Fix resetsegments on 2D change: only change width and height

wled00/FX.h

@@ -378,7 +378,7 @@ typedef struct Segment {
     CRGB* leds;     // local leds[] array (may be a pointer to global)
     static CRGB *_globalLeds;             // global leds[] array
     static uint16_t maxWidth, maxHeight;  // these define matrix width & height (max. segment dimensions)
-    void *jMap; //WLEDMM jMap
+    void *jMap = nullptr; //WLEDMM jMap
 
   private:
     union {

wled00/FX_2Dfcn.cpp

@@ -129,7 +129,13 @@ void WS2812FX::setUpMatrix(bool reset) {
       Segment::maxWidth = _length;
       Segment::maxHeight = 1;
     }
-    if (reset) resetSegments(); //WLEDMM: only if reset
+    if (reset) //resetSegments(); //WLEDMM: only if reset, and only update width and height, keep the fx in place
+      for (segment &seg : _segments) {
+        seg.start = 0;
+        seg.stop = Segment::maxWidth;
+        seg.startY = 0;
+        seg.stopY = Segment::maxHeight;
+      }
   }
 #else
   isMatrix = false; // no matter what config says

wled00/data/index.js

@@ -689,7 +689,7 @@ ${i.psram?inforow("Free PSRAM",(i.psram/1024).toFixed(1)," kB"):""}
 ${i.psusedram?((i.tpram-i.psusedram)>16383?inforow("Max Used PSRAM ☾",((i.tpram-i.psusedram)/1024).toFixed(1)," kB"):inforow("Max Used PSRAM",(i.tpram-i.psusedram)," B")):""}
 <tr><td colspan=2><hr style="height:1px;border-width:0;color:SeaGreen;background-color:SeaGreen"></td></tr>
 ${i.e32model?inforow(i.e32model + " ☾",i.e32cores +" core(s)"," "+i.e32speed+" Mhz"):""}
-${i.e32flash?inforow("Flash "+i.e32flash+" MB"+", mode "+i.e32flashmode+i.e32flashtext + " ☾",i.e32flashspeed," Mhz"):""}
+${i.e32flash?inforow("Flash "+i.e32flash+"MB"+" mode "+i.e32flashmode+i.e32flashtext + " ☾",i.e32flashspeed," Mhz"):""}
 ${i.e32core0code?inforow("Core0 rst reason ☾",i.e32core0code, " "+i.e32core0text):""}
 ${i.e32core1code?inforow("Core1 rst reason ☾",i.e32core1code, " "+i.e32core1text):""}
 <!-- WLEDMM end-->