From 7ca1970fff2080929b8a89e77202d5b660403ce6 Mon Sep 17 00:00:00 2001
From: fishbone-git <kevindf@gmail.com>
Date: Tue, 10 Dec 2019 20:06:00 +0100
Subject: [PATCH] add bouncing balls effect

---
 wled00/FX.cpp | 64 +++++++++++++++++++++++++++++++++++++++++++++++++++
 wled00/FX.h   |  9 +++++---
 2 files changed, 70 insertions(+), 3 deletions(-)

diff --git a/wled00/FX.cpp b/wled00/FX.cpp
index 2bdb75ba9..495c0397a 100644
--- a/wled00/FX.cpp
+++ b/wled00/FX.cpp
@@ -2285,3 +2285,67 @@ uint16_t WS2812FX::mode_spots_fade()
   uint16_t tr = (t >> 1) + (t >> 2);
   return spots_base(tr);
 }
+
+
+/*
+*  Bouncing Balls Effect
+*  Adapted from: https://www.tweaking4all.com/hardware/arduino/adruino-led-strip-effects/
+*/
+uint16_t WS2812FX::mode_BouncingBalls(void) {
+  // number of balls based on intensity setting, 
+  // only has 4 for a few of the higher settings as there is no colour selection
+  // fourth ball is a random colour
+  int balls = int(((SEGMENT.intensity * 6.2) / 255) + 1);
+
+  // ideally use speed for gravity effect on the bounce
+  float Gravity = -9.81;
+
+  const int maxBallCount = 7;
+  static float Height[maxBallCount];
+  static float ImpactVelocity[maxBallCount];
+  static int   Position[maxBallCount];
+  static float TimeSinceLastBounce[maxBallCount];
+  static long  ClockTimeSinceLastBounce[maxBallCount];
+  static int   StartHeight = 1;                 // height in metres (strip length)
+  static float Dampening[maxBallCount] = {0};   // Coefficient of Restitution (bounce damping)
+  static float ImpactVelocityStart=sqrt( -2 * Gravity * StartHeight);
+
+  // Different from the examples, to allow for initialisation of the first bounce
+  if (Dampening[0] == 0) {
+    for (int i = 0 ; i < maxBallCount ; i++) {
+      ClockTimeSinceLastBounce[i] = millis();
+      ImpactVelocity[i] = ImpactVelocityStart;
+      TimeSinceLastBounce[i] = 0;
+      Dampening[i] = 0.90 - float(i)/pow(maxBallCount,2);
+    }
+  }
+  
+  for (int i = 0 ; i < balls ; i++) {
+    TimeSinceLastBounce[i] =  millis() - ClockTimeSinceLastBounce[i];
+    Height[i] = 0.5 * Gravity * pow( TimeSinceLastBounce[i]/1000 , 2.0 ) + ImpactVelocity[i] * TimeSinceLastBounce[i]/1000;
+
+    if ( Height[i] < 0 ) {
+      Height[i] = 0;
+      ImpactVelocity[i] = Dampening[i] * ImpactVelocity[i];
+      ClockTimeSinceLastBounce[i] = millis();
+
+      if ( ImpactVelocity[i] < 0.01 ) {
+        ImpactVelocity[i] = ImpactVelocityStart;
+      }
+    }
+    Position[i] = round( Height[i] * (SEGLEN - 1) / StartHeight);
+  }
+  
+  fill(BLACK);
+
+  for (int i = 0 ; i < balls ; i++) {
+    uint32_t color = SEGCOLOR(i % NUM_COLORS);
+    if (!color) {
+       color = color_wheel(random8());
+    }
+    
+    setPixelColor(Position[i],color);
+  }
+
+  return 20;
+}
\ No newline at end of file
diff --git a/wled00/FX.h b/wled00/FX.h
index 5a3865ae0..5642850a3 100644
--- a/wled00/FX.h
+++ b/wled00/FX.h
@@ -84,7 +84,7 @@
 #define IS_REVERSE      ((SEGMENT.options & REVERSE )     == REVERSE     )
 #define IS_SELECTED     ((SEGMENT.options & SELECTED)     == SELECTED    )
 
-#define MODE_COUNT  87
+#define MODE_COUNT  88
 
 #define FX_MODE_STATIC                   0
 #define FX_MODE_BLINK                    1
@@ -173,6 +173,7 @@
 #define FX_MODE_TRI_STATIC_PATTERN      84
 #define FX_MODE_SPOTS                   85
 #define FX_MODE_SPOTS_FADE              86
+#define FX_MODE_BOUNCINGBALLS           87
 
 
 class WS2812FX {
@@ -317,6 +318,7 @@ class WS2812FX {
       _mode[FX_MODE_TRI_STATIC_PATTERN]      = &WS2812FX::mode_tri_static_pattern;
       _mode[FX_MODE_SPOTS]                   = &WS2812FX::mode_spots;
       _mode[FX_MODE_SPOTS_FADE]              = &WS2812FX::mode_spots_fade;
+      _mode[FX_MODE_BOUNCINGBALLS]           = &WS2812FX::mode_BouncingBalls;
 
       _brightness = DEFAULT_BRIGHTNESS;
       currentPalette = CRGBPalette16(CRGB::Black);
@@ -497,7 +499,8 @@ class WS2812FX {
       mode_static_pattern(void),
 	    mode_tri_static_pattern(void),
       mode_spots(void),
-      mode_spots_fade(void);
+      mode_spots_fade(void),
+      mode_BouncingBalls(void);
 
   private:
     NeoPixelWrapper *bus;
@@ -570,7 +573,7 @@ const char JSON_mode_names[] PROGMEM = R"=====([
 "Two Dots","Two Areas","Circus","Halloween","Tri Chase","Tri Wipe","Tri Fade","Lightning","ICU","Multi Comet",
 "Dual Scanner","Stream 2","Oscillate","Pride 2015","Juggle","Palette","Fire 2012","Colorwaves","Bpm","Fill Noise",
 "Noise 1","Noise 2","Noise 3","Noise 4","Colortwinkles","Lake","Meteor","Smooth Meteor","Railway","Ripple",
-"Twinklefox","Twinklecat","Halloween Eyes","Solid Pattern","Solid Pattern Tri","Spots","Spots Fade"
+"Twinklefox","Twinklecat","Halloween Eyes","Solid Pattern","Solid Pattern Tri","Spots","Spots Fade","Bouncing Balls"
 ])=====";