From b56e80a556f6d8d9a5c3da2897fa937a25be901f Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@users.noreply.github.com>
Date: Mon, 29 Oct 2018 21:52:47 +0100
Subject: [PATCH] - disabled the buffer reallocation option for the light
 buffer.

The entire idea with CPU side buffering simply can not work since the buffer is being used live. To compensate the buffer's size was doubled.
---
 src/hwrenderer/dynlights/hw_lightbuffer.cpp | 35 ++-------------------
 src/hwrenderer/dynlights/hw_lightbuffer.h   |  5 +--
 src/hwrenderer/scene/hw_flats.cpp           |  2 +-
 3 files changed, 4 insertions(+), 38 deletions(-)

diff --git a/src/hwrenderer/dynlights/hw_lightbuffer.cpp b/src/hwrenderer/dynlights/hw_lightbuffer.cpp
index 641015833..a9e24353c 100644
--- a/src/hwrenderer/dynlights/hw_lightbuffer.cpp
+++ b/src/hwrenderer/dynlights/hw_lightbuffer.cpp
@@ -36,7 +36,7 @@ static const int ELEMENT_SIZE = (4*sizeof(float));
 
 FLightBuffer::FLightBuffer()
 {
-	int maxNumberOfLights = 40000;
+	int maxNumberOfLights = 80000;
 	
 	mBufferSize = maxNumberOfLights * ELEMENTS_PER_LIGHT;
 	mByteSize = mBufferSize * ELEMENT_SIZE;
@@ -77,28 +77,6 @@ void FLightBuffer::Clear()
 	mIndex = 0;
 }
 
-void FLightBuffer::CheckSize()
-{
-	// create the new buffer's storage (at least twice as large as the old one)
-	int oldbytesize = mByteSize;
-	unsigned int bufferbytesize = mBufferedData.Size() * 4;
-	if (bufferbytesize > mByteSize)
-	{
-		mByteSize += bufferbytesize;
-	}
-	else
-	{
-		mByteSize *= 2;
-	}
-	mBufferSize = mByteSize / ELEMENT_SIZE;
-	mBuffer->Resize(mByteSize);
-	
-	Map();
-	memcpy(((float*)mBuffer->Memory()) + mBlockSize*4, &mBufferedData[0], bufferbytesize);
-	mBufferedData.Clear();
-	Unmap();
-}
-
 int FLightBuffer::UploadLights(FDynLightData &data)
 {
 	// All meaasurements here are in vec4's.
@@ -145,16 +123,7 @@ int FLightBuffer::UploadLights(FDynLightData &data)
 	}
 	else
 	{
-		// The buffered data always starts at the old buffer's end to avoid more extensive synchronization.
-		std::lock_guard<std::mutex> lock(mBufferMutex);
-		auto index = mBufferedData.Reserve(totalsize);
-		float *copyptr =&mBufferedData[index];
-		// The copy operation must be inside the mutexed block of code here!
-		memcpy(&copyptr[0], parmcnt, ELEMENT_SIZE);
-		memcpy(&copyptr[4], &data.arrays[0][0], size0 * ELEMENT_SIZE);
-		memcpy(&copyptr[4 + 4*size0], &data.arrays[1][0], size1 * ELEMENT_SIZE);
-		memcpy(&copyptr[4 + 4*(size0 + size1)], &data.arrays[2][0], size2 * ELEMENT_SIZE);
-		return mBufferSize + index;
+		return -1;	// Buffer is full. Since it is being used live at the point of the upload we cannot do much here but to abort.
 	}
 }
 
diff --git a/src/hwrenderer/dynlights/hw_lightbuffer.h b/src/hwrenderer/dynlights/hw_lightbuffer.h
index 9cdcbe5a1..6355508ba 100644
--- a/src/hwrenderer/dynlights/hw_lightbuffer.h
+++ b/src/hwrenderer/dynlights/hw_lightbuffer.h
@@ -22,9 +22,6 @@ class FLightBuffer
 	unsigned int mByteSize;
     unsigned int mMaxUploadSize;
     
-    std::mutex mBufferMutex;
-    TArray<float> mBufferedData;
-
 	void CheckSize();
 
 public:
@@ -34,7 +31,7 @@ public:
 	void Clear();
 	int UploadLights(FDynLightData &data);
 	void Map() { mBuffer->Map(); }
-	void Unmap() { mBuffer->Unmap(); if (mBufferedData.Size() > 0) CheckSize(); }
+	void Unmap() { mBuffer->Unmap(); }
 	unsigned int GetBlockSize() const { return mBlockSize; }
 	bool GetBufferType() const { return mBufferType; }
 
diff --git a/src/hwrenderer/scene/hw_flats.cpp b/src/hwrenderer/scene/hw_flats.cpp
index da2a6e604..776346114 100644
--- a/src/hwrenderer/scene/hw_flats.cpp
+++ b/src/hwrenderer/scene/hw_flats.cpp
@@ -184,7 +184,7 @@ void GLFlat::DrawSubsectors(HWDrawInfo *di, FRenderState &state)
 {
 	auto vcount = sector->ibocount;
 
-	if (screen->BuffersArePersistent())
+	if (level.HasDynamicLights && screen->BuffersArePersistent())
 	{
 		SetupLights(di, sector->lighthead, lightdata, sector->PortalGroup);
 	}