all repos — mgba @ 4c38f769565e8ddd7d3a8eef1a41975206c129a0

mGBA Game Boy Advance Emulator

src/platform/libretro/libretro.h (view raw)

   1/* Copyright (C) 2010-2016 The RetroArch team
   2 *
   3 * ---------------------------------------------------------------------------------------
   4 * The following license statement only applies to this libretro API header (libretro.h).
   5 * ---------------------------------------------------------------------------------------
   6 *
   7 * Permission is hereby granted, free of charge,
   8 * to any person obtaining a copy of this software and associated documentation files (the "Software"),
   9 * to deal in the Software without restriction, including without limitation the rights to
  10 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software,
  11 * and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
  12 *
  13 * The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
  14 *
  15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
  16 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
  18 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
  19 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  20 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  21 */
  22
  23#ifndef LIBRETRO_H__
  24#define LIBRETRO_H__
  25
  26#include <stdint.h>
  27#include <stddef.h>
  28#include <limits.h>
  29
  30#ifdef __cplusplus
  31extern "C" {
  32#endif
  33
  34#ifndef __cplusplus
  35#if defined(_MSC_VER) && !defined(SN_TARGET_PS3)
  36/* Hack applied for MSVC when compiling in C89 mode
  37 * as it isn't C99-compliant. */
  38#define bool unsigned char
  39#define true 1
  40#define false 0
  41#else
  42#include <stdbool.h>
  43#endif
  44#endif
  45
  46#ifndef RETRO_CALLCONV
  47#  if defined(__GNUC__) && defined(__i386__) && !defined(__x86_64__)
  48#    define RETRO_CALLCONV __attribute__((cdecl))
  49#  elif defined(_MSC_VER) && defined(_M_X86) && !defined(_M_X64)
  50#    define RETRO_CALLCONV __cdecl
  51#  else
  52#    define RETRO_CALLCONV /* all other platforms only have one calling convention each */
  53#  endif
  54#endif
  55
  56#ifndef RETRO_API
  57#  if defined(_WIN32) || defined(__CYGWIN__) || defined(__MINGW32__)
  58#    ifdef RETRO_IMPORT_SYMBOLS
  59#      ifdef __GNUC__
  60#        define RETRO_API RETRO_CALLCONV __attribute__((__dllimport__))
  61#      else
  62#        define RETRO_API RETRO_CALLCONV __declspec(dllimport)
  63#      endif
  64#    else
  65#      ifdef __GNUC__
  66#        define RETRO_API RETRO_CALLCONV __attribute__((__dllexport__))
  67#      else
  68#        define RETRO_API RETRO_CALLCONV __declspec(dllexport)
  69#      endif
  70#    endif
  71#  else
  72#      if defined(__GNUC__) && __GNUC__ >= 4 && !defined(__CELLOS_LV2__)
  73#        define RETRO_API RETRO_CALLCONV __attribute__((__visibility__("default")))
  74#      else
  75#        define RETRO_API RETRO_CALLCONV
  76#      endif
  77#  endif
  78#endif
  79
  80/* Used for checking API/ABI mismatches that can break libretro 
  81 * implementations.
  82 * It is not incremented for compatible changes to the API.
  83 */
  84#define RETRO_API_VERSION         1
  85
  86/*
  87 * Libretro's fundamental device abstractions.
  88 *
  89 * Libretro's input system consists of some standardized device types,
  90 * such as a joypad (with/without analog), mouse, keyboard, lightgun 
  91 * and a pointer.
  92 *
  93 * The functionality of these devices are fixed, and individual cores 
  94 * map their own concept of a controller to libretro's abstractions.
  95 * This makes it possible for frontends to map the abstract types to a 
  96 * real input device, and not having to worry about binding input 
  97 * correctly to arbitrary controller layouts.
  98 */
  99
 100#define RETRO_DEVICE_TYPE_SHIFT         8
 101#define RETRO_DEVICE_MASK               ((1 << RETRO_DEVICE_TYPE_SHIFT) - 1)
 102#define RETRO_DEVICE_SUBCLASS(base, id) (((id + 1) << RETRO_DEVICE_TYPE_SHIFT) | base)
 103
 104/* Input disabled. */
 105#define RETRO_DEVICE_NONE         0
 106
 107/* The JOYPAD is called RetroPad. It is essentially a Super Nintendo 
 108 * controller, but with additional L2/R2/L3/R3 buttons, similar to a 
 109 * PS1 DualShock. */
 110#define RETRO_DEVICE_JOYPAD       1
 111
 112/* The mouse is a simple mouse, similar to Super Nintendo's mouse.
 113 * X and Y coordinates are reported relatively to last poll (poll callback).
 114 * It is up to the libretro implementation to keep track of where the mouse 
 115 * pointer is supposed to be on the screen.
 116 * The frontend must make sure not to interfere with its own hardware 
 117 * mouse pointer.
 118 */
 119#define RETRO_DEVICE_MOUSE        2
 120
 121/* KEYBOARD device lets one poll for raw key pressed.
 122 * It is poll based, so input callback will return with the current 
 123 * pressed state.
 124 * For event/text based keyboard input, see
 125 * RETRO_ENVIRONMENT_SET_KEYBOARD_CALLBACK.
 126 */
 127#define RETRO_DEVICE_KEYBOARD     3
 128
 129/* Lightgun X/Y coordinates are reported relatively to last poll,
 130 * similar to mouse. */
 131#define RETRO_DEVICE_LIGHTGUN     4
 132
 133/* The ANALOG device is an extension to JOYPAD (RetroPad).
 134 * Similar to DualShock it adds two analog sticks.
 135 * This is treated as a separate device type as it returns values in the 
 136 * full analog range of [-0x8000, 0x7fff]. Positive X axis is right.
 137 * Positive Y axis is down.
 138 * Only use ANALOG type when polling for analog values of the axes.
 139 */
 140#define RETRO_DEVICE_ANALOG       5
 141
 142/* Abstracts the concept of a pointing mechanism, e.g. touch.
 143 * This allows libretro to query in absolute coordinates where on the 
 144 * screen a mouse (or something similar) is being placed.
 145 * For a touch centric device, coordinates reported are the coordinates
 146 * of the press.
 147 *
 148 * Coordinates in X and Y are reported as:
 149 * [-0x7fff, 0x7fff]: -0x7fff corresponds to the far left/top of the screen,
 150 * and 0x7fff corresponds to the far right/bottom of the screen.
 151 * The "screen" is here defined as area that is passed to the frontend and 
 152 * later displayed on the monitor.
 153 *
 154 * The frontend is free to scale/resize this screen as it sees fit, however,
 155 * (X, Y) = (-0x7fff, -0x7fff) will correspond to the top-left pixel of the 
 156 * game image, etc.
 157 *
 158 * To check if the pointer coordinates are valid (e.g. a touch display 
 159 * actually being touched), PRESSED returns 1 or 0.
 160 *
 161 * If using a mouse on a desktop, PRESSED will usually correspond to the 
 162 * left mouse button, but this is a frontend decision.
 163 * PRESSED will only return 1 if the pointer is inside the game screen.
 164 *
 165 * For multi-touch, the index variable can be used to successively query 
 166 * more presses.
 167 * If index = 0 returns true for _PRESSED, coordinates can be extracted
 168 * with _X, _Y for index = 0. One can then query _PRESSED, _X, _Y with 
 169 * index = 1, and so on.
 170 * Eventually _PRESSED will return false for an index. No further presses 
 171 * are registered at this point. */
 172#define RETRO_DEVICE_POINTER      6
 173
 174/* Buttons for the RetroPad (JOYPAD).
 175 * The placement of these is equivalent to placements on the 
 176 * Super Nintendo controller.
 177 * L2/R2/L3/R3 buttons correspond to the PS1 DualShock. */
 178#define RETRO_DEVICE_ID_JOYPAD_B        0
 179#define RETRO_DEVICE_ID_JOYPAD_Y        1
 180#define RETRO_DEVICE_ID_JOYPAD_SELECT   2
 181#define RETRO_DEVICE_ID_JOYPAD_START    3
 182#define RETRO_DEVICE_ID_JOYPAD_UP       4
 183#define RETRO_DEVICE_ID_JOYPAD_DOWN     5
 184#define RETRO_DEVICE_ID_JOYPAD_LEFT     6
 185#define RETRO_DEVICE_ID_JOYPAD_RIGHT    7
 186#define RETRO_DEVICE_ID_JOYPAD_A        8
 187#define RETRO_DEVICE_ID_JOYPAD_X        9
 188#define RETRO_DEVICE_ID_JOYPAD_L       10
 189#define RETRO_DEVICE_ID_JOYPAD_R       11
 190#define RETRO_DEVICE_ID_JOYPAD_L2      12
 191#define RETRO_DEVICE_ID_JOYPAD_R2      13
 192#define RETRO_DEVICE_ID_JOYPAD_L3      14
 193#define RETRO_DEVICE_ID_JOYPAD_R3      15
 194
 195/* Index / Id values for ANALOG device. */
 196#define RETRO_DEVICE_INDEX_ANALOG_LEFT   0
 197#define RETRO_DEVICE_INDEX_ANALOG_RIGHT  1
 198#define RETRO_DEVICE_ID_ANALOG_X         0
 199#define RETRO_DEVICE_ID_ANALOG_Y         1
 200
 201/* Id values for MOUSE. */
 202#define RETRO_DEVICE_ID_MOUSE_X                0
 203#define RETRO_DEVICE_ID_MOUSE_Y                1
 204#define RETRO_DEVICE_ID_MOUSE_LEFT             2
 205#define RETRO_DEVICE_ID_MOUSE_RIGHT            3
 206#define RETRO_DEVICE_ID_MOUSE_WHEELUP          4
 207#define RETRO_DEVICE_ID_MOUSE_WHEELDOWN        5
 208#define RETRO_DEVICE_ID_MOUSE_MIDDLE           6
 209#define RETRO_DEVICE_ID_MOUSE_HORIZ_WHEELUP    7
 210#define RETRO_DEVICE_ID_MOUSE_HORIZ_WHEELDOWN  8
 211
 212/* Id values for LIGHTGUN types. */
 213#define RETRO_DEVICE_ID_LIGHTGUN_X        0
 214#define RETRO_DEVICE_ID_LIGHTGUN_Y        1
 215#define RETRO_DEVICE_ID_LIGHTGUN_TRIGGER  2
 216#define RETRO_DEVICE_ID_LIGHTGUN_CURSOR   3
 217#define RETRO_DEVICE_ID_LIGHTGUN_TURBO    4
 218#define RETRO_DEVICE_ID_LIGHTGUN_PAUSE    5
 219#define RETRO_DEVICE_ID_LIGHTGUN_START    6
 220
 221/* Id values for POINTER. */
 222#define RETRO_DEVICE_ID_POINTER_X         0
 223#define RETRO_DEVICE_ID_POINTER_Y         1
 224#define RETRO_DEVICE_ID_POINTER_PRESSED   2
 225
 226/* Returned from retro_get_region(). */
 227#define RETRO_REGION_NTSC  0
 228#define RETRO_REGION_PAL   1
 229
 230/* Id values for LANGUAGE */
 231enum retro_language
 232{
 233   RETRO_LANGUAGE_ENGLISH             =  0,
 234   RETRO_LANGUAGE_JAPANESE            =  1,
 235   RETRO_LANGUAGE_FRENCH              =  2,
 236   RETRO_LANGUAGE_SPANISH             =  3,
 237   RETRO_LANGUAGE_GERMAN              =  4,
 238   RETRO_LANGUAGE_ITALIAN             =  5,
 239   RETRO_LANGUAGE_DUTCH               =  6,
 240   RETRO_LANGUAGE_PORTUGUESE          =  7,
 241   RETRO_LANGUAGE_RUSSIAN             =  8,
 242   RETRO_LANGUAGE_KOREAN              =  9,
 243   RETRO_LANGUAGE_CHINESE_TRADITIONAL = 10,
 244   RETRO_LANGUAGE_CHINESE_SIMPLIFIED  = 11,
 245   RETRO_LANGUAGE_ESPERANTO           = 12,
 246   RETRO_LANGUAGE_POLISH              = 13,
 247   RETRO_LANGUAGE_LAST,
 248
 249   /* Ensure sizeof(enum) == sizeof(int) */
 250   RETRO_LANGUAGE_DUMMY          = INT_MAX 
 251};
 252
 253/* Passed to retro_get_memory_data/size().
 254 * If the memory type doesn't apply to the 
 255 * implementation NULL/0 can be returned.
 256 */
 257#define RETRO_MEMORY_MASK        0xff
 258
 259/* Regular save RAM. This RAM is usually found on a game cartridge,
 260 * backed up by a battery.
 261 * If save game data is too complex for a single memory buffer,
 262 * the SAVE_DIRECTORY (preferably) or SYSTEM_DIRECTORY environment
 263 * callback can be used. */
 264#define RETRO_MEMORY_SAVE_RAM    0
 265
 266/* Some games have a built-in clock to keep track of time.
 267 * This memory is usually just a couple of bytes to keep track of time.
 268 */
 269#define RETRO_MEMORY_RTC         1
 270
 271/* System ram lets a frontend peek into a game systems main RAM. */
 272#define RETRO_MEMORY_SYSTEM_RAM  2
 273
 274/* Video ram lets a frontend peek into a game systems video RAM (VRAM). */
 275#define RETRO_MEMORY_VIDEO_RAM   3
 276
 277/* Keysyms used for ID in input state callback when polling RETRO_KEYBOARD. */
 278enum retro_key
 279{
 280   RETROK_UNKNOWN        = 0,
 281   RETROK_FIRST          = 0,
 282   RETROK_BACKSPACE      = 8,
 283   RETROK_TAB            = 9,
 284   RETROK_CLEAR          = 12,
 285   RETROK_RETURN         = 13,
 286   RETROK_PAUSE          = 19,
 287   RETROK_ESCAPE         = 27,
 288   RETROK_SPACE          = 32,
 289   RETROK_EXCLAIM        = 33,
 290   RETROK_QUOTEDBL       = 34,
 291   RETROK_HASH           = 35,
 292   RETROK_DOLLAR         = 36,
 293   RETROK_AMPERSAND      = 38,
 294   RETROK_QUOTE          = 39,
 295   RETROK_LEFTPAREN      = 40,
 296   RETROK_RIGHTPAREN     = 41,
 297   RETROK_ASTERISK       = 42,
 298   RETROK_PLUS           = 43,
 299   RETROK_COMMA          = 44,
 300   RETROK_MINUS          = 45,
 301   RETROK_PERIOD         = 46,
 302   RETROK_SLASH          = 47,
 303   RETROK_0              = 48,
 304   RETROK_1              = 49,
 305   RETROK_2              = 50,
 306   RETROK_3              = 51,
 307   RETROK_4              = 52,
 308   RETROK_5              = 53,
 309   RETROK_6              = 54,
 310   RETROK_7              = 55,
 311   RETROK_8              = 56,
 312   RETROK_9              = 57,
 313   RETROK_COLON          = 58,
 314   RETROK_SEMICOLON      = 59,
 315   RETROK_LESS           = 60,
 316   RETROK_EQUALS         = 61,
 317   RETROK_GREATER        = 62,
 318   RETROK_QUESTION       = 63,
 319   RETROK_AT             = 64,
 320   RETROK_LEFTBRACKET    = 91,
 321   RETROK_BACKSLASH      = 92,
 322   RETROK_RIGHTBRACKET   = 93,
 323   RETROK_CARET          = 94,
 324   RETROK_UNDERSCORE     = 95,
 325   RETROK_BACKQUOTE      = 96,
 326   RETROK_a              = 97,
 327   RETROK_b              = 98,
 328   RETROK_c              = 99,
 329   RETROK_d              = 100,
 330   RETROK_e              = 101,
 331   RETROK_f              = 102,
 332   RETROK_g              = 103,
 333   RETROK_h              = 104,
 334   RETROK_i              = 105,
 335   RETROK_j              = 106,
 336   RETROK_k              = 107,
 337   RETROK_l              = 108,
 338   RETROK_m              = 109,
 339   RETROK_n              = 110,
 340   RETROK_o              = 111,
 341   RETROK_p              = 112,
 342   RETROK_q              = 113,
 343   RETROK_r              = 114,
 344   RETROK_s              = 115,
 345   RETROK_t              = 116,
 346   RETROK_u              = 117,
 347   RETROK_v              = 118,
 348   RETROK_w              = 119,
 349   RETROK_x              = 120,
 350   RETROK_y              = 121,
 351   RETROK_z              = 122,
 352   RETROK_DELETE         = 127,
 353
 354   RETROK_KP0            = 256,
 355   RETROK_KP1            = 257,
 356   RETROK_KP2            = 258,
 357   RETROK_KP3            = 259,
 358   RETROK_KP4            = 260,
 359   RETROK_KP5            = 261,
 360   RETROK_KP6            = 262,
 361   RETROK_KP7            = 263,
 362   RETROK_KP8            = 264,
 363   RETROK_KP9            = 265,
 364   RETROK_KP_PERIOD      = 266,
 365   RETROK_KP_DIVIDE      = 267,
 366   RETROK_KP_MULTIPLY    = 268,
 367   RETROK_KP_MINUS       = 269,
 368   RETROK_KP_PLUS        = 270,
 369   RETROK_KP_ENTER       = 271,
 370   RETROK_KP_EQUALS      = 272,
 371
 372   RETROK_UP             = 273,
 373   RETROK_DOWN           = 274,
 374   RETROK_RIGHT          = 275,
 375   RETROK_LEFT           = 276,
 376   RETROK_INSERT         = 277,
 377   RETROK_HOME           = 278,
 378   RETROK_END            = 279,
 379   RETROK_PAGEUP         = 280,
 380   RETROK_PAGEDOWN       = 281,
 381
 382   RETROK_F1             = 282,
 383   RETROK_F2             = 283,
 384   RETROK_F3             = 284,
 385   RETROK_F4             = 285,
 386   RETROK_F5             = 286,
 387   RETROK_F6             = 287,
 388   RETROK_F7             = 288,
 389   RETROK_F8             = 289,
 390   RETROK_F9             = 290,
 391   RETROK_F10            = 291,
 392   RETROK_F11            = 292,
 393   RETROK_F12            = 293,
 394   RETROK_F13            = 294,
 395   RETROK_F14            = 295,
 396   RETROK_F15            = 296,
 397
 398   RETROK_NUMLOCK        = 300,
 399   RETROK_CAPSLOCK       = 301,
 400   RETROK_SCROLLOCK      = 302,
 401   RETROK_RSHIFT         = 303,
 402   RETROK_LSHIFT         = 304,
 403   RETROK_RCTRL          = 305,
 404   RETROK_LCTRL          = 306,
 405   RETROK_RALT           = 307,
 406   RETROK_LALT           = 308,
 407   RETROK_RMETA          = 309,
 408   RETROK_LMETA          = 310,
 409   RETROK_LSUPER         = 311,
 410   RETROK_RSUPER         = 312,
 411   RETROK_MODE           = 313,
 412   RETROK_COMPOSE        = 314,
 413
 414   RETROK_HELP           = 315,
 415   RETROK_PRINT          = 316,
 416   RETROK_SYSREQ         = 317,
 417   RETROK_BREAK          = 318,
 418   RETROK_MENU           = 319,
 419   RETROK_POWER          = 320,
 420   RETROK_EURO           = 321,
 421   RETROK_UNDO           = 322,
 422
 423   RETROK_LAST,
 424
 425   RETROK_DUMMY          = INT_MAX /* Ensure sizeof(enum) == sizeof(int) */
 426};
 427
 428enum retro_mod
 429{
 430   RETROKMOD_NONE       = 0x0000,
 431
 432   RETROKMOD_SHIFT      = 0x01,
 433   RETROKMOD_CTRL       = 0x02,
 434   RETROKMOD_ALT        = 0x04,
 435   RETROKMOD_META       = 0x08,
 436
 437   RETROKMOD_NUMLOCK    = 0x10,
 438   RETROKMOD_CAPSLOCK   = 0x20,
 439   RETROKMOD_SCROLLOCK  = 0x40,
 440
 441   RETROKMOD_DUMMY = INT_MAX /* Ensure sizeof(enum) == sizeof(int) */
 442};
 443
 444/* If set, this call is not part of the public libretro API yet. It can 
 445 * change or be removed at any time. */
 446#define RETRO_ENVIRONMENT_EXPERIMENTAL 0x10000
 447/* Environment callback to be used internally in frontend. */
 448#define RETRO_ENVIRONMENT_PRIVATE 0x20000
 449
 450/* Environment commands. */
 451#define RETRO_ENVIRONMENT_SET_ROTATION  1  /* const unsigned * --
 452                                            * Sets screen rotation of graphics.
 453                                            * Is only implemented if rotation can be accelerated by hardware.
 454                                            * Valid values are 0, 1, 2, 3, which rotates screen by 0, 90, 180, 
 455                                            * 270 degrees counter-clockwise respectively.
 456                                            */
 457#define RETRO_ENVIRONMENT_GET_OVERSCAN  2  /* bool * --
 458                                            * Boolean value whether or not the implementation should use overscan, 
 459                                            * or crop away overscan.
 460                                            */
 461#define RETRO_ENVIRONMENT_GET_CAN_DUPE  3  /* bool * --
 462                                            * Boolean value whether or not frontend supports frame duping,
 463                                            * passing NULL to video frame callback.
 464                                            */
 465
 466                                           /* Environ 4, 5 are no longer supported (GET_VARIABLE / SET_VARIABLES), 
 467                                            * and reserved to avoid possible ABI clash.
 468                                            */
 469
 470#define RETRO_ENVIRONMENT_SET_MESSAGE   6  /* const struct retro_message * --
 471                                            * Sets a message to be displayed in implementation-specific manner 
 472                                            * for a certain amount of 'frames'.
 473                                            * Should not be used for trivial messages, which should simply be 
 474                                            * logged via RETRO_ENVIRONMENT_GET_LOG_INTERFACE (or as a 
 475                                            * fallback, stderr).
 476                                            */
 477#define RETRO_ENVIRONMENT_SHUTDOWN      7  /* N/A (NULL) --
 478                                            * Requests the frontend to shutdown.
 479                                            * Should only be used if game has a specific
 480                                            * way to shutdown the game from a menu item or similar.
 481                                            */
 482#define RETRO_ENVIRONMENT_SET_PERFORMANCE_LEVEL 8
 483                                           /* const unsigned * --
 484                                            * Gives a hint to the frontend how demanding this implementation
 485                                            * is on a system. E.g. reporting a level of 2 means
 486                                            * this implementation should run decently on all frontends
 487                                            * of level 2 and up.
 488                                            *
 489                                            * It can be used by the frontend to potentially warn
 490                                            * about too demanding implementations.
 491                                            *
 492                                            * The levels are "floating".
 493                                            *
 494                                            * This function can be called on a per-game basis,
 495                                            * as certain games an implementation can play might be
 496                                            * particularly demanding.
 497                                            * If called, it should be called in retro_load_game().
 498                                            */
 499#define RETRO_ENVIRONMENT_GET_SYSTEM_DIRECTORY 9
 500                                           /* const char ** --
 501                                            * Returns the "system" directory of the frontend.
 502                                            * This directory can be used to store system specific 
 503                                            * content such as BIOSes, configuration data, etc.
 504                                            * The returned value can be NULL.
 505                                            * If so, no such directory is defined,
 506                                            * and it's up to the implementation to find a suitable directory.
 507                                            *
 508                                            * NOTE: Some cores used this folder also for "save" data such as 
 509                                            * memory cards, etc, for lack of a better place to put it.
 510                                            * This is now discouraged, and if possible, cores should try to 
 511                                            * use the new GET_SAVE_DIRECTORY.
 512                                            */
 513#define RETRO_ENVIRONMENT_SET_PIXEL_FORMAT 10
 514                                           /* const enum retro_pixel_format * --
 515                                            * Sets the internal pixel format used by the implementation.
 516                                            * The default pixel format is RETRO_PIXEL_FORMAT_0RGB1555.
 517                                            * This pixel format however, is deprecated (see enum retro_pixel_format).
 518                                            * If the call returns false, the frontend does not support this pixel 
 519                                            * format.
 520                                            *
 521                                            * This function should be called inside retro_load_game() or 
 522                                            * retro_get_system_av_info().
 523                                            */
 524#define RETRO_ENVIRONMENT_SET_INPUT_DESCRIPTORS 11
 525                                           /* const struct retro_input_descriptor * --
 526                                            * Sets an array of retro_input_descriptors.
 527                                            * It is up to the frontend to present this in a usable way.
 528                                            * The array is terminated by retro_input_descriptor::description 
 529                                            * being set to NULL.
 530                                            * This function can be called at any time, but it is recommended 
 531                                            * to call it as early as possible.
 532                                            */
 533#define RETRO_ENVIRONMENT_SET_KEYBOARD_CALLBACK 12
 534                                           /* const struct retro_keyboard_callback * --
 535                                            * Sets a callback function used to notify core about keyboard events.
 536                                            */
 537#define RETRO_ENVIRONMENT_SET_DISK_CONTROL_INTERFACE 13
 538                                           /* const struct retro_disk_control_callback * --
 539                                            * Sets an interface which frontend can use to eject and insert 
 540                                            * disk images.
 541                                            * This is used for games which consist of multiple images and 
 542                                            * must be manually swapped out by the user (e.g. PSX).
 543                                            */
 544#define RETRO_ENVIRONMENT_SET_HW_RENDER 14
 545                                           /* struct retro_hw_render_callback * --
 546                                            * Sets an interface to let a libretro core render with 
 547                                            * hardware acceleration.
 548                                            * Should be called in retro_load_game().
 549                                            * If successful, libretro cores will be able to render to a 
 550                                            * frontend-provided framebuffer.
 551                                            * The size of this framebuffer will be at least as large as 
 552                                            * max_width/max_height provided in get_av_info().
 553                                            * If HW rendering is used, pass only RETRO_HW_FRAME_BUFFER_VALID or 
 554                                            * NULL to retro_video_refresh_t.
 555                                            */
 556#define RETRO_ENVIRONMENT_GET_VARIABLE 15
 557                                           /* struct retro_variable * --
 558                                            * Interface to acquire user-defined information from environment
 559                                            * that cannot feasibly be supported in a multi-system way.
 560                                            * 'key' should be set to a key which has already been set by 
 561                                            * SET_VARIABLES.
 562                                            * 'data' will be set to a value or NULL.
 563                                            */
 564#define RETRO_ENVIRONMENT_SET_VARIABLES 16
 565                                           /* const struct retro_variable * --
 566                                            * Allows an implementation to signal the environment
 567                                            * which variables it might want to check for later using 
 568                                            * GET_VARIABLE.
 569                                            * This allows the frontend to present these variables to 
 570                                            * a user dynamically.
 571                                            * This should be called as early as possible (ideally in 
 572                                            * retro_set_environment).
 573                                            *
 574                                            * 'data' points to an array of retro_variable structs 
 575                                            * terminated by a { NULL, NULL } element.
 576                                            * retro_variable::key should be namespaced to not collide 
 577                                            * with other implementations' keys. E.g. A core called 
 578                                            * 'foo' should use keys named as 'foo_option'.
 579                                            * retro_variable::value should contain a human readable 
 580                                            * description of the key as well as a '|' delimited list 
 581                                            * of expected values.
 582                                            *
 583                                            * The number of possible options should be very limited, 
 584                                            * i.e. it should be feasible to cycle through options 
 585                                            * without a keyboard.
 586                                            *
 587                                            * First entry should be treated as a default.
 588                                            *
 589                                            * Example entry:
 590                                            * { "foo_option", "Speed hack coprocessor X; false|true" }
 591                                            *
 592                                            * Text before first ';' is description. This ';' must be 
 593                                            * followed by a space, and followed by a list of possible 
 594                                            * values split up with '|'.
 595                                            *
 596                                            * Only strings are operated on. The possible values will 
 597                                            * generally be displayed and stored as-is by the frontend.
 598                                            */
 599#define RETRO_ENVIRONMENT_GET_VARIABLE_UPDATE 17
 600                                           /* bool * --
 601                                            * Result is set to true if some variables are updated by
 602                                            * frontend since last call to RETRO_ENVIRONMENT_GET_VARIABLE.
 603                                            * Variables should be queried with GET_VARIABLE.
 604                                            */
 605#define RETRO_ENVIRONMENT_SET_SUPPORT_NO_GAME 18
 606                                           /* const bool * --
 607                                            * If true, the libretro implementation supports calls to 
 608                                            * retro_load_game() with NULL as argument.
 609                                            * Used by cores which can run without particular game data.
 610                                            * This should be called within retro_set_environment() only.
 611                                            */
 612#define RETRO_ENVIRONMENT_GET_LIBRETRO_PATH 19
 613                                           /* const char ** --
 614                                            * Retrieves the absolute path from where this libretro 
 615                                            * implementation was loaded.
 616                                            * NULL is returned if the libretro was loaded statically 
 617                                            * (i.e. linked statically to frontend), or if the path cannot be 
 618                                            * determined.
 619                                            * Mostly useful in cooperation with SET_SUPPORT_NO_GAME as assets can 
 620                                            * be loaded without ugly hacks.
 621                                            */
 622                                           
 623                                           /* Environment 20 was an obsolete version of SET_AUDIO_CALLBACK. 
 624                                            * It was not used by any known core at the time,
 625                                            * and was removed from the API. */
 626#define RETRO_ENVIRONMENT_SET_AUDIO_CALLBACK 22
 627                                           /* const struct retro_audio_callback * --
 628                                            * Sets an interface which is used to notify a libretro core about audio 
 629                                            * being available for writing.
 630                                            * The callback can be called from any thread, so a core using this must 
 631                                            * have a thread safe audio implementation.
 632                                            * It is intended for games where audio and video are completely 
 633                                            * asynchronous and audio can be generated on the fly.
 634                                            * This interface is not recommended for use with emulators which have 
 635                                            * highly synchronous audio.
 636                                            *
 637                                            * The callback only notifies about writability; the libretro core still 
 638                                            * has to call the normal audio callbacks
 639                                            * to write audio. The audio callbacks must be called from within the 
 640                                            * notification callback.
 641                                            * The amount of audio data to write is up to the implementation.
 642                                            * Generally, the audio callback will be called continously in a loop.
 643                                            *
 644                                            * Due to thread safety guarantees and lack of sync between audio and 
 645                                            * video, a frontend  can selectively disallow this interface based on 
 646                                            * internal configuration. A core using this interface must also 
 647                                            * implement the "normal" audio interface.
 648                                            *
 649                                            * A libretro core using SET_AUDIO_CALLBACK should also make use of 
 650                                            * SET_FRAME_TIME_CALLBACK.
 651                                            */
 652#define RETRO_ENVIRONMENT_SET_FRAME_TIME_CALLBACK 21
 653                                           /* const struct retro_frame_time_callback * --
 654                                            * Lets the core know how much time has passed since last 
 655                                            * invocation of retro_run().
 656                                            * The frontend can tamper with the timing to fake fast-forward, 
 657                                            * slow-motion, frame stepping, etc.
 658                                            * In this case the delta time will use the reference value 
 659                                            * in frame_time_callback..
 660                                            */
 661#define RETRO_ENVIRONMENT_GET_RUMBLE_INTERFACE 23
 662                                           /* struct retro_rumble_interface * --
 663                                            * Gets an interface which is used by a libretro core to set 
 664                                            * state of rumble motors in controllers.
 665                                            * A strong and weak motor is supported, and they can be 
 666                                            * controlled indepedently.
 667                                            */
 668#define RETRO_ENVIRONMENT_GET_INPUT_DEVICE_CAPABILITIES 24
 669                                           /* uint64_t * --
 670                                            * Gets a bitmask telling which device type are expected to be 
 671                                            * handled properly in a call to retro_input_state_t.
 672                                            * Devices which are not handled or recognized always return 
 673                                            * 0 in retro_input_state_t.
 674                                            * Example bitmask: caps = (1 << RETRO_DEVICE_JOYPAD) | (1 << RETRO_DEVICE_ANALOG).
 675                                            * Should only be called in retro_run().
 676                                            */
 677#define RETRO_ENVIRONMENT_GET_SENSOR_INTERFACE (25 | RETRO_ENVIRONMENT_EXPERIMENTAL)
 678                                           /* struct retro_sensor_interface * --
 679                                            * Gets access to the sensor interface.
 680                                            * The purpose of this interface is to allow
 681                                            * setting state related to sensors such as polling rate, 
 682                                            * enabling/disable it entirely, etc.
 683                                            * Reading sensor state is done via the normal 
 684                                            * input_state_callback API.
 685                                            */
 686#define RETRO_ENVIRONMENT_GET_CAMERA_INTERFACE (26 | RETRO_ENVIRONMENT_EXPERIMENTAL)
 687                                           /* struct retro_camera_callback * --
 688                                            * Gets an interface to a video camera driver.
 689                                            * A libretro core can use this interface to get access to a 
 690                                            * video camera.
 691                                            * New video frames are delivered in a callback in same 
 692                                            * thread as retro_run().
 693                                            *
 694                                            * GET_CAMERA_INTERFACE should be called in retro_load_game().
 695                                            *
 696                                            * Depending on the camera implementation used, camera frames 
 697                                            * will be delivered as a raw framebuffer,
 698                                            * or as an OpenGL texture directly.
 699                                            *
 700                                            * The core has to tell the frontend here which types of 
 701                                            * buffers can be handled properly.
 702                                            * An OpenGL texture can only be handled when using a 
 703                                            * libretro GL core (SET_HW_RENDER).
 704                                            * It is recommended to use a libretro GL core when 
 705                                            * using camera interface.
 706                                            *
 707                                            * The camera is not started automatically. The retrieved start/stop 
 708                                            * functions must be used to explicitly
 709                                            * start and stop the camera driver.
 710                                            */
 711#define RETRO_ENVIRONMENT_GET_LOG_INTERFACE 27
 712                                           /* struct retro_log_callback * --
 713                                            * Gets an interface for logging. This is useful for 
 714                                            * logging in a cross-platform way
 715                                            * as certain platforms cannot use use stderr for logging. 
 716                                            * It also allows the frontend to
 717                                            * show logging information in a more suitable way.
 718                                            * If this interface is not used, libretro cores should 
 719                                            * log to stderr as desired.
 720                                            */
 721#define RETRO_ENVIRONMENT_GET_PERF_INTERFACE 28
 722                                           /* struct retro_perf_callback * --
 723                                            * Gets an interface for performance counters. This is useful 
 724                                            * for performance logging in a cross-platform way and for detecting 
 725                                            * architecture-specific features, such as SIMD support.
 726                                            */
 727#define RETRO_ENVIRONMENT_GET_LOCATION_INTERFACE 29
 728                                           /* struct retro_location_callback * --
 729                                            * Gets access to the location interface.
 730                                            * The purpose of this interface is to be able to retrieve 
 731                                            * location-based information from the host device,
 732                                            * such as current latitude / longitude.
 733                                            */
 734#define RETRO_ENVIRONMENT_GET_CONTENT_DIRECTORY 30 /* Old name, kept for compatibility. */
 735#define RETRO_ENVIRONMENT_GET_CORE_ASSETS_DIRECTORY 30
 736                                           /* const char ** --
 737                                            * Returns the "core assets" directory of the frontend.
 738                                            * This directory can be used to store specific assets that the 
 739                                            * core relies upon, such as art assets,
 740                                            * input data, etc etc.
 741                                            * The returned value can be NULL.
 742                                            * If so, no such directory is defined,
 743                                            * and it's up to the implementation to find a suitable directory.
 744                                            */
 745#define RETRO_ENVIRONMENT_GET_SAVE_DIRECTORY 31
 746                                           /* const char ** --
 747                                            * Returns the "save" directory of the frontend.
 748                                            * This directory can be used to store SRAM, memory cards, 
 749                                            * high scores, etc, if the libretro core
 750                                            * cannot use the regular memory interface (retro_get_memory_data()).
 751                                            *
 752                                            * NOTE: libretro cores used to check GET_SYSTEM_DIRECTORY for 
 753                                            * similar things before.
 754                                            * They should still check GET_SYSTEM_DIRECTORY if they want to 
 755                                            * be backwards compatible.
 756                                            * The path here can be NULL. It should only be non-NULL if the 
 757                                            * frontend user has set a specific save path.
 758                                            */
 759#define RETRO_ENVIRONMENT_SET_SYSTEM_AV_INFO 32
 760                                           /* const struct retro_system_av_info * --
 761                                            * Sets a new av_info structure. This can only be called from 
 762                                            * within retro_run().
 763                                            * This should *only* be used if the core is completely altering the 
 764                                            * internal resolutions, aspect ratios, timings, sampling rate, etc.
 765                                            * Calling this can require a full reinitialization of video/audio 
 766                                            * drivers in the frontend,
 767                                            *
 768                                            * so it is important to call it very sparingly, and usually only with 
 769                                            * the users explicit consent.
 770                                            * An eventual driver reinitialize will happen so that video and 
 771                                            * audio callbacks
 772                                            * happening after this call within the same retro_run() call will 
 773                                            * target the newly initialized driver.
 774                                            *
 775                                            * This callback makes it possible to support configurable resolutions 
 776                                            * in games, which can be useful to
 777                                            * avoid setting the "worst case" in max_width/max_height.
 778                                            *
 779                                            * ***HIGHLY RECOMMENDED*** Do not call this callback every time 
 780                                            * resolution changes in an emulator core if it's
 781                                            * expected to be a temporary change, for the reasons of possible 
 782                                            * driver reinitialization.
 783                                            * This call is not a free pass for not trying to provide 
 784                                            * correct values in retro_get_system_av_info(). If you need to change 
 785                                            * things like aspect ratio or nominal width/height, 
 786                                            * use RETRO_ENVIRONMENT_SET_GEOMETRY, which is a softer variant 
 787                                            * of SET_SYSTEM_AV_INFO.
 788                                            *
 789                                            * If this returns false, the frontend does not acknowledge a 
 790                                            * changed av_info struct.
 791                                            */
 792#define RETRO_ENVIRONMENT_SET_PROC_ADDRESS_CALLBACK 33
 793                                           /* const struct retro_get_proc_address_interface * --
 794                                            * Allows a libretro core to announce support for the 
 795                                            * get_proc_address() interface.
 796                                            * This interface allows for a standard way to extend libretro where 
 797                                            * use of environment calls are too indirect,
 798                                            * e.g. for cases where the frontend wants to call directly into the core.
 799                                            *
 800                                            * If a core wants to expose this interface, SET_PROC_ADDRESS_CALLBACK 
 801                                            * **MUST** be called from within retro_set_environment().
 802                                            */
 803#define RETRO_ENVIRONMENT_SET_SUBSYSTEM_INFO 34
 804                                           /* const struct retro_subsystem_info * --
 805                                            * This environment call introduces the concept of libretro "subsystems".
 806                                            * A subsystem is a variant of a libretro core which supports 
 807                                            * different kinds of games.
 808                                            * The purpose of this is to support e.g. emulators which might 
 809                                            * have special needs, e.g. Super Nintendo's Super GameBoy, Sufami Turbo.
 810                                            * It can also be used to pick among subsystems in an explicit way 
 811                                            * if the libretro implementation is a multi-system emulator itself.
 812                                            *
 813                                            * Loading a game via a subsystem is done with retro_load_game_special(),
 814                                            * and this environment call allows a libretro core to expose which 
 815                                            * subsystems are supported for use with retro_load_game_special().
 816                                            * A core passes an array of retro_game_special_info which is terminated 
 817                                            * with a zeroed out retro_game_special_info struct.
 818                                            *
 819                                            * If a core wants to use this functionality, SET_SUBSYSTEM_INFO
 820                                            * **MUST** be called from within retro_set_environment().
 821                                            */
 822#define RETRO_ENVIRONMENT_SET_CONTROLLER_INFO 35
 823                                           /* const struct retro_controller_info * --
 824                                            * This environment call lets a libretro core tell the frontend 
 825                                            * which controller types are recognized in calls to 
 826                                            * retro_set_controller_port_device().
 827                                            *
 828                                            * Some emulators such as Super Nintendo
 829                                            * support multiple lightgun types which must be specifically 
 830                                            * selected from.
 831                                            * It is therefore sometimes necessary for a frontend to be able 
 832                                            * to tell the core about a special kind of input device which is 
 833                                            * not covered by the libretro input API.
 834                                            *
 835                                            * In order for a frontend to understand the workings of an input device,
 836                                            * it must be a specialized type
 837                                            * of the generic device types already defined in the libretro API.
 838                                            *
 839                                            * Which devices are supported can vary per input port.
 840                                            * The core must pass an array of const struct retro_controller_info which 
 841                                            * is terminated with a blanked out struct. Each element of the struct 
 842                                            * corresponds to an ascending port index to 
 843                                            * retro_set_controller_port_device().
 844                                            * Even if special device types are set in the libretro core, 
 845                                            * libretro should only poll input based on the base input device types.
 846                                            */
 847#define RETRO_ENVIRONMENT_SET_MEMORY_MAPS (36 | RETRO_ENVIRONMENT_EXPERIMENTAL)
 848                                           /* const struct retro_memory_map * --
 849                                            * This environment call lets a libretro core tell the frontend 
 850                                            * about the memory maps this core emulates.
 851                                            * This can be used to implement, for example, cheats in a core-agnostic way.
 852                                            *
 853                                            * Should only be used by emulators; it doesn't make much sense for 
 854                                            * anything else.
 855                                            * It is recommended to expose all relevant pointers through 
 856                                            * retro_get_memory_* as well.
 857                                            *
 858                                            * Can be called from retro_init and retro_load_game.
 859                                            */
 860#define RETRO_ENVIRONMENT_SET_GEOMETRY 37
 861                                           /* const struct retro_game_geometry * --
 862                                            * This environment call is similar to SET_SYSTEM_AV_INFO for changing 
 863                                            * video parameters, but provides a guarantee that drivers will not be 
 864                                            * reinitialized.
 865                                            * This can only be called from within retro_run().
 866                                            *
 867                                            * The purpose of this call is to allow a core to alter nominal 
 868                                            * width/heights as well as aspect ratios on-the-fly, which can be 
 869                                            * useful for some emulators to change in run-time.
 870                                            *
 871                                            * max_width/max_height arguments are ignored and cannot be changed
 872                                            * with this call as this could potentially require a reinitialization or a 
 873                                            * non-constant time operation.
 874                                            * If max_width/max_height are to be changed, SET_SYSTEM_AV_INFO is required.
 875                                            *
 876                                            * A frontend must guarantee that this environment call completes in 
 877                                            * constant time.
 878                                            */
 879#define RETRO_ENVIRONMENT_GET_USERNAME 38 
 880                                           /* const char **
 881                                            * Returns the specified username of the frontend, if specified by the user.
 882                                            * This username can be used as a nickname for a core that has online facilities 
 883                                            * or any other mode where personalization of the user is desirable.
 884                                            * The returned value can be NULL.
 885                                            * If this environ callback is used by a core that requires a valid username, 
 886                                            * a default username should be specified by the core.
 887                                            */
 888#define RETRO_ENVIRONMENT_GET_LANGUAGE 39
 889                                           /* unsigned * --
 890                                            * Returns the specified language of the frontend, if specified by the user.
 891                                            * It can be used by the core for localization purposes.
 892                                            */
 893#define RETRO_ENVIRONMENT_GET_CURRENT_SOFTWARE_FRAMEBUFFER (40 | RETRO_ENVIRONMENT_EXPERIMENTAL)
 894                                           /* struct retro_framebuffer * --
 895                                            * Returns a preallocated framebuffer which the core can use for rendering
 896                                            * the frame into when not using SET_HW_RENDER.
 897                                            * The framebuffer returned from this call must not be used
 898                                            * after the current call to retro_run() returns.
 899                                            *
 900                                            * The goal of this call is to allow zero-copy behavior where a core
 901                                            * can render directly into video memory, avoiding extra bandwidth cost by copying
 902                                            * memory from core to video memory.
 903                                            *
 904                                            * If this call succeeds and the core renders into it,
 905                                            * the framebuffer pointer and pitch can be passed to retro_video_refresh_t.
 906                                            * If the buffer from GET_CURRENT_SOFTWARE_FRAMEBUFFER is to be used,
 907                                            * the core must pass the exact
 908                                            * same pointer as returned by GET_CURRENT_SOFTWARE_FRAMEBUFFER;
 909                                            * i.e. passing a pointer which is offset from the
 910                                            * buffer is undefined. The width, height and pitch parameters
 911                                            * must also match exactly to the values obtained from GET_CURRENT_SOFTWARE_FRAMEBUFFER.
 912                                            *
 913                                            * It is possible for a frontend to return a different pixel format
 914                                            * than the one used in SET_PIXEL_FORMAT. This can happen if the frontend
 915                                            * needs to perform conversion.
 916                                            *
 917                                            * It is still valid for a core to render to a different buffer
 918                                            * even if GET_CURRENT_SOFTWARE_FRAMEBUFFER succeeds.
 919                                            *
 920                                            * A frontend must make sure that the pointer obtained from this function is
 921                                            * writeable (and readable).
 922                                            */
 923
 924enum retro_hw_render_interface_type
 925{
 926   RETRO_HW_RENDER_INTERFACE_VULKAN = 0,
 927   RETRO_HW_RENDER_INTERFACE_DUMMY = INT_MAX
 928};
 929
 930/* Base struct. All retro_hw_render_interface_* types
 931 * contain at least these fields. */
 932struct retro_hw_render_interface
 933{
 934   enum retro_hw_render_interface_type interface_type;
 935   unsigned interface_version;
 936};
 937#define RETRO_ENVIRONMENT_GET_HW_RENDER_INTERFACE (41 | RETRO_ENVIRONMENT_EXPERIMENTAL)
 938                                           /* const struct retro_hw_render_interface ** --
 939                                            * Returns an API specific rendering interface for accessing API specific data.
 940                                            * Not all HW rendering APIs support or need this.
 941                                            * The contents of the returned pointer is specific to the rendering API
 942                                            * being used. See the various headers like libretro_vulkan.h, etc.
 943                                            *
 944                                            * GET_HW_RENDER_INTERFACE cannot be called before context_reset has been called.
 945                                            * Similarly, after context_destroyed callback returns,
 946                                            * the contents of the HW_RENDER_INTERFACE are invalidated.
 947                                            */
 948
 949#define RETRO_ENVIRONMENT_SET_SUPPORT_ACHIEVEMENTS (42 | RETRO_ENVIRONMENT_EXPERIMENTAL)
 950                                           /* const bool * --
 951                                            * If true, the libretro implementation supports achievements
 952                                            * either via memory descriptors set with RETRO_ENVIRONMENT_SET_MEMORY_MAPS
 953                                            * or via retro_get_memory_data/retro_get_memory_size.
 954                                            *
 955                                            * This must be called before the first call to retro_run.
 956                                            */
 957
 958enum retro_hw_render_context_negotiation_interface_type
 959{
 960   RETRO_HW_RENDER_CONTEXT_NEGOTIATION_INTERFACE_VULKAN = 0,
 961   RETRO_HW_RENDER_CONTEXT_NEGOTIATION_INTERFACE_DUMMY = INT_MAX
 962};
 963
 964/* Base struct. All retro_hw_render_context_negotiation_interface_* types
 965 * contain at least these fields. */
 966struct retro_hw_render_context_negotiation_interface
 967{
 968   enum retro_hw_render_context_negotiation_interface_type interface_type;
 969   unsigned interface_version;
 970};
 971#define RETRO_ENVIRONMENT_SET_HW_RENDER_CONTEXT_NEGOTIATION_INTERFACE (43 | RETRO_ENVIRONMENT_EXPERIMENTAL)
 972                                           /* const struct retro_hw_render_context_negotiation_interface * --
 973                                            * Sets an interface which lets the libretro core negotiate with frontend how a context is created.
 974                                            * The semantics of this interface depends on which API is used in SET_HW_RENDER earlier.
 975                                            * This interface will be used when the frontend is trying to create a HW rendering context,
 976                                            * so it will be used after SET_HW_RENDER, but before the context_reset callback.
 977                                            */
 978
 979#define RETRO_MEMDESC_CONST     (1 << 0)   /* The frontend will never change this memory area once retro_load_game has returned. */
 980#define RETRO_MEMDESC_BIGENDIAN (1 << 1)   /* The memory area contains big endian data. Default is little endian. */
 981#define RETRO_MEMDESC_ALIGN_2   (1 << 16)  /* All memory access in this area is aligned to their own size, or 2, whichever is smaller. */
 982#define RETRO_MEMDESC_ALIGN_4   (2 << 16)
 983#define RETRO_MEMDESC_ALIGN_8   (3 << 16)
 984#define RETRO_MEMDESC_MINSIZE_2 (1 << 24)  /* All memory in this region is accessed at least 2 bytes at the time. */
 985#define RETRO_MEMDESC_MINSIZE_4 (2 << 24)
 986#define RETRO_MEMDESC_MINSIZE_8 (3 << 24)
 987struct retro_memory_descriptor
 988{
 989   uint64_t flags;
 990
 991   /* Pointer to the start of the relevant ROM or RAM chip.
 992    * It's strongly recommended to use 'offset' if possible, rather than 
 993    * doing math on the pointer.
 994    *
 995    * If the same byte is mapped my multiple descriptors, their descriptors 
 996    * must have the same pointer.
 997    * If 'start' does not point to the first byte in the pointer, put the 
 998    * difference in 'offset' instead.
 999    *
1000    * May be NULL if there's nothing usable here (e.g. hardware registers and 
1001    * open bus). No flags should be set if the pointer is NULL.
1002    * It's recommended to minimize the number of descriptors if possible,
1003    * but not mandatory. */
1004   void *ptr;
1005   size_t offset;
1006
1007   /* This is the location in the emulated address space 
1008    * where the mapping starts. */
1009   size_t start;
1010
1011   /* Which bits must be same as in 'start' for this mapping to apply.
1012    * The first memory descriptor to claim a certain byte is the one 
1013    * that applies.
1014    * A bit which is set in 'start' must also be set in this.
1015    * Can be zero, in which case each byte is assumed mapped exactly once. 
1016    * In this case, 'len' must be a power of two. */
1017   size_t select;
1018
1019   /* If this is nonzero, the set bits are assumed not connected to the 
1020    * memory chip's address pins. */
1021   size_t disconnect;
1022
1023   /* This one tells the size of the current memory area.
1024    * If, after start+disconnect are applied, the address is higher than 
1025    * this, the highest bit of the address is cleared.
1026    *
1027    * If the address is still too high, the next highest bit is cleared.
1028    * Can be zero, in which case it's assumed to be infinite (as limited 
1029    * by 'select' and 'disconnect'). */
1030   size_t len;
1031
1032   /* To go from emulated address to physical address, the following 
1033    * order applies:
1034    * Subtract 'start', pick off 'disconnect', apply 'len', add 'offset'. */
1035
1036   /* The address space name must consist of only a-zA-Z0-9_-, 
1037    * should be as short as feasible (maximum length is 8 plus the NUL),
1038    * and may not be any other address space plus one or more 0-9A-F 
1039    * at the end.
1040    * However, multiple memory descriptors for the same address space is 
1041    * allowed, and the address space name can be empty. NULL is treated 
1042    * as empty.
1043    *
1044    * Address space names are case sensitive, but avoid lowercase if possible.
1045    * The same pointer may exist in multiple address spaces.
1046    *
1047    * Examples:
1048    * blank+blank - valid (multiple things may be mapped in the same namespace)
1049    * 'Sp'+'Sp' - valid (multiple things may be mapped in the same namespace)
1050    * 'A'+'B' - valid (neither is a prefix of each other)
1051    * 'S'+blank - valid ('S' is not in 0-9A-F)
1052    * 'a'+blank - valid ('a' is not in 0-9A-F)
1053    * 'a'+'A' - valid (neither is a prefix of each other)
1054    * 'AR'+blank - valid ('R' is not in 0-9A-F)
1055    * 'ARB'+blank - valid (the B can't be part of the address either, because 
1056    *                      there is no namespace 'AR')
1057    * blank+'B' - not valid, because it's ambigous which address space B1234 
1058    *             would refer to.
1059    * The length can't be used for that purpose; the frontend may want 
1060    * to append arbitrary data to an address, without a separator. */
1061   const char *addrspace;
1062
1063   /* TODO: When finalizing this one, add a description field, which should be
1064    * "WRAM" or something roughly equally long. */
1065
1066   /* TODO: When finalizing this one, replace 'select' with 'limit', which tells
1067    * which bits can vary and still refer to the same address (limit = ~select).
1068    * TODO: limit? range? vary? something else? */
1069
1070   /* TODO: When finalizing this one, if 'len' is above what 'select' (or
1071    * 'limit') allows, it's bankswitched. Bankswitched data must have both 'len'
1072    * and 'select' != 0, and the mappings don't tell how the system switches the
1073    * banks. */
1074
1075   /* TODO: When finalizing this one, fix the 'len' bit removal order.
1076    * For len=0x1800, pointer 0x1C00 should go to 0x1400, not 0x0C00.
1077    * Algorithm: Take bits highest to lowest, but if it goes above len, clear
1078    * the most recent addition and continue on the next bit.
1079    * TODO: Can the above be optimized? Is "remove the lowest bit set in both
1080    * pointer and 'len'" equivalent? */
1081   
1082   /* TODO: Some emulators (MAME?) emulate big endian systems by only accessing
1083    * the emulated memory in 32-bit chunks, native endian. But that's nothing
1084    * compared to Darek Mihocka <http://www.emulators.com/docs/nx07_vm101.htm>
1085    * (section Emulation 103 - Nearly Free Byte Reversal) - he flips the ENTIRE
1086    * RAM backwards! I'll want to represent both of those, via some flags.
1087    * 
1088    * I suspect MAME either didn't think of that idea, or don't want the #ifdef.
1089    * Not sure which, nor do I really care. */
1090   
1091   /* TODO: Some of those flags are unused and/or don't really make sense. Clean
1092    * them up. */
1093};
1094
1095/* The frontend may use the largest value of 'start'+'select' in a 
1096 * certain namespace to infer the size of the address space.
1097 *
1098 * If the address space is larger than that, a mapping with .ptr=NULL 
1099 * should be at the end of the array, with .select set to all ones for 
1100 * as long as the address space is big.
1101 *
1102 * Sample descriptors (minus .ptr, and RETRO_MEMFLAG_ on the flags):
1103 * SNES WRAM:
1104 * .start=0x7E0000, .len=0x20000
1105 * (Note that this must be mapped before the ROM in most cases; some of the 
1106 * ROM mappers 
1107 * try to claim $7E0000, or at least $7E8000.)
1108 * SNES SPC700 RAM:
1109 * .addrspace="S", .len=0x10000
1110 * SNES WRAM mirrors:
1111 * .flags=MIRROR, .start=0x000000, .select=0xC0E000, .len=0x2000
1112 * .flags=MIRROR, .start=0x800000, .select=0xC0E000, .len=0x2000
1113 * SNES WRAM mirrors, alternate equivalent descriptor:
1114 * .flags=MIRROR, .select=0x40E000, .disconnect=~0x1FFF
1115 * (Various similar constructions can be created by combining parts of 
1116 * the above two.)
1117 * SNES LoROM (512KB, mirrored a couple of times):
1118 * .flags=CONST, .start=0x008000, .select=0x408000, .disconnect=0x8000, .len=512*1024
1119 * .flags=CONST, .start=0x400000, .select=0x400000, .disconnect=0x8000, .len=512*1024
1120 * SNES HiROM (4MB):
1121 * .flags=CONST,                 .start=0x400000, .select=0x400000, .len=4*1024*1024
1122 * .flags=CONST, .offset=0x8000, .start=0x008000, .select=0x408000, .len=4*1024*1024
1123 * SNES ExHiROM (8MB):
1124 * .flags=CONST, .offset=0,                  .start=0xC00000, .select=0xC00000, .len=4*1024*1024
1125 * .flags=CONST, .offset=4*1024*1024,        .start=0x400000, .select=0xC00000, .len=4*1024*1024
1126 * .flags=CONST, .offset=0x8000,             .start=0x808000, .select=0xC08000, .len=4*1024*1024
1127 * .flags=CONST, .offset=4*1024*1024+0x8000, .start=0x008000, .select=0xC08000, .len=4*1024*1024
1128 * Clarify the size of the address space:
1129 * .ptr=NULL, .select=0xFFFFFF
1130 * .len can be implied by .select in many of them, but was included for clarity.
1131 */
1132
1133struct retro_memory_map
1134{
1135   const struct retro_memory_descriptor *descriptors;
1136   unsigned num_descriptors;
1137};
1138
1139struct retro_controller_description
1140{
1141   /* Human-readable description of the controller. Even if using a generic 
1142    * input device type, this can be set to the particular device type the 
1143    * core uses. */
1144   const char *desc;
1145
1146   /* Device type passed to retro_set_controller_port_device(). If the device 
1147    * type is a sub-class of a generic input device type, use the 
1148    * RETRO_DEVICE_SUBCLASS macro to create an ID.
1149    *
1150    * E.g. RETRO_DEVICE_SUBCLASS(RETRO_DEVICE_JOYPAD, 1). */
1151   unsigned id;
1152};
1153
1154struct retro_controller_info
1155{
1156   const struct retro_controller_description *types;
1157   unsigned num_types;
1158};
1159
1160struct retro_subsystem_memory_info
1161{
1162   /* The extension associated with a memory type, e.g. "psram". */
1163   const char *extension;
1164
1165   /* The memory type for retro_get_memory(). This should be at 
1166    * least 0x100 to avoid conflict with standardized 
1167    * libretro memory types. */
1168   unsigned type;
1169};
1170
1171struct retro_subsystem_rom_info
1172{
1173   /* Describes what the content is (SGB BIOS, GB ROM, etc). */
1174   const char *desc;
1175
1176   /* Same definition as retro_get_system_info(). */
1177   const char *valid_extensions;
1178
1179   /* Same definition as retro_get_system_info(). */
1180   bool need_fullpath;
1181
1182   /* Same definition as retro_get_system_info(). */
1183   bool block_extract;
1184
1185   /* This is set if the content is required to load a game. 
1186    * If this is set to false, a zeroed-out retro_game_info can be passed. */
1187   bool required;
1188
1189   /* Content can have multiple associated persistent 
1190    * memory types (retro_get_memory()). */
1191   const struct retro_subsystem_memory_info *memory;
1192   unsigned num_memory;
1193};
1194
1195struct retro_subsystem_info
1196{
1197   /* Human-readable string of the subsystem type, e.g. "Super GameBoy" */
1198   const char *desc;
1199
1200   /* A computer friendly short string identifier for the subsystem type.
1201    * This name must be [a-z].
1202    * E.g. if desc is "Super GameBoy", this can be "sgb".
1203    * This identifier can be used for command-line interfaces, etc.
1204    */
1205   const char *ident;
1206
1207   /* Infos for each content file. The first entry is assumed to be the 
1208    * "most significant" content for frontend purposes.
1209    * E.g. with Super GameBoy, the first content should be the GameBoy ROM, 
1210    * as it is the most "significant" content to a user.
1211    * If a frontend creates new file paths based on the content used 
1212    * (e.g. savestates), it should use the path for the first ROM to do so. */
1213   const struct retro_subsystem_rom_info *roms;
1214
1215   /* Number of content files associated with a subsystem. */
1216   unsigned num_roms;
1217   
1218   /* The type passed to retro_load_game_special(). */
1219   unsigned id;
1220};
1221
1222typedef void (RETRO_CALLCONV *retro_proc_address_t)(void);
1223
1224/* libretro API extension functions:
1225 * (None here so far).
1226 *
1227 * Get a symbol from a libretro core.
1228 * Cores should only return symbols which are actual 
1229 * extensions to the libretro API.
1230 *
1231 * Frontends should not use this to obtain symbols to standard 
1232 * libretro entry points (static linking or dlsym).
1233 *
1234 * The symbol name must be equal to the function name, 
1235 * e.g. if void retro_foo(void); exists, the symbol must be called "retro_foo".
1236 * The returned function pointer must be cast to the corresponding type.
1237 */
1238typedef retro_proc_address_t (RETRO_CALLCONV *retro_get_proc_address_t)(const char *sym);
1239
1240struct retro_get_proc_address_interface
1241{
1242   retro_get_proc_address_t get_proc_address;
1243};
1244
1245enum retro_log_level
1246{
1247   RETRO_LOG_DEBUG = 0,
1248   RETRO_LOG_INFO,
1249   RETRO_LOG_WARN,
1250   RETRO_LOG_ERROR,
1251
1252   RETRO_LOG_DUMMY = INT_MAX
1253};
1254
1255/* Logging function. Takes log level argument as well. */
1256typedef void (RETRO_CALLCONV *retro_log_printf_t)(enum retro_log_level level,
1257      const char *fmt, ...);
1258
1259struct retro_log_callback
1260{
1261   retro_log_printf_t log;
1262};
1263
1264/* Performance related functions */
1265
1266/* ID values for SIMD CPU features */
1267#define RETRO_SIMD_SSE      (1 << 0)
1268#define RETRO_SIMD_SSE2     (1 << 1)
1269#define RETRO_SIMD_VMX      (1 << 2)
1270#define RETRO_SIMD_VMX128   (1 << 3)
1271#define RETRO_SIMD_AVX      (1 << 4)
1272#define RETRO_SIMD_NEON     (1 << 5)
1273#define RETRO_SIMD_SSE3     (1 << 6)
1274#define RETRO_SIMD_SSSE3    (1 << 7)
1275#define RETRO_SIMD_MMX      (1 << 8)
1276#define RETRO_SIMD_MMXEXT   (1 << 9)
1277#define RETRO_SIMD_SSE4     (1 << 10)
1278#define RETRO_SIMD_SSE42    (1 << 11)
1279#define RETRO_SIMD_AVX2     (1 << 12)
1280#define RETRO_SIMD_VFPU     (1 << 13)
1281#define RETRO_SIMD_PS       (1 << 14)
1282#define RETRO_SIMD_AES      (1 << 15)
1283#define RETRO_SIMD_VFPV3    (1 << 16)
1284#define RETRO_SIMD_VFPV4    (1 << 17)
1285#define RETRO_SIMD_POPCNT   (1 << 18)
1286#define RETRO_SIMD_MOVBE    (1 << 19)
1287
1288typedef uint64_t retro_perf_tick_t;
1289typedef int64_t retro_time_t;
1290
1291struct retro_perf_counter
1292{
1293   const char *ident;
1294   retro_perf_tick_t start;
1295   retro_perf_tick_t total;
1296   retro_perf_tick_t call_cnt;
1297
1298   bool registered;
1299};
1300
1301/* Returns current time in microseconds.
1302 * Tries to use the most accurate timer available.
1303 */
1304typedef retro_time_t (RETRO_CALLCONV *retro_perf_get_time_usec_t)(void);
1305
1306/* A simple counter. Usually nanoseconds, but can also be CPU cycles.
1307 * Can be used directly if desired (when creating a more sophisticated 
1308 * performance counter system).
1309 * */
1310typedef retro_perf_tick_t (RETRO_CALLCONV *retro_perf_get_counter_t)(void);
1311
1312/* Returns a bit-mask of detected CPU features (RETRO_SIMD_*). */
1313typedef uint64_t (RETRO_CALLCONV *retro_get_cpu_features_t)(void);
1314
1315/* Asks frontend to log and/or display the state of performance counters.
1316 * Performance counters can always be poked into manually as well.
1317 */
1318typedef void (RETRO_CALLCONV *retro_perf_log_t)(void);
1319
1320/* Register a performance counter.
1321 * ident field must be set with a discrete value and other values in 
1322 * retro_perf_counter must be 0.
1323 * Registering can be called multiple times. To avoid calling to 
1324 * frontend redundantly, you can check registered field first. */
1325typedef void (RETRO_CALLCONV *retro_perf_register_t)(struct retro_perf_counter *counter);
1326
1327/* Starts a registered counter. */
1328typedef void (RETRO_CALLCONV *retro_perf_start_t)(struct retro_perf_counter *counter);
1329
1330/* Stops a registered counter. */
1331typedef void (RETRO_CALLCONV *retro_perf_stop_t)(struct retro_perf_counter *counter);
1332
1333/* For convenience it can be useful to wrap register, start and stop in macros.
1334 * E.g.:
1335 * #ifdef LOG_PERFORMANCE
1336 * #define RETRO_PERFORMANCE_INIT(perf_cb, name) static struct retro_perf_counter name = {#name}; if (!name.registered) perf_cb.perf_register(&(name))
1337 * #define RETRO_PERFORMANCE_START(perf_cb, name) perf_cb.perf_start(&(name))
1338 * #define RETRO_PERFORMANCE_STOP(perf_cb, name) perf_cb.perf_stop(&(name))
1339 * #else
1340 * ... Blank macros ...
1341 * #endif
1342 *
1343 * These can then be used mid-functions around code snippets.
1344 *
1345 * extern struct retro_perf_callback perf_cb;  * Somewhere in the core.
1346 *
1347 * void do_some_heavy_work(void)
1348 * {
1349 *    RETRO_PERFORMANCE_INIT(cb, work_1;
1350 *    RETRO_PERFORMANCE_START(cb, work_1);
1351 *    heavy_work_1();
1352 *    RETRO_PERFORMANCE_STOP(cb, work_1);
1353 *
1354 *    RETRO_PERFORMANCE_INIT(cb, work_2);
1355 *    RETRO_PERFORMANCE_START(cb, work_2);
1356 *    heavy_work_2();
1357 *    RETRO_PERFORMANCE_STOP(cb, work_2);
1358 * }
1359 *
1360 * void retro_deinit(void)
1361 * {
1362 *    perf_cb.perf_log();  * Log all perf counters here for example.
1363 * }
1364 */
1365
1366struct retro_perf_callback
1367{
1368   retro_perf_get_time_usec_t    get_time_usec;
1369   retro_get_cpu_features_t      get_cpu_features;
1370
1371   retro_perf_get_counter_t      get_perf_counter;
1372   retro_perf_register_t         perf_register;
1373   retro_perf_start_t            perf_start;
1374   retro_perf_stop_t             perf_stop;
1375   retro_perf_log_t              perf_log;
1376};
1377
1378/* FIXME: Document the sensor API and work out behavior.
1379 * It will be marked as experimental until then.
1380 */
1381enum retro_sensor_action
1382{
1383   RETRO_SENSOR_ACCELEROMETER_ENABLE = 0,
1384   RETRO_SENSOR_ACCELEROMETER_DISABLE,
1385
1386   RETRO_SENSOR_DUMMY = INT_MAX
1387};
1388
1389/* Id values for SENSOR types. */
1390#define RETRO_SENSOR_ACCELEROMETER_X 0
1391#define RETRO_SENSOR_ACCELEROMETER_Y 1
1392#define RETRO_SENSOR_ACCELEROMETER_Z 2
1393
1394typedef bool (RETRO_CALLCONV *retro_set_sensor_state_t)(unsigned port, 
1395      enum retro_sensor_action action, unsigned rate);
1396
1397typedef float (RETRO_CALLCONV *retro_sensor_get_input_t)(unsigned port, unsigned id);
1398
1399struct retro_sensor_interface
1400{
1401   retro_set_sensor_state_t set_sensor_state;
1402   retro_sensor_get_input_t get_sensor_input;
1403};
1404
1405enum retro_camera_buffer
1406{
1407   RETRO_CAMERA_BUFFER_OPENGL_TEXTURE = 0,
1408   RETRO_CAMERA_BUFFER_RAW_FRAMEBUFFER,
1409
1410   RETRO_CAMERA_BUFFER_DUMMY = INT_MAX
1411};
1412
1413/* Starts the camera driver. Can only be called in retro_run(). */
1414typedef bool (RETRO_CALLCONV *retro_camera_start_t)(void);
1415
1416/* Stops the camera driver. Can only be called in retro_run(). */
1417typedef void (RETRO_CALLCONV *retro_camera_stop_t)(void);
1418
1419/* Callback which signals when the camera driver is initialized 
1420 * and/or deinitialized.
1421 * retro_camera_start_t can be called in initialized callback.
1422 */
1423typedef void (RETRO_CALLCONV *retro_camera_lifetime_status_t)(void);
1424
1425/* A callback for raw framebuffer data. buffer points to an XRGB8888 buffer.
1426 * Width, height and pitch are similar to retro_video_refresh_t.
1427 * First pixel is top-left origin.
1428 */
1429typedef void (RETRO_CALLCONV *retro_camera_frame_raw_framebuffer_t)(const uint32_t *buffer, 
1430      unsigned width, unsigned height, size_t pitch);
1431
1432/* A callback for when OpenGL textures are used.
1433 *
1434 * texture_id is a texture owned by camera driver.
1435 * Its state or content should be considered immutable, except for things like 
1436 * texture filtering and clamping.
1437 *
1438 * texture_target is the texture target for the GL texture.
1439 * These can include e.g. GL_TEXTURE_2D, GL_TEXTURE_RECTANGLE, and possibly 
1440 * more depending on extensions.
1441 *
1442 * affine points to a packed 3x3 column-major matrix used to apply an affine 
1443 * transform to texture coordinates. (affine_matrix * vec3(coord_x, coord_y, 1.0))
1444 * After transform, normalized texture coord (0, 0) should be bottom-left 
1445 * and (1, 1) should be top-right (or (width, height) for RECTANGLE).
1446 *
1447 * GL-specific typedefs are avoided here to avoid relying on gl.h in 
1448 * the API definition.
1449 */
1450typedef void (RETRO_CALLCONV *retro_camera_frame_opengl_texture_t)(unsigned texture_id, 
1451      unsigned texture_target, const float *affine);
1452
1453struct retro_camera_callback
1454{
1455   /* Set by libretro core. 
1456    * Example bitmask: caps = (1 << RETRO_CAMERA_BUFFER_OPENGL_TEXTURE) | (1 << RETRO_CAMERA_BUFFER_RAW_FRAMEBUFFER).
1457    */
1458   uint64_t caps; 
1459
1460   /* Desired resolution for camera. Is only used as a hint. */
1461   unsigned width;
1462   unsigned height;
1463
1464   /* Set by frontend. */
1465   retro_camera_start_t start;
1466   retro_camera_stop_t stop;
1467
1468   /* Set by libretro core if raw framebuffer callbacks will be used. */
1469   retro_camera_frame_raw_framebuffer_t frame_raw_framebuffer;
1470
1471   /* Set by libretro core if OpenGL texture callbacks will be used. */
1472   retro_camera_frame_opengl_texture_t frame_opengl_texture; 
1473
1474   /* Set by libretro core. Called after camera driver is initialized and 
1475    * ready to be started.
1476    * Can be NULL, in which this callback is not called.
1477    */
1478   retro_camera_lifetime_status_t initialized;
1479
1480   /* Set by libretro core. Called right before camera driver is 
1481    * deinitialized.
1482    * Can be NULL, in which this callback is not called.
1483    */
1484   retro_camera_lifetime_status_t deinitialized;
1485};
1486
1487/* Sets the interval of time and/or distance at which to update/poll 
1488 * location-based data.
1489 *
1490 * To ensure compatibility with all location-based implementations,
1491 * values for both interval_ms and interval_distance should be provided.
1492 *
1493 * interval_ms is the interval expressed in milliseconds.
1494 * interval_distance is the distance interval expressed in meters.
1495 */
1496typedef void (RETRO_CALLCONV *retro_location_set_interval_t)(unsigned interval_ms,
1497      unsigned interval_distance);
1498
1499/* Start location services. The device will start listening for changes to the
1500 * current location at regular intervals (which are defined with 
1501 * retro_location_set_interval_t). */
1502typedef bool (RETRO_CALLCONV *retro_location_start_t)(void);
1503
1504/* Stop location services. The device will stop listening for changes 
1505 * to the current location. */
1506typedef void (RETRO_CALLCONV *retro_location_stop_t)(void);
1507
1508/* Get the position of the current location. Will set parameters to 
1509 * 0 if no new  location update has happened since the last time. */
1510typedef bool (RETRO_CALLCONV *retro_location_get_position_t)(double *lat, double *lon,
1511      double *horiz_accuracy, double *vert_accuracy);
1512
1513/* Callback which signals when the location driver is initialized 
1514 * and/or deinitialized.
1515 * retro_location_start_t can be called in initialized callback.
1516 */
1517typedef void (RETRO_CALLCONV *retro_location_lifetime_status_t)(void);
1518
1519struct retro_location_callback
1520{
1521   retro_location_start_t         start;
1522   retro_location_stop_t          stop;
1523   retro_location_get_position_t  get_position;
1524   retro_location_set_interval_t  set_interval;
1525
1526   retro_location_lifetime_status_t initialized;
1527   retro_location_lifetime_status_t deinitialized;
1528};
1529
1530enum retro_rumble_effect
1531{
1532   RETRO_RUMBLE_STRONG = 0,
1533   RETRO_RUMBLE_WEAK = 1,
1534
1535   RETRO_RUMBLE_DUMMY = INT_MAX
1536};
1537
1538/* Sets rumble state for joypad plugged in port 'port'. 
1539 * Rumble effects are controlled independently,
1540 * and setting e.g. strong rumble does not override weak rumble.
1541 * Strength has a range of [0, 0xffff].
1542 *
1543 * Returns true if rumble state request was honored. 
1544 * Calling this before first retro_run() is likely to return false. */
1545typedef bool (RETRO_CALLCONV *retro_set_rumble_state_t)(unsigned port, 
1546      enum retro_rumble_effect effect, uint16_t strength);
1547
1548struct retro_rumble_interface
1549{
1550   retro_set_rumble_state_t set_rumble_state;
1551};
1552
1553/* Notifies libretro that audio data should be written. */
1554typedef void (RETRO_CALLCONV *retro_audio_callback_t)(void);
1555
1556/* True: Audio driver in frontend is active, and callback is 
1557 * expected to be called regularily.
1558 * False: Audio driver in frontend is paused or inactive. 
1559 * Audio callback will not be called until set_state has been 
1560 * called with true.
1561 * Initial state is false (inactive).
1562 */
1563typedef void (RETRO_CALLCONV *retro_audio_set_state_callback_t)(bool enabled);
1564
1565struct retro_audio_callback
1566{
1567   retro_audio_callback_t callback;
1568   retro_audio_set_state_callback_t set_state;
1569};
1570
1571/* Notifies a libretro core of time spent since last invocation 
1572 * of retro_run() in microseconds.
1573 *
1574 * It will be called right before retro_run() every frame.
1575 * The frontend can tamper with timing to support cases like 
1576 * fast-forward, slow-motion and framestepping.
1577 *
1578 * In those scenarios the reference frame time value will be used. */
1579typedef int64_t retro_usec_t;
1580typedef void (RETRO_CALLCONV *retro_frame_time_callback_t)(retro_usec_t usec);
1581struct retro_frame_time_callback
1582{
1583   retro_frame_time_callback_t callback;
1584   /* Represents the time of one frame. It is computed as 
1585    * 1000000 / fps, but the implementation will resolve the 
1586    * rounding to ensure that framestepping, etc is exact. */
1587   retro_usec_t reference;
1588};
1589
1590/* Pass this to retro_video_refresh_t if rendering to hardware.
1591 * Passing NULL to retro_video_refresh_t is still a frame dupe as normal.
1592 * */
1593#define RETRO_HW_FRAME_BUFFER_VALID ((void*)-1)
1594
1595/* Invalidates the current HW context.
1596 * Any GL state is lost, and must not be deinitialized explicitly.
1597 * If explicit deinitialization is desired by the libretro core,
1598 * it should implement context_destroy callback.
1599 * If called, all GPU resources must be reinitialized.
1600 * Usually called when frontend reinits video driver.
1601 * Also called first time video driver is initialized, 
1602 * allowing libretro core to initialize resources.
1603 */
1604typedef void (RETRO_CALLCONV *retro_hw_context_reset_t)(void);
1605
1606/* Gets current framebuffer which is to be rendered to.
1607 * Could change every frame potentially.
1608 */
1609typedef uintptr_t (RETRO_CALLCONV *retro_hw_get_current_framebuffer_t)(void);
1610
1611/* Get a symbol from HW context. */
1612typedef retro_proc_address_t (RETRO_CALLCONV *retro_hw_get_proc_address_t)(const char *sym);
1613
1614enum retro_hw_context_type
1615{
1616   RETRO_HW_CONTEXT_NONE             = 0,
1617   /* OpenGL 2.x. Driver can choose to use latest compatibility context. */
1618   RETRO_HW_CONTEXT_OPENGL           = 1, 
1619   /* OpenGL ES 2.0. */
1620   RETRO_HW_CONTEXT_OPENGLES2        = 2,
1621   /* Modern desktop core GL context. Use version_major/
1622    * version_minor fields to set GL version. */
1623   RETRO_HW_CONTEXT_OPENGL_CORE      = 3,
1624   /* OpenGL ES 3.0 */
1625   RETRO_HW_CONTEXT_OPENGLES3        = 4,
1626   /* OpenGL ES 3.1+. Set version_major/version_minor. For GLES2 and GLES3,
1627    * use the corresponding enums directly. */
1628   RETRO_HW_CONTEXT_OPENGLES_VERSION = 5,
1629
1630   /* Vulkan, see RETRO_ENVIRONMENT_GET_HW_RENDER_INTERFACE. */
1631   RETRO_HW_CONTEXT_VULKAN           = 6,
1632
1633   RETRO_HW_CONTEXT_DUMMY = INT_MAX
1634};
1635
1636struct retro_hw_render_callback
1637{
1638   /* Which API to use. Set by libretro core. */
1639   enum retro_hw_context_type context_type;
1640
1641   /* Called when a context has been created or when it has been reset.
1642    * An OpenGL context is only valid after context_reset() has been called.
1643    *
1644    * When context_reset is called, OpenGL resources in the libretro 
1645    * implementation are guaranteed to be invalid.
1646    *
1647    * It is possible that context_reset is called multiple times during an 
1648    * application lifecycle.
1649    * If context_reset is called without any notification (context_destroy),
1650    * the OpenGL context was lost and resources should just be recreated
1651    * without any attempt to "free" old resources.
1652    */
1653   retro_hw_context_reset_t context_reset;
1654
1655   /* Set by frontend.
1656    * TODO: This is rather obsolete. The frontend should not
1657    * be providing preallocated framebuffers. */
1658   retro_hw_get_current_framebuffer_t get_current_framebuffer;
1659
1660   /* Set by frontend. */
1661   retro_hw_get_proc_address_t get_proc_address;
1662
1663   /* Set if render buffers should have depth component attached.
1664    * TODO: Obsolete. */
1665   bool depth;
1666
1667   /* Set if stencil buffers should be attached.
1668    * TODO: Obsolete. */
1669   bool stencil;
1670
1671   /* If depth and stencil are true, a packed 24/8 buffer will be added. 
1672    * Only attaching stencil is invalid and will be ignored. */
1673
1674   /* Use conventional bottom-left origin convention. If false, 
1675    * standard libretro top-left origin semantics are used.
1676    * TODO: Move to GL specific interface. */
1677   bool bottom_left_origin;
1678   
1679   /* Major version number for core GL context or GLES 3.1+. */
1680   unsigned version_major;
1681
1682   /* Minor version number for core GL context or GLES 3.1+. */
1683   unsigned version_minor;
1684
1685   /* If this is true, the frontend will go very far to avoid 
1686    * resetting context in scenarios like toggling fullscreen, etc.
1687    * TODO: Obsolete? Maybe frontend should just always assume this ...
1688    */
1689   bool cache_context;
1690
1691   /* The reset callback might still be called in extreme situations 
1692    * such as if the context is lost beyond recovery.
1693    *
1694    * For optimal stability, set this to false, and allow context to be 
1695    * reset at any time.
1696    */
1697   
1698   /* A callback to be called before the context is destroyed in a 
1699    * controlled way by the frontend. */
1700   retro_hw_context_reset_t context_destroy;
1701
1702   /* OpenGL resources can be deinitialized cleanly at this step.
1703    * context_destroy can be set to NULL, in which resources will 
1704    * just be destroyed without any notification.
1705    *
1706    * Even when context_destroy is non-NULL, it is possible that 
1707    * context_reset is called without any destroy notification.
1708    * This happens if context is lost by external factors (such as 
1709    * notified by GL_ARB_robustness).
1710    *
1711    * In this case, the context is assumed to be already dead,
1712    * and the libretro implementation must not try to free any OpenGL 
1713    * resources in the subsequent context_reset.
1714    */
1715
1716   /* Creates a debug context. */
1717   bool debug_context;
1718};
1719
1720/* Callback type passed in RETRO_ENVIRONMENT_SET_KEYBOARD_CALLBACK. 
1721 * Called by the frontend in response to keyboard events.
1722 * down is set if the key is being pressed, or false if it is being released.
1723 * keycode is the RETROK value of the char.
1724 * character is the text character of the pressed key. (UTF-32).
1725 * key_modifiers is a set of RETROKMOD values or'ed together.
1726 *
1727 * The pressed/keycode state can be indepedent of the character.
1728 * It is also possible that multiple characters are generated from a 
1729 * single keypress.
1730 * Keycode events should be treated separately from character events.
1731 * However, when possible, the frontend should try to synchronize these.
1732 * If only a character is posted, keycode should be RETROK_UNKNOWN.
1733 *
1734 * Similarily if only a keycode event is generated with no corresponding 
1735 * character, character should be 0.
1736 */
1737typedef void (RETRO_CALLCONV *retro_keyboard_event_t)(bool down, unsigned keycode, 
1738      uint32_t character, uint16_t key_modifiers);
1739
1740struct retro_keyboard_callback
1741{
1742   retro_keyboard_event_t callback;
1743};
1744
1745/* Callbacks for RETRO_ENVIRONMENT_SET_DISK_CONTROL_INTERFACE.
1746 * Should be set for implementations which can swap out multiple disk 
1747 * images in runtime.
1748 *
1749 * If the implementation can do this automatically, it should strive to do so.
1750 * However, there are cases where the user must manually do so.
1751 *
1752 * Overview: To swap a disk image, eject the disk image with 
1753 * set_eject_state(true).
1754 * Set the disk index with set_image_index(index). Insert the disk again 
1755 * with set_eject_state(false).
1756 */
1757
1758/* If ejected is true, "ejects" the virtual disk tray.
1759 * When ejected, the disk image index can be set.
1760 */
1761typedef bool (RETRO_CALLCONV *retro_set_eject_state_t)(bool ejected);
1762
1763/* Gets current eject state. The initial state is 'not ejected'. */
1764typedef bool (RETRO_CALLCONV *retro_get_eject_state_t)(void);
1765
1766/* Gets current disk index. First disk is index 0.
1767 * If return value is >= get_num_images(), no disk is currently inserted.
1768 */
1769typedef unsigned (RETRO_CALLCONV *retro_get_image_index_t)(void);
1770
1771/* Sets image index. Can only be called when disk is ejected.
1772 * The implementation supports setting "no disk" by using an 
1773 * index >= get_num_images().
1774 */
1775typedef bool (RETRO_CALLCONV *retro_set_image_index_t)(unsigned index);
1776
1777/* Gets total number of images which are available to use. */
1778typedef unsigned (RETRO_CALLCONV *retro_get_num_images_t)(void);
1779
1780struct retro_game_info;
1781
1782/* Replaces the disk image associated with index.
1783 * Arguments to pass in info have same requirements as retro_load_game().
1784 * Virtual disk tray must be ejected when calling this.
1785 *
1786 * Replacing a disk image with info = NULL will remove the disk image 
1787 * from the internal list.
1788 * As a result, calls to get_image_index() can change.
1789 *
1790 * E.g. replace_image_index(1, NULL), and previous get_image_index() 
1791 * returned 4 before.
1792 * Index 1 will be removed, and the new index is 3.
1793 */
1794typedef bool (RETRO_CALLCONV *retro_replace_image_index_t)(unsigned index,
1795      const struct retro_game_info *info);
1796
1797/* Adds a new valid index (get_num_images()) to the internal disk list.
1798 * This will increment subsequent return values from get_num_images() by 1.
1799 * This image index cannot be used until a disk image has been set 
1800 * with replace_image_index. */
1801typedef bool (RETRO_CALLCONV *retro_add_image_index_t)(void);
1802
1803struct retro_disk_control_callback
1804{
1805   retro_set_eject_state_t set_eject_state;
1806   retro_get_eject_state_t get_eject_state;
1807
1808   retro_get_image_index_t get_image_index;
1809   retro_set_image_index_t set_image_index;
1810   retro_get_num_images_t  get_num_images;
1811
1812   retro_replace_image_index_t replace_image_index;
1813   retro_add_image_index_t add_image_index;
1814};
1815
1816enum retro_pixel_format
1817{
1818   /* 0RGB1555, native endian.
1819    * 0 bit must be set to 0.
1820    * This pixel format is default for compatibility concerns only.
1821    * If a 15/16-bit pixel format is desired, consider using RGB565. */
1822   RETRO_PIXEL_FORMAT_0RGB1555 = 0,
1823
1824   /* XRGB8888, native endian.
1825    * X bits are ignored. */
1826   RETRO_PIXEL_FORMAT_XRGB8888 = 1,
1827
1828   /* RGB565, native endian.
1829    * This pixel format is the recommended format to use if a 15/16-bit
1830    * format is desired as it is the pixel format that is typically 
1831    * available on a wide range of low-power devices.
1832    *
1833    * It is also natively supported in APIs like OpenGL ES. */
1834   RETRO_PIXEL_FORMAT_RGB565   = 2,
1835
1836   /* Ensure sizeof() == sizeof(int). */
1837   RETRO_PIXEL_FORMAT_UNKNOWN  = INT_MAX
1838};
1839
1840struct retro_message
1841{
1842   const char *msg;        /* Message to be displayed. */
1843   unsigned    frames;     /* Duration in frames of message. */
1844};
1845
1846/* Describes how the libretro implementation maps a libretro input bind
1847 * to its internal input system through a human readable string.
1848 * This string can be used to better let a user configure input. */
1849struct retro_input_descriptor
1850{
1851   /* Associates given parameters with a description. */
1852   unsigned port;
1853   unsigned device;
1854   unsigned index;
1855   unsigned id;
1856
1857   /* Human readable description for parameters.
1858    * The pointer must remain valid until
1859    * retro_unload_game() is called. */
1860   const char *description; 
1861};
1862
1863struct retro_system_info
1864{
1865   /* All pointers are owned by libretro implementation, and pointers must 
1866    * remain valid until retro_deinit() is called. */
1867
1868   const char *library_name;      /* Descriptive name of library. Should not 
1869                                   * contain any version numbers, etc. */
1870   const char *library_version;   /* Descriptive version of core. */
1871
1872   const char *valid_extensions;  /* A string listing probably content 
1873                                   * extensions the core will be able to 
1874                                   * load, separated with pipe.
1875                                   * I.e. "bin|rom|iso".
1876                                   * Typically used for a GUI to filter 
1877                                   * out extensions. */
1878
1879   /* If true, retro_load_game() is guaranteed to provide a valid pathname 
1880    * in retro_game_info::path.
1881    * ::data and ::size are both invalid.
1882    *
1883    * If false, ::data and ::size are guaranteed to be valid, but ::path 
1884    * might not be valid.
1885    *
1886    * This is typically set to true for libretro implementations that must 
1887    * load from file.
1888    * Implementations should strive for setting this to false, as it allows 
1889    * the frontend to perform patching, etc. */
1890   bool        need_fullpath;                                       
1891
1892   /* If true, the frontend is not allowed to extract any archives before 
1893    * loading the real content.
1894    * Necessary for certain libretro implementations that load games 
1895    * from zipped archives. */
1896   bool        block_extract;     
1897};
1898
1899struct retro_game_geometry
1900{
1901   unsigned base_width;    /* Nominal video width of game. */
1902   unsigned base_height;   /* Nominal video height of game. */
1903   unsigned max_width;     /* Maximum possible width of game. */
1904   unsigned max_height;    /* Maximum possible height of game. */
1905
1906   float    aspect_ratio;  /* Nominal aspect ratio of game. If
1907                            * aspect_ratio is <= 0.0, an aspect ratio
1908                            * of base_width / base_height is assumed.
1909                            * A frontend could override this setting,
1910                            * if desired. */
1911};
1912
1913struct retro_system_timing
1914{
1915   double fps;             /* FPS of video content. */
1916   double sample_rate;     /* Sampling rate of audio. */
1917};
1918
1919struct retro_system_av_info
1920{
1921   struct retro_game_geometry geometry;
1922   struct retro_system_timing timing;
1923};
1924
1925struct retro_variable
1926{
1927   /* Variable to query in RETRO_ENVIRONMENT_GET_VARIABLE.
1928    * If NULL, obtains the complete environment string if more 
1929    * complex parsing is necessary.
1930    * The environment string is formatted as key-value pairs 
1931    * delimited by semicolons as so:
1932    * "key1=value1;key2=value2;..."
1933    */
1934   const char *key;
1935   
1936   /* Value to be obtained. If key does not exist, it is set to NULL. */
1937   const char *value;
1938};
1939
1940struct retro_game_info
1941{
1942   const char *path;       /* Path to game, UTF-8 encoded.
1943                            * Usually used as a reference.
1944                            * May be NULL if rom was loaded from stdin
1945                            * or similar. 
1946                            * retro_system_info::need_fullpath guaranteed 
1947                            * that this path is valid. */
1948   const void *data;       /* Memory buffer of loaded game. Will be NULL 
1949                            * if need_fullpath was set. */
1950   size_t      size;       /* Size of memory buffer. */
1951   const char *meta;       /* String of implementation specific meta-data. */
1952};
1953
1954#define RETRO_MEMORY_ACCESS_WRITE (1 << 0)
1955   /* The core will write to the buffer provided by retro_framebuffer::data. */
1956#define RETRO_MEMORY_ACCESS_READ (1 << 1)
1957   /* The core will read from retro_framebuffer::data. */
1958#define RETRO_MEMORY_TYPE_CACHED (1 << 0)
1959   /* The memory in data is cached.
1960    * If not cached, random writes and/or reading from the buffer is expected to be very slow. */
1961struct retro_framebuffer
1962{
1963   void *data;                      /* The framebuffer which the core can render into.
1964                                       Set by frontend in GET_CURRENT_SOFTWARE_FRAMEBUFFER.
1965                                       The initial contents of data are unspecified. */
1966   unsigned width;                  /* The framebuffer width used by the core. Set by core. */
1967   unsigned height;                 /* The framebuffer height used by the core. Set by core. */
1968   size_t pitch;                    /* The number of bytes between the beginning of a scanline,
1969                                       and beginning of the next scanline.
1970                                       Set by frontend in GET_CURRENT_SOFTWARE_FRAMEBUFFER. */
1971   enum retro_pixel_format format;  /* The pixel format the core must use to render into data.
1972                                       This format could differ from the format used in
1973                                       SET_PIXEL_FORMAT.
1974                                       Set by frontend in GET_CURRENT_SOFTWARE_FRAMEBUFFER. */
1975
1976   unsigned access_flags;           /* How the core will access the memory in the framebuffer.
1977                                       RETRO_MEMORY_ACCESS_* flags.
1978                                       Set by core. */
1979   unsigned memory_flags;           /* Flags telling core how the memory has been mapped.
1980                                       RETRO_MEMORY_TYPE_* flags.
1981                                       Set by frontend in GET_CURRENT_SOFTWARE_FRAMEBUFFER. */
1982};
1983
1984/* Callbacks */
1985
1986/* Environment callback. Gives implementations a way of performing 
1987 * uncommon tasks. Extensible. */
1988typedef bool (RETRO_CALLCONV *retro_environment_t)(unsigned cmd, void *data);
1989
1990/* Render a frame. Pixel format is 15-bit 0RGB1555 native endian 
1991 * unless changed (see RETRO_ENVIRONMENT_SET_PIXEL_FORMAT).
1992 *
1993 * Width and height specify dimensions of buffer.
1994 * Pitch specifices length in bytes between two lines in buffer.
1995 *
1996 * For performance reasons, it is highly recommended to have a frame 
1997 * that is packed in memory, i.e. pitch == width * byte_per_pixel.
1998 * Certain graphic APIs, such as OpenGL ES, do not like textures 
1999 * that are not packed in memory.
2000 */
2001typedef void (RETRO_CALLCONV *retro_video_refresh_t)(const void *data, unsigned width,
2002      unsigned height, size_t pitch);
2003
2004/* Renders a single audio frame. Should only be used if implementation 
2005 * generates a single sample at a time.
2006 * Format is signed 16-bit native endian.
2007 */
2008typedef void (RETRO_CALLCONV *retro_audio_sample_t)(int16_t left, int16_t right);
2009
2010/* Renders multiple audio frames in one go.
2011 *
2012 * One frame is defined as a sample of left and right channels, interleaved.
2013 * I.e. int16_t buf[4] = { l, r, l, r }; would be 2 frames.
2014 * Only one of the audio callbacks must ever be used.
2015 */
2016typedef size_t (RETRO_CALLCONV *retro_audio_sample_batch_t)(const int16_t *data,
2017      size_t frames);
2018
2019/* Polls input. */
2020typedef void (RETRO_CALLCONV *retro_input_poll_t)(void);
2021
2022/* Queries for input for player 'port'. device will be masked with 
2023 * RETRO_DEVICE_MASK.
2024 *
2025 * Specialization of devices such as RETRO_DEVICE_JOYPAD_MULTITAP that 
2026 * have been set with retro_set_controller_port_device()
2027 * will still use the higher level RETRO_DEVICE_JOYPAD to request input.
2028 */
2029typedef int16_t (RETRO_CALLCONV *retro_input_state_t)(unsigned port, unsigned device, 
2030      unsigned index, unsigned id);
2031
2032/* Sets callbacks. retro_set_environment() is guaranteed to be called 
2033 * before retro_init().
2034 *
2035 * The rest of the set_* functions are guaranteed to have been called 
2036 * before the first call to retro_run() is made. */
2037RETRO_API void retro_set_environment(retro_environment_t);
2038RETRO_API void retro_set_video_refresh(retro_video_refresh_t);
2039RETRO_API void retro_set_audio_sample(retro_audio_sample_t);
2040RETRO_API void retro_set_audio_sample_batch(retro_audio_sample_batch_t);
2041RETRO_API void retro_set_input_poll(retro_input_poll_t);
2042RETRO_API void retro_set_input_state(retro_input_state_t);
2043
2044/* Library global initialization/deinitialization. */
2045RETRO_API void retro_init(void);
2046RETRO_API void retro_deinit(void);
2047
2048/* Must return RETRO_API_VERSION. Used to validate ABI compatibility
2049 * when the API is revised. */
2050RETRO_API unsigned retro_api_version(void);
2051
2052/* Gets statically known system info. Pointers provided in *info 
2053 * must be statically allocated.
2054 * Can be called at any time, even before retro_init(). */
2055RETRO_API void retro_get_system_info(struct retro_system_info *info);
2056
2057/* Gets information about system audio/video timings and geometry.
2058 * Can be called only after retro_load_game() has successfully completed.
2059 * NOTE: The implementation of this function might not initialize every 
2060 * variable if needed.
2061 * E.g. geom.aspect_ratio might not be initialized if core doesn't 
2062 * desire a particular aspect ratio. */
2063RETRO_API void retro_get_system_av_info(struct retro_system_av_info *info);
2064
2065/* Sets device to be used for player 'port'.
2066 * By default, RETRO_DEVICE_JOYPAD is assumed to be plugged into all 
2067 * available ports.
2068 * Setting a particular device type is not a guarantee that libretro cores 
2069 * will only poll input based on that particular device type. It is only a 
2070 * hint to the libretro core when a core cannot automatically detect the 
2071 * appropriate input device type on its own. It is also relevant when a 
2072 * core can change its behavior depending on device type. */
2073RETRO_API void retro_set_controller_port_device(unsigned port, unsigned device);
2074
2075/* Resets the current game. */
2076RETRO_API void retro_reset(void);
2077
2078/* Runs the game for one video frame.
2079 * During retro_run(), input_poll callback must be called at least once.
2080 * 
2081 * If a frame is not rendered for reasons where a game "dropped" a frame,
2082 * this still counts as a frame, and retro_run() should explicitly dupe 
2083 * a frame if GET_CAN_DUPE returns true.
2084 * In this case, the video callback can take a NULL argument for data.
2085 */
2086RETRO_API void retro_run(void);
2087
2088/* Returns the amount of data the implementation requires to serialize 
2089 * internal state (save states).
2090 * Between calls to retro_load_game() and retro_unload_game(), the 
2091 * returned size is never allowed to be larger than a previous returned 
2092 * value, to ensure that the frontend can allocate a save state buffer once.
2093 */
2094RETRO_API size_t retro_serialize_size(void);
2095
2096/* Serializes internal state. If failed, or size is lower than
2097 * retro_serialize_size(), it should return false, true otherwise. */
2098RETRO_API bool retro_serialize(void *data, size_t size);
2099RETRO_API bool retro_unserialize(const void *data, size_t size);
2100
2101RETRO_API void retro_cheat_reset(void);
2102RETRO_API void retro_cheat_set(unsigned index, bool enabled, const char *code);
2103
2104/* Loads a game. */
2105RETRO_API bool retro_load_game(const struct retro_game_info *game);
2106
2107/* Loads a "special" kind of game. Should not be used,
2108 * except in extreme cases. */
2109RETRO_API bool retro_load_game_special(
2110  unsigned game_type,
2111  const struct retro_game_info *info, size_t num_info
2112);
2113
2114/* Unloads a currently loaded game. */
2115RETRO_API void retro_unload_game(void);
2116
2117/* Gets region of game. */
2118RETRO_API unsigned retro_get_region(void);
2119
2120/* Gets region of memory. */
2121RETRO_API void *retro_get_memory_data(unsigned id);
2122RETRO_API size_t retro_get_memory_size(unsigned id);
2123
2124#ifdef __cplusplus
2125}
2126#endif
2127
2128#endif