From 94243ac60513a2770bc38d5f2e15614a4a68d393 Mon Sep 17 00:00:00 2001
From: Blaz Kristan <blaz@kristan-sp.si>
Date: Tue, 6 Sep 2022 21:44:11 +0200
Subject: [PATCH] Better palette blending.

---
 wled00/FX.h       | 21 +++++++++++++++++++--
 wled00/FX_fcn.cpp |  7 +++++--
 wled00/wled.h     |  2 +-
 3 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/wled00/FX.h b/wled00/FX.h
index afa8edec..ddb4bd12 100644
--- a/wled00/FX.h
+++ b/wled00/FX.h
@@ -388,14 +388,31 @@ typedef struct Segment {
       uint8_t       _briT;        // temporary brightness
       uint8_t       _cctT;        // temporary CCT
       CRGBPalette16 _palT;        // temporary palette
+      uint8_t       _prevPaletteBlends; // number of previous palette blends (there are max 128 belnds possible)
       uint8_t       _modeP;       // previous mode/effect
       //uint16_t      _aux0, _aux1; // previous mode/effect runtime data
       //uint32_t      _step, _call; // previous mode/effect runtime data
       //byte         *_data;        // previous mode/effect runtime data
       uint32_t      _start;
       uint16_t      _dur;
-      Transition(uint16_t dur=750) : _briT(255), _cctT(127), _palT(CRGBPalette16(CRGB::Black)), _modeP(FX_MODE_STATIC), _start(millis()), _dur(dur) {}
-      Transition(uint16_t d, uint8_t b, uint8_t c, const uint32_t *o) : _briT(b), _cctT(c), _palT(CRGBPalette16(CRGB::Black)), _modeP(FX_MODE_STATIC), _start(millis()), _dur(d) {
+      Transition(uint16_t dur=750)
+        : _briT(255)
+        , _cctT(127)
+        , _palT(CRGBPalette16(CRGB::Black))
+        , _prevPaletteBlends(0)
+        , _modeP(FX_MODE_STATIC)
+        , _start(millis())
+        , _dur(dur)
+      {}
+      Transition(uint16_t d, uint8_t b, uint8_t c, const uint32_t *o)
+        : _briT(b)
+        , _cctT(c)
+        , _palT(CRGBPalette16(CRGB::Black))
+        , _prevPaletteBlends(0)
+        , _modeP(FX_MODE_STATIC)
+        , _start(millis())
+        , _dur(d)
+      {
         for (size_t i=0; i<NUM_COLORS; i++) _colorT[i] = o[i];
       }
     } *_t;
diff --git a/wled00/FX_fcn.cpp b/wled00/FX_fcn.cpp
index 6aa92360..56ab09c3 100644
--- a/wled00/FX_fcn.cpp
+++ b/wled00/FX_fcn.cpp
@@ -341,8 +341,11 @@ CRGBPalette16 &Segment::currentPalette(CRGBPalette16 &targetPalette, uint8_t pal
   loadPalette(targetPalette, pal);
   if (transitional && _t && progress() < 0xFFFFU) {
     // blend palettes
-    uint8_t blends = map(_t->_dur, 0, 0xFFFF, 48, 6); // do not blend palettes too quickly (0-65.5s)
-    nblendPaletteTowardPalette(_t->_palT, targetPalette, blends);
+    // there are about 255 blend passes of 48 "blends" to completely blend two palettes (in _dur time)
+    // minimum blend time is 100ms maximum is 65535ms
+    uint32_t timeMS = millis() - _t->_start;
+    uint16_t noOfBlends = (255U * timeMS / _t->_dur) - _t->_prevPaletteBlends;
+    for (int i=0; i<noOfBlends; i++, _t->_prevPaletteBlends++) nblendPaletteTowardPalette(_t->_palT, targetPalette, 48);
     targetPalette = _t->_palT; // copy transitioning/temporary palette
   }
   return targetPalette;
diff --git a/wled00/wled.h b/wled00/wled.h
index 5b1b2b79..055d65d3 100644
--- a/wled00/wled.h
+++ b/wled00/wled.h
@@ -8,7 +8,7 @@
  */
 
 // version code in format yymmddb (b = daily build)
-#define VERSION 2209052
+#define VERSION 2209061
 
 //uncomment this if you have a "my_config.h" file you'd like to use
 //#define WLED_USE_MY_CONFIG