From 5ac566b1f505bf9df39a07ff006bff784eb36b08 Mon Sep 17 00:00:00 2001
From: Thomas Kolb <cfr34k-git@tkolb.de>
Date: Sun, 14 Jun 2020 16:12:02 +0000
Subject: [PATCH] New script: particles

---
 particles.lua | 146 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 146 insertions(+)
 create mode 100644 particles.lua

diff --git a/particles.lua b/particles.lua
new file mode 100644
index 0000000..292f3d4
--- /dev/null
+++ b/particles.lua
@@ -0,0 +1,146 @@
+COOLDOWN_FACTOR = 0.9998
+MAX_ENERGY_PROPAGATION = 0.5
+EXPONENT=1.3
+W_EXPONENT=1.8
+OVERDRIVE=1
+FADE_FACTOR = 0.94
+AVG_LEDS_ACTIVATED = 0.03
+
+num_modules = 1
+num_strips = 1
+
+-- maximum energy values for each band
+maxRedEnergy = 1
+maxGreenEnergy = 1
+maxBlueEnergy = 1
+maxWhiteEnergy = 1
+
+-- array storing the flame’s energy for each pixel
+fireRedEnergy = {}
+fireGreenEnergy = {}
+fireBlueEnergy = {}
+fireWhiteEnergy = {}
+
+-- output color buffers
+red = {}
+green = {}
+blue = {}
+white = {}
+
+function limit(val)
+	if val > 1 then
+		return 1
+	elseif val < 0 then
+		return 0
+	else
+		return val
+	end
+end
+
+function fade2black(energyArray)
+	for s = 1,num_strips do
+		for m = 1,num_modules do
+			i = idx(s, m)
+
+			energyArray[i] = energyArray[i] * FADE_FACTOR
+		end
+	end
+end
+
+function distributeEnergy(newEnergy, energyArray)
+	remainingEnergy = AVG_LEDS_ACTIVATED * newEnergy * num_modules * num_strips
+
+	while remainingEnergy > 0 do
+		rndEnergy = math.random() * newEnergy * 2
+		rndStrip = math.floor(math.random() * num_strips)
+		rndModule = math.floor(math.random() * num_modules)
+
+		if rndEnergy > remainingEnergy then
+			rndEnergy = remainingEnergy
+			remainingEnergy = 0
+		else
+			remainingEnergy = remainingEnergy - rndEnergy
+		end
+
+		i = idx(rndStrip+1, rndModule+1)
+		energyArray[i] = energyArray[i] + rndEnergy
+	end
+end
+
+function periodic()
+	local redEnergy = get_energy_in_band(0, 400);
+	local greenEnergy = get_energy_in_band(400, 4000);
+	local blueEnergy = get_energy_in_band(4000, 12000);
+	local whiteEnergy = get_energy_in_band(12000, 22000);
+
+	maxRedEnergy = maxRedEnergy * COOLDOWN_FACTOR
+	if redEnergy > maxRedEnergy then
+		maxRedEnergy = redEnergy
+	end
+
+	maxGreenEnergy = maxGreenEnergy * COOLDOWN_FACTOR
+	if greenEnergy > maxGreenEnergy then
+		maxGreenEnergy = greenEnergy
+	end
+
+	maxBlueEnergy = maxBlueEnergy * COOLDOWN_FACTOR
+	if blueEnergy > maxBlueEnergy then
+		maxBlueEnergy = blueEnergy
+	end
+
+	maxWhiteEnergy = maxWhiteEnergy * COOLDOWN_FACTOR
+	if whiteEnergy > maxWhiteEnergy then
+		maxWhiteEnergy = whiteEnergy
+	end
+
+	fade2black(fireRedEnergy)
+	fade2black(fireGreenEnergy)
+	fade2black(fireBlueEnergy)
+	fade2black(fireWhiteEnergy)
+
+	distributeEnergy(redEnergy / maxRedEnergy, fireRedEnergy)
+	distributeEnergy(greenEnergy / maxGreenEnergy, fireGreenEnergy)
+	distributeEnergy(blueEnergy / maxBlueEnergy, fireBlueEnergy)
+	distributeEnergy(whiteEnergy / maxWhiteEnergy, fireWhiteEnergy)
+
+	-- make colors more exciting + remove the first (flickering) mass
+	-- TODO: update
+	for m = 1,num_modules do
+		for s = 1,num_strips do
+			i = idx(s, m)
+
+			rval = limit(OVERDRIVE * fireRedEnergy[i]^EXPONENT)
+			gval = limit(OVERDRIVE * fireGreenEnergy[i]^EXPONENT)
+			bval = limit(OVERDRIVE * fireBlueEnergy[i]^EXPONENT)
+			wval = limit(OVERDRIVE * fireWhiteEnergy[i]^W_EXPONENT)
+
+			red[i] = rval
+			green[i] = gval
+			blue[i] = bval
+			white[i] = wval
+		end
+	end
+
+	-- return the 4 color arrays
+	return red, green, blue, white
+end
+
+function init(nstrip, nmod, cmod)
+	num_strips = nstrip
+	num_modules = nmod
+
+	for i = 1,(nmod*nstrip) do
+		red[i] = 0
+		green[i] = 0
+		blue[i] = 0
+		white[i] = 0
+
+		fireRedEnergy[i] = 0
+		fireGreenEnergy[i] = 0
+		fireBlueEnergy[i] = 0
+		fireWhiteEnergy[i] = 0
+	end
+
+	-- don't use fading
+	return 0
+end