bugfix #2 for switched-off segments

segments that are "off" were still rendered during transitions.

wled00/FX_fcn.cpp

@@ -1935,6 +1935,7 @@ void WS2812FX::service() {
         now = millis() + timebase;
 #endif
         seg.startFrame();   // WLEDMM
+        if (!_triggered && (seg.currentBri(seg.opacity) == 0) && (seg.lastBri == 0)) continue; // WLEDMM skip totally black segments
         // effect blending (execute previous effect)
         // actual code may be a bit more involved as effects have runtime data including allocated memory
         //if (seg.transitional && seg._modeP) (*_mode[seg._modeP])(progress());
@@ -1944,6 +1945,7 @@ void WS2812FX::service() {
         if (seg.mode != FX_MODE_HALLOWEEN_EYES) seg.call++;
         if (seg.transitional && frameDelay > FRAMETIME) frameDelay = FRAMETIME; // force faster updates during transition
 
+        seg.lastBri = seg.currentBri(seg.on ? seg.opacity:0);                   // WLEDMM remember for next time
         seg.handleTransition();
       }