From ff1925cc0aa768f1ffefb3396e0bf354b3110d62 Mon Sep 17 00:00:00 2001
From: Brandon Wright <bearoso@gmail.com>
Date: Mon, 25 Jun 2018 18:02:10 -0500
Subject: [PATCH] Disable interlace mode for bg modes not 5 or 6.

---
 gfx.cpp | 42 +++++++-----------------------------------
 ppu.cpp |  6 +++++-
 2 files changed, 12 insertions(+), 36 deletions(-)

diff --git a/gfx.cpp b/gfx.cpp
index 73656332..13611a3d 100644
--- a/gfx.cpp
+++ b/gfx.cpp
@@ -369,12 +369,7 @@ void S9xStartScreenRefresh (void)
 			}
 			else
 			{
-			#ifdef USE_OPENGL
-				if (Settings.OpenGLEnable)
-					GFX.RealPPL = SNES_WIDTH;
-				else
-			#endif
-					GFX.RealPPL = GFX.Pitch >> 1;
+				GFX.RealPPL = GFX.Pitch >> 1;
 				IPPU.DoubleWidthPixels = FALSE;
 				IPPU.RenderedScreenWidth = SNES_WIDTH;
 			}
@@ -685,37 +680,14 @@ void S9xUpdateScreen (void)
 		{
 			if (!IPPU.DoubleWidthPixels && (PPU.BGMode == 5 || PPU.BGMode == 6 || IPPU.PseudoHires))
 			{
-			#ifdef USE_OPENGL
-				if (Settings.OpenGLEnable && GFX.RealPPL == 256)
+				// Have to back out of the regular speed hack
+				for (register uint32 y = 0; y < GFX.StartY; y++)
 				{
-					// Have to back out of the speed up hack where the low res.
-					// SNES image was rendered into a 256x239 sized buffer,
-					// ignoring the true, larger size of the buffer.
-					GFX.RealPPL = GFX.Pitch >> 1;
+					register uint16	*p = GFX.Screen + y * GFX.PPL + 255;
+					register uint16	*q = GFX.Screen + y * GFX.PPL + 510;
 
-					for (register int32 y = (int32) GFX.StartY - 1; y >= 0; y--)
-					{
-						register uint16	*p = GFX.Screen + y * GFX.PPL     + 255;
-						register uint16	*q = GFX.Screen + y * GFX.RealPPL + 510;
-
-						for (register int x = 255; x >= 0; x--, p--, q -= 2)
-							*q = *(q + 1) = *p;
-					}
-
-					GFX.PPL = GFX.RealPPL; // = GFX.Pitch >> 1 above
-				}
-				else
-			#endif
-				{
-					// Have to back out of the regular speed hack
-					for (register uint32 y = 0; y < GFX.StartY; y++)
-					{
-						register uint16	*p = GFX.Screen + y * GFX.PPL + 255;
-						register uint16	*q = GFX.Screen + y * GFX.PPL + 510;
-
-						for (register int x = 255; x >= 0; x--, p--, q -= 2)
-							*q = *(q + 1) = *p;
-					}
+					for (register int x = 255; x >= 0; x--, p--, q -= 2)
+						*q = *(q + 1) = *p;
 				}
 
 				IPPU.DoubleWidthPixels = TRUE;
diff --git a/ppu.cpp b/ppu.cpp
index a3ee2f1f..906774e3 100644
--- a/ppu.cpp
+++ b/ppu.cpp
@@ -546,7 +546,10 @@ void S9xSetPPU (uint8 Byte, uint16 Address)
 					PPU.BGMode = Byte & 7;
 					// BJ: BG3Priority only takes effect if BGMode == 1 and the bit is set
 					PPU.BG3Priority = ((Byte & 0x0f) == 0x09);
-					IPPU.Interlace = Memory.FillRAM[0x2133] & 1;
+					if (PPU.BGMode == 6 || PPU.BGMode == 5)
+					    IPPU.Interlace = Memory.FillRAM[0x2133] & 1;
+					else
+					    IPPU.Interlace = 0;
 				#ifdef DEBUGGER
 					missing.modes[PPU.BGMode] = 1;
 				#endif
@@ -1068,6 +1071,7 @@ void S9xSetPPU (uint8 Byte, uint16 Address)
 						FLUSH_REDRAW();
 						if ((Memory.FillRAM[0x2133] ^ Byte) & 2)
 							IPPU.OBJChanged = TRUE;
+
 						IPPU.Interlace = Byte & 1;
 						IPPU.InterlaceOBJ = Byte & 2;
 					}