From c95baf614d2699233b7bf7a474d96aa6c4cf2b78 Mon Sep 17 00:00:00 2001
From: Pierre Bourdon <delroth@gmail.com>
Date: Sun, 20 May 2012 20:56:03 +0200
Subject: [PATCH] Avoid changing video state on useless BP writes

When a game writes the same value that was already configured to a BP
register, Dolphin previously flushed the GPU pipeline and reconfigured
the internal video state (calling SetScissor/SetLineWidth/SetDepthMode).

Some of these useless writes still need to perform actions, for example
writes to the EFB copy trigger or the texture preload registers (which
need to reload the texture from memory).
---
 Source/Core/VideoCommon/Src/BPStructs.cpp | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/Source/Core/VideoCommon/Src/BPStructs.cpp b/Source/Core/VideoCommon/Src/BPStructs.cpp
index 84f2426f26..160ee1a61b 100644
--- a/Source/Core/VideoCommon/Src/BPStructs.cpp
+++ b/Source/Core/VideoCommon/Src/BPStructs.cpp
@@ -130,14 +130,24 @@ void BPWritten(const BPCmd& bp)
 	}  // END ZTP SPEEDUP HACK
 	else 
 	{
-		if (((s32*)&bpmem)[bp.address] != bp.newvalue)
+		if (((s32*)&bpmem)[bp.address] == bp.newvalue)
 		{
-			FlushPipeline();
+			if (!(bp.address == BPMEM_TRIGGER_EFB_COPY
+					|| bp.address == BPMEM_CLEARBBOX1
+					|| bp.address == BPMEM_CLEARBBOX2
+					|| bp.address == BPMEM_SETDRAWDONE
+					|| bp.address == BPMEM_PE_TOKEN_ID
+					|| bp.address == BPMEM_PE_TOKEN_INT_ID
+					|| bp.address == BPMEM_LOADTLUT0
+					|| bp.address == BPMEM_LOADTLUT1
+					|| bp.address == BPMEM_TEXINVALIDATE
+					|| bp.address == BPMEM_PRELOAD_MODE))
+			{
+				return;
+			}
 		}
-		else if (bp.address == BPMEM_TRIGGER_EFB_COPY
-				|| bp.address == BPMEM_CLEARBBOX1
-				|| bp.address == BPMEM_CLEARBBOX2)
-			FlushPipeline();
+
+		FlushPipeline();
 	}
 
 	((u32*)&bpmem)[bp.address] = bp.newvalue;