(void)
{
if (chip8.exit) {
environ_cb(RETRO_ENVIRONMENT_SHUTDOWN, NULL);
return;
}
bool updated = false;
if (environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE_UPDATE, &updated) && updated) {
load_theme();
unsigned long cpu_freq = get_cpu_freq_var(chip8.cpu_freq);
if (cpu_freq != chip8.cpu_freq)
chip8_set_cpu_freq(&chip8, cpu_freq);
}
input_poll_cb();
for (int i = 0; i < 16; i++)
if (input_state_cb(0, RETRO_DEVICE_JOYPAD, 0, hexorder[i]))
chip8.keypad[i] = KEY_DOWN;
else
chip8.keypad[i] = chip8.keypad[i] == KEY_DOWN ? KEY_RELEASED : KEY_UP;
uint64_t cycle_step = ONE_SEC / chip8.cpu_freq;
for (unsigned i = 0; i < (chip8.cpu_freq + cpu_debt) / chip8.refresh_freq && !chip8.exit; i++) {
chip8.total_cycle_time = cycle_step;
chip8_execute(&chip8);
if (chip8.timer_freq != chip8.refresh_freq)
chip8_handle_timers(&chip8);
if (!chip8.beep) {
audio_freq_chip8 = 0;
audio_counter_chip8 = 0;
snd_buf_pntr = 0;
audio_counter_resample += cycle_step;
audio_sample(0);
} else {
uint64_t cycle_audio_step;
if (!audio_freq_chip8) {
audio_freq_chip8 = chip8_get_sound_freq(&chip8);
snd_buf_pntr = 0;
}
cycle_audio_step = ONE_SEC / audio_freq_chip8;
audio_counter_chip8 += cycle_step;
while (audio_counter_chip8 > cycle_audio_step) {
audio_counter_chip8 -= cycle_audio_step;
int16_t sample = get_audio_sample();
audio_counter_resample += cycle_audio_step;
audio_sample(sample);
}
}
}
if (chip8.timer_freq == chip8.refresh_freq) {
if (chip8.DT > 0)
chip8.DT--;
if (chip8.ST > 0)
{
chip8.ST--;
chip8.beep = chip8.ST > 0 ? true : false;
}
}
cpu_debt = (chip8.cpu_freq + cpu_debt) % chip8.refresh_freq;
// Output video
draw_display();
video_cb(frame, DISPLAY_WIDTH, DISPLAY_HEIGHT, sizeof(pixel_t) * DISPLAY_WIDTH);
}
unsigned retro_get_region(void)
{
return RETRO_REGION_NTSC;
}
void retro_get_system_info(struct retro_system_info *info)
{
memset(info, 0, sizeof(*info));
info->library_name = "JAXE";
#ifndef GIT_VERSION
#define GIT_VERSION ""
#endif
info->library_version = "1.0" GIT_VERSION;
info->valid_extensions = VALID_EXTENSIONS;
info->need_fullpath = false;
}
void retro_get_system_av_info(struct retro_system_av_info *info)
{
#ifdef USE_RGB565
int pixelformat = RETRO_PIXEL_FORMAT_RGB565;
#else
int pixelformat = RETRO_PIXEL_FORMAT_XRGB8888;
#endif
memset(info, 0, sizeof(*info));
info->geometry.base_width = DISPLAY_WIDTH;
info->geometry.base_height = DISPLAY_HEIGHT;
info->geometry.max_width = DISPLAY_WIDTH;
info->geometry.max_height = DISPLAY_HEIGHT;
info->geometry.aspect_ratio = ((float)DISPLAY_WIDTH) / ((float)DISPLAY_HEIGHT);
info->timing.fps = chip8.refresh_freq;
info->timing.sample_rate = AUDIO_RESAMPLE_RATE;
environ_cb(RETRO_ENVIRONMENT_SET_PIXEL_FORMAT, &pixelformat);
}
void retro_deinit(void) { }
void retro_reset(void)
{
load_rom();
}
struct serialized_state
{
CHIP8 chip8;
unsigned long cpu_debt;
unsigned int audio_counter_chip8;
unsigned int audio_counter_resample;
unsigned int audio_freq_chip8;
int snd_buf_pntr;
uint8_t sram[NUM_USER_FLAGS];
};
size_t retro_serialize_size(void)
{
return sizeof (struct serialized_state);
}
bool retro_serialize(void *data, size_t size)
{
if (size < sizeof (struct serialized_state))
return false;
struct serialized_state *st = (struct serialized_state *) data;
memcpy(&st->chip8, &chip8, sizeof(st->chip8));
st->cpu_debt = cpu_debt;
st->audio_counter_chip8 = audio_counter_chip8;
st->audio_counter_resample = audio_counter_resample;
st->audio_freq_chip8 = audio_freq_chip8;
st->snd_buf_pntr = snd_buf_pntr;
memcpy(st->sram, sram, sizeof(st->sram));
return true;
}
bool retro_unserialize(const void *data, size_t size)
{
if (size < sizeof (struct serialized_state))
return false;
const struct serialized_state *st = (struct serialized_state *) data;
memcpy(&chip8, &st->chip8, sizeof(chip8));
cpu_debt = st->cpu_debt;
audio_counter_chip8 = st->audio_counter_chip8;
audio_counter_resample = st->audio_counter_resample;
audio_freq_chip8 = st->audio_freq_chip8;
snd_buf_pntr = st->snd_buf_pntr;
memcpy(sram, st->sram, sizeof(st->sram));
return true;
}
size_t retro_get_memory_size(unsigned id)
{
switch(id)
{
case RETRO_MEMORY_SYSTEM_RAM: // System Memory
return MAX_RAM;
case RETRO_MEMORY_SAVE_RAM: // SRAM
return sizeof(sram);
// TODO: VRAM
}
return 0;
}
void *retro_get_memory_data(unsigned id)
{
switch(id)
{
case RETRO_MEMORY_SYSTEM_RAM: // System Memory
return chip8.RAM;
case RETRO_MEMORY_SAVE_RAM: // SRAM
return sram;
// TODO: VRAM
}
return 0;
}
/* Stubs */
unsigned int retro_api_version(void) { return RETRO_API_VERSION; }
void retro_cheat_reset(void) { }
void retro_cheat_set(unsigned idx, bool enabled, const char *code) {
(void) idx;
(void) enabled;
(void) code;
}
bool retro_load_game_special(unsigned game_type, const struct retro_game_info *info, size_t num_info) {
(void) game_type;
(void) info;
(void) num_info;
return false;
}
void retro_set_controller_port_device(unsigned port, unsigned device) {
(void) port;
(void) device;
}