Refactor cheat decoding, add support for Master System cheats.

libretro/libretro.c

@@ -1190,14 +1190,13 @@ static uint32_t decode_cheat(char *string, int index)
    uint32_t address = 0;
    uint16_t data = 0;
    uint8_t ref = 0;
-   /* 16-bit Game Genie code (ABCD-EFGH) */
+
+   if ((system_hw & SYSTEM_PBC) == SYSTEM_MD){
+      //If system is Genesis-based
+
+      //Game-Genie
       if ((strlen(string) >= 9) && (string[4] == '-'))
       {
-      /* 16-bit system only */
-      if ((system_hw & SYSTEM_PBC) != SYSTEM_MD)
-      {
-         return 0;
-      }
          for (i = 0; i < 8; i++)
          {
             if (i == 4) string++;
@@ -1238,14 +1237,36 @@ static uint32_t decode_cheat(char *string, int index)
          /* code length */
          len = 9;
       }
-   /* 8-bit Game Genie code (DDA-AAA-XXX) */
+
-   else if ((strlen(string) >= 11) && (string[3] == '-') && (string[7] == '-'))
+      //Patch and PAR
+      else if ((strlen(string) >=9) && (string[6] == ':'))
       {
-      /* 8-bit system only */
+         /* decode 24-bit address */
-      if ((system_hw & SYSTEM_PBC) == SYSTEM_MD)
+         for (i=0; i<6; i++)
          {
-         return 0;
+            p = strchr (arvalidchars, *string++);
+            if (p == NULL) return 0;
+            n = (p - arvalidchars) & 0xF;
+            address |= (n << ((5 - i) * 4));
          }
+         /* decode 16-bit data */
+         string++;
+         for (i=0; i<4; i++)
+         {
+            p = strchr (arvalidchars, *string++);
+            if (p == NULL) break;
+            n = (p - arvalidchars) & 0xF;
+            data |= (n << ((3 - i) * 4));
+         }
+         /* code length */
+         len = 11;
+      }
+   } else {
+      //If System is Master-based
+
+      //Game Genie
+      if ((strlen(string) >=11) && (string[3] == '-') && (string[7] == '-'))
+      {
          /* decode 8-bit data */
          for (i=0; i<2; i++)
          {
@@ -1291,39 +1312,35 @@ static uint32_t decode_cheat(char *string, int index)
          /* code length */
          len = 11;
       }
-   /* Action Replay code */
+
-   else if (string[6] == ':')
+      //Action Replay
-   {
+      else if ((strlen(string) >=9) && (string[4] == '-')){
-      if ((system_hw & SYSTEM_PBC) == SYSTEM_MD)
+         string+=2;
-      {
+         /* decode 16-bit address */
-         /* 16-bit code (AAAAAA:DDDD) */
-         if (strlen(string) < 11) return 0;
-         /* decode 24-bit address */
-         for (i=0; i<6; i++)
-         {
-            p = strchr (arvalidchars, *string++);
-            if (p == NULL) return 0;
-            n = (p - arvalidchars) & 0xF;
-            address |= (n << ((5 - i) * 4));
-         }
-         /* decode 16-bit data */
-         string++;
          for (i=0; i<4; i++)
          {
             p = strchr (arvalidchars, *string++);
             if (p == NULL) return 0;
             n = (p - arvalidchars) & 0xF;
-            data |= (n << ((3 - i) * 4));
+            address |= (n << ((3 - i) * 4));
+            if (i==1) string++;
+         }
+         /* decode 8-bit data */
+         for (i=0; i<2; i++)
+         {
+            p = strchr (arvalidchars, *string++);
+            if (p == NULL) return 0;
+            n = (p - arvalidchars) & 0xF;
+            data |= (n << ((1 - i) * 4));
          }
          /* code length */
-         len = 11;
+         len = 9;
       }
-      else
+
+      //Fusion RAM
+      else if ((strlen(string) >=7) && (string[4] == ':'))
       {
-         /* 8-bit code (xxAAAA:DD) */
-         if (strlen(string) < 9) return 0;
          /* decode 16-bit address */
-         string+=2;
          for (i=0; i<4; i++)
          {
             p = strchr (arvalidchars, *string++);
@@ -1331,10 +1348,6 @@ static uint32_t decode_cheat(char *string, int index)
             n = (p - arvalidchars) & 0xF;
             address |= (n << ((3 - i) * 4));
          }
-         /* ROM addresses are not supported */
-         if (address < 0xC000) return 0;
-         /* convert to 24-bit Work RAM address */
-         address = 0xFF0000 | (address & 0x1FFF);
          /* decode 8-bit data */
          string++;
          for (i=0; i<2; i++)
@@ -1345,6 +1358,40 @@ static uint32_t decode_cheat(char *string, int index)
             data |= (n << ((1 - i) * 4));
          }
          /* code length */
+         len = 7;
+      }
+
+      //Fusion ROM
+      else if ((strlen(string) >=9) && (string[6] == ':'))
+      {
+         /* decode reference 8-bit data */
+         for (i=0; i<2; i++)
+         {
+            p = strchr (arvalidchars, *string++);
+            if (p == NULL) return 0;
+            n = (p - arvalidchars) & 0xF;
+            ref |= (n << ((1 - i) * 4));
+         }
+         /* decode 16-bit address */
+         for (i=0; i<4; i++)
+         {
+            p = strchr (arvalidchars, *string++);
+            if (p == NULL) return 0;
+            n = (p - arvalidchars) & 0xF;
+            address |= (n << ((3 - i) * 4));
+         }
+         /* decode 8-bit data */
+         string++;
+         for (i=0; i<2; i++)
+         {
+            p = strchr (arvalidchars, *string++);
+            if (p == NULL) return 0;
+            n = (p - arvalidchars) & 0xF;
+            data |= (n << ((1 - i) * 4));
+         }
+         /* update old data value */
+         cheatlist[index].old = ref;
+         /* code length */
          len = 9;
       }
    }
@@ -1894,19 +1941,16 @@ void retro_cheat_set(unsigned index, bool enabled, const char *code)
 {
 	char codeCopy[256];
 	char *buff;
-	bool multiline=0;
+   
+   /* Avoid crashing when giving empty input */
+   if (code=='\0') return;
 
    /* clear existing ROM patches */
    clear_cheats();
 
    /* Detect and split multiline cheats */
 	strcpy(codeCopy,code);
-	if (strstr(code,"+")){
-		multiline=1;
    buff = strtok(codeCopy,"+");
-	} else {
-		buff=codeCopy;
-	}
 
 	while (buff != NULL)
 	{
@@ -1933,8 +1977,6 @@ void retro_cheat_set(unsigned index, bool enabled, const char *code)
             maxcheats++;
          }
       }
-		if (!multiline)
-			break;
       buff = strtok(NULL,"+");
 	}