Libretro: Add option to define FDS savefile format (#105)

Author: Ryunam

libretro/libretro.cpp

@@ -103,6 +103,17 @@ static bool is_pal;
 static byte custpal[64*3];
 static char slash;
 
+static enum {
+   FDS_SAVEFILE_SAV_UPS = 0,
+   FDS_SAVEFILE_UPS,
+   FDS_SAVEFILE_IPS,
+} fds_savefile_format;
+static bool fds_sav_extension;
+static bool fds_ups_extension;
+static bool fds_ips_extension;
+static bool fds_patch_format_ups;
+static bool fds_patch_format_ips;
+
 static const byte royaltea_palette[64][3] =
 {
    {0x5A,0x61,0x65}, {0x00,0x23,0xA8}, {0x0F,0x17,0xB0}, {0x28,0x12,0x9F},
@@ -420,11 +431,18 @@ static void NST_CALLBACK file_io_callback(void*, Api::User::File &file)
          break;
       case Api::User::File::LOAD_FDS:
          {
-            char base[256];
-            sprintf(base, "%s%c%s.sav", g_save_dir, slash, g_basename);
+            std::string base;
+            std::string ext;
+            if (fds_sav_extension)
+               ext = ".sav";
+            else if (fds_ups_extension)
+               ext = ".ups";
+            else if (fds_ips_extension)
+               ext = ".ips";
+            base = std::string(g_save_dir) + slash + g_basename + ext;
             if (log_cb)
-               log_cb(RETRO_LOG_INFO, "Want to load FDS sav from: %s\n", base);
-            std::ifstream in_tmp(base,std::ifstream::in|std::ifstream::binary);
+               log_cb(RETRO_LOG_INFO, "Want to load FDS savefile using %s extension from: %s\n", ext.c_str(), base.c_str());
+            std::ifstream in_tmp(base.c_str(),std::ifstream::in|std::ifstream::binary);
 
             if (!in_tmp.is_open())
                return;
@@ -434,14 +452,23 @@ static void NST_CALLBACK file_io_callback(void*, Api::User::File &file)
          break;
       case Api::User::File::SAVE_FDS:
          {
-            char base[256];
-            sprintf(base, "%s%c%s.sav", g_save_dir, slash, g_basename);
+            std::string base;
+            std::string ext;
+            if (fds_sav_extension)
+               ext = ".sav";
+            else if (fds_ups_extension)
+               ext = ".ups";
+            else if (fds_ips_extension)
+               ext = ".ips";
+            base = std::string(g_save_dir) + slash + g_basename + ext;
             if (log_cb)
-               log_cb(RETRO_LOG_INFO, "Want to save FDS sav to: %s\n", base);
-            std::ofstream out_tmp(base,std::ifstream::out|std::ifstream::binary);
+               log_cb(RETRO_LOG_INFO, "Want to save FDS savefile using %s extension to: %s\n", ext.c_str(), base.c_str());
+            std::ofstream out_tmp(base.c_str(),std::ifstream::out|std::ifstream::binary);
 
-            if (out_tmp.is_open())
+            if ((out_tmp.is_open()) && (fds_patch_format_ups))
                file.GetPatchContent(Api::User::File::PATCH_UPS, out_tmp);
+            else if ((out_tmp.is_open()) && (fds_patch_format_ips))
+               file.GetPatchContent(Api::User::File::PATCH_IPS, out_tmp);
          }
          break;
       default:
@@ -1117,7 +1144,28 @@ static void check_variables(void)
 
    if (environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var))
       fds_auto_insert = (strcmp(var.value, "enabled") == 0);
-   
+
+   var.key = "nestopia_fds_savefile_format";
+
+   if (environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var))
+   {
+      if (strcmp(var.value, "sav_ups") == 0)
+         fds_savefile_format = FDS_SAVEFILE_SAV_UPS;
+      else if (strcmp(var.value, "ups") == 0)
+         fds_savefile_format = FDS_SAVEFILE_UPS;
+      else if (strcmp(var.value, "ips") == 0)
+         fds_savefile_format = FDS_SAVEFILE_IPS;
+
+      /* FDS savefile format checks are positioned here to allow changes at runtime.
+       * This makes it possible to convert any savefile currently in use to the preferred format.*/
+      fds_sav_extension = (fds_savefile_format == FDS_SAVEFILE_SAV_UPS);
+      fds_ups_extension = (fds_savefile_format == FDS_SAVEFILE_UPS);
+      fds_ips_extension = (fds_savefile_format == FDS_SAVEFILE_IPS);
+      fds_patch_format_ups = ((fds_savefile_format == FDS_SAVEFILE_SAV_UPS) ||
+                              (fds_savefile_format == FDS_SAVEFILE_UPS));
+      fds_patch_format_ips = (fds_savefile_format == FDS_SAVEFILE_IPS);
+   }
+
    var.key = "nestopia_blargg_ntsc_filter";
 
    if (environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var))

libretro/libretro_core_options.h

@@ -114,6 +114,21 @@ struct retro_core_option_v2_definition option_defs_us[] = {
       },
       "enabled"
    },
+   {
+      "nestopia_fds_savefile_format",
+      "FDS Savefile Format",
+      NULL,
+      "Define which format will be used by savefiles generated for FDS games. Based on the format chosen, FDS savefiles might be used interchangeably with other cores and standalone emulators. It is recommended to use with caution, as improper handling may cause undesired overwrites, or deletion of the existing saves.",
+      NULL,
+      "system",
+      {
+         { "sav_ups", "SAV + UPS (Default)" },
+         { "ups",     "UPS (Standalone Nestopia)" },
+         { "ips",     "IPS (Mesen)" },
+         { NULL, NULL },
+      },
+      "sav_ups"
+   },
 
 /* Video */