From 6661c1a8e89c733f6d0d5a2aa9689a2436b6a113 Mon Sep 17 00:00:00 2001
From: jal <germangar@gmail.com>
Date: Sun, 11 Jul 2010 12:16:08 +0200
Subject: [PATCH] On grid lighting, redistribute the 25% of the floodlight as
 omnidirectional ambient light, and use only the 75% of it as top-down
 directional light.

---
 tools/quake3/q3map2/light.c | 99 ++++++++++++++++++++-----------------
 1 file changed, 54 insertions(+), 45 deletions(-)

diff --git a/tools/quake3/q3map2/light.c b/tools/quake3/q3map2/light.c
index cf292a79..dee882ee 100644
--- a/tools/quake3/q3map2/light.c
+++ b/tools/quake3/q3map2/light.c
@@ -1421,6 +1421,7 @@ typedef struct
 {
 	vec3_t		dir;
 	vec3_t		color;
+	vec3_t		ambient;
 	int			style;
 }
 contribution_t;
@@ -1514,6 +1515,7 @@ void TraceGrid( int num )
 		/* add a contribution */
 		VectorCopy( trace.color, contributions[ numCon ].color );
 		VectorCopy( trace.direction, contributions[ numCon ].dir );
+		VectorClear( contributions[ numCon ].ambient );
 		contributions[ numCon ].style = trace.light->style;
 		numCon++;
 		
@@ -1533,51 +1535,56 @@ void TraceGrid( int num )
 	
 	/////// Floodlighting for point //////////////////
 	//do our floodlight ambient occlusion loop, and add a single contribution based on the brightest dir
-	if (floodlighty)
-	{
-		int q;
-		float addSize,f;
-		vec3_t col,dir;
-		col[0]=col[1]=col[2]=floodlightIntensity;
-		dir[0]=dir[1]=0;
-		dir[2]=1;
-
-		trace.testOcclusion = qtrue;
-		trace.forceSunlight = qfalse;
-		trace.inhibitRadius = DEFAULT_INHIBIT_RADIUS;
-		trace.testAll = qtrue;
-
-		for (q=0;q<2;q++)
-		{
-			if (q==0) //upper hemisphere
-			{
-				trace.normal[0]=0;
-				trace.normal[1]=0;
-				trace.normal[2]=1;
-			}
-			else //lower hemisphere
-			{
-				trace.normal[0]=0;
-				trace.normal[1]=0;
-				trace.normal[2]=-1;
-			}
-
-			f = FloodLightForSample(&trace, floodlightDistance, floodlight_lowquality);
-
-			contributions[ numCon ].color[0]=col[0]*f;
-			contributions[ numCon ].color[1]=col[1]*f;
-			contributions[ numCon ].color[2]=col[2]*f;
-
-			contributions[ numCon ].dir[0]=dir[0];
-			contributions[ numCon ].dir[1]=dir[1];
-			contributions[ numCon ].dir[2]=dir[2];
-
-			contributions[ numCon ].style = 0;
-			numCon++;
-			/* push average direction around */
-			addSize = VectorLength( col );
-			VectorMA( gp->dir, addSize, dir, gp->dir );
-		}
+	if( floodlighty )
+	{
+		int k;
+		float addSize, f;
+		vec3_t dir = { 0, 0, 1 };
+		float ambientFrac = 0.25f;
+
+		trace.testOcclusion = qtrue;
+		trace.forceSunlight = qfalse;
+		trace.inhibitRadius = DEFAULT_INHIBIT_RADIUS;
+		trace.testAll = qtrue;
+
+		for( k = 0; k < 2; k++ )
+		{
+			if( k == 0 ) // upper hemisphere
+			{
+				trace.normal[0] = 0;
+				trace.normal[1] = 0;
+				trace.normal[2] = 1;
+			}
+			else //lower hemisphere
+			{
+				trace.normal[0] = 0;
+				trace.normal[1] = 0;
+				trace.normal[2] = -1;
+			}
+
+			f = FloodLightForSample( &trace, floodlightDistance, floodlight_lowquality );
+
+			/* add a fraction as pure ambient, half as top-down direction */
+			contributions[ numCon ].color[0]= floodlightRGB[0] * floodlightIntensity * f * ( 1.0f - ambientFrac );
+			contributions[ numCon ].color[1]= floodlightRGB[1] * floodlightIntensity * f * ( 1.0f - ambientFrac );
+			contributions[ numCon ].color[2]= floodlightRGB[2] * floodlightIntensity * f * ( 1.0f - ambientFrac );
+
+			contributions[ numCon ].ambient[0]= floodlightRGB[0] * floodlightIntensity * f * ambientFrac;
+			contributions[ numCon ].ambient[1]= floodlightRGB[1] * floodlightIntensity * f * ambientFrac;
+			contributions[ numCon ].ambient[2]= floodlightRGB[2] * floodlightIntensity * f * ambientFrac;
+
+			contributions[ numCon ].dir[0] = dir[0];
+			contributions[ numCon ].dir[1] = dir[1];
+			contributions[ numCon ].dir[2] = dir[2];
+
+			contributions[ numCon ].style = 0;
+
+			/* push average direction around */
+			addSize = VectorLength( contributions[ numCon ].color );
+			VectorMA( gp->dir, addSize, dir, gp->dir );
+
+			numCon++;
+		}
 	}
 	/////////////////////
 
@@ -1632,6 +1639,8 @@ void TraceGrid( int num )
 		d = 0.25f * (1.0f - d);
 		VectorMA( gp->ambient[ j ], d, contributions[ i ].color, gp->ambient[ j ] );
 
+		VectorAdd( gp->ambient[ j ], contributions[ i ].ambient, gp->ambient[ j ] );
+
 /*
  * div0:
  * the total light average = ambient value + 0.25 * sum of all directional values
-- 
2.39.2