Changed all "double" values to macro FRAC_NUM (defined in synth.h as float), for using the FPU in the Teensy.

Added shortcut if audio output is blocking -> go to MIDI input checking.

EngineMkI.cpp

@@ -36,10 +36,10 @@
 
 #ifdef _WIN32
 #if _MSC_VER < 1800
-    double log2(double n)  {  
+    FRAC_NUM log2(FRAC_NUM n)  {  
         return log(n) / log(2.0);  
     }
-    double round(double n) {
+    FRAC_NUM round(FRAC_NUM n) {
         return n < 0.0 ? ceil(n - 0.5) : floor(n + 0.5);
     }
 #endif

MicroDexed.ino

@@ -21,7 +21,7 @@
 #define MAX_NOTES 10
 #define TEST_MIDI 1
 #define TEST_NOTE 40
-#define TEST_VEL 60
+#define TEST_VEL 127
 //#define ADD_EFFECT_CHORUS 1
 
 // Use these with the Teensy Audio Shield
@@ -180,6 +180,9 @@ void loop()
         break;
     }
 
+    if(!queue1.available())
+      continue;
+      
 #if defined(SHOW_DEXED_TIMING) || defined(SHOW_XRUN)
     elapsedMicros t1;
 #endif

dx7note.cpp

@@ -45,7 +45,7 @@ int32_t osc_freq(int midinote, int mode, int coarse, int fine, int detune) {
   if (mode == 0) {
     logfreq = midinote_to_logfreq(midinote);
     // could use more precision, closer enough for now. those numbers comes from my DX7
-    double detuneRatio = 0.0209 * exp(-0.396 * (((float)logfreq) / (1 << 24))) / 7;
+    FRAC_NUM detuneRatio = 0.0209 * exp(-0.396 * (((float)logfreq) / (1 << 24))) / 7;
     logfreq += detuneRatio * logfreq * (detune - 7);
 
     logfreq += coarsemul[coarse & 31];

env.cc

@@ -39,11 +39,11 @@ const int statics[] = {
     6615, 6615, 5512, 5512, 4410, 3969, 3969, 3439, 2866, 2690, 2249,
     1984, 1896, 1808, 1411, 1367, 1234, 1146, 926, 837, 837, 705,
     573, 573, 529, 441, 441
-    // and so on, I stopped measuring after R=76 (needs to be double-checked anyway)
+    // and so on, I stopped measuring after R=76 (needs to be FRAC_NUM-checked anyway)
 };
 #endif
 
-void Env::init_sr(double sampleRate) {
+void Env::init_sr(FRAC_NUM sampleRate) {
     sr_multiplier = (44100.0 / sampleRate) * (1<<24);
 }
 
@@ -128,7 +128,7 @@ void Env::advance(int newix) {
 #ifdef ACCURATE_ENVELOPE
         if (targetlevel_ == level_) {
             // approximate number of samples at 44.100 kHz to achieve the time
-            // empirically gathered using 2 TF1s, could probably use some double-checking
+            // empirically gathered using 2 TF1s, could probably use some FRAC_NUM-checking
             // and cleanup, but it's pretty close for now.
             int staticrate = rates_[ix_];
             staticrate += rate_scaling_; // needs to be checked, as well, but seems correct

env.cpp

@@ -28,7 +28,7 @@ const int levellut[] = {
     0, 5, 9, 13, 17, 20, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 42, 43, 45, 46
 };
 
-void Env::init_sr(double sampleRate) {
+void Env::init_sr(FRAC_NUM sampleRate) {
     sr_multiplier = (44100.0 / sampleRate) * (1<<24);
 }
 

env.h

@@ -48,7 +48,7 @@ class Env {
   static int scaleoutlevel(int outlevel);
   void getPosition(char *step);
     
-  static void init_sr(double sample_rate);
+  static void init_sr(FRAC_NUM sample_rate);
   void transfer(Env &src);
     
  private:

exp2.cpp

@@ -31,8 +31,8 @@
 int32_t exp2tab[EXP2_N_SAMPLES << 1];
 
 void Exp2::init() {
-  double inc = exp2(1.0 / EXP2_N_SAMPLES);
-  double y = 1 << 30;
+  FRAC_NUM inc = exp2(1.0 / EXP2_N_SAMPLES);
+  FRAC_NUM y = 1 << 30;
   for (int i = 0; i < EXP2_N_SAMPLES; i++) {
     exp2tab[(i << 1) + 1] = (int32_t)floor(y + 0.5);
     y *= inc;
@@ -45,23 +45,23 @@ void Exp2::init() {
 
 int32_t tanhtab[TANH_N_SAMPLES << 1];
 
-static double dtanh(double y) {
+static FRAC_NUM dtanh(FRAC_NUM y) {
   return 1 - y * y;
 }
 
 void Tanh::init() {
-  double step = 4.0 / TANH_N_SAMPLES;
-  double y = 0;
+  FRAC_NUM step = 4.0 / TANH_N_SAMPLES;
+  FRAC_NUM y = 0;
   for (int i = 0; i < TANH_N_SAMPLES; i++) {
     tanhtab[(i << 1) + 1] = (1 << 24) * y + 0.5;
     //printf("%d\n", tanhtab[(i << 1) + 1]);
     // Use a basic 4th order Runge-Kutte to compute tanh from its
     // differential equation.
-    double k1 = dtanh(y);
-    double k2 = dtanh(y + 0.5 * step * k1);
-    double k3 = dtanh(y + 0.5 * step * k2);
-    double k4 = dtanh(y + step * k3);
-    double dy = (step / 6) * (k1 + k4 + 2 * (k2 + k3));
+    FRAC_NUM k1 = dtanh(y);
+    FRAC_NUM k2 = dtanh(y + 0.5 * step * k1);
+    FRAC_NUM k3 = dtanh(y + 0.5 * step * k2);
+    FRAC_NUM k4 = dtanh(y + step * k3);
+    FRAC_NUM dy = (step / 6) * (k1 + k4 + 2 * (k2 + k3));
     y += dy;
   }
   for (int i = 0; i < TANH_N_SAMPLES - 1; i++) {

fm_op_kernel.cc

@@ -212,7 +212,7 @@ void FmOpKernel::compute_pure(int32_t *output, int32_t phase0, int32_t freq,
 
 #if 0
 // Results: accuracy 370.0 mean, 15480 worst case (near freq = 0.5)
-// with double accuracy initialization: mean 1.55, worst 58 (near freq = 0)
+// with FRAC_NUM accuracy initialization: mean 1.55, worst 58 (near freq = 0)
 // with high accuracy: mean 4.2, worst 292 (near freq = 0.5)
 void FmOpKernel::compute_pure(int32_t *output, int32_t phase0, int32_t freq,
                               int32_t gain1, int32_t gain2, bool add) {
@@ -221,7 +221,7 @@ void FmOpKernel::compute_pure(int32_t *output, int32_t phase0, int32_t freq,
     int32_t phase = phase0;
 #ifdef DOUBLE_ACCURACY
     int32_t u = floor((1 << 30) * sin(phase * (M_PI / (1 << 23))) + 0.5);
-    double a_d = sin(freq * (M_PI / (1 << 24)));
+    FRAC_NUM a_d = sin(freq * (M_PI / (1 << 24)));
     int32_t v = floor((1LL << 31) * a_d * cos((phase - freq * 0.5) *
                                               (M_PI / (1 << 23))) + 0.5);
     int32_t aa = floor((1LL << 31) * a_d * a_d + 0.5);

fm_op_kernel.cpp

@@ -212,7 +212,7 @@ void FmOpKernel::compute_pure(int32_t *output, int32_t phase0, int32_t freq,
 
 #if 0
 // Results: accuracy 370.0 mean, 15480 worst case (near freq = 0.5)
-// with double accuracy initialization: mean 1.55, worst 58 (near freq = 0)
+// with FRAC_NUM accuracy initialization: mean 1.55, worst 58 (near freq = 0)
 // with high accuracy: mean 4.2, worst 292 (near freq = 0.5)
 void FmOpKernel::compute_pure(int32_t *output, int32_t phase0, int32_t freq,
                               int32_t gain1, int32_t gain2, bool add) {
@@ -221,7 +221,7 @@ void FmOpKernel::compute_pure(int32_t *output, int32_t phase0, int32_t freq,
     int32_t phase = phase0;
 #ifdef DOUBLE_ACCURACY
     int32_t u = floor((1 << 30) * sin(phase * (M_PI / (1 << 23))) + 0.5);
-    double a_d = sin(freq * (M_PI / (1 << 24)));
+    FRAC_NUM a_d = sin(freq * (M_PI / (1 << 24)));
     int32_t v = floor((1LL << 31) * a_d * cos((phase - freq * 0.5) *
                                               (M_PI / (1 << 23))) + 0.5);
     int32_t aa = floor((1LL << 31) * a_d * a_d + 0.5);

freqlut.cpp

@@ -32,9 +32,9 @@
 
 int32_t lut[N_SAMPLES + 1];
 
-void Freqlut::init(double sample_rate) {
-  double y = (1LL << (24 + MAX_LOGFREQ_INT)) / sample_rate;
-  double inc = pow(2, 1.0 / N_SAMPLES);
+void Freqlut::init(FRAC_NUM sample_rate) {
+  FRAC_NUM y = (1LL << (24 + MAX_LOGFREQ_INT)) / sample_rate;
+  FRAC_NUM inc = pow(2, 1.0 / N_SAMPLES);
   for (int i = 0; i < N_SAMPLES + 1; i++) {
     lut[i] = (int32_t)floor(y + 0.5);
     y *= inc;

freqlut.h

@@ -14,8 +14,10 @@
  * limitations under the License.
  */
 
+#include "synth.h"
+
 class Freqlut {
  public:
-  static void init(double sample_rate);
+  static void init(FRAC_NUM sample_rate);
   static int32_t lookup(int32_t logfreq);
 };

lfo.cpp

@@ -23,7 +23,7 @@
 
 uint32_t Lfo::unit_;
 
-void Lfo::init(double sample_rate) {
+void Lfo::init(FRAC_NUM sample_rate) {
     // constant is 1 << 32 / 15.5s / 11
     Lfo::unit_ = (int32_t)(_N_ * 25190424 / sample_rate + 0.5);
 }

lfo.h

@@ -18,7 +18,7 @@
 
 class Lfo {
  public:
-  static void init(double sample_rate);
+  static void init(FRAC_NUM sample_rate);
   void reset(const uint8_t params[6]);
 
   // result is 0..1 in Q24

pitchenv.cpp

@@ -19,7 +19,7 @@
 
 int PitchEnv::unit_;
 
-void PitchEnv::init(double sample_rate) {
+void PitchEnv::init(FRAC_NUM sample_rate) {
   unit_ = _N_ * (1 << 24) / (21.3 * sample_rate) + 0.5;
 }
 

pitchenv.h

@@ -21,7 +21,7 @@
 
 class PitchEnv {
  public:
-  static void init(double sample_rate);
+  static void init(FRAC_NUM sample_rate);
 
   // The rates and levels arrays are calibrated to match the Dx7 parameters
   // (ie, value 0..99).

sin.cpp

@@ -29,7 +29,7 @@ int32_t sintab[SIN_N_SAMPLES + 1];
 #endif
 
 void Sin::init() {
-  double dphase = 2 * M_PI / SIN_N_SAMPLES;
+  FRAC_NUM dphase = 2 * M_PI / SIN_N_SAMPLES;
   int32_t c = (int32_t)floor(cos(dphase) * (1 << 30) + 0.5);
   int32_t s = (int32_t)floor(sin(dphase) * (1 << 30) + 0.5);
   int32_t u = 1 << 30;

synth.h

@@ -62,4 +62,6 @@ inline static T max(const T& a, const T& b) {
 
 #define QER(n,b) ( ((float)n)/(1<<b) )
 
+#define FRAC_NUM float
+
 #endif  // __SYNTH_H