all repos — mgba @ f28e20d4aab2e3f48feeec4cc576a05ae9aa144f

mGBA Game Boy Advance Emulator

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 <mgba-util/common.h>
  9
 10#include <mgba/core/blip_buf.h>
 11#include <mgba/core/cheats.h>
 12#include <mgba/core/core.h>
 13#include <mgba/core/log.h>
 14#include <mgba/core/version.h>
 15#ifdef M_CORE_GB
 16#include <mgba/gb/core.h>
 17#include <mgba/internal/gb/gb.h>
 18#endif
 19#ifdef M_CORE_GBA
 20#include <mgba/gba/core.h>
 21#include <mgba/gba/interface.h>
 22#include <mgba/internal/gba/gba.h>
 23#endif
 24#include <mgba-util/circle-buffer.h>
 25#include <mgba-util/memory.h>
 26#include <mgba-util/vfs.h>
 27
 28#define SAMPLES 1024
 29#define RUMBLE_PWM 35
 30
 31static retro_environment_t environCallback;
 32static retro_video_refresh_t videoCallback;
 33static retro_audio_sample_batch_t audioCallback;
 34static retro_input_poll_t inputPollCallback;
 35static retro_input_state_t inputCallback;
 36static retro_log_printf_t logCallback;
 37static retro_set_rumble_state_t rumbleCallback;
 38
 39static void GBARetroLog(struct mLogger* logger, int category, enum mLogLevel level, const char* format, va_list args);
 40
 41static void _postAudioBuffer(struct mAVStream*, blip_t* left, blip_t* right);
 42static void _setRumble(struct mRumble* rumble, int enable);
 43static uint8_t _readLux(struct GBALuminanceSource* lux);
 44static void _updateLux(struct GBALuminanceSource* lux);
 45
 46static struct mCore* core;
 47static void* outputBuffer;
 48static void* data;
 49static size_t dataSize;
 50static void* savedata;
 51static struct mAVStream stream;
 52static int rumbleLevel;
 53static struct CircleBuffer rumbleHistory;
 54static struct mRumble rumble;
 55static struct GBALuminanceSource lux;
 56static int luxLevel;
 57static struct mLogger logger;
 58
 59static void _reloadSettings(void) {
 60	struct mCoreOptions opts = {
 61		.useBios = true,
 62		.volume = 0x100,
 63	};
 64
 65	struct retro_variable var;
 66	enum GBModel model;
 67	const char* modelName;
 68
 69	var.key = "mgba_gb_model";
 70	var.value = 0;
 71	if (environCallback(RETRO_ENVIRONMENT_GET_VARIABLE, &var) && var.value) {
 72		if (strcmp(var.value, "Game Boy") == 0) {
 73			model = GB_MODEL_DMG;
 74		} else if (strcmp(var.value, "Super Game Boy") == 0) {
 75			model = GB_MODEL_SGB;
 76		} else if (strcmp(var.value, "Game Boy Color") == 0) {
 77			model = GB_MODEL_CGB;
 78		} else if (strcmp(var.value, "Game Boy Advance") == 0) {
 79			model = GB_MODEL_AGB;
 80		} else {
 81			model = GB_MODEL_AUTODETECT;
 82		}
 83
 84		modelName = GBModelToName(model);
 85		mCoreConfigSetDefaultValue(&core->config, "gb.model", modelName);
 86		mCoreConfigSetDefaultValue(&core->config, "sgb.model", modelName);
 87		mCoreConfigSetDefaultValue(&core->config, "cgb.model", modelName);
 88	}
 89
 90	var.key = "mgba_use_bios";
 91	var.value = 0;
 92	if (environCallback(RETRO_ENVIRONMENT_GET_VARIABLE, &var) && var.value) {
 93		opts.useBios = strcmp(var.value, "ON") == 0;
 94	}
 95
 96	var.key = "mgba_skip_bios";
 97	var.value = 0;
 98	if (environCallback(RETRO_ENVIRONMENT_GET_VARIABLE, &var) && var.value) {
 99		opts.skipBios = strcmp(var.value, "ON") == 0;
100	}
101
102	var.key = "mgba_sgb_borders";
103	var.value = 0;
104	if (environCallback(RETRO_ENVIRONMENT_GET_VARIABLE, &var) && var.value) {
105		if (strcmp(var.value, "ON") == 0) {
106			mCoreConfigSetDefaultIntValue(&core->config, "sgb.borders", true);
107		} else {
108			mCoreConfigSetDefaultIntValue(&core->config, "sgb.borders", false);
109		}
110	}
111
112	var.key = "mgba_idle_optimization";
113	var.value = 0;
114	if (environCallback(RETRO_ENVIRONMENT_GET_VARIABLE, &var) && var.value) {
115		if (strcmp(var.value, "Don't Remove") == 0) {
116			mCoreConfigSetDefaultValue(&core->config, "idleOptimization", "ignore");
117		} else if (strcmp(var.value, "Remove Known") == 0) {
118			mCoreConfigSetDefaultValue(&core->config, "idleOptimization", "remove");
119		} else if (strcmp(var.value, "Detect and Remove") == 0) {
120			mCoreConfigSetDefaultValue(&core->config, "idleOptimization", "detect");
121		}
122	}
123
124	var.key = "mgba_frameskip";
125	var.value = 0;
126	if (environCallback(RETRO_ENVIRONMENT_GET_VARIABLE, &var) && var.value) {
127		opts.frameskip = strtol(var.value, NULL, 10);
128
129	}
130
131	mCoreConfigLoadDefaults(&core->config, &opts);
132	mCoreLoadConfig(core);
133}
134
135unsigned retro_api_version(void) {
136	return RETRO_API_VERSION;
137}
138
139void retro_set_environment(retro_environment_t env) {
140	environCallback = env;
141
142	struct retro_variable vars[] = {
143		{ "mgba_solar_sensor_level", "Solar sensor level; 0|1|2|3|4|5|6|7|8|9|10" },
144		{ "mgba_allow_opposing_directions", "Allow opposing directional input; OFF|ON" },
145		{ "mgba_gb_model", "Game Boy model (requires restart); Autodetect|Game Boy|Super Game Boy|Game Boy Color|Game Boy Advance" },
146		{ "mgba_use_bios", "Use BIOS file if found (requires restart); ON|OFF" },
147		{ "mgba_skip_bios", "Skip BIOS intro (requires restart); OFF|ON" },
148		{ "mgba_sgb_borders", "Use Super Game Boy borders (requires restart); ON|OFF" },
149		{ "mgba_idle_optimization", "Idle loop removal; Remove Known|Detect and Remove|Don't Remove" },
150		{ "mgba_frameskip", "Frameskip; 0|1|2|3|4|5|6|7|8|9|10" },
151		{ 0, 0 }
152	};
153
154	environCallback(RETRO_ENVIRONMENT_SET_VARIABLES, vars);
155}
156
157void retro_set_video_refresh(retro_video_refresh_t video) {
158	videoCallback = video;
159}
160
161void retro_set_audio_sample(retro_audio_sample_t audio) {
162	UNUSED(audio);
163}
164
165void retro_set_audio_sample_batch(retro_audio_sample_batch_t audioBatch) {
166	audioCallback = audioBatch;
167}
168
169void retro_set_input_poll(retro_input_poll_t inputPoll) {
170	inputPollCallback = inputPoll;
171}
172
173void retro_set_input_state(retro_input_state_t input) {
174	inputCallback = input;
175}
176
177void retro_get_system_info(struct retro_system_info* info) {
178	info->need_fullpath = false;
179	info->valid_extensions = "gba|gb|gbc";
180	info->library_version = projectVersion;
181	info->library_name = projectName;
182	info->block_extract = false;
183}
184
185void retro_get_system_av_info(struct retro_system_av_info* info) {
186	unsigned width, height;
187	core->desiredVideoDimensions(core, &width, &height);
188	info->geometry.base_width = width;
189	info->geometry.base_height = height;
190	info->geometry.max_width = width;
191	info->geometry.max_height = height;
192	info->geometry.aspect_ratio = width / (double) height;
193	info->timing.fps = core->frequency(core) / (float) core->frameCycles(core);
194	info->timing.sample_rate = 32768;
195}
196
197void retro_init(void) {
198	enum retro_pixel_format fmt;
199#ifdef COLOR_16_BIT
200#ifdef COLOR_5_6_5
201	fmt = RETRO_PIXEL_FORMAT_RGB565;
202#else
203#warning This pixel format is unsupported. Please use -DCOLOR_16-BIT -DCOLOR_5_6_5
204	fmt = RETRO_PIXEL_FORMAT_0RGB1555;
205#endif
206#else
207#warning This pixel format is unsupported. Please use -DCOLOR_16-BIT -DCOLOR_5_6_5
208	fmt = RETRO_PIXEL_FORMAT_XRGB8888;
209#endif
210	environCallback(RETRO_ENVIRONMENT_SET_PIXEL_FORMAT, &fmt);
211
212	struct retro_input_descriptor inputDescriptors[] = {
213		{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_A, "A" },
214		{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_B, "B" },
215		{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_SELECT, "Select" },
216		{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_START, "Start" },
217		{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_RIGHT, "Right" },
218		{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_LEFT, "Left" },
219		{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_UP, "Up" },
220		{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_DOWN, "Down" },
221		{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_R, "R" },
222		{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_L, "L" },
223		{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_R3, "Brighten Solar Sensor" },
224		{ 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_L3, "Darken Solar Sensor" },
225		{ 0 }
226	};
227	environCallback(RETRO_ENVIRONMENT_SET_INPUT_DESCRIPTORS, &inputDescriptors);
228
229	// TODO: RETRO_ENVIRONMENT_SET_SUPPORT_NO_GAME when BIOS booting is supported
230
231	struct retro_rumble_interface rumbleInterface;
232	if (environCallback(RETRO_ENVIRONMENT_GET_RUMBLE_INTERFACE, &rumbleInterface)) {
233		rumbleCallback = rumbleInterface.set_rumble_state;
234		CircleBufferInit(&rumbleHistory, RUMBLE_PWM);
235		rumble.setRumble = _setRumble;
236	} else {
237		rumbleCallback = 0;
238	}
239
240	luxLevel = 0;
241	lux.readLuminance = _readLux;
242	lux.sample = _updateLux;
243	_updateLux(&lux);
244
245	struct retro_log_callback log;
246	if (environCallback(RETRO_ENVIRONMENT_GET_LOG_INTERFACE, &log)) {
247		logCallback = log.log;
248	} else {
249		logCallback = 0;
250	}
251	logger.log = GBARetroLog;
252	mLogSetDefaultLogger(&logger);
253
254	stream.videoDimensionsChanged = 0;
255	stream.postAudioFrame = 0;
256	stream.postAudioBuffer = _postAudioBuffer;
257	stream.postVideoFrame = 0;
258}
259
260void retro_deinit(void) {
261	free(outputBuffer);
262}
263
264void retro_run(void) {
265	uint16_t keys;
266	inputPollCallback();
267
268	bool updated = false;
269	if (environCallback(RETRO_ENVIRONMENT_GET_VARIABLE_UPDATE, &updated) && updated) {
270		struct retro_variable var = {
271			.key = "mgba_allow_opposing_directions",
272			.value = 0
273		};
274		if (environCallback(RETRO_ENVIRONMENT_GET_VARIABLE, &var) && var.value) {
275			((struct GBA*) core->board)->allowOpposingDirections = strcmp(var.value, "yes") == 0;
276		}
277
278		var.key = "mgba_frameskip";
279		var.value = 0;
280		if (environCallback(RETRO_ENVIRONMENT_GET_VARIABLE, &var) && var.value) {
281			mCoreConfigSetUIntValue(&core->config, "frameskip", strtol(var.value, NULL, 10));
282			mCoreLoadConfig(core);
283		}
284	}
285
286	keys = 0;
287	keys |= (!!inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_A)) << 0;
288	keys |= (!!inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_B)) << 1;
289	keys |= (!!inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_SELECT)) << 2;
290	keys |= (!!inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_START)) << 3;
291	keys |= (!!inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_RIGHT)) << 4;
292	keys |= (!!inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_LEFT)) << 5;
293	keys |= (!!inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_UP)) << 6;
294	keys |= (!!inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_DOWN)) << 7;
295	keys |= (!!inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_R)) << 8;
296	keys |= (!!inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_L)) << 9;
297	core->setKeys(core, keys);
298
299	static bool wasAdjustingLux = false;
300	if (wasAdjustingLux) {
301		wasAdjustingLux = inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_R3) ||
302		                  inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_L3);
303	} else {
304		if (inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_R3)) {
305			++luxLevel;
306			if (luxLevel > 10) {
307				luxLevel = 10;
308			}
309			wasAdjustingLux = true;
310		} else if (inputCallback(0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_L3)) {
311			--luxLevel;
312			if (luxLevel < 0) {
313				luxLevel = 0;
314			}
315			wasAdjustingLux = true;
316		}
317	}
318
319	core->runFrame(core);
320	unsigned width, height;
321	core->desiredVideoDimensions(core, &width, &height);
322	videoCallback(outputBuffer, width, height, BYTES_PER_PIXEL * 256);
323}
324
325static void _setupMaps(struct mCore* core) {
326#ifdef M_CORE_GBA
327	if (core->platform(core) == PLATFORM_GBA) {
328		struct GBA* gba = core->board;
329		struct retro_memory_descriptor descs[11];
330		struct retro_memory_map mmaps;
331		size_t romSize = gba->memory.romSize + (gba->memory.romSize & 1);
332
333		memset(descs, 0, sizeof(descs));
334		size_t savedataSize = retro_get_memory_size(RETRO_MEMORY_SAVE_RAM);
335
336		/* Map internal working RAM */
337		descs[0].ptr    = gba->memory.iwram;
338		descs[0].start  = BASE_WORKING_IRAM;
339		descs[0].len    = SIZE_WORKING_IRAM;
340		descs[0].select = 0xFF000000;
341
342		/* Map working RAM */
343		descs[1].ptr    = gba->memory.wram;
344		descs[1].start  = BASE_WORKING_RAM;
345		descs[1].len    = SIZE_WORKING_RAM;
346		descs[1].select = 0xFF000000;
347
348		/* Map save RAM */
349		/* TODO: if SRAM is flash, use start=0 addrspace="S" instead */
350		descs[2].ptr    = savedataSize ? savedata : NULL;
351		descs[2].start  = BASE_CART_SRAM;
352		descs[2].len    = savedataSize;
353
354		/* Map ROM */
355		descs[3].ptr    = gba->memory.rom;
356		descs[3].start  = BASE_CART0;
357		descs[3].len    = romSize;
358		descs[3].flags  = RETRO_MEMDESC_CONST;
359
360		descs[4].ptr    = gba->memory.rom;
361		descs[4].start  = BASE_CART1;
362		descs[4].len    = romSize;
363		descs[4].flags  = RETRO_MEMDESC_CONST;
364
365		descs[5].ptr    = gba->memory.rom;
366		descs[5].start  = BASE_CART2;
367		descs[5].len    = romSize;
368		descs[5].flags  = RETRO_MEMDESC_CONST;
369
370		/* Map BIOS */
371		descs[6].ptr    = gba->memory.bios;
372		descs[6].start  = BASE_BIOS;
373		descs[6].len    = SIZE_BIOS;
374		descs[6].flags  = RETRO_MEMDESC_CONST;
375
376		/* Map VRAM */
377		descs[7].ptr    = gba->video.vram;
378		descs[7].start  = BASE_VRAM;
379		descs[7].len    = SIZE_VRAM;
380		descs[7].select = 0xFF000000;
381
382		/* Map palette RAM */
383		descs[8].ptr    = gba->video.palette;
384		descs[8].start  = BASE_PALETTE_RAM;
385		descs[8].len    = SIZE_PALETTE_RAM;
386		descs[8].select = 0xFF000000;
387
388		/* Map OAM */
389		descs[9].ptr    = &gba->video.oam; /* video.oam is a structure */
390		descs[9].start  = BASE_OAM;
391		descs[9].len    = SIZE_OAM;
392		descs[9].select = 0xFF000000;
393
394		/* Map mmapped I/O */
395		descs[10].ptr    = gba->memory.io;
396		descs[10].start  = BASE_IO;
397		descs[10].len    = SIZE_IO;
398
399		mmaps.descriptors = descs;
400		mmaps.num_descriptors = sizeof(descs) / sizeof(descs[0]);
401
402		bool yes = true;
403		environCallback(RETRO_ENVIRONMENT_SET_MEMORY_MAPS, &mmaps);
404		environCallback(RETRO_ENVIRONMENT_SET_SUPPORT_ACHIEVEMENTS, &yes);
405	}
406#endif
407}
408
409void retro_reset(void) {
410	core->reset(core);
411	_setupMaps(core);
412
413	if (rumbleCallback) {
414		CircleBufferClear(&rumbleHistory);
415	}
416}
417
418bool retro_load_game(const struct retro_game_info* game) {
419	struct VFile* rom;
420	if (game->data) {
421		data = anonymousMemoryMap(game->size);
422		dataSize = game->size;
423		memcpy(data, game->data, game->size);
424		rom = VFileFromMemory(data, game->size);
425	} else {
426		data = 0;
427		rom = VFileOpen(game->path, O_RDONLY);
428	}
429	if (!rom) {
430		return false;
431	}
432
433	core = mCoreFindVF(rom);
434	if (!core) {
435		rom->close(rom);
436		mappedMemoryFree(data, game->size);
437		return false;
438	}
439	mCoreInitConfig(core, NULL);
440	core->init(core);
441	core->setAVStream(core, &stream);
442
443	size_t size = 256 * 224 * BYTES_PER_PIXEL;
444	outputBuffer = malloc(size);
445	memset(outputBuffer, 0xFF, size);
446	core->setVideoBuffer(core, outputBuffer, 256);
447
448	core->setAudioBufferSize(core, SAMPLES);
449
450	blip_set_rates(core->getAudioChannel(core, 0), core->frequency(core), 32768);
451	blip_set_rates(core->getAudioChannel(core, 1), core->frequency(core), 32768);
452
453	core->setPeripheral(core, mPERIPH_RUMBLE, &rumble);
454
455	savedata = anonymousMemoryMap(SIZE_CART_FLASH1M);
456	struct VFile* save = VFileFromMemory(savedata, SIZE_CART_FLASH1M);
457
458	_reloadSettings();
459	core->loadROM(core, rom);
460	core->loadSave(core, save);
461
462	const char* sysDir = 0;
463	const char* biosName = 0;
464	char biosPath[PATH_MAX];
465	environCallback(RETRO_ENVIRONMENT_GET_SYSTEM_DIRECTORY, &sysDir);
466
467#ifdef M_CORE_GBA
468	if (core->platform(core) == PLATFORM_GBA) {
469		core->setPeripheral(core, mPERIPH_GBA_LUMINANCE, &lux);
470		biosName = "gba_bios.bin";
471
472	}
473#endif
474
475#ifdef M_CORE_GB
476	if (core->platform(core) == PLATFORM_GB) {
477		const char* modelName = mCoreConfigGetValue(&core->config, "gb.model");
478		struct GB* gb = core->board;
479
480		if (modelName) {
481			gb->model = GBNameToModel(modelName);
482		} else {
483			GBDetectModel(gb);
484		}
485
486		switch (gb->model) {
487		case GB_MODEL_AGB:
488		case GB_MODEL_CGB:
489			biosName = "gbc_bios.bin";
490			break;
491		case GB_MODEL_SGB:
492			biosName = "sgb_bios.bin";
493			break;
494		case GB_MODEL_DMG:
495		default:
496			biosName = "gb_bios.bin";
497			break;
498		};
499	}
500#endif
501
502	if (core->opts.useBios && sysDir && biosName) {
503		snprintf(biosPath, sizeof(biosPath), "%s%s%s", sysDir, PATH_SEP, biosName);
504		struct VFile* bios = VFileOpen(biosPath, O_RDONLY);
505		if (bios) {
506			core->loadBIOS(core, bios, 0);
507		}
508	}
509
510	core->reset(core);
511	_setupMaps(core);
512
513	return true;
514}
515
516void retro_unload_game(void) {
517	if (!core) {
518		return;
519	}
520	core->deinit(core);
521	mappedMemoryFree(data, dataSize);
522	data = 0;
523	mappedMemoryFree(savedata, SIZE_CART_FLASH1M);
524	savedata = 0;
525	CircleBufferDeinit(&rumbleHistory);
526}
527
528size_t retro_serialize_size(void) {
529	return core->stateSize(core);
530}
531
532bool retro_serialize(void* data, size_t size) {
533	if (size != retro_serialize_size()) {
534		return false;
535	}
536	core->saveState(core, data);
537	return true;
538}
539
540bool retro_unserialize(const void* data, size_t size) {
541	if (size != retro_serialize_size()) {
542		return false;
543	}
544	core->loadState(core, data);
545	return true;
546}
547
548void retro_cheat_reset(void) {
549	mCheatDeviceClear(core->cheatDevice(core));
550}
551
552void retro_cheat_set(unsigned index, bool enabled, const char* code) {
553	UNUSED(index);
554	UNUSED(enabled);
555	struct mCheatDevice* device = core->cheatDevice(core);
556	struct mCheatSet* cheatSet = NULL;
557	if (mCheatSetsSize(&device->cheats)) {
558		cheatSet = *mCheatSetsGetPointer(&device->cheats, 0);
559	} else {
560		cheatSet = device->createSet(device, NULL);
561		mCheatAddSet(device, cheatSet);
562	}
563	// Convert the super wonky unportable libretro format to something normal
564	char realCode[] = "XXXXXXXX XXXXXXXX";
565	size_t len = strlen(code) + 1; // Include null terminator
566	size_t i, pos;
567	for (i = 0, pos = 0; i < len; ++i) {
568		if (isspace((int) code[i]) || code[i] == '+') {
569			realCode[pos] = ' ';
570		} else {
571			realCode[pos] = code[i];
572		}
573		if ((pos == 13 && (realCode[pos] == ' ' || !realCode[pos])) || pos == 17) {
574			realCode[pos] = '\0';
575			mCheatAddLine(cheatSet, realCode, 0);
576			pos = 0;
577			continue;
578		}
579		++pos;
580	}
581}
582
583unsigned retro_get_region(void) {
584	return RETRO_REGION_NTSC; // TODO: This isn't strictly true
585}
586
587void retro_set_controller_port_device(unsigned port, unsigned device) {
588	UNUSED(port);
589	UNUSED(device);
590}
591
592bool retro_load_game_special(unsigned game_type, const struct retro_game_info* info, size_t num_info) {
593	UNUSED(game_type);
594	UNUSED(info);
595	UNUSED(num_info);
596	return false;
597}
598
599void* retro_get_memory_data(unsigned id) {
600	if (id != RETRO_MEMORY_SAVE_RAM) {
601		return 0;
602	}
603	return savedata;
604}
605
606size_t retro_get_memory_size(unsigned id) {
607	if (id != RETRO_MEMORY_SAVE_RAM) {
608		return 0;
609	}
610#ifdef M_CORE_GBA
611	if (core->platform(core) == PLATFORM_GBA) {
612		switch (((struct GBA*) core->board)->memory.savedata.type) {
613		case SAVEDATA_AUTODETECT:
614			return SIZE_CART_FLASH1M;
615		default:
616			return GBASavedataSize(&((struct GBA*) core->board)->memory.savedata);
617		}
618	}
619#endif
620#ifdef M_CORE_GB
621	if (core->platform(core) == PLATFORM_GB) {
622		return ((struct GB*) core->board)->sramSize;
623	}
624#endif
625	return 0;
626}
627
628void GBARetroLog(struct mLogger* logger, int category, enum mLogLevel level, const char* format, va_list args) {
629	UNUSED(logger);
630	if (!logCallback) {
631		return;
632	}
633
634	char message[128];
635	vsnprintf(message, sizeof(message), format, args);
636
637	enum retro_log_level retroLevel = RETRO_LOG_INFO;
638	switch (level) {
639	case mLOG_ERROR:
640	case mLOG_FATAL:
641		retroLevel = RETRO_LOG_ERROR;
642		break;
643	case mLOG_WARN:
644		retroLevel = RETRO_LOG_WARN;
645		break;
646	case mLOG_INFO:
647		retroLevel = RETRO_LOG_INFO;
648		break;
649	case mLOG_GAME_ERROR:
650	case mLOG_STUB:
651#ifdef NDEBUG
652		return;
653#else
654		retroLevel = RETRO_LOG_DEBUG;
655		break;
656#endif
657	case mLOG_DEBUG:
658		retroLevel = RETRO_LOG_DEBUG;
659		break;
660	}
661#ifdef NDEBUG
662	static int biosCat = -1;
663	if (biosCat < 0) {
664		biosCat = mLogCategoryById("gba.bios");
665	}
666
667	if (category == biosCat) {
668		return;
669	}
670#endif
671	logCallback(retroLevel, "%s: %s\n", mLogCategoryName(category), message);
672}
673
674static void _postAudioBuffer(struct mAVStream* stream, blip_t* left, blip_t* right) {
675	UNUSED(stream);
676	int16_t samples[SAMPLES * 2];
677	blip_read_samples(left, samples, SAMPLES, true);
678	blip_read_samples(right, samples + 1, SAMPLES, true);
679	audioCallback(samples, SAMPLES);
680}
681
682static void _setRumble(struct mRumble* rumble, int enable) {
683	UNUSED(rumble);
684	if (!rumbleCallback) {
685		return;
686	}
687	rumbleLevel += enable;
688	if (CircleBufferSize(&rumbleHistory) == RUMBLE_PWM) {
689		int8_t oldLevel;
690		CircleBufferRead8(&rumbleHistory, &oldLevel);
691		rumbleLevel -= oldLevel;
692	}
693	CircleBufferWrite8(&rumbleHistory, enable);
694	rumbleCallback(0, RETRO_RUMBLE_STRONG, rumbleLevel * 0xFFFF / RUMBLE_PWM);
695	rumbleCallback(0, RETRO_RUMBLE_WEAK, rumbleLevel * 0xFFFF / RUMBLE_PWM);
696}
697
698static void _updateLux(struct GBALuminanceSource* lux) {
699	UNUSED(lux);
700	struct retro_variable var = {
701		.key = "mgba_solar_sensor_level",
702		.value = 0
703	};
704
705	bool updated = false;
706	if (!environCallback(RETRO_ENVIRONMENT_GET_VARIABLE_UPDATE, &updated) || !updated) {
707		return;
708	}
709	if (!environCallback(RETRO_ENVIRONMENT_GET_VARIABLE, &var) || !var.value) {
710		return;
711	}
712
713	char* end;
714	int newLuxLevel = strtol(var.value, &end, 10);
715	if (!*end) {
716		if (newLuxLevel > 10) {
717			luxLevel = 10;
718		} else if (newLuxLevel < 0) {
719			luxLevel = 0;
720		} else {
721			luxLevel = newLuxLevel;
722		}
723	}
724}
725
726static uint8_t _readLux(struct GBALuminanceSource* lux) {
727	UNUSED(lux);
728	int value = 0x16;
729	if (luxLevel > 0) {
730		value += GBA_LUX_LEVELS[luxLevel - 1];
731	}
732	return 0xFF - value;
733}