From 6aa87784a3c649481fe3504af83e4f8a4f8bf9c2 Mon Sep 17 00:00:00 2001
From: Robert Beckebans <robert.beckebans@gmail.com>
Date: Fri, 25 Dec 2015 12:03:59 +0100
Subject: [PATCH] Tweaked HDR/ambient

---
 base/renderprogs/postprocess.pixel |  4 ++--
 base/renderprogs/tonemap.pixel     | 37 ++++++++++++++++++++----------
 neo/renderer/RenderSystem_init.cpp |  2 +-
 3 files changed, 28 insertions(+), 15 deletions(-)

diff --git a/base/renderprogs/postprocess.pixel b/base/renderprogs/postprocess.pixel
index 76f9ae87..85802cc1 100644
--- a/base/renderprogs/postprocess.pixel
+++ b/base/renderprogs/postprocess.pixel
@@ -47,14 +47,14 @@ struct PS_OUT
 
 #define USE_TECHNICOLOR						1		// [0 or 1]
 
-#define Technicolor_Amount					0.6		// [0.00 to 1.00]
+#define Technicolor_Amount					0.5		// [0.00 to 1.00]
 #define Technicolor_Power					4.0		// [0.00 to 8.00]
 #define Technicolor_RedNegativeAmount		0.88	// [0.00 to 1.00]
 #define Technicolor_GreenNegativeAmount		0.88	// [0.00 to 1.00]
 #define Technicolor_BlueNegativeAmount		0.88	// [0.00 to 1.00]
 
 #define USE_VIBRANCE						1
-#define Vibrance							0.5		// [-1.00 to 1.00]
+#define Vibrance							0.5	// [-1.00 to 1.00]
 #define	Vibrance_RGB_Balance				float3( 1.0, 1.0, 1.0 )
 
 #define USE_FILMGRAIN 						1
diff --git a/base/renderprogs/tonemap.pixel b/base/renderprogs/tonemap.pixel
index 74129c30..e4a1c038 100644
--- a/base/renderprogs/tonemap.pixel
+++ b/base/renderprogs/tonemap.pixel
@@ -43,13 +43,13 @@ struct PS_OUT
 	float4 color : COLOR;
 };
 
-float A = 0.15;
-float B = 0.50;
-float C = 0.10;
-float D = 0.20;
-float E = 0.02;
-float F = 0.30;
-float W = 11.2;
+float A = 0.22; // shoulder strength
+float B = 0.3;	// linear strength
+float C = 0.10;	// linear angle
+float D = 0.20;	// toe strength
+float E = 0.01;	// toe numerator
+float F = 0.30;	// toe denominator
+float W = 11.2;	// linear white point
  
 float3 Uncharted2Tonemap( float3 x )
 {
@@ -98,16 +98,29 @@ void main( PS_IN fragment, out PS_OUT result )
 	float Ymax = hdrMaxLuminance;
 
 	
-#if 1
+#if 0
 	// advanced Reinhard operator, artistically desirable to burn out bright areas
-	//float L = Yr * ( 1.0 + Yr / ( Ymax * Ymax ) ) / ( 1.0 + Yr );
+	float L = Yr * ( 1.0 + Yr / ( Ymax * Ymax ) ) / ( 1.0 + Yr );
+	color.rgb *= L;
 	
+	// http://freespace.virgin.net/hugo.elias/graphics/x_posure.htm
 	// exponential tone mapper that is very similar to the Uncharted one
 	// very good in keeping the colors natural
-	float L = 1.0 - exp( -Yr );
-	color.rgb *= L;
+	//float exposure = 1.0;
+	//float L = ( 1.0 - exp( -Yr * exposure ) );
+	//color.rgb *= L;
+	
+	// Kodak filmic tone mappping, includes gamma correction
+	//float3 rgb = max( float3( 0 ), color.rgb - float3( 0.004 ) );
+	//color.rgb = rgb * ( float3( 0.5 ) + 6.2 * rgb ) / ( float3( 0.06 ) + rgb * ( float3( 1.7 ) + 6.2 * rgb ) );
+	
+	// http://iwasbeingirony.blogspot.de/2010/04/approximating-film-with-tonemapping.html
+	//const float cutoff = 0.025;
+	//color.rgb += ( cutoff * 2.0 - color.rgb ) * saturate( cutoff * 2 - color.rgb ) * ( 0.25 / cutoff ) - cutoff;
+	//color.rgb = color.rgb * ( float3( 0.5 ) + 6.2 * color.rgb ) / ( float3( 0.06 ) + color.rgb * ( float3( 1.7 ) + 6.2 * color.rgb ) );
+	
 #else
-	// Uncharted 2 tone mapper but looks weird :(
+	// Uncharted 2 tone mapping based on Kodak film curve
 
 	//float exposure = ( hdrKey / hdrAverageLuminance ) * 0.2;
 	//float exposure = Yr * 1.0;
diff --git a/neo/renderer/RenderSystem_init.cpp b/neo/renderer/RenderSystem_init.cpp
index b2ea2f17..5742aea9 100644
--- a/neo/renderer/RenderSystem_init.cpp
+++ b/neo/renderer/RenderSystem_init.cpp
@@ -258,7 +258,7 @@ idCVar r_ldrContrastThreshold( "r_ldrContrastThreshold", "1.1", CVAR_RENDERER |
 idCVar r_ldrContrastOffset( "r_ldrContrastOffset", "3", CVAR_RENDERER | CVAR_FLOAT, "" );
 
 idCVar r_useFilmicPostProcessEffects( "r_useFilmicPostProcessEffects", "1", CVAR_RENDERER | CVAR_ARCHIVE | CVAR_BOOL, "apply several post process effects to mimic a filmic look" );
-idCVar r_forceAmbient( "r_forceAmbient", "0.3", CVAR_RENDERER | CVAR_FLOAT, "render additional ambient pass to make the game less dark", 0.0f, 0.4f );
+idCVar r_forceAmbient( "r_forceAmbient", "0.2", CVAR_RENDERER | CVAR_FLOAT, "render additional ambient pass to make the game less dark", 0.0f, 0.4f );
 // RB end
 
 const char* fileExten[3] = { "tga", "png", "jpg" };