WLED math optimisations.

CHANGELOG.md

@@ -2,6 +2,11 @@
 
 ### Builds after release 0.12.0
 
+#### Build 2104151
+
+-   `NUM_STRIPS` no longer required with compile-time strip defaults
+-   Further optimizations in wled_math.h
+
 #### Build 2104150
 
 -   Added ability to add multiple busses as compile time defaults using the esp32_multistrip usermod define syntax

wled00/FX_fcn.cpp

@@ -70,13 +70,13 @@ void WS2812FX::finalizeInit(void)
   if (busses.getNumBusses() == 0) {
     const uint8_t defDataPins[] = {DATA_PINS};
     const uint16_t defCounts[] = {PIXEL_COUNTS};
-    const uint8_t defDataPinsNo = ((sizeof defDataPins) / (sizeof defDataPins[0]));
-    const uint8_t defCountsNo = ((sizeof defCounts) / (sizeof defCounts[0]));
+    const uint8_t defNumBusses = ((sizeof defDataPins) / (sizeof defDataPins[0]));  // min 1
+    const uint8_t defNumCounts = ((sizeof defCounts) / (sizeof defCounts[0]));      // min 1
     uint16_t prevLen = 0;
-    for (uint8_t i = 0; i < defDataPinsNo; i++) {
+    for (uint8_t i = 0; i < defNumBusses && i < WLED_MAX_BUSSES; i++) {
       uint8_t defPin[] = {defDataPins[i]};
       uint16_t start = prevLen;
-      uint16_t count = (i < defCountsNo) ? defCounts[i] : defCounts[i>0?i-1:0];
+      uint16_t count = (i < defNumCounts) ? defCounts[i] : defCounts[i>0?i-1:0];
       prevLen += count;
       BusConfig defCfg = BusConfig(DEFAULT_LED_TYPE, defPin, start, count, COL_ORDER_GRB);
       busses.add(defCfg);

wled00/cfg.cpp

@@ -464,7 +464,6 @@ void serializeConfig() {
     Bus *bus = busses.getBus(s);
     if (!bus || bus->getLength()==0) break;
     JsonObject ins = hw_led_ins.createNestedObject();
-    ins["en"] = true;
     ins[F("start")] = bus->getStart();
     ins[F("len")] = bus->getLength();
     JsonArray ins_pin = ins.createNestedArray("pin");

wled00/ntp.cpp

@@ -319,32 +319,32 @@ int getSunriseUTC(int year, int month, int day, float lat, float lon, bool sunse
   //1. first calculate the day of the year
   float N1 = 275 * month / 9;
   float N2 = (month + 9) / 12;
-  float N3 = (1 + floor((year - 4 * floor(year / 4) + 2) / 3));
+  float N3 = (1 + floor_t((year - 4 * floor_t(year / 4) + 2) / 3));
   float N = N1 - (N2 * N3) + day - 30;
 
   //2. convert the longitude to hour value and calculate an approximate time
-  float lngHour = lon / 15.0;      
+  float lngHour = lon / 15.0f;      
   float t = N + (((sunset ? 18 : 6) - lngHour) / 24);
   
   //3. calculate the Sun's mean anomaly   
-  float M = (0.9856 * t) - 3.289;
+  float M = (0.9856f * t) - 3.289f;
 
   //4. calculate the Sun's true longitude
-  float L = fmod(M + (1.916 * sin_t(DEG_TO_RAD*M)) + (0.020 * sin_t(2*DEG_TO_RAD*M)) + 282.634, 360.0);
+  float L = fmod_t(M + (1.916f * sin_t(DEG_TO_RAD*M)) + (0.020f * sin_t(2*DEG_TO_RAD*M)) + 282.634f, 360.0f);
 
   //5a. calculate the Sun's right ascension      
-  float RA = fmod(RAD_TO_DEG*atan_t(0.91764 * tan_t(DEG_TO_RAD*L)), 360.0);
+  float RA = fmod_t(RAD_TO_DEG*atan_t(0.91764f * tan_t(DEG_TO_RAD*L)), 360.0f);
 
   //5b. right ascension value needs to be in the same quadrant as L   
-  float Lquadrant  = floor( L/90) * 90;
-  float RAquadrant = floor(RA/90) * 90;
+  float Lquadrant  = floor_t( L/90) * 90;
+  float RAquadrant = floor_t(RA/90) * 90;
   RA = RA + (Lquadrant - RAquadrant);
 
   //5c. right ascension value needs to be converted into hours   
-  RA /= 15.;
+  RA /= 15.0f;
 
   //6. calculate the Sun's declination
-  float sinDec = 0.39782 * sin_t(DEG_TO_RAD*L);
+  float sinDec = 0.39782f * sin_t(DEG_TO_RAD*L);
   float cosDec = cos_t(asin_t(sinDec));
 
   //7a. calculate the Sun's local hour angle
@@ -354,13 +354,13 @@ int getSunriseUTC(int year, int month, int day, float lat, float lon, bool sunse
 
   //7b. finish calculating H and convert into hours
   float H = sunset ? RAD_TO_DEG*acos_t(cosH) : 360 - RAD_TO_DEG*acos_t(cosH);
-  H /= 15.;
+  H /= 15.0f;
 
   //8. calculate local mean time of rising/setting      
-  float T = H + RA - (0.06571 * t) - 6.622;
+  float T = H + RA - (0.06571f * t) - 6.622f;
 
   //9. adjust back to UTC
-  float UT = fmod(T - lngHour, 24.0);
+  float UT = fmod_t(T - lngHour, 24.0f);
 
   // return in minutes from midnight
 	return UT*60;

wled00/wled.h

@@ -8,7 +8,7 @@
  */
 
 // version code in format yymmddb (b = daily build)
-#define VERSION 2104150
+#define VERSION 2104151
 
 //uncomment this if you have a "my_config.h" file you'd like to use
 //#define WLED_USE_MY_CONFIG

wled00/wled_math.h

@@ -13,7 +13,7 @@
 
 #define modd(x, y) ((x) - (int)((x) / (y)) * (y))
 
-double cos_t(double x)
+float cos_t(float x)
 {
   x = modd(x, TWO_PI);
   char sign = 1;
@@ -22,17 +22,17 @@ double cos_t(double x)
       x -= PI;
       sign = -1;
   }
-  double xx = x * x;
+  float xx = x * x;
 
   return sign * (1 - ((xx) / (2)) + ((xx * xx) / (24)) - ((xx * xx * xx) / (720)) + ((xx * xx * xx * xx) / (40320)) - ((xx * xx * xx * xx * xx) / (3628800)) + ((xx * xx * xx * xx * xx * xx) / (479001600)));
 }
 
-double sin_t(double x) {
+float sin_t(float x) {
   return cos_t(HALF_PI - x);
 }
 
-double tan_t(double x) {
-  double c = cos_t(x);
+float tan_t(float x) {
+  float c = cos_t(x);
   if (c==0.0) return 0;
   return sin_t(x) / c;
 }
@@ -63,9 +63,21 @@ float asin_t(float x) {
 #define B -0.287434475393028
 #define C ((HALF_PI/2) - A - B)
 
-double atan_t(double x) {
-  double xx = x * x;
+float atan_t(float x) {
+  float xx = x * x;
   return ((A*xx + B)*xx + C)*x;
 }
 
+float floor_t(float x) {
+  bool neg = x < 0;
+  int val = x;
+  if (neg) val--;
+  return val;
+}
+
+float fmod_t(float num, float denom) {
+  int tquot = num / denom;
+  return num - tquot * denom;
+}
+
 #endif