libretro#91: Optionally create empty disk images. Also show a notific…

…ation when DISK.ROM is required but not loaded

EMULib/FDIDisk.c

@@ -678,6 +678,8 @@ int SaveFDI(FDIDisk *D,const char *FileName,int Format)
   RFILE *F;
   byte *P,*T;
 
+  if (!FileName) return(0);
+
   /* Must have a disk to save */
   if(!D->Data) return(0);
 

README.md

@@ -12,7 +12,8 @@ Source : http://fms.komkon.org/fMSX/
 * .cas .CAS - for fMSX tape files
 * .m3u .M3U - for multidisk software
 
-The supplied location must exist and must be a readable file with one of the listed extensions. If, e.g., it points to a directory or non-existent file, 
+The supplied location must exist and must be a readable file with one of the listed extensions. 
+If, e.g., it points to a directory or non-existent file, 
 no image is loaded and this core will boot into MSX-BASIC. It is not possible to insert a disk into a running core.
 
 
@@ -45,6 +46,27 @@ Note:
 * images can only be swapped in the 'eject' state
 
 
+## Creating empty disk images
+An MSX computer will boot into an MSX-BASIC prompt when no cartridge or executable disk is inserted.
+By default, attempts to do disk I/O will then result in 'Disk offline' errors.
+
+To create an empty disk image, which can be written to from MSX-BASIC, set both of these options:
+* "Create empty disk image when none loaded": Yes (option `fmsx_phantom_disk`)
+* "Save changes to .dsk": Immediate or On close (option `fmsx_flush_disk`)
+Without the latter setting, changes to the created disk will be lost.
+
+This option can also be used to create User Disks for multi-disk games.
+
+The following situations can arise:
+* _no content selected when starting core_: changes will be lost; no filename is known
+* _non-existent .cas, .rom, .m3u or .fdi selected_: changes will be lost
+* _non-existent .dsk image selected_: .dsk image created on host filesystem
+* _non-existent file listed in .m3u_: .dsk image created on host filesystem
+* _RGUI > Quick Menu > Disk Control > Disk Image Append_: RGUI enforces an _existing_ file to be chosen.
+  However, this can, e.g., be a zero-byte file. 
+  As long as it has a .dsk file extension, a valid .dsk image file will be created & saved.
+
+
 ## Cheats
 "To make cheat codes for `Game.rom`, create `Game.cht` containing codes in `00AAAAAA-DD` and `00AAAAAA-DDDD` formats, one per line. 
 Where `AAAAAA` is the ROM address and `DD` is the value to write there. For 16bit values, use `DDDD`.
@@ -77,6 +99,7 @@ A restart is required after changing most of these options.
 |`fmsx_allsprites`|Show all sprites - do not emulate VDP hardware limitation|No*|Yes
 |`fmsx_font`|load a fixed text font from  RetroArch's `system_directory`|standard*|DEFAULT.FNT|ITALIC.FNT|INTERNAT.FNT|CYRILLIC.FNT|KOREAN.FNT|JAPANESE.FNT
 |`fmsx_flush_disk`|Save changes to .dsk image|Never*|Immediate|On close
+|`fmsx_phantom_disk`|Create empty disk image when none loaded|No*|Yes
 |`fmsx_custom_keyboard_XXX`<br>where XXX is `up`,`down`,`left`,`right`,`a`,`b`,`y`,`x`,`start`,`select`,`l`,`r`,`l2`,`r2`,`l3`,`r3`|For User 1 Device Type 'Custom Keyboard', map RetroPad button to selected MSX keyboard key|left&vert;up&vert;right&vert;down&vert;<br>shift&vert;ctrl&vert;graph&vert;<br>backspace&vert;tab&vert;escape&vert;space&vert;capslock&vert;select&vert;home&vert;enter&vert;del&vert;insert&vert;country&vert;dead&vert;stop&vert;<br>f1&vert;f2&vert;f3&vert;f4&vert;f5&vert;<br>keypad0~9&vert;kp_multiply&vert;kp_plus&vert;kp_divide&vert;kp_minus&vert;kp_comma&vert;kp_period&vert;<br>backquote&vert;minus&vert;equals&vert;leftbracket&vert;rightbracket&vert;backslash&vert;semicolon&vert;quote&vert;comma&vert;period&vert;slash&vert;<br>0-9&vert;a-z&vert;<br>
 |`fmsx_log_level`|Configure the amount of fMSX logging|Off*&vert;Info&vert;Debug&vert;Spam
 
@@ -107,12 +130,13 @@ These BIOS ROMs are required for execution:
 * MSX2+: MSX2P.ROM, MSX2PEXT.ROM
 
 Optional; loaded when found:
-* DISK.ROM
+* DISK.ROM - required to be able to run .dsk and .m3u images. 
+  A notification will be shown for 10s when loading such an image without a proper DISK.ROM in place.
 * FMPAC.ROM
 * KANJI.ROM
 * MSXDOS2.ROM (MSX2/2+)
 * PAINTER.ROM (MSX2/2+) - press space during boot to start
-* RS232.ROM
+* RS232.ROM - although serial COM I/O is removed in this core
 * CMOS.ROM
 * GMASTER2.ROM, GMASTER.ROM
 

fMSX/MSX.c

@@ -110,6 +110,7 @@ byte *SRAMData[MAXSLOTS];          /* SRAM (battery backed)  */
 
 /** Disk images used by fMSX *********************************/
 const char *DSKName[MAXDRIVES] = { "DRIVEA.DSK","DRIVEB.DSK" };
+byte DiskROMLoaded = 0;            /* 1 when DISK.ROM loaded */
 
 /** Fixed font used by fMSX **********************************/
 const char *FNTName = "DEFAULT.FNT"; /* Font file for text   */
@@ -439,6 +440,7 @@ int StartMSX(int NewMode,int NewRAMPages,int NewVRAMPages)
   CheatsON    = 0;
   CheatCount  = 0;
   MCFCount    = 0;
+  DiskROMLoaded = 0;
 
   /* Zero cartridge related data */
   for(J=0;J<MAXSLOTS;++J)
@@ -778,6 +780,7 @@ int ResetMSX(int NewMode,int NewRAMPages,int NewVRAMPages)
     if(Verbose && log_cb) log_cb(RETRO_LOG_INFO,"  Opening DISK.ROM...");
     P1=LoadROM("DISK.ROM",0x4000,0);
     PRINTRESULT(P1);
+    DiskROMLoaded=!!P1;
 
     /* Change to the working directory */
     if(WorkDir && chdir(WorkDir))

libretro.c

@@ -53,7 +53,8 @@ char *autotype=0;
 #define FLUSH_NEVER     0
 #define FLUSH_IMMEDIATE 1
 #define FLUSH_ON_CLOSE  2
-int disk_flush=FLUSH_NEVER;
+static int disk_flush=FLUSH_NEVER;
+static bool phantom_disk = false;
 
 extern int MCFCount;
 int current_cheat;
@@ -63,6 +64,9 @@ extern int RAMPages ;
 
 extern int VPeriod;
 
+extern byte DiskROMLoaded;
+bool require_disk_rom = false;
+
 #define SND_RATE 48000
 #define AUDIO_BUFFER_SIZE 1024 // .78 frames at 60Hz, .94 frames at 50Hz
 
@@ -515,6 +519,7 @@ void retro_set_environment(retro_environment_t cb)
       { "fmsx_allsprites", "Show all sprites; No|Yes" },
       { "fmsx_font", "Text font; standard|DEFAULT.FNT|ITALIC.FNT|INTERNAT.FNT|CYRILLIC.FNT|KOREAN.FNT|JAPANESE.FNT" },
       { "fmsx_flush_disk", "Save changes to .dsk; Never|Immediate|On close" },
+      { "fmsx_phantom_disk", "Create empty disk when none loaded; No|Yes" },
       { "fmsx_custom_keyboard_up", up_value},
       { "fmsx_custom_keyboard_down", down_value},
       { "fmsx_custom_keyboard_left", left_value},
@@ -577,7 +582,7 @@ void disk_flush_on_close(void)
 {
    if(disk_flush==FLUSH_ON_CLOSE && FDD[0].Dirty)
    {
-      SaveFDI(&FDD[0],DSKName[0],FMT_MSXDSK);
+      SaveFDI(&FDD[0],DSKName_buffer,FMT_MSXDSK);
       FDD[0].Dirty = 0;
    }
 }
@@ -617,17 +622,21 @@ bool set_image_index(unsigned index)
    if(disk_index == disk_images)
    {
       //retroarch is trying to set "no disk in tray"
-      ChangeDisk(0, NULL);
+      ChangeDisk(0,NULL);
       return true;
    }
 
    strncpy(DSKName_buffer, disk_paths[disk_index], PATH_MAX-1);
    DSKName_buffer[PATH_MAX-1] = 0;
    DSKName[0]=DSKName_buffer;
-   if(!ChangeDisk(0,DSKName[0]) && log_cb) {
-      log_cb(RETRO_LOG_ERROR, "%s %s\n", "could not load", disk_paths[disk_index]);
-      return false;
-   }
+   if(!ChangeDisk(0,DSKName[0]))
+      if (phantom_disk)
+         ChangeDisk(0,"");
+      else
+      {
+         if (log_cb) log_cb(RETRO_LOG_ERROR, "%s %s\n", "could not load", disk_paths[disk_index]);
+         return false;
+      }
 
    return true;
 }
@@ -923,6 +932,12 @@ static void check_variables(void)
    if (environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var) && var.value && strcmp(var.value, "Yes") == 0)
       Mode |= MSX_PATCHBDOS;
 
+   var.key = "fmsx_phantom_disk";
+   var.value = NULL;
+
+   if (environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var) && var.value && strcmp(var.value, "Yes") == 0)
+      phantom_disk=true;
+
    var.key = "fmsx_flush_disk";
    var.value = NULL;
 
@@ -1196,6 +1211,8 @@ bool retro_load_game(const struct retro_game_info *info)
    static char CasName_buffer[PATH_MAX];
    struct retro_keyboard_callback keyboard_event_callback;
    enum retro_pixel_format fmt = RETRO_PIXEL_FORMAT_RGB565;
+   bool have_image = false;
+   char *dot;
 
    if (!environ_cb(RETRO_ENVIRONMENT_SET_PIXEL_FORMAT, &fmt))
    {
@@ -1243,21 +1260,25 @@ bool retro_load_game(const struct retro_game_info *info)
 
    if (info && path_is_valid(info->path))
    {
-      char *dot = strrchr(info->path, '.');
+      dot = strrchr(info->path, '.');
       if (dot && ( !strcasecmp(dot, ".rom") || !strcasecmp(dot, ".mx1") || !strcasecmp(dot, ".mx2") ))
       {
          strcpy(ROMName_buffer, info->path);
          ROMName[0]=ROMName_buffer;
+         have_image = true;
       }
       else if (dot && ( !strcasecmp(dot, ".dsk") || !strcasecmp(dot, ".fdi") ))
       {
          strcpy(DSKName_buffer, info->path);
          DSKName[0]=DSKName_buffer;
+         have_image = true;
+         require_disk_rom = true;
       }
       else if (dot && !strcasecmp(dot, ".cas"))
       {
          strcpy(CasName_buffer, info->path);
          CasName=CasName_buffer;
+         have_image = true;
       }
       else if (dot && !strcasecmp(dot, ".m3u"))
       {
@@ -1269,6 +1290,8 @@ bool retro_load_game(const struct retro_game_info *info)
          set_image_index(0);
          disk_inserted = true;
          attach_disk_swap_interface();
+         have_image = true;
+         require_disk_rom = true;
       }
 
       if (try_loading_palette(info->path, "pal") || try_loading_palette(info->path, "PAL")) {}
@@ -1277,6 +1300,7 @@ bool retro_load_game(const struct retro_game_info *info)
    {
       ROMName[0]=NULL;
       DSKName[0]=NULL;
+      DSKName_buffer[0]=0;
       CasName=NULL;
    }
 
@@ -1289,14 +1313,23 @@ bool retro_load_game(const struct retro_game_info *info)
       SetColor(i, 0, 0, 0);
 
    for(i = 0; i < 256; i++)
-     BPal[i]=PIXEL(((i>>2)&0x07)*255/7,((i>>5)&0x07)*255/7,(i&0x03)*255/3);
+      BPal[i]=PIXEL(((i>>2)&0x07)*255/7,((i>>5)&0x07)*255/7,(i&0x03)*255/3);
 
    InitSound(SND_RATE, 0);
    SetChannels(255/MAXCHANNELS, (1<<MAXCHANNELS)-1);
 
    StartMSX(Mode,RAMPages,VRAMPages);
+   if (!have_image && phantom_disk)
+   {
+      if (info && (dot = strrchr(info->path, '.')) && !strcasecmp(dot, ".dsk"))
+         strcpy(DSKName_buffer, info->path);
+      ChangeDisk(0,"");
+      require_disk_rom = true;
+   }
    if (info) load_core_specific_cheats(info->path);
    update_fps();
+   if (require_disk_rom && !DiskROMLoaded)
+      show_message("DISK.ROM not loaded; content will not start", 10 * fps);
    setup_tape_autotype();
    return true;
 }
@@ -1483,7 +1516,7 @@ void retro_run(void)
    // debounce 1s before flushing to .dsk
    if(disk_flush==FLUSH_IMMEDIATE && FDD[0].Dirty && ++FDD[0].Dirty >= fps)
    {
-      SaveFDI(&FDD[0],DSKName[0],FMT_MSXDSK);
+      SaveFDI(&FDD[0],DSKName_buffer,FMT_MSXDSK);
       FDD[0].Dirty = 0;
    }
 }