From e1f77790ccf35a54a08c2d213640dee67350e267 Mon Sep 17 00:00:00 2001
From: zeromus <zeromus@users.sf.net>
Date: Thu, 2 Apr 2009 22:27:06 +0000
Subject: [PATCH] tweaks to lag frame

---
 desmume/src/MMU.cpp             | 31 ++++++++++++++++---------------
 desmume/src/MMU.h               |  1 -
 desmume/src/NDSSystem.cpp       | 10 ++++++++++
 desmume/src/NDSSystem.h         |  3 +++
 desmume/src/softrender_config.h |  2 +-
 desmume/src/windows/main.cpp    |  2 +-
 6 files changed, 31 insertions(+), 18 deletions(-)

diff --git a/desmume/src/MMU.cpp b/desmume/src/MMU.cpp
index c0bcf674a..f1d23b949 100644
--- a/desmume/src/MMU.cpp
+++ b/desmume/src/MMU.cpp
@@ -52,9 +52,6 @@
 #define ASSERT_UNALIGNED(x)
 #endif
 
-int LagFrameFlag=0;
-
-
 //http://home.utah.edu/~nahaj/factoring/isqrt.c.html
 static u64 isqrt (u64 x) {
   u64   squaredbit, remainder, root;
@@ -2864,12 +2861,6 @@ void FASTCALL _MMU_ARM9_write32(u32 adr, u32 val)
 	T1WriteLong(MMU.MMU_MEM[ARMCPU_ARM9][adr>>20], adr&MMU.MMU_MASK[ARMCPU_ARM9][adr>>20], val);
 }
 
-void CheckLag(u32 adr) {
-
-	if (adr == 0x04000130 || 0x04000136)
-		LagFrameFlag=0;
-}
-
 //================================================= MMU ARM9 read 08
 u8 FASTCALL _MMU_ARM9_read08(u32 adr)
 {
@@ -2891,7 +2882,6 @@ u8 FASTCALL _MMU_ARM9_read08(u32 adr)
 	if ((adr>=0x9000000)&&(adr<0x9900000))
 		return (unsigned char)cflash_read(adr);
 #endif
-	CheckLag(adr);
 
 #ifdef _MMU_DEBUG
 		mmu_log_debug_ARM9(adr, "(read08) %0x%X", 
@@ -2926,13 +2916,12 @@ u16 FASTCALL _MMU_ARM9_read16(u32 adr)
 
 	adr &= 0x0FFFFFFF;
 
-	CheckLag(adr);
-
 	if (adr >> 24 == 4)
 	{
-		/* Address is an IO register */
+		// Address is an IO register
 		switch(adr)
 		{
+			// ============================================= 3D
 			case 0x04000604:
 				return (gfx3d_GetNumPolys()&2047);
 			case 0x04000606:
@@ -2960,6 +2949,12 @@ u16 FASTCALL _MMU_ARM9_read16(u32 adr)
 			case REG_TM2CNTL :
 			case REG_TM3CNTL :
 				return MMU.timer[ARMCPU_ARM9][(adr&0xF)>>2];
+
+			case 0x04000130:
+			case 0x04000136:
+				//not sure whether these should trigger from byte reads
+				LagFrameFlag=0;
+				break;
 			
 			case REG_POSTFLG :
 				return 1;
@@ -3011,8 +3006,6 @@ u32 FASTCALL _MMU_ARM9_read32(u32 adr)
 
 	adr &= 0x0FFFFFFF;
 
-	CheckLag(adr);
-
 	// Address is an IO register
 	if((adr >> 24) == 4)
 	{
@@ -4014,6 +4007,14 @@ u16 FASTCALL _MMU_ARM7_read16(u32 adr)
 			case REG_TM2CNTL :
 			case REG_TM3CNTL :
 				return MMU.timer[ARMCPU_ARM7][(adr&0xF)>>2];
+
+
+			case 0x04000130:
+			case 0x04000136:
+				//here is an example of what not to do:
+				//since the arm7 polls this every frame, we shouldnt count this as an input check
+				//LagFrameFlag=0;
+				break;
 			
 			case REG_POSTFLG :
 				return 1;
diff --git a/desmume/src/MMU.h b/desmume/src/MMU.h
index b18737757..8ab88fdc1 100644
--- a/desmume/src/MMU.h
+++ b/desmume/src/MMU.h
@@ -126,7 +126,6 @@ struct MMU_struct {
 
 extern MMU_struct MMU;
 
-extern int LagFrameFlag;
 
 struct armcpu_memory_iface {
   /** the 32 bit instruction prefetch */
diff --git a/desmume/src/NDSSystem.cpp b/desmume/src/NDSSystem.cpp
index 29c86ddc0..79f3d8f78 100644
--- a/desmume/src/NDSSystem.cpp
+++ b/desmume/src/NDSSystem.cpp
@@ -65,6 +65,8 @@ BOOL fw_success = FALSE;
 NDSSystem nds;
 
 int lagframecounter=0;
+int LagFrameFlag=0;
+int lastLag=0;
 
 /* ------------------------------------------------------------------------- */
 /* FIRMWARE DECRYPTION */
@@ -1422,6 +1424,7 @@ u32 NDS_exec(s32 nb)
 {
 	int i, j;
 
+	//TODO - since NDS_exec is not necessarily called one frame at a time, this could be wrong.
 	LagFrameFlag=1;
 
 	nb += nds.cycles;//(nds.cycles>>26)<<26;
@@ -2213,7 +2216,14 @@ u32 NDS_exec(s32 nb)
 	}
 
 	if(LagFrameFlag)
+	{
 		lagframecounter++;
+	}
+	else 
+	{
+		lastLag = lagframecounter;
+		lagframecounter = 0;
+	}
 
 	return nds.cycles;
 }
diff --git a/desmume/src/NDSSystem.h b/desmume/src/NDSSystem.h
index 45113a7b0..36af8407f 100644
--- a/desmume/src/NDSSystem.h
+++ b/desmume/src/NDSSystem.h
@@ -331,6 +331,9 @@ public:
 extern Driver* driver;
 
 extern std::string InputDisplayString;
+extern int LagFrameFlag;
+extern int lastLag;
+
 #endif
 
  	  	 
diff --git a/desmume/src/softrender_config.h b/desmume/src/softrender_config.h
index c01bf43ac..1e6c43189 100644
--- a/desmume/src/softrender_config.h
+++ b/desmume/src/softrender_config.h
@@ -11,4 +11,4 @@ typedef unsigned int quad;
 
 }
 
-#endif
\ No newline at end of file
+#endif
diff --git a/desmume/src/windows/main.cpp b/desmume/src/windows/main.cpp
index 518e0a600..4e85326c7 100644
--- a/desmume/src/windows/main.cpp
+++ b/desmume/src/windows/main.cpp
@@ -1015,7 +1015,7 @@ DWORD WINAPI run()
 				frameCounter++;
 				if (frameCounterDisplay) osd->addFixed(0, 25, "%d",frameCounter);
 				if (ShowInputDisplay) osd->addFixed(0, 45, "%s",InputDisplayString.c_str());
-				if (ShowLagFrameCounter) osd->addFixed(0, 65, "%d",lagframecounter);
+				if (ShowLagFrameCounter) osd->addFixed(0, 65, "%d",lastLag);
 				DisplayMessage();
 				CheckMessages();
 		}