From 688bdb9526d42181368e64ceaa6828727a10188c Mon Sep 17 00:00:00 2001
From: notaz <notasas@gmail.com>
Date: Sat, 12 Nov 2022 23:05:52 +0200
Subject: [PATCH] cdrom: make the timing hack conditional

libretro/pcsx_rearmed#707
---
 libpcsxcore/cdrom.c     | 11 +++++++--
 libpcsxcore/database.c  | 53 ++++++++++++++++++++++++++++++++---------
 libpcsxcore/psxcommon.h |  3 +++
 3 files changed, 54 insertions(+), 13 deletions(-)

diff --git a/libpcsxcore/cdrom.c b/libpcsxcore/cdrom.c
index 0f1479e2..18d6bf9e 100644
--- a/libpcsxcore/cdrom.c
+++ b/libpcsxcore/cdrom.c
@@ -597,8 +597,14 @@ static u32 cdrAlignTimingHack(u32 cycles)
 	 * active), but before the game's handler loop reads I_STAT. The time
 	 * window for this is quite small (~1k cycles of so). Apparently this
 	 * somehow happens naturally on the real hardware.
+	 *
+	 * Note: always enforcing this breaks other games like Crash PAL version
+	 * (inputs get dropped because bios handler doesn't see interrupts).
 	 */
-	u32 vint_rel = rcnts[3].cycleStart + 63000 - psxRegs.cycle;
+	u32 vint_rel;
+	if (psxRegs.cycle - rcnts[3].cycleStart > 250000)
+		return cycles;
+	vint_rel = rcnts[3].cycleStart + 63000 - psxRegs.cycle;
 	vint_rel += PSXCLK / 60;
 	while ((s32)(vint_rel - cycles) < 0)
 		vint_rel += PSXCLK / 60;
@@ -1154,7 +1160,8 @@ void cdrInterrupt(void) {
 
 			cycles = (cdr.Mode & 0x80) ? cdReadTime : cdReadTime * 2;
 			cycles += seekTime;
-			cycles = cdrAlignTimingHack(cycles);
+			if (Config.hacks.cdr_read_timing)
+				cycles = cdrAlignTimingHack(cycles);
 			CDRPLAYREAD_INT(cycles, 1);
 
 			SetPlaySeekRead(cdr.StatP, STATUS_SEEK);
diff --git a/libpcsxcore/database.c b/libpcsxcore/database.c
index 1ea8d43b..f947b068 100644
--- a/libpcsxcore/database.c
+++ b/libpcsxcore/database.c
@@ -5,16 +5,32 @@
 /* It's duplicated from emu_if.c */
 #define ARRAY_SIZE(x) (sizeof(x) / sizeof(x[0]))
 
-static const char MemorycardHack_db[8][10] =
+static const char * const MemorycardHack_db[] =
 {
 	/* Lifeforce Tenka, also known as Codename Tenka */
-	{"SLES00613"},
-	{"SLED00690"},
-	{"SLES00614"},
-	{"SLES00615"},
-	{"SLES00616"},
-	{"SLES00617"},
-	{"SCUS94409"}
+	"SLES00613", "SLED00690", "SLES00614", "SLES00615",
+	"SLES00616", "SLES00617", "SCUS94409"
+};
+
+static const char * const cdr_read_hack_db[] =
+{
+	/* T'ai Fu - Wrath of the Tiger */
+	"SLUS00787",
+};
+
+#define HACK_ENTRY(var, list) \
+	{ #var, &Config.hacks.var, list, ARRAY_SIZE(list) }
+
+static const struct
+{
+	const char *name;
+	boolean *var;
+	const char * const * id_list;
+	size_t id_list_len;
+}
+hack_db[] =
+{
+	HACK_ENTRY(cdr_read_timing, cdr_read_hack_db),
 };
 
 static const struct
@@ -42,10 +58,24 @@ cycle_multiplier_overrides[] =
 /* Function for automatic patching according to GameID. */
 void Apply_Hacks_Cdrom()
 {
-	uint32_t i;
-	
+	size_t i, j;
+
+	memset(&Config.hacks, 0, sizeof(Config.hacks));
+
+	for (i = 0; i < ARRAY_SIZE(hack_db); i++)
+	{
+		for (j = 0; j < hack_db[i].id_list_len; j++)
+		{
+			if (strncmp(CdromId, hack_db[i].id_list[j], 9))
+				continue;
+			*hack_db[i].var = 1;
+			SysPrintf("using hack: %s\n", hack_db[i].name);
+			break;
+		}
+	}
+
 	/* Apply Memory card hack for Codename Tenka. (The game needs one of the memory card slots to be empty) */
-	for(i=0;i<ARRAY_SIZE(MemorycardHack_db);i++)
+	for (i = 0; i < ARRAY_SIZE(MemorycardHack_db); i++)
 	{
 		if (strncmp(CdromId, MemorycardHack_db[i], 9) == 0)
 		{
@@ -53,6 +83,7 @@ void Apply_Hacks_Cdrom()
 			Config.Mcd2[0] = 0;
 			/* This also needs to be done because in sio.c, they don't use Config.Mcd2 for that purpose */
 			McdDisable[1] = 1;
+			break;
 		}
 	}
 
diff --git a/libpcsxcore/psxcommon.h b/libpcsxcore/psxcommon.h
index 522abbc8..e0876cf5 100644
--- a/libpcsxcore/psxcommon.h
+++ b/libpcsxcore/psxcommon.h
@@ -145,6 +145,9 @@ typedef struct {
 	int cycle_multiplier_override;
 	u8 Cpu; // CPU_DYNAREC or CPU_INTERPRETER
 	u8 PsxType; // PSX_TYPE_NTSC or PSX_TYPE_PAL
+	struct {
+		boolean cdr_read_timing;
+	} hacks;
 #ifdef _WIN32
 	char Lang[256];
 #endif
-- 
2.39.2