Merge pull request #36 from ilag11111/cheatSupport

Add cheats to SNES games
libretro · Mar 26, 2017 · a9204c5 · a9204c5
2 parents 5b802d8 + da026a5
commit a9204c5
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Showing 5 changed files with 175 additions and 8 deletions.
diff --git a/gb/cheat/cheat.cpp b/gb/cheat/cheat.cpp
@@ -1,4 +1,5 @@
 #include <gb/gb.hpp>
+#include <iostream>
 
 namespace GameBoy {
 
@@ -25,4 +26,22 @@ optional<unsigned> Cheat::find(unsigned addr, unsigned comp) {
   return false;
 }
 
+bool Cheat::decode(const char *part, unsigned &addr, unsigned &comp, unsigned &data) {
+  /* Code Types
+   * RAW:
+   *   AAAA:DD
+   * Game Genie: http://gamehacking.org/library/114
+   * GameShark: 0BDDAAAA - Byteswapped Address, bank+1
+   * Codebreaker: 0BAAAA-DD
+   * Xploder: Unknown
+   */
+  std::cerr << "[bsnes]: Decoding cheats not implemented." << std::endl;
+  return false;
+}
+
+void Cheat::synchronize() {
+  std::cerr << "[bsnes]: Synchronizing cheats not implemented." << std::endl;
+  return;
+}
+
 }
diff --git a/gb/cheat/cheat.hpp b/gb/cheat/cheat.hpp
@@ -12,6 +12,9 @@ struct Cheat {
   void append(unsigned addr, unsigned data);
   void append(unsigned addr, unsigned comp, unsigned data);
   optional<unsigned> find(unsigned addr, unsigned comp);
+
+  bool decode(const char *part, unsigned &addr, unsigned &comp, unsigned &data);
+  void synchronize();
 };
 
 extern Cheat cheat;
diff --git a/sfc/cheat/cheat.cpp b/sfc/cheat/cheat.cpp
@@ -1,4 +1,6 @@
 #include <sfc/sfc.hpp>
+#include <iostream>
+#include <cstdlib>
 
 #define CHEAT_CPP
 namespace SuperFamicom {
@@ -29,4 +31,146 @@ optional<unsigned> Cheat::find(unsigned addr, unsigned comp) {
   return false;
 }
 
+static char genie_replace(char input){
+  switch (input){
+    case '0':
+      return '4';
+    case '1':
+      return '6';
+    case '2':
+      return 'D';
+    case '3':
+      return 'E';
+    case '4':
+      return '2';
+    case '5':
+      return '7';
+    case '6':
+      return '8';
+    case '7':
+      return '3';
+    case '8':
+      return 'B';
+    case '9':
+      return '5';
+    case 'A':
+    case 'a':
+      return 'C';
+    case 'B':
+    case 'b':
+      return '9';
+    case 'C':
+    case 'c':
+      return 'A';
+    case 'D':
+    case 'd':
+      return '0';
+    case 'E':
+    case 'e':
+      return 'F';
+    case 'F':
+    case 'f':
+      return '1';
+  }
+}
+
+bool Cheat::decode(const char *part, unsigned &addr, unsigned &data) {
+  char addr_str[7], data_str[3];
+  addr_str[6]=0;
+  data_str[2]=0;
+  addr=data=0;
+
+  //RAW
+  if (strlen(part)>=9 && part[6]==':') {
+    strncpy(addr_str,part,6);
+    strncpy(data_str,part+7,2);
+    addr=strtoul(addr_str,'\0',16);
+    data=strtoul(data_str,'\0',16);
+  }
+
+  //Game Genie
+  else if (strlen(part)>=9 && part[4]=='-') {
+    strncpy(data_str,part,2);
+    strncpy(addr_str,part+2,2);
+    strncpy(addr_str+2,part+5,4);
+    for (int i=0;i<2;i++)
+      data_str[i]=genie_replace(data_str[i]);
+    for (int i=0;i<6;i++)
+      addr_str[i]=genie_replace(addr_str[i]);
+    data=strtoul(data_str,'\0',16);
+    int addr_scrambled=strtoul(addr_str,'\0',16);
+    addr=(addr_scrambled&0x003C00)<<10;
+    addr|=(addr_scrambled&0x00003C)<<14;
+    addr|=(addr_scrambled&0xF00000)>>8;
+    addr|=(addr_scrambled&0x000003)<<10;
+    addr|=(addr_scrambled&0x00C000)>>6;
+    addr|=(addr_scrambled&0x0F0000)>>12;
+    addr|=(addr_scrambled&0x0003C0)>>6;
+    return true;
+  }
+
+  //PAR & X-Terminator
+  else if (strlen(part)==8) {
+    strncpy(addr_str,part,6);
+    strncpy(data_str,part+6,2);
+    addr=strtoul(addr_str,'\0',16);
+    data=strtoul(data_str,'\0',16);
+  }
+
+  //Gold Finger
+  else if (strlen(part)==14) {
+    if (part[13]=='1'){
+      std::cout << "[bsnes]: CHEAT: Goldfinger SRAM cheats not supported: " << part << std::endl;
+      return false;
+    }
+    addr_str[0]='0';
+    strncpy(addr_str+1,part,5);
+    strncpy(data_str,part+5,2);
+    if (part[7]!='X' && part[7]!='x')
+      std::cout << "[bsnes]: CHEAT: Goldfinger multibyte cheats not supported: " << part << std::endl;
+
+    char pair_str[3];
+    pair_str[2]=0;
+    int csum_calc=0,csum_code;
+    for (int i=0;i<6;i++){
+      if (i<3){
+        strncpy(pair_str,addr_str+2*i,2);
+      } else {
+        strncpy(pair_str,part+2*i-1,2);
+      }
+      csum_calc+=strtoul(pair_str,'\0',16);
+    }
+    csum_calc-=0x160;
+    csum_calc&=0xFF;
+    strncpy(pair_str,part+11,2);
+    csum_code=strtoul(pair_str,'\0',16);
+    if (csum_calc!=csum_code){
+      std::cout << "[bsnes]: CHEAT: Goldfinger calculated checksum '" << std::hex << csum_calc <<  "' doesn't match code: " << part << std::endl;
+      return false;
+    }
+
+    int addr_scrambled=strtoul(addr_str,'\0',16);
+    addr=(addr_scrambled&0x7FFF)|((addr_scrambled&0x7F8000)<<1)|0x8000;
+    data=strtoul(data_str,'\0',16);
+    std::cout << "CHEAT: " << part << " decoded as " << std::hex <<  addr << ":" << data << std::endl;
+  }
+
+  //Unknown
+  else {
+    std::cout << "[bsnes]: CHEAT: Unrecognized code type: " << part << std::endl;
+    return false;
+  }
+
+  if (addr == 0 || data == 0){
+    std::cout << "[bsnes]: CHEAT: Decoding failed: " << part << std::endl;
+    return false;
+  }
+
+  return true;
+}
+
+void Cheat::synchronize() {
+  return;
+}
+
 }
diff --git a/sfc/cheat/cheat.hpp b/sfc/cheat/cheat.hpp
@@ -12,6 +12,9 @@ struct Cheat {
   void append(unsigned addr, unsigned data);
   void append(unsigned addr, unsigned comp, unsigned data);
   optional<unsigned> find(unsigned addr, unsigned comp);
+
+  bool decode(const char *part, unsigned &addr, unsigned &data);
+  void synchronize();
 };
 
 extern Cheat cheat;
diff --git a/target-libretro/libretro.cpp b/target-libretro/libretro.cpp
@@ -401,17 +401,16 @@ Interface::Interface() {
   core_bind.iface = &core_interface;
 }
 
-void Interface::setCheats(const lstring &) {
-#if 0
+void Interface::setCheats(const lstring & list) {
   if(core_interface.mode == SuperFamicomCartridge::ModeSuperGameBoy) {
     GameBoy::cheat.reset();
     for(auto &code : list) {
       lstring codelist;
       codelist.split("+", code);
       for(auto &part : codelist) {
         unsigned addr, data, comp;
-        if(GameBoy::Cheat::decode(part, addr, data, comp)) {
-          GameBoy::cheat.append({addr, data, comp});
+        if(GameBoy::cheat.decode(part, addr, comp, data)) {
+          GameBoy::cheat.append(addr, comp, data);
         }
       }
     }
@@ -425,14 +424,13 @@ void Interface::setCheats(const lstring &) {
     codelist.split("+", code);
     for(auto &part : codelist) {
       unsigned addr, data;
-      if(SuperFamicom::Cheat::decode(part, addr, data)) {
-        SuperFamicom::cheat.append({addr, data});
+      if(SuperFamicom::cheat.decode(part, addr, data)) {
+        SuperFamicom::cheat.append(addr, data);
       }
     }
   }
 
   SuperFamicom::cheat.synchronize();
-#endif
 }
 
 unsigned retro_api_version(void) {
@@ -584,7 +582,7 @@ void retro_cheat_reset(void) {
 }
 
 void retro_cheat_set(unsigned index, bool enable, const char *code) {
-  cheatList.reserve(index+1);
+  cheatList.resize(index+1);
   cheatList[index].enable = enable;
   cheatList[index].code = code;