src/platform/libretro/libretro.c (view raw)
1/* Copyright (c) 2013-2015 Jeffrey Pfau
2 *
3 * This Source Code Form is subject to the terms of the Mozilla Public
4 * License, v. 2.0. If a copy of the MPL was not distributed with this
5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6#include "libretro.h"
7
8#include "util/common.h"
9
10#include "core/core.h"
11#include "core/version.h"
12#ifdef M_CORE_GB
13#include "gb/core.h"
14#include "gb/gb.h"
15#endif
16#ifdef M_CORE_GBA
17#include "gba/bios.h"
18#include "gba/core.h"
19#include "gba/cheats.h"
20#include "gba/core.h"
21#include "gba/serialize.h"
22#endif
23#include "util/circle-buffer.h"
24#include "util/memory.h"
25#include "util/vfs.h"
26
27#define SAMPLES 1024
28#define RUMBLE_PWM 35
29
30static retro_environment_t environCallback;
31static retro_video_refresh_t videoCallback;
32static retro_audio_sample_batch_t audioCallback;
33static retro_input_poll_t inputPollCallback;
34static retro_input_state_t inputCallback;
35static retro_log_printf_t logCallback;
36static retro_set_rumble_state_t rumbleCallback;
37
38static void GBARetroLog(struct mLogger* logger, int category, enum mLogLevel level, const char* format, va_list args);
39
40static void _postAudioBuffer(struct mAVStream*, blip_t* left, blip_t* right);
41static void _setRumble(struct mRumble* rumble, int enable);
42static uint8_t _readLux(struct GBALuminanceSource* lux);
43static void _updateLux(struct GBALuminanceSource* lux);
44
45static struct mCore* core;
46static void* outputBuffer;
47static void* data;
48static size_t dataSize;
49static void* savedata;
50static struct mAVStream stream;
51static int rumbleLevel;
52static struct CircleBuffer rumbleHistory;
53static struct mRumble rumble;
54static struct GBALuminanceSource lux;
55static int luxLevel;
56static struct mLogger logger;
57
58static void _reloadSettings(void) {
59 struct mCoreOptions opts = {
60 .useBios = true,
61 .volume = 0x100,
62 };
63
64 struct retro_variable var;
65
66 var.key = "mgba_use_bios";
67 var.value = 0;
68 if (environCallback(RETRO_ENVIRONMENT_GET_VARIABLE, &var) && var.value) {
69 opts.useBios = strcmp(var.value, "ON") == 0;
70 }
71
72 var.key = "mgba_skip_bios";
73 var.value = 0;
74 if (environCallback(RETRO_ENVIRONMENT_GET_VARIABLE, &var) && var.value) {
75 opts.skipBios = strcmp(var.value, "ON") == 0;
76 }
77
78 var.key = "mgba_idle_optimization";
79 var.value = 0;
80 if (environCallback(RETRO_ENVIRONMENT_GET_VARIABLE, &var) && var.value) {
81 if (strcmp(var.value, "Don't Remove") == 0) {
82 mCoreConfigSetDefaultValue(&core->config, "idleOptimization", "ignore");
83 } else if (strcmp(var.value, "Remove Known") == 0) {
84 mCoreConfigSetDefaultValue(&core->config, "idleOptimization", "remove");
85 } else if (strcmp(var.value, "Detect and Remove") == 0) {
86 mCoreConfigSetDefaultValue(&core->config, "idleOptimization", "detect");
87 }
88 }
89
90 mCoreConfigLoadDefaults(&core->config, &opts);
91 mCoreLoadConfig(core);
92}
93
94unsigned retro_api_version(void) {
95 return RETRO_API_VERSION;
96}
97
98void retro_set_environment(retro_environment_t env) {
99 environCallback = env;
100
101 struct retro_variable vars[] = {
102 { "mgba_solar_sensor_level", "Solar sensor level; 0|1|2|3|4|5|6|7|8|9|10" },
103 { "mgba_allow_opposing_directions", "Allow opposing directional input; OFF|ON" },
104 { "mgba_use_bios", "Use BIOS file if found; ON|OFF" },
105 { "mgba_skip_bios", "Skip BIOS intro; OFF|ON" },
106 { "mgba_idle_optimization", "Idle loop removal; Remove Known|Detect and Remove|Don't Remove" },
107 { 0, 0 }
108 };
109
110 environCallback(RETRO_ENVIRONMENT_SET_VARIABLES, vars);
111}
112
113void retro_set_video_refresh(retro_video_refresh_t video) {
114 videoCallback = video;
115}
116
117void retro_set_audio_sample(retro_audio_sample_t audio) {
118 UNUSED(audio);
119}
120
121void retro_set_audio_sample_batch(retro_audio_sample_batch_t audioBatch) {
122 audioCallback = audioBatch;
123}
124
125void retro_set_input_poll(retro_input_poll_t inputPoll) {
126 inputPollCallback = inputPoll;
127}
128
129void retro_set_input_state(retro_input_state_t input) {
130 inputCallback = input;
131}
132
133void retro_get_system_info(struct retro_system_info* info) {
134 info->need_fullpath = false;
135 info->valid_extensions = "gba|gb|gbc";
136 info->library_version = projectVersion;
137 info->library_name = projectName;
138 info->block_extract = false;
139}
140
141void retro_get_system_av_info(struct retro_system_av_info* info) {
142 unsigned width, height;
143 core->desiredVideoDimensions(core, &width, &height);
144 info->geometry.base_width = width;
145 info->geometry.base_height = height;
146 info->geometry.max_width = width;
147 info->geometry.max_height = height;
148 info->geometry.aspect_ratio = width / (double) height;
149 info->timing.fps = GBA_ARM7TDMI_FREQUENCY / (float) VIDEO_TOTAL_LENGTH;
150 info->timing.sample_rate = 32768;
151}
152
153void retro_init(void) {
154 enum retro_pixel_format fmt;
155#ifdef COLOR_16_BIT
156#ifdef COLOR_5_6_5
157 fmt = RETRO_PIXEL_FORMAT_RGB565;
158#else
159#warning This pixel format is unsupported. Please use -DCOLOR_16-BIT -DCOLOR_5_6_5
160 fmt = RETRO_PIXEL_FORMAT_0RGB1555;
161#endif
162#else
163#warning This pixel format is unsupported. Please use -DCOLOR_16-BIT -DCOLOR_5_6_5
164 fmt = RETRO_PIXEL_FORMAT_XRGB8888;
165#endif
166 environCallback(RETRO_ENVIRONMENT_SET_PIXEL_FORMAT, &fmt);
167
168 struct retro_input_descriptor inputDescriptors[] = {
169 { 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_A, "A" },
170 { 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_B, "B" },
171 { 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_SELECT, "Select" },
172 { 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_START, "Start" },
173 { 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_RIGHT, "Right" },
174 { 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_LEFT, "Left" },
175 { 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_UP, "Up" },
176 { 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_DOWN, "Down" },
177 { 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_R, "R" },
178 { 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_L, "L" },
179 { 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_R3, "Brighten Solar Sensor" },
180 { 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_L3, "Darken Solar Sensor" }
181 };
182 environCallback(RETRO_ENVIRONMENT_SET_INPUT_DESCRIPTORS, &inputDescriptors);
183
184 // TODO: RETRO_ENVIRONMENT_SET_SUPPORT_NO_GAME when BIOS booting is supported
185
186 struct retro_rumble_interface rumbleInterface;
187 if (environCallback(RETRO_ENVIRONMENT_GET_RUMBLE_INTERFACE, &rumbleInterface)) {
188 rumbleCallback = rumbleInterface.set_rumble_state;
189 CircleBufferInit(&rumbleHistory, RUMBLE_PWM);
190 rumble.setRumble = _setRumble;
191 } else {
192 rumbleCallback = 0;
193 }
194
195 luxLevel = 0;
196 lux.readLuminance = _readLux;
197 lux.sample = _updateLux;
198 _updateLux(&lux);
199
200 struct retro_log_callback log;
201 if (environCallback(RETRO_ENVIRONMENT_GET_LOG_INTERFACE, &log)) {
202 logCallback = log.log;
203 } else {
204 logCallback = 0;
205 }
206 logger.log = GBARetroLog;
207 mLogSetDefaultLogger(&logger);
208
209 stream.videoDimensionsChanged = 0;
210 stream.postAudioFrame = 0;
211 stream.postAudioBuffer = _postAudioBuffer;
212 stream.postVideoFrame = 0;
213}
214
215void retro_deinit(void) {
216 free(outputBuffer);
217}
218
219void retro_run(void) {
220 uint16_t keys;
221 inputPollCallback();
222
223 struct retro_variable var = {
224 .key = "mgba_allow_opposing_directions",
225 .value = 0
226 };
227
228 bool updated = false;
229 if (environCallback(RETRO_ENVIRONMENT_GET_VARIABLE_UPDATE, &updated) && updated) {
230 if (environCallback(RETRO_ENVIRONMENT_GET_VARIABLE, &var) && var.value) {
231 ((struct GBA*) core->board)->allowOpposingDirections = strcmp(var.value, "yes") == 0;
232 }
233 }
234
235 keys = 0;
236 keys |= (!!inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_A)) << 0;
237 keys |= (!!inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_B)) << 1;
238 keys |= (!!inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_SELECT)) << 2;
239 keys |= (!!inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_START)) << 3;
240 keys |= (!!inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_RIGHT)) << 4;
241 keys |= (!!inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_LEFT)) << 5;
242 keys |= (!!inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_UP)) << 6;
243 keys |= (!!inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_DOWN)) << 7;
244 keys |= (!!inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_R)) << 8;
245 keys |= (!!inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_L)) << 9;
246 core->setKeys(core, keys);
247
248 static bool wasAdjustingLux = false;
249 if (wasAdjustingLux) {
250 wasAdjustingLux = inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_R3) ||
251 inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_L3);
252 } else {
253 if (inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_R3)) {
254 ++luxLevel;
255 if (luxLevel > 10) {
256 luxLevel = 10;
257 }
258 wasAdjustingLux = true;
259 } else if (inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_L3)) {
260 --luxLevel;
261 if (luxLevel < 0) {
262 luxLevel = 0;
263 }
264 wasAdjustingLux = true;
265 }
266 }
267
268 core->runFrame(core);
269 unsigned width, height;
270 core->desiredVideoDimensions(core, &width, &height);
271 videoCallback(outputBuffer, width, height, BYTES_PER_PIXEL * 256);
272}
273
274void static _setupMaps(struct mCore* core) {
275#ifdef M_CORE_GBA
276 if (core->platform(core) == PLATFORM_GBA) {
277 struct GBA* gba = core->board;
278 gba->luminanceSource = &lux;
279
280 const char* sysDir = 0;
281 if (environCallback(RETRO_ENVIRONMENT_GET_SYSTEM_DIRECTORY, &sysDir)) {
282 char biosPath[PATH_MAX];
283 snprintf(biosPath, sizeof(biosPath), "%s%s%s", sysDir, PATH_SEP, "gba_bios.bin");
284 struct VFile* bios = VFileOpen(biosPath, O_RDONLY);
285 if (bios) {
286 core->loadBIOS(core, bios, 0);
287 }
288 }
289
290 struct retro_memory_descriptor descs[11];
291 struct retro_memory_map mmaps;
292 size_t romSize = game->size + (game->size & 1);
293
294 memset(descs, 0, sizeof(descs));
295 size_t savedataSize = retro_get_memory_size(RETRO_MEMORY_SAVE_RAM);
296
297 /* Map internal working RAM */
298 descs[0].ptr = gba->memory.iwram;
299 descs[0].start = BASE_WORKING_IRAM;
300 descs[0].len = SIZE_WORKING_IRAM;
301 descs[0].select = 0xFF000000;
302
303 /* Map working RAM */
304 descs[1].ptr = gba->memory.wram;
305 descs[1].start = BASE_WORKING_RAM;
306 descs[1].len = SIZE_WORKING_RAM;
307 descs[1].select = 0xFF000000;
308
309 /* Map save RAM */
310 /* TODO: if SRAM is flash, use start=0 addrspace="S" instead */
311 descs[2].ptr = savedataSize ? savedata : NULL;
312 descs[2].start = BASE_CART_SRAM;
313 descs[2].len = savedataSize;
314
315 /* Map ROM */
316 descs[3].ptr = gba->memory.rom;
317 descs[3].start = BASE_CART0;
318 descs[3].len = romSize;
319 descs[3].flags = RETRO_MEMDESC_CONST;
320
321 descs[4].ptr = gba->memory.rom;
322 descs[4].start = BASE_CART1;
323 descs[4].len = romSize;
324 descs[4].flags = RETRO_MEMDESC_CONST;
325
326 descs[5].ptr = gba->memory.rom;
327 descs[5].start = BASE_CART2;
328 descs[5].len = romSize;
329 descs[5].flags = RETRO_MEMDESC_CONST;
330
331 /* Map BIOS */
332 descs[6].ptr = gba->memory.bios;
333 descs[6].start = BASE_BIOS;
334 descs[6].len = SIZE_BIOS;
335 descs[6].flags = RETRO_MEMDESC_CONST;
336
337 /* Map VRAM */
338 descs[7].ptr = gba->video.vram;
339 descs[7].start = BASE_VRAM;
340 descs[7].len = SIZE_VRAM;
341 descs[7].select = 0xFF000000;
342
343 /* Map palette RAM */
344 descs[8].ptr = gba->video.palette;
345 descs[8].start = BASE_PALETTE_RAM;
346 descs[8].len = SIZE_PALETTE_RAM;
347 descs[8].select = 0xFF000000;
348
349 /* Map OAM */
350 descs[9].ptr = &gba->video.oam; /* video.oam is a structure */
351 descs[9].start = BASE_OAM;
352 descs[9].len = SIZE_OAM;
353 descs[9].select = 0xFF000000;
354
355 /* Map mmapped I/O */
356 descs[10].ptr = gba->memory.io;
357 descs[10].start = BASE_IO;
358 descs[10].len = SIZE_IO;
359
360 mmaps.descriptors = descs;
361 mmaps.num_descriptors = sizeof(descs) / sizeof(descs[0]);
362
363 bool yes = true;
364 environCallback(RETRO_ENVIRONMENT_SET_MEMORY_MAPS, &mmaps);
365 environCallback(RETRO_ENVIRONMENT_SET_SUPPORT_ACHIEVEMENTS, &yes);
366 }
367#endif
368}
369
370void retro_reset(void) {
371 core->reset(core);
372 _setupMaps(core);
373
374 if (rumbleCallback) {
375 CircleBufferClear(&rumbleHistory);
376 }
377}
378
379bool retro_load_game(const struct retro_game_info* game) {
380 struct VFile* rom;
381 if (game->data) {
382 data = anonymousMemoryMap(game->size);
383 dataSize = game->size;
384 memcpy(data, game->data, game->size);
385 rom = VFileFromMemory(data, game->size);
386 } else {
387 data = 0;
388 rom = VFileOpen(game->path, O_RDONLY);
389 }
390 if (!rom) {
391 return false;
392 }
393
394 core = mCoreFindVF(rom);
395 if (!core) {
396 rom->close(rom);
397 mappedMemoryFree(data, game->size);
398 return false;
399 }
400 mCoreInitConfig(core, NULL);
401 core->init(core);
402 core->setAVStream(core, &stream);
403
404 outputBuffer = malloc(256 * VIDEO_VERTICAL_PIXELS * BYTES_PER_PIXEL);
405 core->setVideoBuffer(core, outputBuffer, 256);
406
407 core->setAudioBufferSize(core, SAMPLES);
408
409 blip_set_rates(core->getAudioChannel(core, 0), core->frequency(core), 32768);
410 blip_set_rates(core->getAudioChannel(core, 1), core->frequency(core), 32768);
411
412 core->setRumble(core, &rumble);
413
414 savedata = anonymousMemoryMap(SIZE_CART_FLASH1M);
415 struct VFile* save = VFileFromMemory(savedata, SIZE_CART_FLASH1M);
416
417 _reloadSettings();
418 core->loadROM(core, rom);
419 core->loadSave(core, save);
420 core->reset(core);
421
422 _setupMaps(core);
423
424 return true;
425}
426
427void retro_unload_game(void) {
428 if (!core) {
429 return;
430 }
431 core->deinit(core);
432 mappedMemoryFree(data, dataSize);
433 data = 0;
434 mappedMemoryFree(savedata, SIZE_CART_FLASH1M);
435 savedata = 0;
436 CircleBufferDeinit(&rumbleHistory);
437}
438
439size_t retro_serialize_size(void) {
440 return sizeof(struct GBASerializedState);
441}
442
443bool retro_serialize(void* data, size_t size) {
444 if (size != retro_serialize_size()) {
445 return false;
446 }
447 GBASerialize(core->board, data);
448 return true;
449}
450
451bool retro_unserialize(const void* data, size_t size) {
452 if (size != retro_serialize_size()) {
453 return false;
454 }
455 GBADeserialize(core->board, data);
456 return true;
457}
458
459void retro_cheat_reset(void) {
460 mCheatDeviceClear(core->cheatDevice(core));
461}
462
463void retro_cheat_set(unsigned index, bool enabled, const char* code) {
464 UNUSED(index);
465 UNUSED(enabled);
466 struct mCheatDevice* device = core->cheatDevice(core);
467 struct mCheatSet* cheatSet = NULL;
468 if (mCheatSetsSize(&device->cheats)) {
469 cheatSet = *mCheatSetsGetPointer(&device->cheats, 0);
470 } else {
471 cheatSet = device->createSet(device, NULL);
472 mCheatAddSet(device, cheatSet);
473 }
474 // Convert the super wonky unportable libretro format to something normal
475 char realCode[] = "XXXXXXXX XXXXXXXX";
476 size_t len = strlen(code) + 1; // Include null terminator
477 size_t i, pos;
478 for (i = 0, pos = 0; i < len; ++i) {
479 if (isspace((int) code[i]) || code[i] == '+') {
480 realCode[pos] = ' ';
481 } else {
482 realCode[pos] = code[i];
483 }
484 if ((pos == 13 && (realCode[pos] == ' ' || !realCode[pos])) || pos == 17) {
485 realCode[pos] = '\0';
486 mCheatAddLine(cheatSet, realCode, 0);
487 pos = 0;
488 continue;
489 }
490 ++pos;
491 }
492}
493
494unsigned retro_get_region(void) {
495 return RETRO_REGION_NTSC; // TODO: This isn't strictly true
496}
497
498void retro_set_controller_port_device(unsigned port, unsigned device) {
499 UNUSED(port);
500 UNUSED(device);
501}
502
503bool retro_load_game_special(unsigned game_type, const struct retro_game_info* info, size_t num_info) {
504 UNUSED(game_type);
505 UNUSED(info);
506 UNUSED(num_info);
507 return false;
508}
509
510void* retro_get_memory_data(unsigned id) {
511 if (id != RETRO_MEMORY_SAVE_RAM) {
512 return 0;
513 }
514 return savedata;
515}
516
517size_t retro_get_memory_size(unsigned id) {
518 if (id != RETRO_MEMORY_SAVE_RAM) {
519 return 0;
520 }
521 switch (((struct GBA*) core->board)->memory.savedata.type) {
522 case SAVEDATA_AUTODETECT:
523 case SAVEDATA_FLASH1M:
524 return SIZE_CART_FLASH1M;
525 case SAVEDATA_FLASH512:
526 return SIZE_CART_FLASH512;
527 case SAVEDATA_EEPROM:
528 return SIZE_CART_EEPROM;
529 case SAVEDATA_SRAM:
530 return SIZE_CART_SRAM;
531 case SAVEDATA_FORCE_NONE:
532 return 0;
533 }
534 return 0;
535}
536
537void GBARetroLog(struct mLogger* logger, int category, enum mLogLevel level, const char* format, va_list args) {
538 UNUSED(logger);
539 if (!logCallback) {
540 return;
541 }
542
543 char message[128];
544 vsnprintf(message, sizeof(message), format, args);
545
546 enum retro_log_level retroLevel = RETRO_LOG_INFO;
547 switch (level) {
548 case mLOG_ERROR:
549 case mLOG_FATAL:
550 retroLevel = RETRO_LOG_ERROR;
551 break;
552 case mLOG_WARN:
553 retroLevel = RETRO_LOG_WARN;
554 break;
555 case mLOG_INFO:
556 retroLevel = RETRO_LOG_INFO;
557 break;
558 case mLOG_GAME_ERROR:
559 case mLOG_STUB:
560#ifdef NDEBUG
561 return;
562#else
563 retroLevel = RETRO_LOG_DEBUG;
564 break;
565#endif
566 case mLOG_DEBUG:
567 retroLevel = RETRO_LOG_DEBUG;
568 break;
569 }
570#ifdef NDEBUG
571 if (category == _mLOG_CAT_GBA_BIOS()) {
572 return;
573 }
574#endif
575 logCallback(retroLevel, "%s: %s\n", mLogCategoryName(category), message);
576}
577
578static void _postAudioBuffer(struct mAVStream* stream, blip_t* left, blip_t* right) {
579 UNUSED(stream);
580 int16_t samples[SAMPLES * 2];
581 blip_read_samples(left, samples, SAMPLES, true);
582 blip_read_samples(right, samples + 1, SAMPLES, true);
583 audioCallback(samples, SAMPLES);
584}
585
586static void _setRumble(struct mRumble* rumble, int enable) {
587 UNUSED(rumble);
588 if (!rumbleCallback) {
589 return;
590 }
591 rumbleLevel += enable;
592 if (CircleBufferSize(&rumbleHistory) == RUMBLE_PWM) {
593 int8_t oldLevel;
594 CircleBufferRead8(&rumbleHistory, &oldLevel);
595 rumbleLevel -= oldLevel;
596 }
597 CircleBufferWrite8(&rumbleHistory, enable);
598 rumbleCallback(0, RETRO_RUMBLE_STRONG, rumbleLevel * 0xFFFF / RUMBLE_PWM);
599 rumbleCallback(0, RETRO_RUMBLE_WEAK, rumbleLevel * 0xFFFF / RUMBLE_PWM);
600}
601
602static void _updateLux(struct GBALuminanceSource* lux) {
603 UNUSED(lux);
604 struct retro_variable var = {
605 .key = "mgba_solar_sensor_level",
606 .value = 0
607 };
608
609 bool updated = false;
610 if (!environCallback(RETRO_ENVIRONMENT_GET_VARIABLE_UPDATE, &updated) || !updated) {
611 return;
612 }
613 if (!environCallback(RETRO_ENVIRONMENT_GET_VARIABLE, &var) || !var.value) {
614 return;
615 }
616
617 char* end;
618 int newLuxLevel = strtol(var.value, &end, 10);
619 if (!*end) {
620 if (newLuxLevel > 10) {
621 luxLevel = 10;
622 } else if (newLuxLevel < 0) {
623 luxLevel = 0;
624 } else {
625 luxLevel = newLuxLevel;
626 }
627 }
628}
629
630static uint8_t _readLux(struct GBALuminanceSource* lux) {
631 UNUSED(lux);
632 int value = 0x16;
633 if (luxLevel > 0) {
634 value += GBA_LUX_LEVELS[luxLevel - 1];
635 }
636 return 0xFF - value;
637}