From e708dc478117d0073e9ab14429a638b960002e66 Mon Sep 17 00:00:00 2001
From: devinacker <d@revenant1.net>
Date: Sun, 10 Jun 2018 22:55:22 -0400
Subject: [PATCH] improve handling of cheats to handle things other than WRAM
 (closes #97)

note: mirroring detection for cheats doesn't work for two addresses in
the same 64kb bank i.e. the lowest 16 bits of both addresses must still
be the same
---
 README.md                           |  7 -------
 bsnes/snes/cheat/cheat-inline.hpp   |  2 +-
 bsnes/snes/cheat/cheat.cpp          | 29 +++--------------------------
 bsnes/snes/cheat/cheat.hpp          |  7 +++----
 bsnes/snes/memory/memory-inline.hpp |  2 +-
 5 files changed, 8 insertions(+), 39 deletions(-)

diff --git a/README.md b/README.md
index 01d93be..00447d6 100644
--- a/README.md
+++ b/README.md
@@ -25,13 +25,6 @@ Non-debugging features:
 - IPS and BPS soft patching
 - Multiple emulation improvements backported from bsnes/higan (mostly via bsnes-classic)
 
-## Coming soon
-
-- On-the-fly ROM saving and reloading from the memory editor for quick hacking and testing
-- More keyboard shortcuts for menus, etc.
-- Automatic saving/loading breakpoints between sessions
-- Similar addressing improvements for cheats
-
 ## Building on Windows
 
 - Get mingw-w64 (http://mingw-w64.yaxm.org/doku.php/download)
diff --git a/bsnes/snes/cheat/cheat-inline.hpp b/bsnes/snes/cheat/cheat-inline.hpp
index a80f47f..9ef28cb 100644
--- a/bsnes/snes/cheat/cheat-inline.hpp
+++ b/bsnes/snes/cheat/cheat-inline.hpp
@@ -1,2 +1,2 @@
 bool Cheat::active() const { return cheat_enabled; }
-bool Cheat::exists(unsigned addr) const { return bitmask[addr >> 3] & 1 << (addr & 7); }
+bool Cheat::exists(uint16 addr) const { return bitmask[addr >> 3] & 1 << (addr & 7); }
diff --git a/bsnes/snes/cheat/cheat.cpp b/bsnes/snes/cheat/cheat.cpp
index 40fdf7c..51de966 100644
--- a/bsnes/snes/cheat/cheat.cpp
+++ b/bsnes/snes/cheat/cheat.cpp
@@ -25,34 +25,21 @@ void Cheat::synchronize() {
     for(unsigned n = 0; n < code.addr.size(); n++) {
       code_enabled = true;
 
-      unsigned addr = mirror(code.addr[n]);
+      uint16 addr = code.addr[n];
       bitmask[addr >> 3] |= 1 << (addr & 7);
-      if((addr & 0xffe000) == 0x7e0000) {
-        //mirror $7e:0000-1fff to $00-3f|80-bf:0000-1fff
-        unsigned mirroraddr;
-        for(unsigned x = 0; x <= 0x3f; x++) {
-          mirroraddr = ((0x00 + x) << 16) + (addr & 0x1fff);
-          bitmask[mirroraddr >> 3] |= 1 << (mirroraddr & 7);
-
-          mirroraddr = ((0x80 + x) << 16) + (addr & 0x1fff);
-          bitmask[mirroraddr >> 3] |= 1 << (mirroraddr & 7);
-        }
-      }
     }
   }
 
   cheat_enabled = system_enabled && code_enabled;
 }
 
-bool Cheat::read(unsigned addr, uint8 &data) const {
-  addr = mirror(addr);
-
+bool Cheat::read(unsigned addr, uint8 &data, Bus &bus) const {
   for(unsigned i = 0; i < size(); i++) {
     const CheatCode &code = operator[](i);
     if(code.enabled == false) continue;
 
     for(unsigned n = 0; n < code.addr.size(); n++) {
-      if(addr == mirror(code.addr[n])) {
+      if(bus.is_mirror(addr, code.addr[n])) {
         data = code.data[n];
         return true;
       }
@@ -149,16 +136,6 @@ bool Cheat::encode(string &s, unsigned addr, uint8 data, Type type) {
   }
 }
 
-//========
-//internal
-//========
-
-unsigned Cheat::mirror(unsigned addr) const {
-  //$00-3f|80-bf:0000-1fff -> $7e:0000-1fff
-  if((addr & 0x40e000) == 0x000000) return (0x7e0000 + (addr & 0x1fff));  
-  return addr;
-}
-
 //=========
 //CheatCode
 //=========
diff --git a/bsnes/snes/cheat/cheat.hpp b/bsnes/snes/cheat/cheat.hpp
index ac4b43e..d13de53 100644
--- a/bsnes/snes/cheat/cheat.hpp
+++ b/bsnes/snes/cheat/cheat.hpp
@@ -14,10 +14,10 @@ public:
   bool enabled() const;
   void enable(bool);
   void synchronize();
-  bool read(unsigned, uint8&) const;
+  bool read(unsigned, uint8&, Bus&) const;
 
   inline bool active() const;
-  inline bool exists(unsigned addr) const;
+  inline bool exists(uint16 addr) const;
 
   Cheat();
 
@@ -25,11 +25,10 @@ public:
   static bool encode(string&, unsigned, uint8, Type);
 
 private:
-  uint8 bitmask[0x200000];
+  uint8 bitmask[0x2000];
   bool system_enabled;
   bool code_enabled;
   bool cheat_enabled;
-  unsigned mirror(unsigned) const;
 };
 
 extern Cheat cheat;
diff --git a/bsnes/snes/memory/memory-inline.hpp b/bsnes/snes/memory/memory-inline.hpp
index 8bbcd7c..215b369 100644
--- a/bsnes/snes/memory/memory-inline.hpp
+++ b/bsnes/snes/memory/memory-inline.hpp
@@ -63,7 +63,7 @@ uint8 Bus::read(uint24 addr) {
   #if defined(CHEAT_SYSTEM)
   if(cheat.active() && cheat.exists(addr)) {
     uint8 r;
-    if(cheat.read(addr, r)) return r;
+    if(cheat.read(addr, r, *this)) return r;
   }
   #endif
   Page &p = page[addr >> 8];