Fix ioq3 compatibility bug with lightgrid and only one light.

[xonotic/netradiant.git] / tools / quake3 / q3map2 / light.c

diff --git a/tools/quake3/q3map2/light.c b/tools/quake3/q3map2/light.c
index 79098148cbe5c503b33cf27497ed6c33fe486ec8..b8ad379f158b9ab853d966d97f0fc3b44b18cfe4 100644 (file)
--- a/tools/quake3/q3map2/light.c
+++ b/tools/quake3/q3map2/light.c
@@ -1771,7 +1771,17 @@ void TraceGrid( int num ){
                        }
 
                /* vortex: apply gridscale and gridambientscale here */
-               ColorToBytes( color, bgp->ambient[ i ], gridScale * gridAmbientScale );
+               if (gp->directed[0] || gp->directed[1] || gp->directed[2]) {
+                       /*
+                        * HACK: if there's a non-zero directed component, this
+                        * lightgrid cell is useful. However, ioq3 skips grid
+                        * cells with zero ambient. So let's force ambient to be
+                        * nonzero unless directed is zero too.
+                        */
+                       ColorToBytesNonZero(color, bgp->ambient[i], gridScale * gridAmbientScale);
+               } else {
+                       ColorToBytes(color, bgp->ambient[i], gridScale * gridAmbientScale);
+               }
                ColorToBytes( gp->directed[ i ], bgp->directed[ i ], gridScale );
        }