From 858ec974f7ec9ca14fdf6266ce4b80d9c0515168 Mon Sep 17 00:00:00 2001
From: Garux <garux@mail.ru>
Date: Mon, 8 Mar 2021 13:34:58 +0300
Subject: [PATCH] * -saturation light switch, default = 1, affects lightmaps
 and vertex color; > 1 = saturate, 0 = grayscale, < 0 = complementary colors

---
 Makefile                            |  2 --
 tools/quake3/q3map2/light.cpp       |  7 +++++++
 tools/quake3/q3map2/light_ydnar.cpp | 18 ++++++++++++++++++
 tools/quake3/q3map2/q3map2.h        |  1 +
 4 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index 6f1f7236..5b873069 100644
--- a/Makefile
+++ b/Makefile
@@ -583,7 +583,6 @@ $(INSTALLDIR)/q3map2.$(EXE): \
 	libddslib.$(A) \
 	libfilematch.$(A) \
 	libl_net.$(A) \
-	libmathlib.$(A) \
 	libpicomodel.$(A) \
 	$(if $(findstring $(OS),Win32),icons/q3map2.o,) \
 
@@ -749,7 +748,6 @@ $(INSTALLDIR)/radiant.$(EXE): \
 	libcmdlib.$(A) \
 	libgtkutil.$(A) \
 	libl_net.$(A) \
-	libmathlib.$(A) \
 	libprofile.$(A) \
 	libquickhull.$(A) \
 	libxmllib.$(A) \
diff --git a/tools/quake3/q3map2/light.cpp b/tools/quake3/q3map2/light.cpp
index b9838264..296fc755 100644
--- a/tools/quake3/q3map2/light.cpp
+++ b/tools/quake3/q3map2/light.cpp
@@ -2248,6 +2248,13 @@ int LightMain( int argc, char **argv ){
 			lightmapContrast = ( 259 * ( lightmapContrast + 255 ) ) / ( 255 * ( 259 - lightmapContrast ) );
 		}
 
+		/* Lighting saturation */
+		else if( striEqual( argv[ i ], "-saturation" ) ){
+			g_lightmapSaturation = atof( argv[ i + 1 ] );
+			Sys_Printf( "Lighting saturation set to %f\n", g_lightmapSaturation );
+			i++;
+		}
+
 		/* ydnar switches */
 		else if ( striEqual( argv[ i ], "-bounce" ) ) {
 			bounce = std::max( 0, atoi( argv[ i + 1 ] ) );
diff --git a/tools/quake3/q3map2/light_ydnar.cpp b/tools/quake3/q3map2/light_ydnar.cpp
index 9ace44b1..0e60fc60 100644
--- a/tools/quake3/q3map2/light_ydnar.cpp
+++ b/tools/quake3/q3map2/light_ydnar.cpp
@@ -32,6 +32,21 @@
 #include "q3map2.h"
 
 
+// http://www.graficaobscura.com/matrix/index.html
+static void color_saturate( Vector3& color, float saturation ){
+	/* This is the luminance vector. Notice here that we do not use the standard NTSC weights of 0.299, 0.587, and 0.114.
+	The NTSC weights are only applicable to RGB colors in a gamma 2.2 color space. For linear RGB colors these values are better. */
+	const Vector3 rgb2gray( 0.3086, 0.6094, 0.0820 );
+	Matrix4 tra( g_matrix4_identity );
+	tra.x().vec3().set( rgb2gray.x() * ( 1 - saturation ) );
+	tra.y().vec3().set( rgb2gray.y() * ( 1 - saturation ) );
+	tra.z().vec3().set( rgb2gray.z() * ( 1 - saturation ) );
+	tra.xx() += saturation;
+	tra.yy() += saturation;
+	tra.zz() += saturation;
+	matrix4_transform_direction( tra, color );
+}
+
 
 
 /*
@@ -53,6 +68,9 @@ Vector3b ColorToBytes( const Vector3& color, float scale ){
 	/* make a local copy */
 	Vector3 sample = color * scale;
 
+	if( g_lightmapSaturation != 1 )
+		color_saturate( sample, g_lightmapSaturation );
+
 	/* muck with it */
 	gamma = 1.0f / lightmapGamma;
 	for ( i = 0; i < 3; i++ )
diff --git a/tools/quake3/q3map2/q3map2.h b/tools/quake3/q3map2/q3map2.h
index 20300db1..51133f9c 100644
--- a/tools/quake3/q3map2/q3map2.h
+++ b/tools/quake3/q3map2/q3map2.h
@@ -2345,6 +2345,7 @@ Q_EXTERN float lightmapExposure Q_ASSIGN( 0.0f );
 Q_EXTERN float lightmapCompensate Q_ASSIGN( 1.0f );
 Q_EXTERN float lightmapBrightness Q_ASSIGN( 1.0f );
 Q_EXTERN float lightmapContrast Q_ASSIGN( 1.0f );
+inline float g_lightmapSaturation = 1;
 
 /* ydnar: for runtime tweaking of falloff tolerance */
 Q_EXTERN float falloffTolerance Q_ASSIGN( 1.0f );