From bdff05feafe2e0c8af5aed444a56089439c1440d Mon Sep 17 00:00:00 2001
From: Blaz Kristan <blaz@kristan-sp.si>
Date: Sat, 5 Aug 2023 13:53:12 +0200
Subject: [PATCH 1/2] Palette blending optimisation.

---
 wled00/FX.h       |  1 -
 wled00/FX_fcn.cpp | 13 ++++---------
 2 files changed, 4 insertions(+), 10 deletions(-)

diff --git a/wled00/FX.h b/wled00/FX.h
index fc8f16b9..a1627a29 100644
--- a/wled00/FX.h
+++ b/wled00/FX.h
@@ -399,7 +399,6 @@ typedef struct Segment {
     static CRGBPalette16 _randomPalette;
     static CRGBPalette16 _newRandomPalette;
     static unsigned long _lastPaletteChange;
-    static uint8_t       _noOfBlendsRemaining;
 
     // transition data, valid only if transitional==true, holds values during transition (72 bytes)
     struct Transition {
diff --git a/wled00/FX_fcn.cpp b/wled00/FX_fcn.cpp
index c76e22a2..5cbebe1e 100644
--- a/wled00/FX_fcn.cpp
+++ b/wled00/FX_fcn.cpp
@@ -80,7 +80,6 @@ uint16_t Segment::maxHeight = 1;
 CRGBPalette16 Segment::_randomPalette = CRGBPalette16(DEFAULT_COLOR);
 CRGBPalette16 Segment::_newRandomPalette = CRGBPalette16(DEFAULT_COLOR);
 unsigned long Segment::_lastPaletteChange = 0; // perhaps it should be per segment
-uint8_t       Segment::_noOfBlendsRemaining = 0;
 
 // copy constructor
 Segment::Segment(const Segment &orig) {
@@ -216,7 +215,7 @@ CRGBPalette16 &Segment::loadPalette(CRGBPalette16 &targetPalette, uint8_t pal) {
                         CHSV(random8(), random8(160, 255), random8(128, 255)),
                         CHSV(random8(), random8(160, 255), random8(128, 255)));
         _lastPaletteChange = millis();
-        _noOfBlendsRemaining = 255;
+        handleRandomPalette(); // do initial blend
       }
       targetPalette = _randomPalette;
       break;}
@@ -348,13 +347,9 @@ void Segment::handleTransition() {
 
 // relies on WS2812FX::service() to call it max every 8ms or more (MIN_SHOW_DELAY)
 void Segment::handleRandomPalette() {
-  if (_noOfBlendsRemaining > 0) {
-    // there needs to be 255 palette blends (48) for full blend
-    size_t noOfBlends = 3; // blending time ~850ms when MIN_SHOW_DELAY>10
-    if (noOfBlends > _noOfBlendsRemaining) noOfBlends = _noOfBlendsRemaining;
-    for (size_t i=0; i<noOfBlends; i++) nblendPaletteTowardPalette(_randomPalette, _newRandomPalette, 48);
-    _noOfBlendsRemaining -= noOfBlends;
-  }
+  // just do a blend; if the palettes are identical it will just compare 48 bytes (same as _randomPalette == _newRandomPalette)
+  // this will slowly blend _newRandomPalette into _randomPalette every 15ms or 8ms (depending on MIN_SHOW_DELAY)
+  nblendPaletteTowardPalette(_randomPalette, _newRandomPalette, 48);
 }
 
 // segId is given when called from network callback, changes are queued if that segment is currently in its effect function

From 45d7e664884a5d561435fa9a915f8ea96323a650 Mon Sep 17 00:00:00 2001
From: Frank <frank.moehle@outlook.de>
Date: Sat, 5 Aug 2023 23:29:23 +0200
Subject: [PATCH 2/2] effects bugfix: prevent crash when SEGLEN==1

* Blurz and a few other effects would crash (or behave unexpectedly) for single pixel segments
* replaced a few "MAX" by "max", because MAX will evaluate its arguments twice so its very inefficient.
---
 wled00/FX.cpp | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/wled00/FX.cpp b/wled00/FX.cpp
index 834c17e9..b962bb58 100644
--- a/wled00/FX.cpp
+++ b/wled00/FX.cpp
@@ -713,7 +713,7 @@ uint16_t mode_hyper_sparkle(void) {
 
   if (strip.now - SEGENV.aux0 > SEGENV.step) {
     if (random8((255-SEGMENT.intensity) >> 4) == 0) {
-      for (int i = 0; i < MAX(1, SEGLEN/3); i++) {
+      for (int i = 0; i < max(1, SEGLEN/3); i++) {
         SEGMENT.setPixelColor(random16(SEGLEN), SEGCOLOR(1));
       }
     }
@@ -1220,7 +1220,7 @@ uint16_t mode_fireworks() {
   if (valid1) { if (SEGMENT.is2D()) SEGMENT.setPixelColorXY(x, y, sv1); else SEGMENT.setPixelColor(SEGENV.aux0, sv1); } // restore spark color after blur
   if (valid2) { if (SEGMENT.is2D()) SEGMENT.setPixelColorXY(x, y, sv2); else SEGMENT.setPixelColor(SEGENV.aux1, sv2); } // restore old spark color after blur
 
-  for (int i=0; i<MAX(1, width/20); i++) {
+  for (int i=0; i<max(1, width/20); i++) {
     if (random8(129 - (SEGMENT.intensity >> 1)) == 0) {
       uint16_t index = random16(width*height);
       x = index % width;
@@ -3023,7 +3023,7 @@ uint16_t candle(bool multi)
   if (multi)
   {
     //allocate segment data
-    uint16_t dataSize = (SEGLEN -1) *3; //max. 1365 pixels (ESP8266)
+    uint16_t dataSize = max(1, SEGLEN -1) *3; //max. 1365 pixels (ESP8266)
     if (!SEGENV.allocateData(dataSize)) return candle(false); //allocation failed
   }
 
@@ -3156,7 +3156,7 @@ uint16_t mode_starburst(void) {
     if (random8((144-(SEGMENT.speed >> 1))) == 0 && stars[j].birth == 0)
     {
       // Pick a random color and location.
-      uint16_t startPos = random16(SEGLEN-1);
+      uint16_t startPos = (SEGLEN > 1) ? random16(SEGLEN-1) : 0;
       float multiplier = (float)(random8())/255.0 * 1.0;
 
       stars[j].color = CRGB(SEGMENT.color_wheel(random8()));
@@ -3400,7 +3400,7 @@ uint16_t mode_drip(void)
       uint8_t numDrops = 1 + (SEGMENT.intensity >> 6); // 255>>6 = 3
 
       float gravity = -0.0005 - (SEGMENT.speed/50000.0);
-      gravity *= SEGLEN-1;
+      gravity *= max(1, SEGLEN-1);
       int sourcedrop = 12;
 
       for (int j=0;j<numDrops;j++) {
@@ -6679,7 +6679,7 @@ uint16_t mode_blurz(void) {                    // Blurz. By Andrew Tuline.
   SEGENV.step += FRAMETIME;
   if (SEGENV.step > SPEED_FORMULA_L) {
     uint16_t segLoc = random16(SEGLEN);
-    SEGMENT.setPixelColor(segLoc, color_blend(SEGCOLOR(1), SEGMENT.color_from_palette(2*fftResult[SEGENV.aux0%16]*240/(SEGLEN-1), false, PALETTE_SOLID_WRAP, 0), 2*fftResult[SEGENV.aux0%16]));
+    SEGMENT.setPixelColor(segLoc, color_blend(SEGCOLOR(1), SEGMENT.color_from_palette(2*fftResult[SEGENV.aux0%16]*240/max(1, SEGLEN-1), false, PALETTE_SOLID_WRAP, 0), 2*fftResult[SEGENV.aux0%16]));
     ++(SEGENV.aux0) %= 16; // make sure it doesn't cross 16
 
     SEGENV.step = 1;