Method do_fire

crawl-ref/source/beam.cc:1218–1484

}

void bolt::do_fire()
{
    initialise_fire();

    if (range < extra_range_used && range > 0)
    {
#ifdef DEBUG
        dprf(DIAG_BEAM, "fire_beam() called on already done beam "
             "'%s'", name.c_str());
#endif
        return;
    }

    apply_beam_conducts();
    cursor_control coff(false);

    msg_generated = false;
    if (!aimed_at_feet)
    {
        choose_ray();
        // Take *one* step, so as not to hurt the source.
        ray.advance();
    }

    // Tracks if the *last* cell seen was a wall monster, therefore pretend
    // next cell is solid for purposes of bouncing or stopping the beam.
    bool wall_monster_hit = false;

    // Note: nothing but this loop should be changing the ray.
    while (map_bounds(pos()))
    {
        if (range_used() > range)
        {
            ray.regress();
            extra_range_used++;
            ASSERT(range_used() >= range);
            break;
        }

        const dungeon_feature_type feat = env.grid(pos());

        if (in_bounds(target)
            // Starburst beams are essentially untargeted; some might even hit
            // a victim if others have LOF blocked.
            && origin_spell != SPELL_STARBURST
            // We ran into a solid wall with a real beam...
            && (feat_is_solid(feat)
                && flavour != BEAM_DIGGING && flavour <= BEAM_LAST_REAL
                && !cell_is_solid(target)
            // Or hit a monster that'll stop our beam...
                || at_blocking_monster())
            // and it's a player tracer that cares about blocked paths...
            && is_tracer() && tracer->is_collecting_warnings() && YOU_KILL(thrower)
            // and we're actually between you and the target...
            && !passed_target && pos() != target && pos() != source
            // ?
            && !tracer->has_hit_foe() && bounces == 0 && reflections == 0
            // and you aren't shooting out of LOS.