Added ROM memory domain, core option to ignore EDC/L-EC errors (#239)

* added ROM memory region

* new optimizations for volume hacks

* safer bit shifting for volume scaling

* added core option to ignore cd edc errors

Author: eadmaster

libretro-common/include/libretro.h

@@ -322,6 +322,9 @@ enum retro_language
 /* Video ram lets a frontend peek into a game systems video RAM (VRAM). */
 #define RETRO_MEMORY_VIDEO_RAM   3
 
+/* ROM lets a frontend peek into a game systems ROM. */
+#define RETRO_MEMORY_ROM   4
+
 /* Keysyms used for ID in input state callback when polling RETRO_KEYBOARD. */
 enum retro_key
 {

libretro.cpp

@@ -1873,6 +1873,16 @@ static void check_variables(bool first_run)
       do_cdsettings = true;
       setting_pce_fast_cdpsgvolume = atoi(var.value);
    }
+   
+   var.key      = "pce_fast_cdignoreerrors";
+   setting_pce_fast_cdignoreerrors = false;
+
+   if (environ_cb(RETRO_ENVIRONMENT_GET_VARIABLE, &var) && var.value)
+      if (strcmp(var.value, "enabled") == 0)
+      {
+         setting_pce_fast_cdignoreerrors = true;
+      }
+
 
    var.key = "pce_fast_cdspeed";
 
@@ -2615,6 +2625,8 @@ void *retro_get_memory_data(unsigned type)
          return BaseRAM;
       case RETRO_MEMORY_VIDEO_RAM:
          return vdc->VRAM;
+      case RETRO_MEMORY_ROM:
+         return ROMSpace;
       default:
          break;
    }
@@ -2634,6 +2646,8 @@ size_t retro_get_memory_size(unsigned type)
          return 8192;
       case RETRO_MEMORY_VIDEO_RAM:
          return 65536;
+      case RETRO_MEMORY_ROM:
+         return (0x88 * 8192 + 8192);  // TODO: dynamic based on loaded content?
       default:
          break;
    }

libretro_core_options.h

@@ -731,6 +731,21 @@ struct retro_core_option_v2_definition option_defs_us[] = {
       },
       "100"
    },
+   {
+      "pce_fast_cdignoreerrors",
+      "CD Ignore EDC/L-EC Errors",
+      NULL,
+      "Ignore EDC/L-EC errors. Needed for compatibility with some hacks.",
+      NULL,
+      "cd",
+      {
+         { "disabled", NULL },
+         { "enabled", NULL },
+         { NULL, NULL },
+      },
+      "disabled"
+   },
+
    {
       "pce_fast_nospritelimit",
       "No Sprite Limit",

mednafen/pce_fast/pcecd_drive.cpp

@@ -158,6 +158,8 @@ static int32 CDReadTimer;
 static uint32 SectorAddr;
 static uint32 SectorCount;
 
+bool setting_pce_fast_cdignoreerrors;
+
 
 enum
 {
@@ -412,7 +414,12 @@ static void CommandCCError(int key, int asc = 0, int ascq = 0)
 
 static bool ValidateRawDataSector(uint8 *data, const uint32 lba)
 {
- if(!edc_lec_check_and_correct(data, false))
+ bool c = edc_lec_check_and_correct(data, false);
+ 
+ //if(!c)
+ //    printf("failed ValidateRawDataSector: %x\n", lba);
+     
+ if(!c && !setting_pce_fast_cdignoreerrors)
  {
     din.Flush();
     cd.data_transfer_done = false;

mednafen/pce_fast/pcecd_drive.h

@@ -16,6 +16,7 @@ struct pcecd_drive_bus_t
 };
 
 extern pcecd_drive_bus_t cd_bus; // Don't access this structure directly by name outside of pcecd_drive.c, but use the macros below.
+extern bool setting_pce_fast_cdignoreerrors;
 
 // Signals under our(the "target") control.
 #define PCECD_Drive_IO_mask	0x001

mednafen/pce_fast/psg.cpp

@@ -50,8 +50,8 @@ void PCEFast_PSG::UpdateOutput_Norm(const int32 timestamp, psg_channel *ch)
 
    if(ch->user_volume < 100)
    {
-       delta0 = (samp[0] - ch->blip_prev_samp[0]) * ch->user_volume / 100;
-       delta1 = (samp[1] - ch->blip_prev_samp[1]) * ch->user_volume / 100;
+       delta0 = ((samp[0] - ch->blip_prev_samp[0]) * ch->user_volume * 164) >> 14;
+       delta1 = ((samp[1] - ch->blip_prev_samp[1]) * ch->user_volume * 164) >> 14;
    } else {
        delta0 = samp[0] - ch->blip_prev_samp[0];
        delta1 = samp[1] - ch->blip_prev_samp[1];
@@ -76,8 +76,8 @@ void PCEFast_PSG::UpdateOutput_Noise(const int32 timestamp, psg_channel *ch)
 
    if(ch->user_volume < 100)
    {
-       delta0 = (samp[0] - ch->blip_prev_samp[0]) * ch->user_volume / 100;
-       delta1 = (samp[1] - ch->blip_prev_samp[1]) * ch->user_volume / 100;
+       delta0 = ((samp[0] - ch->blip_prev_samp[0]) * ch->user_volume * 164) >> 14;
+       delta1 = ((samp[1] - ch->blip_prev_samp[1]) * ch->user_volume * 164) >> 14;
    } else {
        delta0 = samp[0] - ch->blip_prev_samp[0];
        delta1 = samp[1] - ch->blip_prev_samp[1];
@@ -100,8 +100,8 @@ void PCEFast_PSG::UpdateOutput_Off(const int32 timestamp, psg_channel *ch)
 
    if(ch->user_volume < 100)
    {
-       delta0 = (samp[0] - ch->blip_prev_samp[0]) * ch->user_volume / 100;
-       delta1 = (samp[1] - ch->blip_prev_samp[1]) * ch->user_volume / 100;
+       delta0 = ((samp[0] - ch->blip_prev_samp[0]) * ch->user_volume * 164) >> 14;
+       delta1 = ((samp[1] - ch->blip_prev_samp[1]) * ch->user_volume * 164) >> 14;
    } else {
        delta0 = samp[0] - ch->blip_prev_samp[0];
        delta1 = samp[1] - ch->blip_prev_samp[1];
@@ -126,8 +126,8 @@ void PCEFast_PSG::UpdateOutput_Accum(const int32 timestamp, psg_channel *ch)
 
    if(ch->user_volume < 100)
    {
-       delta0 = (samp[0] - ch->blip_prev_samp[0]) * ch->user_volume / 100;
-       delta1 = (samp[1] - ch->blip_prev_samp[1]) * ch->user_volume / 100;
+       delta0 = ((samp[0] - ch->blip_prev_samp[0]) * ch->user_volume * 164) >> 14;
+       delta1 = ((samp[1] - ch->blip_prev_samp[1]) * ch->user_volume * 164) >> 14;
    } else {
        delta0 = samp[0] - ch->blip_prev_samp[0];
        delta1 = samp[1] - ch->blip_prev_samp[1];