deluxemapping: ignore light contribution from the other side of a surface

diff --git a/tools/quake3/q3map2/light.c b/tools/quake3/q3map2/light.c
index 868bb8d118cf4735c6e180d4666bc3ef1dc45d84..b07314c03e310d9422e19bf29f86660b36028dbb 100644 (file)
--- a/tools/quake3/q3map2/light.c
+++ b/tools/quake3/q3map2/light.c
@@ -750,8 +750,9 @@ int LightContributionToSample( trace_t *trace )
        float                   add;
        float                   dist;
        float                   addDeluxe = 0.0f, addDeluxeBounceScale = 0.25f;
-       qboolean                angledDeluxe = qfalse;
+       qboolean                angledDeluxe = qtrue;
        float                   colorBrightness;
+       qboolean                doAddDeluxe = qtrue;
        
        /* get light */
        light = trace->light;
@@ -821,7 +822,12 @@ int LightContributionToSample( trace_t *trace )
                        
                        /* twosided lighting */
                        if( trace->twoSided )
-                               angle = fabs( angle );
+                       {
+                               angle = -angle;
+
+                               /* no deluxemap contribution from "other side" light */
+                               doAddDeluxe = qfalse;
+                       }
                        
                        /* attenuate */
                        angle *= -DotProduct( light->normal, trace->direction );
@@ -864,6 +870,9 @@ int LightContributionToSample( trace_t *trace )
                                        dist = SetupTrace( trace );
                                        if( dist >= light->envelope )
                                                return 0;
+
+                                       /* no deluxemap contribution from "other side" light */
+                                       doAddDeluxe = qfalse;
                                }
                                else
                                        return 0;
@@ -898,8 +907,13 @@ int LightContributionToSample( trace_t *trace )
                        float dot = DotProduct( trace->normal, trace->direction ); 
 
                        /* twosided lighting */
-                       if( trace->twoSided )
-                               dot = fabs( dot );
+                       if( trace->twoSided && dot < 0 )
+                       {
+                               dot = -dot;
+
+                               /* no deluxemap contribution from "other side" light */
+                               doAddDeluxe = qfalse;
+                       }
 
                        /* jal: optional half Lambert attenuation (http://developer.valvesoftware.com/wiki/Half_Lambert) */
                        if( lightAngleHL )
@@ -1010,8 +1024,13 @@ int LightContributionToSample( trace_t *trace )
                        float dot = DotProduct( trace->normal, trace->direction ); 
 
                        /* twosided lighting */
-                       if( trace->twoSided )
-                               dot = fabs( dot );
+                       if( trace->twoSided && dot < 0 )
+                       {
+                               dot = -dot;
+
+                               /* no deluxemap contribution from "other side" light */
+                               doAddDeluxe = qfalse;
+                       }
 
                        /* jal: optional half Lambert attenuation (http://developer.valvesoftware.com/wiki/Half_Lambert) */
                        if( lightAngleHL )
@@ -1108,11 +1127,16 @@ int LightContributionToSample( trace_t *trace )
        if( bouncing )
        {
                addDeluxe *= addDeluxeBounceScale;
+               /* better NOT increase it beyond the original value
                if( addDeluxe < 0.00390625f )
                        addDeluxe = 0.00390625f;
+               */
        }
 
-       VectorScale( trace->direction, addDeluxe, trace->directionContribution );
+       if(doAddDeluxe)
+       {
+               VectorScale( trace->direction, addDeluxe, trace->directionContribution );
+       }
        
        /* setup trace */
        trace->testAll = qfalse;