From 2c843d964027089a747453afc0b07d0eac5835d9 Mon Sep 17 00:00:00 2001
From: notaz <notasas@gmail.com>
Date: Mon, 23 Jul 2012 00:29:46 +0300
Subject: [PATCH] cheat: add some undo logic

---
 frontend/main.c     |  1 +
 libpcsxcore/cheat.c | 24 +++++++++++++++++++++++-
 libpcsxcore/cheat.h |  2 ++
 3 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/frontend/main.c b/frontend/main.c
index 9d3cc333..15eae716 100644
--- a/frontend/main.c
+++ b/frontend/main.c
@@ -342,6 +342,7 @@ static void parse_cwcheat(void)
 			}
 			Cheats[NumCheats].Descr = strdup(name);
 			Cheats[NumCheats].Enabled = 0;
+			Cheats[NumCheats].WasEnabled = 0;
 			Cheats[NumCheats].First = NumCodes;
 			Cheats[NumCheats].n = 0;
 			NumCheats++;
diff --git a/libpcsxcore/cheat.c b/libpcsxcore/cheat.c
index 9ce7ed8d..a016aeec 100644
--- a/libpcsxcore/cheat.c
+++ b/libpcsxcore/cheat.c
@@ -108,6 +108,7 @@ void LoadCheats(const char *filename) {
 				Cheats[NumCheats].Descr = strdup(buf + 1);
 				Cheats[NumCheats].Enabled = 0;
 			}
+			Cheats[NumCheats].WasEnabled = 0;
 
 			Cheats[NumCheats].First = NumCodes;
 
@@ -182,11 +183,15 @@ void SaveCheats(const char *filename) {
 // apply all enabled cheats
 void ApplyCheats() {
 	int		i, j, k, endindex;
+	int		was_enabled;
 
 	for (i = 0; i < NumCheats; i++) {
+		was_enabled = Cheats[i].WasEnabled;
 		if (!Cheats[i].Enabled) {
-			continue;
+			if (!Cheats[i].WasEnabled)
+				continue;
 		}
+		Cheats[i].WasEnabled = Cheats[i].Enabled;
 
 		// process all cheat codes
 		endindex = Cheats[i].First + Cheats[i].n;
@@ -197,6 +202,22 @@ void ApplyCheats() {
 			u16		val = CheatCodes[j].Val;
 			u32		taddr;
 
+			if (!was_enabled) {
+				switch (type) {
+					case CHEAT_CONST16:
+						CheatCodes[j].OldVal = psxMu16(addr);
+						break;
+					case CHEAT_CONST8:
+						CheatCodes[j].OldVal = psxMu8(addr);
+						break;
+				}
+			}
+			else if (!Cheats[i].Enabled) {
+				val = CheatCodes[j].OldVal;
+				if (type != CHEAT_CONST16 && type != CHEAT_CONST8)
+					continue;
+			}
+
 			switch (type) {
 				case CHEAT_CONST8:
 					psxMu8ref(addr) = (u8)val;
@@ -321,6 +342,7 @@ int AddCheat(const char *descr, char *code) {
 
 	Cheats[NumCheats].Descr = strdup(descr[0] ? descr : _("(Untitled)"));
 	Cheats[NumCheats].Enabled = 0;
+	Cheats[NumCheats].WasEnabled = 0;
 	Cheats[NumCheats].First = NumCodes;
 	Cheats[NumCheats].n = 0;
 
diff --git a/libpcsxcore/cheat.h b/libpcsxcore/cheat.h
index c533b93f..b3d8bc4a 100644
--- a/libpcsxcore/cheat.h
+++ b/libpcsxcore/cheat.h
@@ -26,6 +26,7 @@ extern "C" {
 typedef struct {
 	uint32_t	Addr;
 	uint16_t	Val;
+	uint16_t	OldVal;
 } CheatCode;
 
 typedef struct {
@@ -33,6 +34,7 @@ typedef struct {
 	int			First;		// index of the first cheat code
 	int			n;			// number of cheat codes for this cheat
 	int			Enabled;
+	int			WasEnabled;
 } Cheat;
 
 void ClearAllCheats();
-- 
2.39.2