From aa7af0711a247bd6ff836a3907c7b115abe956df Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@users.noreply.github.com>
Date: Mon, 10 Jan 2022 19:11:41 +0100
Subject: [PATCH] - fine tuning of the new light modes.

---
 source/core/rendering/scene/hw_drawinfo.h   |  2 +-
 source/core/rendering/scene/hw_lighting.cpp | 22 ++++-----------------
 source/core/rendering/scene/hw_setcolor.cpp | 22 ++++++++++++---------
 3 files changed, 18 insertions(+), 28 deletions(-)

diff --git a/source/core/rendering/scene/hw_drawinfo.h b/source/core/rendering/scene/hw_drawinfo.h
index d3e5ed82c..8d8a3acc5 100644
--- a/source/core/rendering/scene/hw_drawinfo.h
+++ b/source/core/rendering/scene/hw_drawinfo.h
@@ -138,7 +138,7 @@ private:
 	int CalcLightLevel(int lightlevel, int rellight, bool weapon, int blendfactor);
 	PalEntry CalcLightColor(int light, PalEntry pe, int blendfactor);
 	void SetShaderLight(FRenderState& state, float level, float olight);
-	void SetFog(FRenderState& state, int lightlevel, int rellight, bool fullbright, const FColormap* cmap, bool isadditive);
+	void SetFog(FRenderState& state, int lightlevel, float visibility, bool fullbright, const FColormap* cmap, bool isadditive);
 
 	float GetFogDensity(int lightlevel, PalEntry fogcolor, int sectorfogdensity, int blendfactor);
 
diff --git a/source/core/rendering/scene/hw_lighting.cpp b/source/core/rendering/scene/hw_lighting.cpp
index 805df15f4..f1d310867 100644
--- a/source/core/rendering/scene/hw_lighting.cpp
+++ b/source/core/rendering/scene/hw_lighting.cpp
@@ -43,26 +43,12 @@ CUSTOM_CVAR(Int, gl_distfog, 70, CVAR_ARCHIVE | CVAR_GLOBALCONFIG)
 {
 	for (int i = 0; i < 256; i++)
 	{
+		int l = i >> 1;
+		if (i < 64) l = -32 + i;
 
-		if (i < 164)
-		{
-			distfogtable[0][i] = (float)((gl_distfog >> 1) + (gl_distfog)*(164 - i) / 164);
-		}
-		else if (i < 230)
-		{
-			distfogtable[0][i] = (float)((gl_distfog >> 1) - (gl_distfog >> 1)*(i - 164) / (230 - 164));
-		}
-		else distfogtable[0][i] = 0;
+		distfogtable[0][i] = (float)((gl_distfog >> 1) + (gl_distfog)*(164 - l) / 164);
 
-		if (i < 128)
-		{
-			distfogtable[1][i] = 6.f + (float)((gl_distfog >> 1) + (gl_distfog)*(128 - i) / 48);
-		}
-		else if (i < 216)
-		{
-			distfogtable[1][i] = (216.f - i) / ((216.f - 128.f)) * gl_distfog / 10;
-		}
-		else distfogtable[1][i] = 0;
+		distfogtable[1][i] = 5.f + (float)((gl_distfog >> 1) + (float)((gl_distfog)*(128 - (i >> 1)) / 70));
 	}
 }
 
diff --git a/source/core/rendering/scene/hw_setcolor.cpp b/source/core/rendering/scene/hw_setcolor.cpp
index 1de7ebb96..aca090672 100644
--- a/source/core/rendering/scene/hw_setcolor.cpp
+++ b/source/core/rendering/scene/hw_setcolor.cpp
@@ -93,7 +93,7 @@ void HWDrawInfo::SetShaderLight(FRenderState &state, float level, float olight)
 //
 //==========================================================================
 
-void HWDrawInfo::SetFog(FRenderState &state, int lightlevel, int rellight, bool fullbright, const FColormap *cmap, bool isadditive)
+void HWDrawInfo::SetFog(FRenderState &state, int lightlevel, float visibility, bool fullbright, const FColormap *cmap, bool isadditive)
 {
 	PalEntry fogcolor;
 	float fogdensity;
@@ -101,7 +101,7 @@ void HWDrawInfo::SetFog(FRenderState &state, int lightlevel, int rellight, bool
 	if (cmap != nullptr && !fullbright)
 	{
 		fogcolor = cmap->FadeColor;
-		fogdensity = GetFogDensity(lightlevel, fogcolor, cmap->FogDensity, cmap->BlendFactor);
+		fogdensity = GetFogDensity(lightlevel, fogcolor, cmap->FogDensity, cmap->BlendFactor) * visibility;
 		fogcolor.a = 0;
 	}
 	else
@@ -160,16 +160,20 @@ void SetLightAndFog(HWDrawInfo* di, FRenderState& state, PalEntry fade, int pale
 
 	if (!di->isBuildSoftwareLighting() && !foggy)
 	{
-		bool fullbright = ShadeDiv < 1 / 1000.f;
+		bool fullbright = ShadeDiv < 1 / 1000.f || g_visibility == 0;
 		float inverselight = shade * 255.f / numshades;
-		if (fullbright) inverselight /= ShadeDiv;
-		int vislight = 10 - sizeToBits(int(visibility));
-		int gvis = -sizeToBits(g_visibility) * 2;
-		int rellight = 10 - sizeToBits(g_visibility + g_relvisibility) - gvis;
+		if (inverselight < 0) fullbright = true;
+		if (!fullbright) inverselight /= ShadeDiv;
 		int lightlevel = !fullbright ? clamp(int(255 - inverselight), 0, 255) : 255;
+
+		int rellight = 0;
+		if (g_relvisibility)
+		{
+			rellight = sizeToBits(g_visibility) - sizeToBits(g_visibility + g_relvisibility);
+		}
 		FColormap cm = { 0xffffffff };
-		di->SetColor(state, lightlevel, rellight, fullbright, cm, alpha);
-		di->SetFog(state, lightlevel/2 + gvis + vislight, rellight, fullbright, &cm, false);
+		di->SetColor(state, lightlevel, 32*rellight, fullbright, cm, alpha);
+		di->SetFog(state, lightlevel, visibility * g_visibility * (1.f/512.f), fullbright, &cm, false);
 		return;
 	}
 	// Fog must be done before the texture so that the texture selector can override it.