Display gaps in peek, fix segment overflow bug (#5105)

- display gaps in peek 
- fix segment overflow bug when loading preset with larger bounds than current setup

Author: DedeHai

wled00/FX.cpp

@@ -172,7 +172,7 @@ uint16_t mode_copy_segment(void) {
     } else { // 1D source, source can be expanded into 2D
       for (unsigned i = 0; i < SEGMENT.vLength(); i++) {
         if(SEGMENT.check2) {
-          sourcecolor = strip.getPixelColor(i + sourcesegment.start); // read from global buffer (reads the last rendered frame)
+          sourcecolor = strip.getPixelColorNoMap(i + sourcesegment.start); // read from global buffer (reads the last rendered frame)
         }
         else {
           sourcesegment.setDrawDimensions(); // set to source segment dimensions

wled00/FX.h

@@ -965,7 +965,8 @@ class WS2812FX {
     };
 
     unsigned long now, timebase;
-    inline uint32_t getPixelColor(unsigned n) const { return (n < getLengthTotal()) ? _pixels[n] : 0; } // returns color of pixel n
+    inline uint32_t getPixelColor(unsigned n) const { return (getMappedPixelIndex(n) < getLengthTotal()) ? _pixels[n] : 0; } // returns color of pixel n, black if out of (mapped) bounds
+    inline uint32_t getPixelColorNoMap(unsigned n) const { return (n < getLengthTotal()) ? _pixels[n] : 0; } // ignores mapping table
     inline uint32_t getLastShow() const             { return _lastShow; }                 // returns millis() timestamp of last strip.show() call
 
     const char *getModeData(unsigned id = 0) const  { return (id && id < _modeCount) ? _modeData[id] : PSTR("Solid"); }

wled00/FX_fcn.cpp

@@ -458,7 +458,7 @@ void Segment::setGeometry(uint16_t i1, uint16_t i2, uint8_t grp, uint8_t spc, ui
     return;
   }
   if (i1 < Segment::maxWidth || (i1 >= Segment::maxWidth*Segment::maxHeight && i1 < strip.getLengthTotal())) start = i1; // Segment::maxWidth equals strip.getLengthTotal() for 1D
-  stop = i2 > Segment::maxWidth*Segment::maxHeight ? MIN(i2,strip.getLengthTotal()) : constrain(i2, 1, Segment::maxWidth);
+  stop = i2 > Segment::maxWidth*Segment::maxHeight && i1 >= Segment::maxWidth*Segment::maxHeight ? MIN(i2,strip.getLengthTotal()) : constrain(i2, 1, Segment::maxWidth); // check for 2D trailing strip
   startY = 0;
   stopY  = 1;
   #ifndef WLED_DISABLE_2D

wled00/ws.cpp

@@ -230,7 +230,7 @@ bool sendLiveLedsWs(uint32_t wsClient)
 #ifndef WLED_DISABLE_2D
     if (strip.isMatrix && n>1 && (i/Segment::maxWidth)%n) i += Segment::maxWidth * (n-1);
 #endif
-    uint32_t c = strip.getPixelColor(i);
+    uint32_t c = strip.getPixelColor(i); // note: LEDs mapped outside of valid range are set to black
     uint8_t r = R(c);
     uint8_t g = G(c);
     uint8_t b = B(c);