From 7345ecd97e131907d2d1ce6de9438dcd60793d6c Mon Sep 17 00:00:00 2001
From: zilmar <zilmar@pj64-emu.com>
Date: Sat, 7 Feb 2015 10:19:49 +1100
Subject: [PATCH] basic timing support for VI_V_CURRENT_LINE_REG alternating
 scan fields by cxd4

---
 Source/Project64/N64 System/Mips/Memory Class.h     |  3 ++-
 .../N64 System/Mips/Memory Virtual Mem.cpp          | 13 +++++++++----
 .../Project64/N64 System/Mips/Memory Virtual Mem.h  |  2 ++
 Source/Project64/N64 System/N64 Class.cpp           |  2 ++
 4 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/Source/Project64/N64 System/Mips/Memory Class.h b/Source/Project64/N64 System/Mips/Memory Class.h
index 9994eb8e2..e10dc7302 100644
--- a/Source/Project64/N64 System/Mips/Memory Class.h	
+++ b/Source/Project64/N64 System/Mips/Memory Class.h	
@@ -48,7 +48,8 @@ public:
 	virtual bool  ValidVaddr   ( DWORD VAddr ) const = 0;
 
 	virtual int   MemoryFilter ( DWORD dwExptCode, void * lpExceptionPointer ) = 0;
-	
+	virtual void  UpdateFieldSerration ( unsigned int interlaced ) = 0;
+
 	//Protect the Memory from being written to
 	virtual void  ProtectMemory    ( DWORD StartVaddr, DWORD EndVaddr ) = 0;
 	virtual void  UnProtectMemory  ( DWORD StartVaddr, DWORD EndVaddr ) = 0;
diff --git a/Source/Project64/N64 System/Mips/Memory Virtual Mem.cpp b/Source/Project64/N64 System/Mips/Memory Virtual Mem.cpp
index f6335c9ba..2249b13de 100644
--- a/Source/Project64/N64 System/Mips/Memory Virtual Mem.cpp	
+++ b/Source/Project64/N64 System/Mips/Memory Virtual Mem.cpp	
@@ -31,6 +31,7 @@ CMipsMemoryVM::CMipsMemoryVM ( CMipsMemory_CallBack * CallBack, bool SavesReadOn
 	m_RomWroteValue(0),
 	m_HalfLine(0),
 	m_HalfLineCheck(false),
+	m_FieldSerration(0),
 	m_TempValue(0)
 { 
 	g_Settings->RegisterChangeCB(Game_RDRamSize,this,(CSettings::SettingChangedFunc)RdramChanged);
@@ -2633,8 +2634,6 @@ void CMipsMemoryVM::UpdateHalfLine (void)
 		m_HalfLine = 0;
 		return;
 	}
-	m_HalfLine = (DWORD)(NextViTimer / g_System->ViRefreshRate());
-	m_HalfLine &= ~1;
 
 	int check_value = (int)(m_HalfLineCheck - NextViTimer);
 	if (check_value > 0 && check_value < 40)
@@ -2646,11 +2645,17 @@ void CMipsMemoryVM::UpdateHalfLine (void)
 		}
 		g_SystemTimer->UpdateTimers();
 		NextViTimer = g_SystemTimer->GetTimer(CSystemTimer::ViTimer);
-		m_HalfLine = (DWORD)(NextViTimer / g_System->ViRefreshRate());
-		m_HalfLine &= ~1;
 	}
+	m_HalfLine = (DWORD)(NextViTimer / g_System->ViRefreshRate());
+	m_HalfLine &= ~1;
+	m_HalfLine |= m_FieldSerration;
 	m_HalfLineCheck = NextViTimer;
+}
 
+void CMipsMemoryVM::UpdateFieldSerration (unsigned int interlaced)
+{
+	m_FieldSerration ^= 1;
+	m_FieldSerration &= interlaced;
 }
 
 void CMipsMemoryVM::ProtectMemory( DWORD StartVaddr, DWORD EndVaddr ) 
diff --git a/Source/Project64/N64 System/Mips/Memory Virtual Mem.h b/Source/Project64/N64 System/Mips/Memory Virtual Mem.h
index 9e1f30ede..07aeafe39 100644
--- a/Source/Project64/N64 System/Mips/Memory Virtual Mem.h	
+++ b/Source/Project64/N64 System/Mips/Memory Virtual Mem.h	
@@ -57,6 +57,7 @@ public:
 	BOOL  SD_PAddr     ( DWORD PAddr, QWORD Value );
 
 	int   MemoryFilter ( DWORD dwExptCode, void * lpExceptionPointer );
+	void  UpdateFieldSerration (unsigned int interlaced);
 	
 	//Protect the Memory from being written to
 	void  ProtectMemory    ( DWORD StartVaddr, DWORD EndVaddr );
@@ -156,6 +157,7 @@ private:
 	void UpdateHalfLine       ( void );
 	DWORD         m_HalfLine;
 	DWORD         m_HalfLineCheck;
+	DWORD         m_FieldSerration;
 	DWORD         m_TempValue;
 
 	//Initilizing and reseting information about the memory system
diff --git a/Source/Project64/N64 System/N64 Class.cpp b/Source/Project64/N64 System/N64 Class.cpp
index 5e4705fd9..1399672ba 100644
--- a/Source/Project64/N64 System/N64 Class.cpp	
+++ b/Source/Project64/N64 System/N64 Class.cpp	
@@ -1797,6 +1797,8 @@ void CN64System::RefreshScreen ( void ) {
 		WriteTrace(TraceError,__FUNCTION__ ": Exception caught");
 	}
 
+	g_MMU->UpdateFieldSerration((m_Reg.VI_STATUS_REG & 0x40) != 0);
+	
 	if ((bBasicMode() || bLimitFPS() ) && !bSyncToAudio()) {
 		if (bShowCPUPer()) { m_CPU_Usage.StartTimer(Timer_Idel); }
 		DWORD FrameRate;