From 4147d6c67e5cd1ed0945df111a2ffa43912905c9 Mon Sep 17 00:00:00 2001
From: Blaz Kristan <blaz@kristan-sp.si>
Date: Mon, 16 Jan 2023 18:53:52 +0100
Subject: [PATCH] FX: GameOfLife - better glider detection - correct behaviour
 during transition - optimisations

---
 wled00/FX.cpp | 45 ++++++++++++++++++++++++---------------------
 1 file changed, 24 insertions(+), 21 deletions(-)

diff --git a/wled00/FX.cpp b/wled00/FX.cpp
index 139c0c3ab..cfd5d170a 100644
--- a/wled00/FX.cpp
+++ b/wled00/FX.cpp
@@ -4835,7 +4835,7 @@ static const char _data_FX_MODE_2DFRIZZLES[] PROGMEM = "Frizzles@X frequency,Y f
 ///////////////////////////////////////////
 typedef struct ColorCount {
   CRGB color;
-  int8_t  count;
+  int8_t count;
 } colorCount;
 
 uint16_t mode_2Dgameoflife(void) { // Written by Ewoud Wijma, inspired by https://natureofcode.com/book/chapter-7-cellular-automata/ and https://github.com/DougHaber/nlife-color
@@ -4844,17 +4844,18 @@ uint16_t mode_2Dgameoflife(void) { // Written by Ewoud Wijma, inspired by https:
   const uint16_t cols = SEGMENT.virtualWidth();
   const uint16_t rows = SEGMENT.virtualHeight();
   const uint16_t dataSize = sizeof(CRGB) * SEGMENT.length();  // using width*height prevents reallocation if mirroring is enabled
+  const uint16_t crcBufferLen = (SEGMENT.width() + SEGMENT.height())*71/100; // roughly sqrt(2)/2 for better repetition detection (Ewowi)
 
-  if (!SEGENV.allocateData(dataSize + sizeof(unsigned long))) return mode_static(); //allocation failed
+  if (!SEGENV.allocateData(dataSize + sizeof(uint16_t)*crcBufferLen)) return mode_static(); //allocation failed
   CRGB *prevLeds = reinterpret_cast<CRGB*>(SEGENV.data);
-  unsigned long *resetMillis = reinterpret_cast<unsigned long*>(SEGENV.data + dataSize); // triggers reset
+  uint16_t *crcBuffer = reinterpret_cast<uint16_t*>(SEGENV.data + dataSize); 
 
   CRGB backgroundColor = SEGCOLOR(1);
 
-  if (SEGENV.call == 0 || strip.now - *resetMillis > 5000) {
-    *resetMillis = strip.now;
-
-    random16_set_seed(strip.now); //seed the random generator
+  if (SEGENV.call == 0 || strip.now - SEGMENT.step > 5000) {
+    SEGENV.step = strip.now;
+    SEGENV.aux0 = 0;
+    random16_set_seed(millis()>>2); //seed the random generator
 
     //give the leds random state and colors (based on intensity, colors from palette or all posible colors are chosen)
     for (int x = 0; x < cols; x++) for (int y = 0; y < rows; y++) {
@@ -4862,17 +4863,18 @@ uint16_t mode_2Dgameoflife(void) { // Written by Ewoud Wijma, inspired by https:
       if (state == 0)
         SEGMENT.setPixelColorXY(x,y, backgroundColor);
       else
-        SEGMENT.setPixelColorXY(x,y, SEGMENT.color_from_palette(random8(), false, PALETTE_SOLID_WRAP, 0));
+        SEGMENT.setPixelColorXY(x,y, SEGMENT.color_from_palette(random8(), false, PALETTE_SOLID_WRAP, 255));
     }
 
     for (int y = 0; y < rows; y++) for (int x = 0; x < cols; x++) prevLeds[XY(x,y)] = CRGB::Black;
-
-
-    SEGENV.aux1 = 0;
-    SEGENV.aux0 = 0xFFFF;
+    memset(crcBuffer, 0, sizeof(uint16_t)*crcBufferLen);
+  } else if (strip.now - SEGENV.step < FRAMETIME_FIXED * map(SEGMENT.speed,0,255,64,4)) {
+    // update only when appropriate time passes (in 42 FPS slots)
+    return FRAMETIME;
   }
 
   //copy previous leds (save previous generation)
+  //NOTE: using lossy getPixelColor() is a benefit as endlessly repeating patterns will eventually fade out causing a reset
   for (int x = 0; x < cols; x++) for (int y = 0; y < rows; y++) prevLeds[XY(x,y)] = SEGMENT.getPixelColorXY(x,y);
 
   //calculate new leds
@@ -4909,8 +4911,8 @@ uint16_t mode_2Dgameoflife(void) { // Written by Ewoud Wijma, inspired by https:
     uint32_t bgc = RGBW32(backgroundColor.r, backgroundColor.g, backgroundColor.b, 0);
     if      ((col != bgc) && (neighbors <  2)) SEGMENT.setPixelColorXY(x,y, bgc); // Loneliness
     else if ((col != bgc) && (neighbors >  3)) SEGMENT.setPixelColorXY(x,y, bgc); // Overpopulation
-    else if ((col == bgc) && (neighbors == 3)) {                                              // Reproduction
-      //find dominantcolor and assign to cell
+    else if ((col == bgc) && (neighbors == 3)) {                                  // Reproduction
+      //find dominant color and assign to cell
       colorCount dominantColorCount = {backgroundColor, 0};
       for (int i=0; i<9 && colorsCount[i].count != 0; i++)
         if (colorsCount[i].count > dominantColorCount.count) dominantColorCount = colorsCount[i];
@@ -4920,16 +4922,17 @@ uint16_t mode_2Dgameoflife(void) { // Written by Ewoud Wijma, inspired by https:
   } //x,y
 
   // calculate CRC16 of leds
-  uint16_t crc = crc16((const unsigned char*)prevLeds, dataSize-1); //ewowi: prevLeds instead of leds work as well, tbd: compare more patterns, see SR!
-
+  uint16_t crc = crc16((const unsigned char*)prevLeds, dataSize);
   // check if we had same CRC and reset if needed
+  bool repetition = false;
+  for (int i=0; i<crcBufferLen && !repetition; i++) repetition = (crc == crcBuffer[i]); // (Ewowi)
   // same CRC would mean image did not change or was repeating itself
-  if (!(crc == SEGENV.aux0 || crc == SEGENV.aux1)) *resetMillis = strip.now; //if no repetition avoid reset
-  // remember last two
-  SEGENV.aux1 = SEGENV.aux0;
-  SEGENV.aux0 = crc;
+  if (!repetition) SEGENV.step = strip.now; //if no repetition avoid reset
+  // remember CRCs across frames
+  crcBuffer[SEGENV.aux0] = crc;
+  ++SEGENV.aux0 %= crcBufferLen;
 
-  return FRAMETIME_FIXED * (128-(SEGMENT.speed>>1)); // update only when appropriate time passes (in 42 FPS slots)
+  return FRAMETIME;
 } // mode_2Dgameoflife()
 static const char _data_FX_MODE_2DGAMEOFLIFE[] PROGMEM = "Game Of Life@!;!,!;!;2";