From dee90fa7aa2d6252f1fe4b51ba11b82e71add9df Mon Sep 17 00:00:00 2001
From: donkopunchstania <donkopunchstania@gmail.com>
Date: Thu, 12 Nov 2009 01:51:40 +0000
Subject: [PATCH] The WGP does not loop if the write pointer is set beyond the
 end of the fifo. Updated the video plugins this time.

git-svn-id: https://dolphin-emu.googlecode.com/svn/trunk@4531 8ced0084-cf51-0410-be5f-012b33b47a6e
---
 Source/Core/Core/Src/HW/GPFifo.cpp            | 10 +++-------
 .../Core/VideoCommon/Src/CommandProcessor.cpp | 19 ++++++++++++-------
 Source/Core/VideoCommon/Src/Fifo.cpp          |  9 ++++++---
 3 files changed, 21 insertions(+), 17 deletions(-)

diff --git a/Source/Core/Core/Src/HW/GPFifo.cpp b/Source/Core/Core/Src/HW/GPFifo.cpp
index 01d38ed0f5..fa3e751941 100644
--- a/Source/Core/Core/Src/HW/GPFifo.cpp
+++ b/Source/Core/Core/Src/HW/GPFifo.cpp
@@ -80,14 +80,10 @@ void STACKALIGN CheckGatherPipe()
 		memcpy(m_gatherPipe, m_gatherPipe + GATHER_PIPE_SIZE, m_gatherPipeCount);
 		
 		// increase the CPUWritePointer
-		ProcessorInterface::Fifo_CPUWritePointer += GATHER_PIPE_SIZE; 
-
-		if (ProcessorInterface::Fifo_CPUWritePointer > ProcessorInterface::Fifo_CPUEnd)
-			_assert_msg_(DYNA_REC, 0, "Fifo_CPUWritePointer out of bounds: %08x (end = %08x)", 
-						ProcessorInterface::Fifo_CPUWritePointer, ProcessorInterface::Fifo_CPUEnd);
-
-		if (ProcessorInterface::Fifo_CPUWritePointer >= ProcessorInterface::Fifo_CPUEnd)
+		if (ProcessorInterface::Fifo_CPUWritePointer == ProcessorInterface::Fifo_CPUEnd)
 			ProcessorInterface::Fifo_CPUWritePointer = ProcessorInterface::Fifo_CPUBase;
+        else
+            ProcessorInterface::Fifo_CPUWritePointer += GATHER_PIPE_SIZE;
 
         // TODO store video plugin pointer
 		CPluginManager::GetInstance().GetVideo()->Video_GatherPipeBursted();
diff --git a/Source/Core/VideoCommon/Src/CommandProcessor.cpp b/Source/Core/VideoCommon/Src/CommandProcessor.cpp
index fccf3e44e6..b7ab90d64a 100644
--- a/Source/Core/VideoCommon/Src/CommandProcessor.cpp
+++ b/Source/Core/VideoCommon/Src/CommandProcessor.cpp
@@ -590,9 +590,11 @@ void STACKALIGN GatherPipeBursted()
 	if (g_VideoInitialize.bOnThread)
 	{
 		// update the fifo-pointer
-		fifo.CPWritePointer += GATHER_PIPE_SIZE;
-		if (fifo.CPWritePointer >= fifo.CPEnd)
+        if (fifo.CPWritePointer >= fifo.CPEnd)
 			fifo.CPWritePointer = fifo.CPBase;
+        else
+		    fifo.CPWritePointer += GATHER_PIPE_SIZE;
+		
         Common::AtomicAdd(fifo.CPReadWriteDistance, GATHER_PIPE_SIZE);
 
 		// High watermark overflow handling (hacked way)
@@ -626,9 +628,10 @@ void STACKALIGN GatherPipeBursted()
 	}
 	else
 	{
-		fifo.CPWritePointer += GATHER_PIPE_SIZE;
 		if (fifo.CPWritePointer >= fifo.CPEnd)
 			fifo.CPWritePointer = fifo.CPBase;
+        else
+		    fifo.CPWritePointer += GATHER_PIPE_SIZE;
 		// check if we are in sync
 		_assert_msg_(COMMANDPROCESSOR, fifo.CPWritePointer	== *(g_VideoInitialize.Fifo_CPUWritePointer), "FIFOs linked but out of sync");
 		_assert_msg_(COMMANDPROCESSOR, fifo.CPBase			== *(g_VideoInitialize.Fifo_CPUBase), "FIFOs linked but out of sync");
@@ -666,14 +669,11 @@ void CatchUpGPU()
 			}
 
 			// read the data and send it to the VideoPlugin
-			fifo.CPReadPointer += 32;
 			// We are going to do FP math on the main thread so have to save the current state
 			SaveSSEState();
 			LoadDefaultSSEState();
 			Fifo_SendFifoData(ptr,32);
 			LoadSSEState();
-			// adjust
-			ptr += 32;
 
 			fifo.CPReadWriteDistance -= 32;
 
@@ -685,6 +685,11 @@ void CatchUpGPU()
 				ptr = Memory_GetPtr(fifo.CPReadPointer);
 				INFO_LOG(COMMANDPROCESSOR, "BUFFER LOOP");
 			}
+            else
+            {
+                fifo.CPReadPointer += 32;
+			    ptr += 32;
+            }
 		}
 	}
 }
@@ -712,7 +717,7 @@ void UpdateFifoRegister()
 	if (wp >= rp)
 		dist = wp - rp;
 	else
-		dist = (wp - fifo.CPBase) + (fifo.CPEnd - rp);
+		dist = (wp - fifo.CPBase) + ((fifo.CPEnd + GATHER_PIPE_SIZE) - rp);
 
 	Common::AtomicStore(fifo.CPReadWriteDistance, dist);
 
diff --git a/Source/Core/VideoCommon/Src/Fifo.cpp b/Source/Core/VideoCommon/Src/Fifo.cpp
index 6285e37afe..0375fdfd0a 100644
--- a/Source/Core/VideoCommon/Src/Fifo.cpp
+++ b/Source/Core/VideoCommon/Src/Fifo.cpp
@@ -165,18 +165,21 @@ void Fifo_EnterLoop(const SVideoInitialize &video_initialize)
 						break;
 					}
 					distToSend = 32;
-					readPtr += 32;
+					
 					if ( readPtr >= _fifo.CPEnd) 
 						readPtr = _fifo.CPBase;
+                    else
+                        readPtr += 32;
 				}
 				else
 				{
 					distToSend = _fifo.CPReadWriteDistance;
 					// send 1024B chunk max length to have better control over PeekMessages' period
 					distToSend = distToSend > 1024 ? 1024 : distToSend;
-					if ((distToSend + readPtr) >= _fifo.CPEnd) // TODO: better?
+                    // add 32 bytes because the cp end points to the start of the last 32 byte chunk
+					if ((distToSend + readPtr) >= (_fifo.CPEnd + 32)) // TODO: better?
 					{
-						distToSend =_fifo.CPEnd - readPtr;
+						distToSend =(_fifo.CPEnd + 32) - readPtr;
 						readPtr = _fifo.CPBase;
 					}
 					else