Update Lua API to support 2D LED arrays

It’s a whole new dimension!

config.h

@@ -16,13 +16,13 @@
 // configuration variables for musiclight2
 
 // networking
-#define HOST "musiclight0.wiese.icmp.camp"
+#define HOST "192.168.42.1"
 #define PORT 2703
 
 // FFT transformation parameters
 #define FFT_EXPONENT 8 // ATTENTION: when you change this, run gen_lut.py with this value as argument
 #define BLOCK_LEN (1 << FFT_EXPONENT) // 2^FFT_EXPONENT
-#define SAMPLE_RATE 48000
+#define SAMPLE_RATE 44100
 #define DATALEN (BLOCK_LEN / 2)
 
 // Number of parts in the sample buffer

config.lua

@@ -1,7 +1,8 @@
-WS2801_HOST = "10.42.6.183"
+WS2801_HOST = "192.168.42.1"
 WS2801_PORT = 2703
 
 NUM_MODULES = 16
+NUM_STRIPS  =  8
 CENTER_MODULE = 8
 
 GAMMA = 2.0

flame.lua

@@ -157,25 +157,35 @@ function periodic()
 	end
 
 	-- make colors more exciting + remove the first (flickering) mass
-	for i = 1,num_modules do
-		red[i]   = limit(OVERDRIVE * r_tmp[i+1]^EXPONENT)
-		green[i] = limit(OVERDRIVE * g_tmp[i+1]^EXPONENT)
-		blue[i]  = limit(OVERDRIVE * b_tmp[i+1]^EXPONENT)
-		white[i]  = limit(OVERDRIVE * w_tmp[i+1]^W_EXPONENT)
+	for m = 1,num_modules do
+		rval = limit(OVERDRIVE * r_tmp[m+1]^EXPONENT)
+		gval = limit(OVERDRIVE * g_tmp[m+1]^EXPONENT)
+		bval = limit(OVERDRIVE * b_tmp[m+1]^EXPONENT)
+		wval = limit(OVERDRIVE * w_tmp[m+1]^W_EXPONENT)
+
+		for s = 1,num_strip do
+			i = idx(s, m)
+
+			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(nmod, cmod)
+function init(nstrip, nmod, cmod)
+	num_strip = nstrip
 	num_modules = nmod
 	center_module = nmod --cmod
 
 	num_masses = nmod+1 --math.floor(nmod/2)
 	excitement_pos = 1
 
-	for i = 1,nmod do
+	for i = 1,(nmod*nstrip) do
 		red[i] = 0
 		green[i] = 0
 		blue[i] = 0

lua_wrappers.c

@@ -15,6 +15,7 @@
 #include <lua5.3/lauxlib.h>
 
 #include "fft.h"
+#include "utils.h"
 
 #include "config.h"
 
@@ -66,9 +67,24 @@ static int l_get_rms(lua_State *L) {
   return 1; // number of return values
 }
 
+// calculate the position in the output arrays from strip and module index
+static int l_idx(lua_State *L) {
+  luaL_checktype(L, 1, LUA_TNUMBER);
+  int strip = lua_tointeger(L, 1) - 1; // -1 because Lua counts from 1
+
+  luaL_checktype(L, 2, LUA_TNUMBER);
+  int module = lua_tointeger(L, 2) - 1; // -1 because Lua counts from 1
+
+  lua_pushnumber(L, idx(strip, module) + 1); // +1 because Lua counts from 1
+
+  return 1; // number of return values
+}
+
 void lua_register_funcs(lua_State *L) {
   lua_register(L, "get_energy_in_band", l_get_energy_in_band);
   lua_register(L, "get_fft", l_get_fft);
   lua_register(L, "get_signal", l_get_signal);
   lua_register(L, "get_rms", l_get_rms);
+
+  lua_register(L, "idx", l_idx);
 }

main.c

@@ -36,11 +36,8 @@
 // Number of new samples put into the buffer each frame
 #define READ_SAMPLES (BLOCK_LEN / BUFFER_PARTS)
 
-#define NUM_SK6812 8
-
 value_type fft[BLOCK_LEN];
 value_type rms;
-value_type redEnergy, greenEnergy, blueEnergy;
 value_type lastUpdateTime = 0;
 
 sample signal[BLOCK_LEN];
@@ -49,6 +46,9 @@ sem_t  fftSemaphore;
 
 struct sk6812_ctx sk6812;
 
+int num_modules;
+int num_strips;
+
 int running = 1;
 
 void* fft_thread(void *param) {
@@ -181,7 +181,11 @@ int main(int argc, char **argv) {
 
   lua_getglobal(L, "NUM_MODULES");
   if(!lua_isnumber(L, -1)) return 2;
-  int num_modules = lua_tointeger(L, -1);
+  num_modules = lua_tointeger(L, -1);
+
+  lua_getglobal(L, "NUM_STRIPS");
+  if(!lua_isnumber(L, -1)) return 2;
+  num_strips = lua_tointeger(L, -1);
 
   lua_getglobal(L, "CENTER_MODULE");
   if(!lua_isnumber(L, -1)) return 2;
@@ -198,10 +202,10 @@ int main(int argc, char **argv) {
   lua_setglobal(L, "DATALEN");
 
   // allocate arrays
-  red = malloc(num_modules * sizeof(double));
-  green = malloc(num_modules * sizeof(double));
-  blue = malloc(num_modules * sizeof(double));
-  white = malloc(num_modules * sizeof(double));
+  red = malloc(num_strips * num_modules * sizeof(double));
+  green = malloc(num_strips * num_modules * sizeof(double));
+  blue = malloc(num_strips * num_modules * sizeof(double));
+  white = malloc(num_strips * num_modules * sizeof(double));
 
   // load and initialize the script
   if(luaL_loadfile(L, argv[1])) {
@@ -215,9 +219,10 @@ int main(int argc, char **argv) {
 
   // call the init function
   lua_getglobal(L, "init");
+  lua_pushnumber(L, num_strips);
   lua_pushnumber(L, num_modules);
   lua_pushnumber(L, center_module);
-  if(lua_pcall(L, 2, 1, 0)) {
+  if(lua_pcall(L, 3, 1, 0)) {
     lua_showerror(L, "lua_pcall(init) failed.");
   }
 
@@ -247,27 +252,29 @@ int main(int argc, char **argv) {
       }
 
       // read the return values (reverse order, as lua uses a stack)
-      lua_readdoublearray(L, white, num_modules);
-      lua_readdoublearray(L, blue, num_modules);
-      lua_readdoublearray(L, green, num_modules);
-      lua_readdoublearray(L, red, num_modules);
+      lua_readdoublearray(L, white, num_strips*num_modules);
+      lua_readdoublearray(L, blue, num_strips*num_modules);
+      lua_readdoublearray(L, green, num_strips*num_modules);
+      lua_readdoublearray(L, red, num_strips*num_modules);
 
-      for(int s = 0; s < NUM_SK6812; s++) {
+      for(int s = 0; s < num_strips; s++) {
         if(useFading) {
           for(i = 0; i < num_modules; i++) {
+            int lidx = idx(s, i);
             sk6812_fade_color(&sk6812, s, i,
-                255 * gamma_correct(red[i], gamma),
-                255 * gamma_correct(green[i], gamma),
-                255 * gamma_correct(blue[i], gamma),
-                255 * gamma_correct(white[i], gamma));
+                255 * gamma_correct(red[lidx], gamma),
+                255 * gamma_correct(green[lidx], gamma),
+                255 * gamma_correct(blue[lidx], gamma),
+                255 * gamma_correct(white[lidx], gamma));
           }
         } else {
           for(i = 0; i < num_modules; i++) {
+            int lidx = idx(s, i);
             sk6812_set_color(&sk6812, s, i,
-                255 * gamma_correct(red[i], gamma),
-                255 * gamma_correct(green[i], gamma),
-                255 * gamma_correct(blue[i], gamma),
-                255 * gamma_correct(white[i], gamma));
+                255 * gamma_correct(red[lidx], gamma),
+                255 * gamma_correct(green[lidx], gamma),
+                255 * gamma_correct(blue[lidx], gamma),
+                255 * gamma_correct(white[lidx], gamma));
           }
         }
       }
@@ -278,7 +285,7 @@ int main(int argc, char **argv) {
         printf("Idle for 1 second -> stopping updates.\n");
 
         for(i = 0; i < num_modules; i++) {
-          for(int s = 0; s < NUM_SK6812; s++) {
+          for(int s = 0; s < num_strips; s++) {
             sk6812_fade_color(&sk6812, s, i, 0, 0, 0, 20);
           }
         }
@@ -296,9 +303,7 @@ int main(int argc, char **argv) {
     sleep_until(nextFrame);
   }
 
-  for(int i = 0; i < NUM_SK6812; i++) {
   sk6812_shutdown(&sk6812);
-  }
 
   // free arrays
   free(red);

old_scripts/README.txt

@@ -0,0 +1,2 @@
+The scripts in this directory are no longer compatible with the current API and
+are preserved just for their algorithms.

old_scripts/flame.lua

@@ -0,0 +1,206 @@
+COOLDOWN_FACTOR = 0.9998
+OVERDRIVE = 1.70
+EXPONENT = 1.5
+W_EXPONENT = 2.2
+
+M = 10.0   -- mass
+D = 1   -- spring strength
+DAMPING = {} -- filled in init()
+
+num_modules = 16
+center_module = 16
+
+num_masses = math.floor(num_modules/2)
+excitement_pos = 1
+
+-- maximum energy values for each band
+maxRedEnergy = 1
+maxGreenEnergy = 1
+maxBlueEnergy = 1
+maxWhiteEnergy = 1
+
+-- spring-mass-grid values
+pos_r = {}
+pos_g = {}
+pos_b = {}
+pos_w = {}
+
+vel_r = {}
+vel_g = {}
+vel_b = {}
+vel_w = {}
+
+acc_r = {}
+acc_g = {}
+acc_b = {}
+acc_w = {}
+
+-- output color buffers
+red = {}
+green = {}
+blue = {}
+white = {}
+
+r_tmp = {}
+g_tmp = {}
+b_tmp = {}
+w_tmp = {}
+
+function limit(val)
+	if val > 1 then
+		return 1
+	elseif val < 0 then
+		return 0
+	else
+		return val
+	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);
+	local centerIndex = 2 * center_module + 1;
+
+	--print(maxRedEnergy .. "\t" .. maxGreenEnergy .. "\t" .. maxBlueEnergy .. "\t" .. maxWhiteEnergy)
+
+	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
+
+	-- update the spring-mass string
+
+	-- the outside masses are special, as they are auto-returned to 0 position
+	--         { spring-mass pendulum                       }  { friction   }
+	--acc_r[1] = (-pos_r[1] + (pos_r[2] - pos_r[1])) * D / M
+	--acc_g[1] = (-pos_g[1] + (pos_g[2] - pos_g[1])) * D / M
+	--acc_b[1] = (-pos_b[1] + (pos_b[2] - pos_b[1])) * D / M
+	--acc_w[1] = (-pos_w[1] + (pos_w[2] - pos_w[1])) * D / M
+
+	acc_r[num_masses] = (-pos_r[num_masses] + (pos_r[num_masses-1] - pos_r[num_masses])) * D / M
+	acc_g[num_masses] = (-pos_g[num_masses] + (pos_g[num_masses-1] - pos_g[num_masses])) * D / M
+	acc_b[num_masses] = (-pos_b[num_masses] + (pos_b[num_masses-1] - pos_b[num_masses])) * D / M
+	acc_w[num_masses] = (-pos_w[num_masses] + (pos_w[num_masses-1] - pos_w[num_masses])) * D / M
+
+	-- inside masses are only influenced by their neighbors
+	for i = 2,num_masses-1 do
+		acc_r[i] = (pos_r[i-1] + pos_r[i+1] - 2 * pos_r[i]) * D / M
+		acc_g[i] = (pos_g[i-1] + pos_g[i+1] - 2 * pos_g[i]) * D / M
+		acc_b[i] = (pos_b[i-1] + pos_b[i+1] - 2 * pos_b[i]) * D / M
+		acc_w[i] = (pos_w[i-1] + pos_w[i+1] - 2 * pos_w[i]) * D / M
+	end
+
+	-- update velocity and position
+	for i = 1,num_masses do
+		vel_r[i] = DAMPING[i] * (vel_r[i] + acc_r[i])
+		vel_g[i] = DAMPING[i] * (vel_g[i] + acc_g[i])
+		vel_b[i] = DAMPING[i] * (vel_b[i] + acc_b[i])
+		vel_w[i] = DAMPING[i] * (vel_w[i] + acc_w[i])
+
+		pos_r[i] = pos_r[i] + vel_r[i]
+		pos_g[i] = pos_g[i] + vel_g[i]
+		pos_b[i] = pos_b[i] + vel_b[i]
+		pos_w[i] = pos_w[i] + vel_w[i]
+	end
+
+	-- set the new position for the center module
+	newRed = redEnergy / maxRedEnergy
+	pos_r[excitement_pos] = newRed
+	vel_r[excitement_pos] = 0
+	acc_r[excitement_pos] = 0
+
+	newGreen = greenEnergy / maxGreenEnergy
+	pos_g[excitement_pos] = newGreen
+	vel_g[excitement_pos] = 0
+	acc_g[excitement_pos] = 0
+
+	newBlue = blueEnergy / maxBlueEnergy
+	pos_b[excitement_pos] = newBlue
+	vel_b[excitement_pos] = 0
+	acc_b[excitement_pos] = 0
+
+	newWhite = whiteEnergy / maxWhiteEnergy
+	pos_w[excitement_pos] = newWhite
+	vel_w[excitement_pos] = 0
+	acc_w[excitement_pos] = 0
+
+	-- map to LED modules
+	for i = 1,num_masses do
+		r_tmp[i] = pos_r[i]
+		g_tmp[i] = pos_g[i]
+		b_tmp[i] = pos_b[i]
+		w_tmp[i] = pos_w[i]
+
+		--r_tmp[num_modules-i+1] = pos_r[i]
+		--g_tmp[num_modules-i+1] = pos_g[i]
+		--b_tmp[num_modules-i+1] = pos_b[i]
+		--w_tmp[num_modules-i+1] = pos_w[i]
+
+		--print(i, pos_r[i])
+	end
+
+	-- make colors more exciting + remove the first (flickering) mass
+	for i = 1,num_modules do
+		red[i]   = limit(OVERDRIVE * r_tmp[i+1]^EXPONENT)
+		green[i] = limit(OVERDRIVE * g_tmp[i+1]^EXPONENT)
+		blue[i]  = limit(OVERDRIVE * b_tmp[i+1]^EXPONENT)
+		white[i]  = limit(OVERDRIVE * w_tmp[i+1]^W_EXPONENT)
+	end
+
+	-- return the 4 color arrays
+	return red, green, blue, white
+end
+
+function init(nmod, cmod)
+	num_modules = nmod
+	center_module = nmod --cmod
+
+	num_masses = nmod+1 --math.floor(nmod/2)
+	excitement_pos = 1
+
+	for i = 1,nmod do
+		red[i] = 0
+		green[i] = 0
+		blue[i] = 0
+		white[i] = 0
+	end
+
+	for i = 1,num_masses do
+		pos_r[i] = 0
+		pos_g[i] = 0
+		pos_b[i] = 0
+		pos_w[i] = 0
+
+		vel_r[i] = 0
+		vel_g[i] = 0
+		vel_b[i] = 0
+		vel_w[i] = 0
+
+		acc_r[i] = 0
+		acc_g[i] = 0
+		acc_b[i] = 0
+		acc_w[i] = 0
+
+		DAMPING[i] = 1 - 0.15 * math.abs((i - excitement_pos) / num_masses)^2
+	end
+
+	-- don't use fading
+	return 0
+end

run_mpd.sh

@@ -1,4 +1,4 @@
 #!/bin/sh
 
 #dd if=/tmp/mpd.fifo bs=1024 | ./musiclight2
-./musiclight2 $* < /tmp/mpd.fifo
+./musiclight2 $* < /tmp/musiclight.fifo

utils.c

@@ -15,6 +15,8 @@
 
 #include "utils.h"
 
+extern int num_modules;
+
 double get_hires_time(void) {
   struct timespec clk;
   clock_gettime(CLOCK_REALTIME, &clk);
@@ -41,3 +43,7 @@ void sleep_until(double hires_time) {
 	} while(ret == EINTR);
 }
 
+int idx(int strip, int module)
+{
+  return strip * num_modules + module;
+}

utils.h

@@ -14,5 +14,6 @@
 double get_hires_time(void);
 void fsleep(double d);
 void sleep_until(double hires_time);
+int idx(int strip, int module);
 
 #endif // UTILS_H