new option -extradist to improve lighting a bit, also a light entity field _extradist of the same purpose

tools/quake3/q3map2/light.c

@@ -401,6 +401,10 @@ void CreateEntityLights( void )
 		else
 			light->color[ 0 ] = light->color[ 1 ] = light->color[ 2 ] = 1.0f;
 
+		light->extraDist = FloatForKey( e, "_extradist" );
+		if(light->extraDist == 0.0f)
+			light->extraDist = extraDist;
+		
 		intensity = intensity * pointScale;
 		light->photons = intensity;
 
@@ -821,6 +825,12 @@ int LightContributionToSample( trace_t *trace )
 			else if( angle < 0.0f &&
 				(trace->twoSided || (light->flags & LIGHT_TWOSIDED)) )
 				angle = -angle;
+
+			/* clamp the distance to prevent super hot spots */
+			dist = sqrt(dist * dist + light->extraDist * light->extraDist);
+			if( dist < 16.0f )
+				dist = 16.0f;
+
 			add = light->photons / (dist * dist) * angle;
 		}
 		else
@@ -861,6 +871,7 @@ int LightContributionToSample( trace_t *trace )
 			return 0;
 
 		/* clamp the distance to prevent super hot spots */
+		dist = sqrt(dist * dist + light->extraDist * light->extraDist);
 		if( dist < 16.0f )
 			dist = 16.0f;
 
@@ -907,7 +918,7 @@ int LightContributionToSample( trace_t *trace )
 				add = 0.0f;
 		}
 		else
-			add = light->photons / (dist * dist) * angle;
+			add = (light->photons / (dist * dist)) * angle;
 		
 		/* handle spotlights */
 		if( light->type == EMIT_SPOT )
@@ -1156,6 +1167,7 @@ int LightContributionToPoint( trace_t *trace )
 	if( light->type == EMIT_AREA && faster )
 	{
 		/* clamp the distance to prevent super hot spots */
+		dist = sqrt(dist * dist + light->extraDist * light->extraDist);
 		if( dist < 16.0f )
 			dist = 16.0f;
 
@@ -1202,6 +1214,7 @@ int LightContributionToPoint( trace_t *trace )
 	else if( light->type == EMIT_POINT || light->type == EMIT_SPOT )
 	{
 		/* clamp the distance to prevent super hot spots */
+		dist = sqrt(dist * dist + light->extraDist * light->extraDist);
 		if( dist < 16.0f )
 			dist = 16.0f;
 		
@@ -2228,6 +2241,15 @@ int LightMain( int argc, char **argv )
 			Sys_Printf( "Enabling Quake 3 lighting model (nonlinear default)\n" );
 		}
 
+		else if( !strcmp( argv[ i ], "-extradist" ) )
+		{
+			extraDist = atof( argv[ i + 1 ] );
+			if( extraDist < 0 )
+				extraDist = 0;
+			i++;
+			Sys_Printf( "Default extra radius set to %f units\n", extraDist );
+		}
+		
 		else if( !strcmp( argv[ i ], "-sunonly" ) )
 		{
 			sunOnly = qtrue;

tools/quake3/q3map2/q3map2.h

@@ -1304,6 +1304,7 @@ typedef struct light_s
 	float				radiusByDist;	/* for spotlights */
 	float				fade;			/* ydnar: from wolf, for linear lights */
 	float				angleScale;		/* ydnar: stolen from vlight for K */
+	float				extraDist;		/* "extra dimension" distance of the light, to kill hot spots */
 
 	float				add;			/* ydnar: used for area lights */
 	float				envelope;		/* ydnar: units until falloff < tolerance */
@@ -2141,6 +2142,7 @@ light global variables
 
 /* commandline arguments */
 Q_EXTERN qboolean			wolfLight Q_ASSIGN( qfalse );
+Q_EXTERN float				extraDist Q_ASSIGN( 0.0f );
 Q_EXTERN qboolean			loMem Q_ASSIGN( qfalse );
 Q_EXTERN qboolean			noStyles Q_ASSIGN( qfalse );
 Q_EXTERN qboolean			keepLights Q_ASSIGN( qfalse );