Various speed-ups, fixes and cleanups

* decay_avg
* Member modem must be initialised.

src/include/misc.h

@@ -55,19 +55,14 @@ inline double clamp(double x, double min, double max)
 	return (x < min) ? min : ((x > max) ? max : x);
 }
 
-inline double decayavg(double average, double input, double weight)
+/// This is always called with an int weight
+inline double decayavg(double average, double input, int weight)
 {
-	if (weight <= 1.0) return input;
-	return input * (1.0 / weight) + average * (1.0 - (1.0 / weight));
+	if (weight <= 1) return input;
+	return ( ( input - average ) / (double)weight ) + average ;
 }
 
 // following are defined inline to provide best performance
-
-inline double rect(double x)
-{
-	return 1.0;
-}
-
 inline double blackman(double x)
 {
 	return (0.42 - 0.50 * cos(2 * M_PI * x) + 0.08 * cos(4 * M_PI * x));
@@ -102,6 +97,4 @@ void BlackmanWindow(double *array, int n);
 // Simple about effective as Hamming or Hanning
 void TriangularWindow(double *array, int n);
 
-#define fftabs(a,b) sqrt((a)*(a) + (b)*(b))
-
 #endif

src/misc/misc.cxx

@@ -153,8 +153,9 @@ void RectWindow(double *array, int n) {
 // Hamming - used by gmfsk
 void HammingWindow(double *array, int n) {
 	double pwr = 0.0;
+	double inv_n = 1.0 / (double)n;
 	for (int i = 0; i < n; i++) {
-		array[i] = hamming((double)i/(double)n);
+		array[i] = hamming((double)i * inv_n);
 		pwr += array[i] * array[i];
 	}
 	pwr = sqrt((double)n/pwr);
@@ -165,8 +166,9 @@ void HammingWindow(double *array, int n) {
 // Hanning - used by winpsk
 void HanningWindow(double *array, int n) {
 	double pwr = 0.0;
+	double inv_n = 1.0 / (double)n;
 	for (int i = 0; i < n; i++) {
-		array[i] = hanning((double)i/(double)n);
+		array[i] = hanning((double)i * inv_n);
 		pwr += array[i] * array[i];
 	}
 	pwr = sqrt((double)n/pwr);
@@ -177,8 +179,9 @@ void HanningWindow(double *array, int n) {
 // Best lob suppression - least in band ripple
 void BlackmanWindow(double *array, int n) {
 	double pwr = 0.0;
+	double inv_n = 1.0 / (double)n;
 	for (int i = 0; i < n; i++) {
-		array[i] = blackman((double)i/(double)n);
+		array[i] = blackman((double)i * inv_n);
 		pwr += array[i] * array[i];
 	}
 	pwr = sqrt((double)n/pwr);
@@ -190,8 +193,9 @@ void BlackmanWindow(double *array, int n) {
 void TriangularWindow(double *array, int n) {
 	double pwr = 0.0;
 	for (int i = 0; i < n; i++) array[i] = 1.0;
+	double inv_n = 1.0 / (double)n;
 	for (int i = 0; i < n / 4; i++) {
-			array[i] = 4.0 * (double)i / (double)n;
+			array[i] = 4.0 * (double)i * inv_n ;
 			array[n-i] = array[i];
 	}
 	for (int i = 0; i < n; i++)	pwr += array[i] * array[i];

src/trx/modem.cxx

@@ -201,6 +201,8 @@ modem::modem()
 	PTTphaseacc = 0.0;
 	s2n_ncount = s2n_sum = s2n_sum2 = s2n_metric = 0.0;
 	s2n_valid = false;
+
+	bandwidth = 0.0;
 }
 
 // modem types CW and RTTY do not use the base init()