TraceCallback

This is called during a trace when any Actor in the blockmap is hit, any line is hit, or any plane is hit. This can also be called when crossing portals if set to do so. Custom logic handling for what happens when something is hit happens in this function. Generally Results' HitType is looked at to determine what should be examined in the results.

class GhostFinder : LineTracer
{
    bool bHitGhost;

    // This is where we'll examine the results to check for ghosts
    override ETraceStatus TraceCallback()
    {
        // Check if we hit an actor. If so, does it have the ghost flag?
        if (results.HitType == TRACE_HitActor && results.HitActor.bGhost)
        {
            bHitGhost = true;

            // Tell the trace to terminate
            return TRACE_Stop;
        }

        // If we didn't hit an actor or it doesn't have the ghost flag, ignore it and keep going
        return TRACE_Skip;
    }
}

virtual ETraceStatus TraceCallback()
{
   // Normally you would examine Results.HitType (for ETraceResult), and determine either:
   //  - stop tracing and return the entity that was found (return TRACE_Stop)
   //  - ignore some object, like noclip, e.g. only count solid walls and floors, and ignore actors (return TRACE_Skip)
   //  - find last object of some type (return TRACE_Continue)
   //  - stop tracing entirely and assume we found nothing (return TRACE_Abort)
   // TRACE_Abort and TRACE_Continue are of limited use in scripting.

   return TRACE_Stop; // default callback returns first hit, whatever it is.
}