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] 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;