setPixelSegment() optimization

wled00/FX.h

@@ -657,7 +657,6 @@ class WS2812FX {
       setPixelColor(uint16_t n, uint8_t r, uint8_t g, uint8_t b, uint8_t w = 0),
       show(void),
 			setTargetFps(uint8_t fps),
-      setPixelSegment(uint8_t n),
       deserializeMap(uint8_t n=0);
 
     bool
@@ -688,6 +687,7 @@ class WS2812FX {
       //getFirstSelectedSegment(void),
       getMainSegmentId(void),
 			getTargetFps(void),
+      setPixelSegment(uint8_t n),
       gamma8(uint8_t),
       gamma8_cal(uint8_t, float),
       sin_gap(uint16_t),

wled00/FX_fcn.cpp

@@ -716,36 +716,16 @@ bool WS2812FX::checkSegmentAlignment() {
 }
 
 //After this function is called, setPixelColor() will use that segment (offsets, grouping, ... will apply)
-//Note: If called in an interrupt (e.g. JSON API), it must be reset with "setPixelColor(255)",
+//Note: If called in an interrupt (e.g. JSON API), original segment must be restored,
 //otherwise it can lead to a crash on ESP32 because _segment_index is modified while in use by the main thread
-#ifdef ARDUINO_ARCH_ESP32
-uint8_t _segment_index_prev = 0;
-uint16_t _virtualSegmentLength_prev = 0;
-bool _ps_set = false;
-#endif
-
-void WS2812FX::setPixelSegment(uint8_t n)
+uint8_t WS2812FX::setPixelSegment(uint8_t n)
 {
+  uint8_t prevSegId = _segment_index;
   if (n < MAX_NUM_SEGMENTS) {
-		#ifdef ARDUINO_ARCH_ESP32
-		if (!_ps_set) {
-			_segment_index_prev = _segment_index;
-			_virtualSegmentLength_prev = _virtualSegmentLength;
-			_ps_set = true;
-		}
-		#endif
     _segment_index = n;
     _virtualSegmentLength = SEGMENT.virtualLength();
-  } else {
-		_virtualSegmentLength = 0;
-		#ifdef ARDUINO_ARCH_ESP32
-		if (_ps_set) {
-			_segment_index = _segment_index_prev;
-			_virtualSegmentLength = _virtualSegmentLength_prev;
-			_ps_set = false;
-		}
-		#endif
   }
+  return prevSegId;
 }
 
 void WS2812FX::setRange(uint16_t i, uint16_t i2, uint32_t col)

wled00/json.cpp

@@ -189,7 +189,7 @@ void deserializeSegment(JsonObject elem, byte it, byte presetId)
 
   JsonArray iarr = elem[F("i")]; //set individual LEDs
   if (!iarr.isNull()) {
-    strip.setPixelSegment(id);
+    uint8_t oldSegId = strip.setPixelSegment(id);
 
     //freeze and init to black
     if (!seg.getOption(SEG_OPTION_FREEZE)) {
@@ -235,7 +235,7 @@ void deserializeSegment(JsonObject elem, byte it, byte presetId)
         set = 0;
       }
     }
-    strip.setPixelSegment(255);
+    strip.setPixelSegment(oldSegId);
     strip.trigger();
   } else if (!elem["frz"] && iarr.isNull()) { //return to regular effect
     seg.setOption(SEG_OPTION_FREEZE, false);