snes9x/libretro/libretro.cpp

#include "libretro.h"

#include "snes9x.h"
#include "memmap.h"
#include "srtc.h"
#include "apu/apu.h"
#include "apu/bapu/snes/snes.hpp"
#include "gfx.h"
#include "snapshot.h"
#include "controls.h"
#include "cheats.h"
#include "movie.h"
#include "logger.h"
#include "display.h"
#include "conffile.h"
#include <stdio.h>
#ifdef _WIN32
#include <direct.h>
#else
#include <unistd.h>
#endif
#include <sys/stat.h>
#include <sys/types.h>
#include <fcntl.h>

#define RETRO_DEVICE_JOYPAD_MULTITAP ((1 << 8) | RETRO_DEVICE_JOYPAD)
#define RETRO_DEVICE_LIGHTGUN_SUPER_SCOPE ((1 << 8) | RETRO_DEVICE_LIGHTGUN)
#define RETRO_DEVICE_LIGHTGUN_JUSTIFIER ((2 << 8) | RETRO_DEVICE_LIGHTGUN)
#define RETRO_DEVICE_LIGHTGUN_JUSTIFIERS ((3 << 8) | RETRO_DEVICE_LIGHTGUN)

#define RETRO_MEMORY_SNES_BSX_RAM ((1 << 8) | RETRO_MEMORY_SAVE_RAM)
#define RETRO_MEMORY_SNES_BSX_PRAM ((2 << 8) | RETRO_MEMORY_SAVE_RAM)
#define RETRO_MEMORY_SNES_SUFAMI_TURBO_A_RAM ((3 << 8) | RETRO_MEMORY_SAVE_RAM)
#define RETRO_MEMORY_SNES_SUFAMI_TURBO_B_RAM ((4 << 8) | RETRO_MEMORY_SAVE_RAM)
#define RETRO_MEMORY_SNES_GAME_BOY_RAM ((5 << 8) | RETRO_MEMORY_SAVE_RAM)
#define RETRO_MEMORY_SNES_GAME_BOY_RTC ((6 << 8) | RETRO_MEMORY_RTC)

#define RETRO_GAME_TYPE_BSX					0x101 | 0x1000
#define RETRO_GAME_TYPE_BSX_SLOTTED		0x102 | 0x1000
#define RETRO_GAME_TYPE_SUFAMI_TURBO		0x103 | 0x1000
#define RETRO_GAME_TYPE_SUPER_GAME_BOY  0x104 | 0x1000
#define RETRO_GAME_TYPE_MULTI_CART		0x105 | 0x1000


#define SNES_4_3 4.0f / 3.0f
#define SNES_8_7 8.0f / 7.0f

char g_rom_dir[1024];
char g_basename[1024];

bool hires_blend = false;
static uint16 *gfx_blend;

char retro_system_directory[4096];
char retro_save_directory[4096];

retro_log_printf_t log_cb = NULL;
static retro_video_refresh_t video_cb = NULL;
static retro_audio_sample_t audio_cb = NULL;
static retro_audio_sample_batch_t audio_batch_cb = NULL;
static retro_input_poll_t poll_cb = NULL;
static retro_input_state_t input_state_cb = NULL;

static void extract_basename(char *buf, const char *path, size_t size)
{
    const char *base = strrchr(path, '/');
    if (!base)
        base = strrchr(path, '\\');
    if (!base)
        base = path;

    if (*base == '\\' || *base == '/')
        base++;

    strncpy(buf, base, size - 1);
    buf[size - 1] = '\0';

    char *ext = strrchr(buf, '.');
    if (ext)
        *ext = '\0';
}

static void extract_directory(char *buf, const char *path, size_t size)
{
    strncpy(buf, path, size - 1);
    buf[size - 1] = '\0';

    char *base = strrchr(buf, '/');
    if (!base)
        base = strrchr(buf, '\\');

    if (base)
        *base = '\0';
    else
        buf[0] = '\0';
}

void retro_set_video_refresh(retro_video_refresh_t cb)
{
    video_cb = cb;
}

void retro_set_audio_sample(retro_audio_sample_t cb)
{
    audio_cb = cb;
}

void retro_set_audio_sample_batch(retro_audio_sample_batch_t cb)
{
    audio_batch_cb = cb;
}

void retro_set_input_poll(retro_input_poll_t cb)
{
    poll_cb = cb;
}

void retro_set_input_state(retro_input_state_t cb)
{
    input_state_cb = cb;
}

enum overscan_mode {
    OVERSCAN_CROP_ON,
    OVERSCAN_CROP_OFF,
    OVERSCAN_CROP_AUTO
};
enum aspect_mode {
    ASPECT_RATIO_4_3,
    ASPECT_RATIO_8_7,
    ASPECT_RATIO_NTSC,
    ASPECT_RATIO_PAL,
    ASPECT_RATIO_AUTO
};
static retro_environment_t environ_cb;
static overscan_mode crop_overscan_mode = OVERSCAN_CROP_ON; // default to crop
static aspect_mode aspect_ratio_mode = ASPECT_RATIO_4_3; // default to 4:3
static bool rom_loaded = false;

void retro_set_environment(retro_environment_t cb)
{
    environ_cb = cb;

    static const struct retro_subsystem_memory_info multi_a_memory[] = {
        { "srm", RETRO_MEMORY_SNES_SUFAMI_TURBO_A_RAM },
    };

    static const struct retro_subsystem_memory_info multi_b_memory[] = {
        { "srm", RETRO_MEMORY_SNES_SUFAMI_TURBO_B_RAM },
    };

    static const struct retro_subsystem_rom_info multicart_roms[] = {
        { "Cart A", "smc|sfc|swc|fig|bs", false, false, false, multi_a_memory, 1 },
        { "Add-On B", "smc|sfc|swc|fig|bs", false, false, false, multi_b_memory, 1 },
    };

    static const struct retro_subsystem_info subsystems[] = {
        { "Multi-Cart Link", "multicart_addon", multicart_roms, 2, RETRO_GAME_TYPE_MULTI_CART },
        {}
    };

    cb(RETRO_ENVIRONMENT_SET_SUBSYSTEM_INFO,  (void*)subsystems);


    struct retro_variable variables[] = {
        // These variable names and possible values constitute an ABI with ZMZ (ZSNES Libretro player).
        // Changing "Show layer 1" is fine, but don't change "layer_1"/etc or the possible values ("Yes|No").
        // Adding more variables and rearranging them is safe.
        { "snes9x_up_down_allowed", "Allow Opposing Directions; disabled|enabled" },
        { "snes9x_hires_blend", "Hires Blending; disabled|enabled" },
        { "snes9x_overclock", "SuperFX Frequency; 100%|200%|400%|600%|800%|1000%" },
        //{ "snes9x_overclock_cycles", "Reduce Slowdown (Hack, Unsafe); disabled|compatible|max" },
        //{ "snes9x_reduce_sprite_flicker", "Reduce Flickering (Hack, Unsafe); disabled|enabled" },
        { "snes9x_layer_1", "Show layer 1; enabled|disabled" },
        { "snes9x_layer_2", "Show layer 2; enabled|disabled" },
        { "snes9x_layer_3", "Show layer 3; enabled|disabled" },
        { "snes9x_layer_4", "Show layer 4; enabled|disabled" },
        { "snes9x_layer_5", "Show sprite layer; enabled|disabled" },
        { "snes9x_gfx_clip", "Enable graphic clip windows; enabled|disabled" },
        { "snes9x_gfx_transp", "Enable transparency effects; enabled|disabled" },
        { "snes9x_gfx_hires", "Enable hires mode; enabled|disabled" },
        { "snes9x_sndchan_1", "Enable sound channel 1; enabled|disabled" },
        { "snes9x_sndchan_2", "Enable sound channel 2; enabled|disabled" },
        { "snes9x_sndchan_3", "Enable sound channel 3; enabled|disabled" },
        { "snes9x_sndchan_4", "Enable sound channel 4; enabled|disabled" },
        { "snes9x_sndchan_5", "Enable sound channel 5; enabled|disabled" },
        { "snes9x_sndchan_6", "Enable sound channel 6; enabled|disabled" },
        { "snes9x_sndchan_7", "Enable sound channel 7; enabled|disabled" },
        { "snes9x_sndchan_8", "Enable sound channel 8; enabled|disabled" },
        { "snes9x_overscan", "Crop overscan; enabled|disabled|auto" },
        { "snes9x_aspect", "Preferred aspect ratio; 4:3|8:7|auto|ntsc|pal" },
        { NULL, NULL },
    };

    environ_cb(RETRO_ENVIRONMENT_SET_VARIABLES, variables);

    const struct retro_controller_description port_1[] = {
        { "SNES Joypad", RETRO_DEVICE_JOYPAD },
        { "SNES Mouse", RETRO_DEVICE_MOUSE },
        { "Multitap", RETRO_DEVICE_JOYPAD_MULTITAP },
    };

    const struct retro_controller_description port_2[] = {
        { "SNES Joypad", RETRO_DEVICE_JOYPAD },
        { "SNES Mouse", RETRO_DEVICE_MOUSE },
        { "Multitap", RETRO_DEVICE_JOYPAD_MULTITAP },
        { "SuperScope", RETRO_DEVICE_LIGHTGUN_SUPER_SCOPE },
        { "Justifier", RETRO_DEVICE_LIGHTGUN_JUSTIFIER },
    };

    const struct retro_controller_info ports[] = {
        { port_1, 3 },
        { port_2, 5 },
        { 0, 0 },
    };

    environ_cb(RETRO_ENVIRONMENT_SET_CONTROLLER_INFO, (void*)ports);
}

void update_geometry(void)
{
    struct retro_system_av_info av_info;
    retro_get_system_av_info(&av_info);
    environ_cb(RETRO_ENVIRONMENT_SET_GEOMETRY, &av_info);
}

static void update_variables(void)
{
    bool geometry_update = false;
    char key[256];
    struct retro_variable var;

    var.key = "snes9x_hires_blend";
    var.value = NULL;

    if (environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var))
        hires_blend = !strcmp(var.value, "disabled") ? false : true;
    else
        hires_blend = false;

    var.key = "snes9x_overclock_superfx";
    var.value = NULL;

    if (environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var))
    {
        int freq = atoi(var.value);
        Settings.SuperFXClockMultiplier = freq;
    }

    var.key = "snes9x_hires_blend";
    var.value = NULL;

    if (environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var))
        hires_blend = !strcmp(var.value, "disabled") ? false : true;
    else
        hires_blend = false;

    var.key = "snes9x_up_down_allowed";
    var.value = NULL;

    if (environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var))
    {
        Settings.UpAndDown = !strcmp(var.value, "disabled") ? false : true;
    }
    else
        Settings.UpAndDown = false;

    int disabled_channels=0;
    strcpy(key, "snes9x_sndchan_x");
    var.key=key;
    for (int i=0;i<8;i++)
    {
        key[strlen("snes9x_sndchan_")]='1'+i;
        var.value=NULL;
        if (environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var) && !strcmp("disabled", var.value))
            disabled_channels|=1<<i;
    }
    S9xSetSoundControl(disabled_channels^0xFF);


    int disabled_layers=0;
    strcpy(key, "snes9x_layer_x");
    for (int i=0;i<5;i++)
    {
        key[strlen("snes9x_layer_")]='1'+i;
        var.value=NULL;
        if (environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var) && !strcmp("disabled", var.value))
            disabled_layers|=1<<i;
    }
    Settings.BG_Forced=disabled_layers;

    //for some reason, Transparency seems to control both the fixed color and the windowing registers?
    var.key="snes9x_gfx_clip";
    var.value=NULL;
    Settings.DisableGraphicWindows=(environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var) && !strcmp("disabled", var.value));

    var.key="snes9x_gfx_transp";
    var.value=NULL;
    Settings.Transparency=!(environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var) && !strcmp("disabled", var.value));

    var.key="snes9x_gfx_hires";
    var.value=NULL;
    Settings.SupportHiRes=!(environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var) && !strcmp("disabled", var.value));

    var.key = "snes9x_overscan";

    if (environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var) && var.value)
    {
        overscan_mode newval = OVERSCAN_CROP_AUTO;
        if (strcmp(var.value, "enabled") == 0)
            newval = OVERSCAN_CROP_ON;
        else if (strcmp(var.value, "disabled") == 0)
            newval = OVERSCAN_CROP_OFF;

        if (newval != crop_overscan_mode)
        {
            crop_overscan_mode = newval;
            geometry_update = true;
        }
    }

    var.key = "snes9x_aspect";

    if (environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var) && var.value)
    {
        aspect_mode newval = ASPECT_RATIO_AUTO;
        if (strcmp(var.value, "ntsc") == 0)
            newval = ASPECT_RATIO_NTSC;
        else if (strcmp(var.value, "pal") == 0)
            newval = ASPECT_RATIO_PAL;
        else if (strcmp(var.value, "4:3") == 0)
            newval = ASPECT_RATIO_4_3;
        else if (strcmp(var.value, "8:7") == 0)
            newval = ASPECT_RATIO_8_7;

        if (newval != aspect_ratio_mode)
        {
            aspect_ratio_mode = newval;
            geometry_update = true;
        }
    }

    if (geometry_update)
        update_geometry();
}

static void S9xAudioCallback(void*)
{
    const int BUFFER_SIZE = 256;
    // This is called every time 128 to 132 samples are generated, which happens about 8 times per frame.  A buffer size of 256 samples is enough here.
    static int16_t audio_buf[BUFFER_SIZE];

    S9xFinalizeSamples();
    size_t avail = S9xGetSampleCount();
    while (avail >= BUFFER_SIZE)
    {
        //this loop will never be entered, but handle oversized sample counts just in case
        S9xMixSamples((uint8*)audio_buf, BUFFER_SIZE);
        audio_batch_cb(audio_buf, BUFFER_SIZE >> 1);

        avail -= BUFFER_SIZE;
    }
    if (avail > 0)
    {
        S9xMixSamples((uint8*)audio_buf, avail);
        audio_batch_cb(audio_buf, avail >> 1);
    }
}

void retro_get_system_info(struct retro_system_info *info)
{
    memset(info,0,sizeof(retro_system_info));

    info->library_name = "Snes9x";
#ifndef GIT_VERSION
#define GIT_VERSION ""
#endif
    info->library_version = VERSION GIT_VERSION;
    info->valid_extensions = "smc|sfc|swc|fig|bs";
    info->need_fullpath = false;
    info->block_extract = false;
}

float get_aspect_ratio(unsigned width, unsigned height)
{
    if (aspect_ratio_mode == ASPECT_RATIO_4_3)
    {
        return SNES_4_3;
    }
    else if (aspect_ratio_mode == ASPECT_RATIO_8_7)
    {
        return SNES_8_7;
    }

    // OV2: not sure if these really make sense - NTSC is similar to 4:3, PAL looks weird
    float sample_frequency_ntsc = 135000000.0f / 11.0f;
    float sample_frequency_pal = 14750000.0;

    float sample_freq = retro_get_region() == RETRO_REGION_NTSC ? sample_frequency_ntsc : sample_frequency_pal;
    float dot_rate = SNES::cpu.frequency / 4.0;

    if (aspect_ratio_mode == ASPECT_RATIO_NTSC) // ntsc
    {
        sample_freq = sample_frequency_ntsc;
        dot_rate = NTSC_MASTER_CLOCK / 4.0;
    }
    else if (aspect_ratio_mode == ASPECT_RATIO_PAL) // pal
    {
        sample_freq = sample_frequency_pal;
        dot_rate = PAL_MASTER_CLOCK / 4.0;
    }

    float par = sample_freq / 2.0 / dot_rate;
    return (float)width * par / (float)height;
}

void retro_get_system_av_info(struct retro_system_av_info *info)
{
    memset(info,0,sizeof(retro_system_av_info));
    unsigned width = SNES_WIDTH;
    unsigned height = PPU.ScreenHeight;
    if (crop_overscan_mode == OVERSCAN_CROP_ON)
        height = SNES_HEIGHT;
    else if (crop_overscan_mode == OVERSCAN_CROP_OFF)
        height = SNES_HEIGHT_EXTENDED;

    info->geometry.base_width = width;
    info->geometry.base_height = height;
    info->geometry.max_width = MAX_SNES_WIDTH;
    info->geometry.max_height = MAX_SNES_HEIGHT;
    info->geometry.aspect_ratio = get_aspect_ratio(width, height);
    info->timing.sample_rate = 32040;
    info->timing.fps = retro_get_region() == RETRO_REGION_NTSC ? 21477272.0 / 357366.0 : 21281370.0 / 425568.0;
}

unsigned retro_api_version()
{
    return RETRO_API_VERSION;
}


void retro_reset()
{
    S9xSoftReset();
}

static unsigned snes_devices[2];
void retro_set_controller_port_device(unsigned port, unsigned device)
{
    if (port < 2)
    {
        int offset = snes_devices[0] == RETRO_DEVICE_JOYPAD_MULTITAP ? 4 : 1;
        switch (device)
        {
            case RETRO_DEVICE_JOYPAD:
            S9xSetController(port, CTL_JOYPAD, port * offset, 0, 0, 0);
            snes_devices[port] = RETRO_DEVICE_JOYPAD;
            break;
            case RETRO_DEVICE_JOYPAD_MULTITAP:
            S9xSetController(port, CTL_MP5, port * offset, port * offset + 1, port * offset + 2, port * offset + 3);
            snes_devices[port] = RETRO_DEVICE_JOYPAD_MULTITAP;
            break;
            case RETRO_DEVICE_MOUSE:
            S9xSetController(port, CTL_MOUSE, port, 0, 0, 0);
            snes_devices[port] = RETRO_DEVICE_MOUSE;
            break;
            case RETRO_DEVICE_LIGHTGUN_SUPER_SCOPE:
            S9xSetController(port, CTL_SUPERSCOPE, 0, 0, 0, 0);
            snes_devices[port] = RETRO_DEVICE_LIGHTGUN_SUPER_SCOPE;
            break;
            case RETRO_DEVICE_LIGHTGUN_JUSTIFIER:
            S9xSetController(port, CTL_JUSTIFIER, 0, 0, 0, 0);
            snes_devices[port] = RETRO_DEVICE_LIGHTGUN_JUSTIFIER;
            break;
            default:
            if (log_cb)
                log_cb(RETRO_LOG_ERROR, "[libretro]: Invalid device (%d).\n", device);
        }
        if (!port)
            retro_set_controller_port_device(1, snes_devices[1]);
    }
    else if(device != RETRO_DEVICE_NONE)
        log_cb(RETRO_LOG_INFO, "[libretro]: Nonexistent Port (%d).\n", port);
}

void retro_cheat_reset()
{
    S9xDeleteCheats();
}

void retro_cheat_set(unsigned index, bool enabled, const char *codeline)
{
    char codeCopy[256];
    char* code;

    if (codeline == (char *)'\0') return;

    strcpy(codeCopy,codeline);
    code=strtok(codeCopy,"+,.; ");
    while (code != NULL) {
        //Convert GH RAW to PAR
        if (strlen(code)==9 && code[6]==':')
        {
            code[6]=code[7];
            code[7]=code[8];
            code[8]='\0';
        }

        /* Goldfinger was broken and nobody noticed. Removed */
        if (S9xAddCheatGroup ("retro", code) >= 0)
        {
            if (enabled)
                S9xEnableCheatGroup (Cheat.g.size () - 1);
        }
        else
        {
            printf("CHEAT: Failed to recognize %s\n",code);
        }

        code=strtok(NULL,"+,.; "); // bad code, ignore
    }

    S9xCheatsEnable();
}

#define MAX_MAPS 32
static struct retro_memory_descriptor memorydesc[MAX_MAPS];
static unsigned memorydesc_c;

static bool merge_mapping()
{
    if (memorydesc_c==1) return false;//can't merge the only one
    struct retro_memory_descriptor * a=&memorydesc[MAX_MAPS - (memorydesc_c-1)];
    struct retro_memory_descriptor * b=&memorydesc[MAX_MAPS - memorydesc_c];

    if (a->flags != b->flags) return false;
    if (a->disconnect != b->disconnect) return false;
    if (a->len != b->len) return false;
    if (a->addrspace || b->addrspace) return false;//we don't use these
    if (((char*)a->ptr)+a->offset==((char*)b->ptr)+b->offset && a->select==b->select)
    {
        a->select&=~(a->start^b->start);
        memorydesc_c--;
        return true;
    }
    uint32 len=a->len;
    if (!len) len=(0x1000000 - a->select);
    if (len && ((len-1) & (len | a->disconnect))==0 && ((char*)a->ptr)+a->offset+len == ((char*)b->ptr)+b->offset)
    {
        a->select &=~ len;
        a->disconnect &=~ len;
        memorydesc_c--;
        return true;
    }
    return false;
}

void S9xAppendMapping(struct retro_memory_descriptor *desc)
{
    //do it backwards - snes9x defines the last one to win, while we define the first one to win
    //printf("add %x\n",desc->start);
    memcpy(&memorydesc[MAX_MAPS - (++memorydesc_c)], desc, sizeof(struct retro_memory_descriptor));
    while (merge_mapping()) {}
}

static void init_descriptors(void)
{
    struct retro_input_descriptor desc[] = {
        { 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_LEFT,  "D-Pad Left" },
        { 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_UP,		"D-Pad Up" },
        { 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_DOWN,  "D-Pad Down" },
        { 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_RIGHT, "D-Pad Right" },
        { 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_B,		"B" },
        { 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_A,		"A" },
        { 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_X,		"X" },
        { 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_Y,		"Y" },
        { 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_L,		"L" },
        { 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_R,		"R" },
        { 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_SELECT,	"Select" },
        { 0, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_START,		"Start" },

        { 1, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_LEFT,  "D-Pad Left" },
        { 1, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_UP,		"D-Pad Up" },
        { 1, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_DOWN,  "D-Pad Down" },
        { 1, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_RIGHT, "D-Pad Right" },
        { 1, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_B,		"B" },
        { 1, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_A,		"A" },
        { 1, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_X,		"X" },
        { 1, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_Y,		"Y" },
        { 1, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_L,		"L" },
        { 1, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_R,		"R" },
        { 1, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_SELECT,	"Select" },
        { 1, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_START,		"Start" },

        { 2, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_LEFT,  "D-Pad Left" },
        { 2, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_UP,		"D-Pad Up" },
        { 2, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_DOWN,  "D-Pad Down" },
        { 2, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_RIGHT, "D-Pad Right" },
        { 2, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_B,		"B" },
        { 2, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_A,		"A" },
        { 2, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_X,		"X" },
        { 2, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_Y,		"Y" },
        { 2, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_L,		"L" },
        { 2, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_R,		"R" },
        { 2, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_SELECT,	"Select" },
        { 2, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_START,		"Start" },

        { 3, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_LEFT,  "D-Pad Left" },
        { 3, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_UP,		"D-Pad Up" },
        { 3, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_DOWN,  "D-Pad Down" },
        { 3, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_RIGHT, "D-Pad Right" },
        { 3, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_B,		"B" },
        { 3, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_A,		"A" },
        { 3, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_X,		"X" },
        { 3, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_Y,		"Y" },
        { 3, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_L,		"L" },
        { 3, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_R,		"R" },
        { 3, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_SELECT,	"Select" },
        { 3, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_START,		"Start" },

        { 4, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_LEFT,  "D-Pad Left" },
        { 4, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_UP,		"D-Pad Up" },
        { 4, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_DOWN,  "D-Pad Down" },
        { 4, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_RIGHT, "D-Pad Right" },
        { 4, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_B,		"B" },
        { 4, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_A,		"A" },
        { 4, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_X,		"X" },
        { 4, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_Y,		"Y" },
        { 4, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_L,		"L" },
        { 4, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_R,		"R" },
        { 4, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_SELECT,	"Select" },
        { 4, RETRO_DEVICE_JOYPAD, 0, RETRO_DEVICE_ID_JOYPAD_START,		"Start" },

        { 0, 0, 0, 0, NULL },
    };

    environ_cb(RETRO_ENVIRONMENT_SET_INPUT_DESCRIPTORS, desc);
}

static bool valid_normal_bank (uint8 bankbyte)
{
    switch (bankbyte)
    {
        case 32: case 33: case 48: case 49:
            return (true);
    }

    return (false);
}

static int is_bsx (uint8 *p)
{
    if ((p[26] == 0x33 || p[26] == 0xFF) && (!p[21] || (p[21] & 131) == 128) && valid_normal_bank(p[24]))
    {
        unsigned char	m = p[22];

        if (!m && !p[23])
            return (2);

        if ((m == 0xFF && p[23] == 0xFF) || (!(m & 0xF) && ((m >> 4) - 1 < 12)))
            return (1);
    }

    return (0);
}

static void Remove_Header(uint8_t *&romptr, size_t &romsize, bool multicart_sufami)
{
    if (romptr==0 || romsize==0) return;

    uint32 calc_size = (romsize / 0x2000) * 0x2000;
    if ((romsize - calc_size == 512 && !Settings.ForceNoHeader) || Settings.ForceHeader)
    {
        romptr += 512;
        romsize -= 512;

        if(log_cb) log_cb(RETRO_LOG_INFO,"[libretro]: ROM header removed\n");
    }

    if (multicart_sufami)
    {
        if (strncmp((const char*)(romptr+0x100000), "BANDAI SFC-ADX", 14) == 0 &&
            strncmp((const char*)(romptr+0x000000), "BANDAI SFC-ADX", 14) == 0)
        {
            romptr += 0x100000;
            romsize -= 0x100000;

            if(log_cb) log_cb(RETRO_LOG_INFO,"[libretro]: Sufami Turbo Multi-ROM bios removed\n");
        }
    }
}

static bool8 LoadBIOS(uint8 *biosrom, char *biosname, int biossize)
{
    FILE	*fp;
    char	name[PATH_MAX + 1];
    bool8 r = FALSE;

    strcpy(name, S9xGetDirectory(ROMFILENAME_DIR));
    strcat(name, SLASH_STR);
    strcat(name, biosname);

    fp = fopen(name, "rb");
    if (!fp)
    {
        strcpy(name, S9xGetDirectory(BIOS_DIR));
        strcat(name, SLASH_STR);
        strcat(name, biosname);

        fp = fopen(name, "rb");
    }

    if (fp)
    {
        size_t size;

        size = fread((void *) biosrom, 1, biossize, fp);
        fclose(fp);
        if (size == biossize)
            r = TRUE;
    }

    return (r);
}

static bool8 is_SufamiTurbo_Cart (const uint8 *data, uint32 size)
{
    if (size >= 0x80000 && size <= 0x100000 &&
        strncmp((char *) data, "BANDAI SFC-ADX", 14) == 0 && strncmp((char * ) (data + 0x10), "SFC-ADX BACKUP", 14) != 0)
        return (TRUE);
    else
        return (FALSE);
}

bool retro_load_game(const struct retro_game_info *game)
{
    init_descriptors();

    update_variables();

    if(game->data == NULL && game->size == 0 && game->path != NULL)
        rom_loaded = Memory.LoadROM(game->path);
    else
    {
        uint8 *biosrom = new uint8[0x100000];

        if (game->path != NULL)
        {
            extract_basename(g_basename, game->path, sizeof(g_basename));
            extract_directory(g_rom_dir, game->path, sizeof(g_rom_dir));
        }

        if (is_SufamiTurbo_Cart((uint8 *) game->data, game->size)) {
            if (rom_loaded = LoadBIOS(biosrom,"STBIOS.bin",0x40000))
            rom_loaded = Memory.LoadMultiCartMem((const uint8_t*)game->data, game->size, 0, 0, biosrom, 0x40000);
        }

        else
        if ((is_bsx((uint8 *) game->data + 0x7fc0)==1) | (is_bsx((uint8 *) game->data + 0xffc0)==1)) {
            if (rom_loaded = LoadBIOS(biosrom,"BS-X.bin",0x100000))
            rom_loaded = Memory.LoadMultiCartMem(biosrom, 0x100000, (const uint8_t*)game->data, game->size, 0, 0);
        }

        else
            rom_loaded = Memory.LoadROMMem((const uint8_t*)game->data ,game->size);

        if(biosrom) delete[] biosrom;
    }

    int pixel_format = RGB555;
    if(environ_cb)
    {
        pixel_format = RGB565;
        enum retro_pixel_format fmt = RETRO_PIXEL_FORMAT_RGB565;
        if (!environ_cb(RETRO_ENVIRONMENT_SET_PIXEL_FORMAT, &fmt))
            pixel_format = RGB555;
    }
    S9xGraphicsDeinit();
    S9xSetRenderPixelFormat(pixel_format);
    S9xGraphicsInit();

    struct retro_memory_map map={ memorydesc+MAX_MAPS-memorydesc_c, memorydesc_c };
    if (rom_loaded)
    {
        environ_cb(RETRO_ENVIRONMENT_SET_MEMORY_MAPS, &map);
        update_geometry();
    }

    if (!rom_loaded && log_cb)
        log_cb(RETRO_LOG_ERROR, "[libretro]: Rom loading failed...\n");

    return rom_loaded;
}

bool retro_load_game_special(unsigned game_type, const struct retro_game_info *info, size_t num_info)
{
    uint8_t *romptr[3];
    size_t romsize[3];

    for(size_t lcv=0; lcv<num_info; lcv++)
    {
        romptr[lcv] = (uint8_t *) info[lcv].data;
        romsize[lcv] = info[lcv].size;

        Remove_Header(romptr[lcv], romsize[lcv], true);
    }

    init_descriptors();
    memorydesc_c = 0;
    rom_loaded = false;

    update_variables();

    switch (game_type) {
        case RETRO_GAME_TYPE_BSX:
            if(num_info == 1) {
            rom_loaded = Memory.LoadROMMem((const uint8_t*)romptr[0],romsize[0]);
            } else if(num_info == 2) {
            memcpy(Memory.BIOSROM,(const uint8_t*)romptr[0],info[0].size);
            rom_loaded = Memory.LoadROMMem((const uint8_t*)romptr[1],info[1].size);
            }

            if (!rom_loaded && log_cb)
            log_cb(RETRO_LOG_ERROR, "[libretro]: BSX ROM loading failed...\n");

            break;

        case RETRO_GAME_TYPE_BSX_SLOTTED:
        case RETRO_GAME_TYPE_MULTI_CART:
            if(num_info == 2) {
            if (is_SufamiTurbo_Cart((const uint8_t*)romptr[0], romsize[0])) {
                uint8 *biosrom = new uint8[0x40000];
                uint8 *biosptr = biosrom;

                if (LoadBIOS(biosptr,"STBIOS.bin",0x40000)) {
                    if (log_cb) log_cb(RETRO_LOG_INFO, "[libretro]: Loading Sufami Turbo link game\n");

                    rom_loaded = Memory.LoadMultiCartMem((const uint8_t*)romptr[0], romsize[0],
                                (const uint8_t*)romptr[1], romsize[1], biosptr, 0x40000);
                }

                if (biosrom) delete[] biosrom;
            }

            else {
                if (log_cb) log_cb(RETRO_LOG_INFO, "[libretro]: Loading Multi-Cart link game\n");

                rom_loaded = Memory.LoadMultiCartMem((const uint8_t*)romptr[0], romsize[0],
                            (const uint8_t*)romptr[1], romsize[1], NULL, 0);
            }
            }

            if (!rom_loaded && log_cb)
            log_cb(RETRO_LOG_ERROR, "[libretro]: Multirom loading failed...\n");

            break;

        case RETRO_GAME_TYPE_SUFAMI_TURBO:
            if(num_info == 2) {
            uint8 *biosrom = new uint8[0x100000];

            if ((rom_loaded = LoadBIOS(biosrom,"STBIOS.bin",0x100000)))
                rom_loaded = Memory.LoadMultiCartMem((const uint8_t*)romptr[0], romsize[0],
                            (const uint8_t*)romptr[1], romsize[1], biosrom, 0x40000);

            if (biosrom) delete[] biosrom;
            }

            if (!rom_loaded && log_cb)
            log_cb(RETRO_LOG_ERROR, "[libretro]: Sufami Turbo ROM loading failed...\n");

            break;

        default:
            rom_loaded = false;
            log_cb(RETRO_LOG_ERROR, "[libretro]: Multi-cart ROM loading failed...\n");
            break;
    }

    if (rom_loaded)
    {
        int pixel_format = RGB555;
        if(environ_cb)
        {
            pixel_format = RGB565;
            enum retro_pixel_format fmt = RETRO_PIXEL_FORMAT_RGB565;
            if (!environ_cb(RETRO_ENVIRONMENT_SET_PIXEL_FORMAT, &fmt))
                pixel_format = RGB555;
        }
        S9xGraphicsDeinit();
        S9xSetRenderPixelFormat(pixel_format);
        S9xGraphicsInit();

        struct retro_memory_map map={ memorydesc+MAX_MAPS-memorydesc_c, memorydesc_c };
        environ_cb(RETRO_ENVIRONMENT_SET_MEMORY_MAPS, &map);
        update_geometry();
        audio_interp_max = 32768;
    }

    return rom_loaded;
}

void retro_unload_game(void)
{}

static void map_buttons();

static void check_system_specs(void)
{
    /* TODO - might have to variably set performance level based on SuperFX/SA-1/etc */
    unsigned level = 12;
    environ_cb(RETRO_ENVIRONMENT_SET_PERFORMANCE_LEVEL, &level);
}

void retro_init(void)
{
    struct retro_log_callback log;

    if (environ_cb(RETRO_ENVIRONMENT_GET_LOG_INTERFACE, &log))
        log_cb = log.log;
    else
        log_cb = NULL;

    const char *dir = NULL;

    if (environ_cb(RETRO_ENVIRONMENT_GET_SYSTEM_DIRECTORY, &dir) && dir)
        snprintf(retro_system_directory, sizeof(retro_system_directory), "%s", dir);
    else
        snprintf(retro_system_directory, sizeof(retro_system_directory), "%s", ".");

    if (environ_cb(RETRO_ENVIRONMENT_GET_SAVE_DIRECTORY, &dir) && dir)
        snprintf(retro_save_directory, sizeof(retro_save_directory), "%s", dir);
    else
        snprintf(retro_save_directory, sizeof(retro_save_directory), "%s", ".");

    // State that SNES9X supports achievements.
    bool achievements = true;
    environ_cb(RETRO_ENVIRONMENT_SET_SUPPORT_ACHIEVEMENTS, &achievements);

    memset(&Settings, 0, sizeof(Settings));
    Settings.MouseMaster = TRUE;
    Settings.SuperScopeMaster = TRUE;
    Settings.JustifierMaster = TRUE;
    Settings.MultiPlayer5Master = TRUE;
    Settings.FrameTimePAL = 20000;
    Settings.FrameTimeNTSC = 16667;
    Settings.SixteenBitSound = TRUE;
    Settings.Stereo = TRUE;
    Settings.SoundPlaybackRate = 32040;
    Settings.SoundInputRate = 32040;
    Settings.SupportHiRes = TRUE;
    Settings.Transparency = TRUE;
    Settings.AutoDisplayMessages = TRUE;
    Settings.InitialInfoStringTimeout = 120;
    Settings.HDMATimingHack = 100;
    Settings.BlockInvalidVRAMAccessMaster = TRUE;
    Settings.CartAName[0] = 0;
    Settings.CartBName[0] = 0;
    Settings.AutoSaveDelay = 1;
    Settings.DontSaveOopsSnapshot = TRUE;

    CPU.Flags = 0;

    if (!Memory.Init() || !S9xInitAPU())
    {
        Memory.Deinit();
        S9xDeinitAPU();

        if (log_cb)
            log_cb(RETRO_LOG_ERROR, "[libretro]: Failed to init Memory or APU.\n");
        exit(1);
    }

    //very slow devices will still pop

    //this needs to be applied to all snes9x cores

    //increasing the buffer size does not cause extra lag(tested with 1000ms buffer)
    //bool8 S9xInitSound (int buffer_ms, int lag_ms)

    S9xInitSound(32, 0); //give it a 1.9 frame long buffer, or 1026 samples.  The audio buffer is flushed every 128-132 samples anyway, so it won't get anywhere near there.

    S9xSetSoundMute(FALSE);
    S9xSetSamplesAvailableCallback(S9xAudioCallback, NULL);

    GFX.Pitch = MAX_SNES_WIDTH * sizeof(uint16);
    GFX.Screen = (uint16*) calloc(1, GFX.Pitch * MAX_SNES_HEIGHT);
    gfx_blend = (uint16*) calloc(1, GFX.Pitch * MAX_SNES_HEIGHT);
    S9xGraphicsInit();

    S9xInitInputDevices();
    for (int i = 0; i < 2; i++)
    {
        S9xSetController(i, CTL_JOYPAD, i, 0, 0, 0);
        snes_devices[i] = RETRO_DEVICE_JOYPAD;
    }

    S9xUnmapAllControls();
    map_buttons();
    check_system_specs();
}

#define MAP_BUTTON(id, name) S9xMapButton((id), S9xGetCommandT((name)), false)
#define MAKE_BUTTON(pad, btn) (((pad)<<4)|(btn))

#define PAD_1 1
#define PAD_2 2
#define PAD_3 3
#define PAD_4 4
#define PAD_5 5

#define BTN_B RETRO_DEVICE_ID_JOYPAD_B
#define BTN_Y RETRO_DEVICE_ID_JOYPAD_Y
#define BTN_SELECT RETRO_DEVICE_ID_JOYPAD_SELECT
#define BTN_START RETRO_DEVICE_ID_JOYPAD_START
#define BTN_UP RETRO_DEVICE_ID_JOYPAD_UP
#define BTN_DOWN RETRO_DEVICE_ID_JOYPAD_DOWN
#define BTN_LEFT RETRO_DEVICE_ID_JOYPAD_LEFT
#define BTN_RIGHT RETRO_DEVICE_ID_JOYPAD_RIGHT
#define BTN_A RETRO_DEVICE_ID_JOYPAD_A
#define BTN_X RETRO_DEVICE_ID_JOYPAD_X
#define BTN_L RETRO_DEVICE_ID_JOYPAD_L
#define BTN_R RETRO_DEVICE_ID_JOYPAD_R
#define BTN_FIRST BTN_B
#define BTN_LAST BTN_R

#define MOUSE_X RETRO_DEVICE_ID_MOUSE_X
#define MOUSE_Y RETRO_DEVICE_ID_MOUSE_Y
#define MOUSE_LEFT RETRO_DEVICE_ID_MOUSE_LEFT
#define MOUSE_RIGHT RETRO_DEVICE_ID_MOUSE_RIGHT
#define MOUSE_FIRST MOUSE_X
#define MOUSE_LAST MOUSE_RIGHT

#define SCOPE_X RETRO_DEVICE_ID_SUPER_SCOPE_X
#define SCOPE_Y RETRO_DEVICE_ID_SUPER_SCOPE_Y
#define SCOPE_TRIGGER RETRO_DEVICE_ID_LIGHTGUN_TRIGGER
#define SCOPE_CURSOR RETRO_DEVICE_ID_LIGHTGUN_CURSOR
#define SCOPE_TURBO RETRO_DEVICE_ID_LIGHTGUN_TURBO
#define SCOPE_PAUSE RETRO_DEVICE_ID_LIGHTGUN_PAUSE
#define SCOPE_FIRST SCOPE_X
#define SCOPE_LAST SCOPE_PAUSE

#define JUSTIFIER_X RETRO_DEVICE_ID_JUSTIFIER_X
#define JUSTIFIER_Y RETRO_DEVICE_ID_JUSTIFIER_Y
#define JUSTIFIER_TRIGGER RETRO_DEVICE_ID_LIGHTGUN_TRIGGER
#define JUSTIFIER_OFFSCREEN RETRO_DEVICE_ID_LIGHTGUN_TURBO
#define JUSTIFIER_START RETRO_DEVICE_ID_LIGHTGUN_PAUSE
#define JUSTIFIER_FIRST JUSTIFIER_X
#define JUSTIFIER_LAST JUSTIFIER_START

#define BTN_POINTER (BTN_LAST + 1)
#define BTN_POINTER2 (BTN_POINTER + 1)


static void map_buttons()
{
    MAP_BUTTON(MAKE_BUTTON(PAD_1, BTN_A), "Joypad1 A");
    MAP_BUTTON(MAKE_BUTTON(PAD_1, BTN_B), "Joypad1 B");
    MAP_BUTTON(MAKE_BUTTON(PAD_1, BTN_X), "Joypad1 X");
    MAP_BUTTON(MAKE_BUTTON(PAD_1, BTN_Y), "Joypad1 Y");
    MAP_BUTTON(MAKE_BUTTON(PAD_1, BTN_SELECT), "{Joypad1 Select,Mouse1 L}");
    MAP_BUTTON(MAKE_BUTTON(PAD_1, BTN_START), "{Joypad1 Start,Mouse1 R}");
    MAP_BUTTON(MAKE_BUTTON(PAD_1, BTN_L), "Joypad1 L");
    MAP_BUTTON(MAKE_BUTTON(PAD_1, BTN_R), "Joypad1 R");
    MAP_BUTTON(MAKE_BUTTON(PAD_1, BTN_LEFT), "Joypad1 Left");
    MAP_BUTTON(MAKE_BUTTON(PAD_1, BTN_RIGHT), "Joypad1 Right");
    MAP_BUTTON(MAKE_BUTTON(PAD_1, BTN_UP), "Joypad1 Up");
    MAP_BUTTON(MAKE_BUTTON(PAD_1, BTN_DOWN), "Joypad1 Down");
    S9xMapPointer((BTN_POINTER), S9xGetCommandT("Pointer Mouse1+Superscope+Justifier1"), false);
    S9xMapPointer((BTN_POINTER2), S9xGetCommandT("Pointer Mouse2"), false);

    MAP_BUTTON(MAKE_BUTTON(PAD_2, BTN_A), "Joypad2 A");
    MAP_BUTTON(MAKE_BUTTON(PAD_2, BTN_B), "Joypad2 B");
    MAP_BUTTON(MAKE_BUTTON(PAD_2, BTN_X), "Joypad2 X");
    MAP_BUTTON(MAKE_BUTTON(PAD_2, BTN_Y), "Joypad2 Y");
    MAP_BUTTON(MAKE_BUTTON(PAD_2, BTN_SELECT), "{Joypad2 Select,Mouse2 L,Superscope Fire,Justifier1 Trigger}");
    MAP_BUTTON(MAKE_BUTTON(PAD_2, BTN_START), "{Joypad2 Start,Mouse2 R,Superscope Cursor,Justifier1 Start}");
    MAP_BUTTON(MAKE_BUTTON(PAD_2, BTN_L), "Joypad2 L");
    MAP_BUTTON(MAKE_BUTTON(PAD_2, BTN_R), "Joypad2 R");
    MAP_BUTTON(MAKE_BUTTON(PAD_2, BTN_LEFT), "Joypad2 Left");
    MAP_BUTTON(MAKE_BUTTON(PAD_2, BTN_RIGHT), "Joypad2 Right");
    MAP_BUTTON(MAKE_BUTTON(PAD_2, BTN_UP), "{Joypad2 Up,Superscope ToggleTurbo,Justifier1 AimOffscreen}");
    MAP_BUTTON(MAKE_BUTTON(PAD_2, BTN_DOWN), "{Joypad2 Down,Superscope Pause}");

    MAP_BUTTON(MAKE_BUTTON(PAD_3, BTN_A), "Joypad3 A");
    MAP_BUTTON(MAKE_BUTTON(PAD_3, BTN_B), "Joypad3 B");
    MAP_BUTTON(MAKE_BUTTON(PAD_3, BTN_X), "Joypad3 X");
    MAP_BUTTON(MAKE_BUTTON(PAD_3, BTN_Y), "Joypad3 Y");
    MAP_BUTTON(MAKE_BUTTON(PAD_3, BTN_SELECT), "Joypad3 Select");
    MAP_BUTTON(MAKE_BUTTON(PAD_3, BTN_START), "Joypad3 Start");
    MAP_BUTTON(MAKE_BUTTON(PAD_3, BTN_L), "Joypad3 L");
    MAP_BUTTON(MAKE_BUTTON(PAD_3, BTN_R), "Joypad3 R");
    MAP_BUTTON(MAKE_BUTTON(PAD_3, BTN_LEFT), "Joypad3 Left");
    MAP_BUTTON(MAKE_BUTTON(PAD_3, BTN_RIGHT), "Joypad3 Right");
    MAP_BUTTON(MAKE_BUTTON(PAD_3, BTN_UP), "Joypad3 Up");
    MAP_BUTTON(MAKE_BUTTON(PAD_3, BTN_DOWN), "Joypad3 Down");

    MAP_BUTTON(MAKE_BUTTON(PAD_4, BTN_A), "Joypad4 A");
    MAP_BUTTON(MAKE_BUTTON(PAD_4, BTN_B), "Joypad4 B");
    MAP_BUTTON(MAKE_BUTTON(PAD_4, BTN_X), "Joypad4 X");
    MAP_BUTTON(MAKE_BUTTON(PAD_4, BTN_Y), "Joypad4 Y");
    MAP_BUTTON(MAKE_BUTTON(PAD_4, BTN_SELECT), "Joypad4 Select");
    MAP_BUTTON(MAKE_BUTTON(PAD_4, BTN_START), "Joypad4 Start");
    MAP_BUTTON(MAKE_BUTTON(PAD_4, BTN_L), "Joypad4 L");
    MAP_BUTTON(MAKE_BUTTON(PAD_4, BTN_R), "Joypad4 R");
    MAP_BUTTON(MAKE_BUTTON(PAD_4, BTN_LEFT), "Joypad4 Left");
    MAP_BUTTON(MAKE_BUTTON(PAD_4, BTN_RIGHT), "Joypad4 Right");
    MAP_BUTTON(MAKE_BUTTON(PAD_4, BTN_UP), "Joypad4 Up");
    MAP_BUTTON(MAKE_BUTTON(PAD_4, BTN_DOWN), "Joypad4 Down");

    MAP_BUTTON(MAKE_BUTTON(PAD_5, BTN_A), "Joypad5 A");
    MAP_BUTTON(MAKE_BUTTON(PAD_5, BTN_B), "Joypad5 B");
    MAP_BUTTON(MAKE_BUTTON(PAD_5, BTN_X), "Joypad5 X");
    MAP_BUTTON(MAKE_BUTTON(PAD_5, BTN_Y), "Joypad5 Y");
    MAP_BUTTON(MAKE_BUTTON(PAD_5, BTN_SELECT), "Joypad5 Select");
    MAP_BUTTON(MAKE_BUTTON(PAD_5, BTN_START), "Joypad5 Start");
    MAP_BUTTON(MAKE_BUTTON(PAD_5, BTN_L), "Joypad5 L");
    MAP_BUTTON(MAKE_BUTTON(PAD_5, BTN_R), "Joypad5 R");
    MAP_BUTTON(MAKE_BUTTON(PAD_5, BTN_LEFT), "Joypad5 Left");
    MAP_BUTTON(MAKE_BUTTON(PAD_5, BTN_RIGHT), "Joypad5 Right");
    MAP_BUTTON(MAKE_BUTTON(PAD_5, BTN_UP), "Joypad5 Up");
    MAP_BUTTON(MAKE_BUTTON(PAD_5, BTN_DOWN), "Joypad5 Down");

}

// libretro uses relative values for analogue devices.
// S9x seems to use absolute values, but do convert these into relative values in the core. (Why?!)
// Hack around it. :)

static int16_t snes_mouse_state[2][2] = {{0}, {0}};
static int16_t snes_scope_state[2] = {0};
static int16_t snes_justifier_state[2][2] = {{0}, {0}};
static void report_buttons()
{
    int offset = snes_devices[0] == RETRO_DEVICE_JOYPAD_MULTITAP ? 4 : 1;

    int runahead_poll = 0;
    int result = -1;
    if(environ_cb(RETRO_ENVIRONMENT_GET_AUDIO_VIDEO_ENABLE, &result))
    {
            // runahead off: 3
            // runahead secondary off: 0,0,0,0,0,3
            runahead_poll = (result & 0x0b)==3;

            // runahead secondary on: 2,8,8,8,8,9  (messy sync problems)
    }

    for (int port = 0; port <= 1; port++)
    {
        switch (snes_devices[port])
        {
            case RETRO_DEVICE_JOYPAD:
            for (int i = BTN_FIRST; i <= BTN_LAST; i++)
                S9xReportButton(MAKE_BUTTON(port * offset + 1, i), input_state_cb(port * offset, RETRO_DEVICE_JOYPAD, 0, i));
            break;

            case RETRO_DEVICE_JOYPAD_MULTITAP:
            for (int j = 0; j < 4; j++)
                for (int i = BTN_FIRST; i <= BTN_LAST; i++)
                    S9xReportButton(MAKE_BUTTON(port * offset + j + 1, i), input_state_cb(port * offset + j, RETRO_DEVICE_JOYPAD, 0, i));
            break;

            case RETRO_DEVICE_MOUSE:
            if(runahead_poll)
            {
                snes_mouse_state[port][0] = input_state_cb(port, RETRO_DEVICE_MOUSE, 0, RETRO_DEVICE_ID_MOUSE_X);
                snes_mouse_state[port][1] = input_state_cb(port, RETRO_DEVICE_MOUSE, 0, RETRO_DEVICE_ID_MOUSE_Y);
            }
            S9xReportPointer(BTN_POINTER + port, snes_mouse_state[port][0], snes_mouse_state[port][1]);
            for (int i = MOUSE_LEFT; i <= MOUSE_LAST; i++)
                S9xReportButton(MAKE_BUTTON(port + 1, i), input_state_cb(port, RETRO_DEVICE_MOUSE, 0, i));
            break;

            case RETRO_DEVICE_LIGHTGUN_SUPER_SCOPE:
            if(runahead_poll)
            {
                snes_scope_state[0] += input_state_cb(port, RETRO_DEVICE_LIGHTGUN_SUPER_SCOPE, 0, RETRO_DEVICE_ID_LIGHTGUN_X);
                snes_scope_state[1] += input_state_cb(port, RETRO_DEVICE_LIGHTGUN_SUPER_SCOPE, 0, RETRO_DEVICE_ID_LIGHTGUN_Y);
            }
            if (snes_scope_state[0] < 0) snes_scope_state[0] = 0;
            else if (snes_scope_state[0] > (SNES_WIDTH-1)) snes_scope_state[0] = SNES_WIDTH-1;
            if (snes_scope_state[1] < 0) snes_scope_state[1] = 0;
            else if (snes_scope_state[1] > (SNES_HEIGHT-1)) snes_scope_state[1] = SNES_HEIGHT-1;
            S9xReportPointer(BTN_POINTER, snes_scope_state[0], snes_scope_state[1]);
            for (int i = SCOPE_TRIGGER; i <= SCOPE_LAST; i++)
                S9xReportButton(MAKE_BUTTON(2, i), input_state_cb(port, RETRO_DEVICE_LIGHTGUN, 0, i));
            break;

            case RETRO_DEVICE_LIGHTGUN_JUSTIFIER:
            case RETRO_DEVICE_LIGHTGUN_JUSTIFIERS:
            if(runahead_poll)
            {
                snes_justifier_state[port][0] += input_state_cb(port, RETRO_DEVICE_LIGHTGUN_JUSTIFIER, 0, RETRO_DEVICE_ID_LIGHTGUN_X);
                snes_justifier_state[port][1] += input_state_cb(port, RETRO_DEVICE_LIGHTGUN_JUSTIFIER, 0, RETRO_DEVICE_ID_LIGHTGUN_Y);
            }
            if (snes_justifier_state[port][0] < 0) snes_justifier_state[port][0] = 0;
            else if (snes_justifier_state[port][0] > (SNES_WIDTH-1)) snes_justifier_state[port][0] = SNES_WIDTH-1;
            if (snes_justifier_state[port][1] < 0) snes_justifier_state[port][1] = 0;
            else if (snes_justifier_state[port][1] > (SNES_HEIGHT-1)) snes_justifier_state[port][1] = SNES_HEIGHT-1;
            S9xReportPointer(BTN_POINTER, snes_justifier_state[port][0], snes_justifier_state[port][1]);
            for (int i = JUSTIFIER_TRIGGER; i <= JUSTIFIER_LAST; i++)
                S9xReportButton(MAKE_BUTTON(2, i), input_state_cb(port, RETRO_DEVICE_LIGHTGUN, 0, i));
            break;

            default:
            if (log_cb)
                log_cb(RETRO_LOG_ERROR, "[libretro]: Unknown device...\n");
        }
    }
}

void retro_run()
{
    static uint16 height = PPU.ScreenHeight;
    bool updated = false;
    if (environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE_UPDATE, &updated) && updated)
        update_variables();
    if (height != PPU.ScreenHeight)
    {
        update_geometry();
        height = PPU.ScreenHeight;
    }

    int result = -1;
    bool okay = environ_cb(RETRO_ENVIRONMENT_GET_AUDIO_VIDEO_ENABLE, &result);
    if (okay)
    {
        bool audioEnabled = 0 != (result & 2);
        bool videoEnabled = 0 != (result & 1);
        IPPU.RenderThisFrame = videoEnabled;
        S9xSetSoundMute(!audioEnabled);
    }
    else
    {
        IPPU.RenderThisFrame = true;
        S9xSetSoundMute(false);
    }

    poll_cb();
    report_buttons();
    S9xMainLoop();
    S9xAudioCallback(NULL);
}

void retro_deinit()
{
    S9xDeinitAPU();
    Memory.Deinit();
    S9xGraphicsDeinit();
    S9xUnmapAllControls();

    free(GFX.Screen);
    free(gfx_blend);
}


unsigned retro_get_region()
{
    return Settings.PAL ? RETRO_REGION_PAL : RETRO_REGION_NTSC;
}

void* retro_get_memory_data(unsigned type)
{
    void* data;

    switch(type) {
        case RETRO_MEMORY_SNES_SUFAMI_TURBO_A_RAM:
        case RETRO_MEMORY_SAVE_RAM:
            data = Memory.SRAM;
            break;
        case RETRO_MEMORY_SNES_SUFAMI_TURBO_B_RAM:
            data = Multi.sramB;
            break;
        case RETRO_MEMORY_RTC:
            data = RTCData.reg;
            break;
        case RETRO_MEMORY_SYSTEM_RAM:
        data = Memory.RAM;
        break;
        case RETRO_MEMORY_VIDEO_RAM:
        data = Memory.VRAM;
        break;
        //case RETRO_MEMORY_ROM:
        //	data = Memory.ROM;
        //	break;
        default:
            data = NULL;
            break;
    }

    return data;
}

size_t retro_get_memory_size(unsigned type)
{
    size_t size;

    switch(type) {
        case RETRO_MEMORY_SNES_SUFAMI_TURBO_A_RAM:
        case RETRO_MEMORY_SAVE_RAM:
            size = (unsigned) (Memory.SRAMSize ? (1 << (Memory.SRAMSize + 3)) * 128 : 0);
            if (size > 0x20000)
            size = 0x20000;
            break;
        case RETRO_MEMORY_SNES_SUFAMI_TURBO_B_RAM:
            size = (unsigned) (Multi.cartType==4 && Multi.sramSizeB ? (1 << (Multi.sramSizeB + 3)) * 128 : 0);
            break;
        case RETRO_MEMORY_RTC:
            size = (Settings.SRTC || Settings.SPC7110RTC)?20:0;
            break;
        case RETRO_MEMORY_SYSTEM_RAM:
            size = 128 * 1024;
            break;
        case RETRO_MEMORY_VIDEO_RAM:
            size = 64 * 1024;
            break;
        //case RETRO_MEMORY_ROM:
        //	size = Memory.CalculatedSize;
        //	break;
        default:
            size = 0;
            break;
    }

    return size;
}

size_t retro_serialize_size()
{
    return rom_loaded ? S9xFreezeSize() : 0;
}

bool retro_serialize(void *data, size_t size)
{
    if (S9xFreezeGameMem((uint8_t*)data,size) == FALSE)
        return false;

    return true;
}

bool retro_unserialize(const void* data, size_t size)
{
    if (S9xUnfreezeGameMem((const uint8_t*)data,size) != SUCCESS)
        return false;

    return true;
}

bool8 S9xDeinitUpdate(int width, int height)
{
    if (crop_overscan_mode == OVERSCAN_CROP_ON)
    {
        if (height >= SNES_HEIGHT << 1)
        {
            height = SNES_HEIGHT << 1;
        }
        else
        {
            height = SNES_HEIGHT;
        }
    }
    else if (crop_overscan_mode == OVERSCAN_CROP_OFF)
    {
        if (height > SNES_HEIGHT_EXTENDED)
        {
            if (height < SNES_HEIGHT_EXTENDED << 1)
            memset(GFX.Screen + (GFX.Pitch >> 1) * height,0,GFX.Pitch * ((SNES_HEIGHT_EXTENDED << 1) - height));
            height = SNES_HEIGHT_EXTENDED << 1;
        }
        else
        {
            if (height < SNES_HEIGHT_EXTENDED)
            memset(GFX.Screen + (GFX.Pitch >> 1) * height,0,GFX.Pitch * (SNES_HEIGHT_EXTENDED - height));
            height = SNES_HEIGHT_EXTENDED;
        }
    }


        if(width==MAX_SNES_WIDTH && hires_blend)
        {
#define AVERAGE_565(el0, el1) (((el0) & (el1)) + ((((el0) ^ (el1)) & 0xF7DE) >> 1))
        for (register int y = 0; y < height; y++)
        {
            register uint16 *input = (uint16 *) ((uint8 *) GFX.Screen + y * GFX.Pitch);
            register uint16 *output = (uint16 *) ((uint8 *) gfx_blend + y * GFX.Pitch);
            register uint16 l, r;

            l = 0;
            for (register int x = 0; x < (width >> 1); x++)
            {
            r = *input++;
            *output++ = AVERAGE_565 (l, r);
            l = r;

            r = *input++;
            *output++ = AVERAGE_565 (l, r);
            l = r;
            }
        }

        video_cb(gfx_blend, width, height, GFX.Pitch);
    }
    else
    { 
        video_cb(GFX.Screen, width, height, GFX.Pitch);
    }

    return TRUE;
}

bool8 S9xContinueUpdate(int width, int height)
{
    S9xDeinitUpdate(width, height);
    return true;
}

// Dummy functions that should probably be implemented correctly later.
void S9xParsePortConfig(ConfigFile&, int) {}
void S9xSyncSpeed() {}
const char* S9xStringInput(const char* in) { return in; }

#ifdef _WIN32
#define SLASH '\\'
#else
#define SLASH '/'
#endif

const char* S9xGetFilename(const char* in, s9x_getdirtype type)
{
    static char newpath[2048];

    newpath[0] = '\0';

    switch (type)
    {
        case ROMFILENAME_DIR:
            sprintf(newpath, "%s%c%s%s", g_rom_dir, SLASH, g_basename, in);
            return newpath;
        default:
            break;
    }

    return in;
}

const char* S9xGetDirectory(s9x_getdirtype type)
{
    switch (type)
    {
        case ROMFILENAME_DIR:
            return g_rom_dir;
        case BIOS_DIR:
            return retro_system_directory;
        default:
            break;
    }

    return "";
}
void S9xInitInputDevices() {}
const char* S9xChooseFilename(unsigned char) { return ""; }
void S9xHandlePortCommand(s9xcommand_t, short, short) {}
bool S9xPollButton(unsigned int, bool*) { return false; }
void S9xToggleSoundChannel(int) {}
const char* S9xGetFilenameInc(const char* in, s9x_getdirtype) { return ""; }
const char* S9xBasename(const char* in) { return in; }
bool8 S9xInitUpdate() { return TRUE; }
void S9xExtraUsage() {}
bool8 S9xOpenSoundDevice() { return TRUE; }
bool S9xPollAxis(unsigned int, short*) { return FALSE; }
void S9xSetPalette() {}
void S9xParseArg(char**, int&, int) {}
void S9xExit() {}
bool S9xPollPointer(unsigned int, short*, short*) { return false; }

const char *S9xChooseMovieFilename(unsigned char) { return NULL; }
void S9xMessage(int type, int, const char* s)
{
    if (!log_cb) return;

    switch (type)
    {
        case S9X_DEBUG:
            log_cb(RETRO_LOG_DEBUG, "%s\n", s);
            break;
        case S9X_WARNING:
            log_cb(RETRO_LOG_WARN, "%s\n", s);
            break;
        case S9X_INFO:
            log_cb(RETRO_LOG_INFO, "%s\n", s);
            break;
        case S9X_ERROR:
            log_cb(RETRO_LOG_ERROR, "%s\n", s);
            break;
        default:
            log_cb(RETRO_LOG_DEBUG, "%s\n", s);
            break;
    }
}

bool8 S9xOpenSnapshotFile(const char* filepath, bool8 read_only, STREAM *file)
{
    if(read_only)
    {
        if((*file = OPEN_STREAM(filepath, "rb")) != 0)
        {
            return (TRUE);
        }
    }
    else
    {
        if((*file = OPEN_STREAM(filepath, "wb")) != 0)
        {
            return (TRUE);
        }
    }
    return (FALSE);
}

void S9xCloseSnapshotFile(STREAM file)
{
    CLOSE_STREAM(file);
}

void S9xAutoSaveSRAM()
{
    return;
}

#ifndef __WIN32__
// S9x weirdness.
void _splitpath (const char *path, char *drive, char *dir, char *fname, char *ext)
{
    *drive = 0;

    const char	*slash = strrchr(path, SLASH_CHAR),
            *dot	= strrchr(path, '.');

    if (dot && slash && dot < slash)
        dot = NULL;

    if (!slash)
    {
        *dir = 0;

        strcpy(fname, path);

        if (dot)
        {
            fname[dot - path] = 0;
            strcpy(ext, dot + 1);
        }
        else
            *ext = 0;
    }
    else
    {
        strcpy(dir, path);
        dir[slash - path] = 0;

        strcpy(fname, slash + 1);

        if (dot)
        {
            fname[dot - slash - 1] = 0;
            strcpy(ext, dot + 1);
        }
        else
            *ext = 0;
    }
}

void _makepath (char *path, const char *, const char *dir, const char *fname, const char *ext)
{
    if (dir && *dir)
    {
        strcpy(path, dir);
        strcat(path, SLASH_STR);
    }
    else
        *path = 0;

    strcat(path, fname);

    if (ext && *ext)
    {
        strcat(path, ".");
        strcat(path, ext);
    }
}
#endif // __WIN32__