wirtz
/
OpenTheremin_V3_with_MIDI
mirror of https://github.com/MrDham/OpenTheremin_V3_with_MIDI.git
1
0
Fork 0
Code Issues Releases Wiki Activity

Update application.cpp

Browse Source
MrDham-remove-float-calc
MrDham 5 months ago committed by GitHub
parent 718822081c
commit af0b16f051
No known key found for this signature in database
GPG Key ID: B5690EEEBB952194
1 changed files with 109 additions and 38 deletions
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Show Stats Download Patch File Download Diff File
  1. 147
      Open_Theremin_V3/application.cpp

147
Open_Theremin_V3/application.cpp
Unescape View File

@ -42,8 +42,8 @@ static uint16_t old_midi_bend = 0;
static uint8_t midi_bend_low;
static uint8_t midi_bend_high;
static double double_log_freq = 0;
static double midi_key_follow = 0.5;
static uint32_t long_log_note = 0;
static uint32_t midi_key_follow = 2048; ;
// Configuration parameters
static uint8_t registerValue = 2;
@ -57,12 +57,12 @@ static uint8_t flag_pitch_bend_on = 1;
static uint8_t loop_midi_cc = 7;
static uint8_t rod_midi_cc = 255;
static uint8_t rod_midi_cc_lo = 255;
static double rod_cc_scale = 1;
static uint32_t rod_cc_scale = 128;
// tweakable paramameters
#define VELOCITY_SENS 9 // How easy it is to reach highest velocity (127). Something betwen 5 and 12.
#define PLAYER_ACCURACY 0.2 // between 0 (very accurate players) and 0.5 (not accurate at all)
#define PLAYER_ACCURACY 819 // between 0 (very accurate players) and 2048 (not accurate at all)
static uint16_t data_pot_value = 0;
static uint16_t old_data_pot_value = 0;
@ -496,6 +496,76 @@ EEPROM.put(2,volumeXn0);
}
// calculate log2 of an unsigned from 1 to 65535 into a 4.12 fixed point unsigned
// To avoid use of log (double) function
uint16_t Application::log2U16 (uint16_t lin_input)
{
uint32_t long_lin; // To turn input into a 16.16 fixed point
//unsigned long bit_pos;
uint32_t log_output; // 4.12 fixed point log calculation
int32_t long_x1;
int32_t long_x2;
int32_t long_x3;
const int32_t POLY_A0 = 37;
const int32_t POLY_A1 = 46390;
const int32_t POLY_A2 = -18778;
const int32_t POLY_A3 = 5155;
if (lin_input != 0)
{
long_lin = (uint32_t) (lin_input) << 16;
log_output = 0;
// Calculate integer part of log2 and reduce long_lin into 16.16 between 1 and 2
if (long_lin >= 16777216) // 2^(8 + 16)
{
log_output += 8 << 12;
long_lin = long_lin >> 8;
}
if (long_lin >= 1048576) // 2^(4 + 16)
{
log_output += 4 << 12;
long_lin = long_lin >> 4;
}
if (long_lin >= 262144) // 2^(2 + 16)
{
log_output += 2 << 12;
long_lin = long_lin >> 2;
}
if (long_lin >= 131072) // 2^(1 + 16)
{
log_output += 1 << 12;
long_lin = long_lin >> 1;
}
// long_lin is between 1 and 2 now (16.16 fixed point)
// Calculate 3rd degree polynomial approximation log(x)=Polynomial(x-1) in signed long s15.16 and reduce to unsigned 4.12 at the very end.
long_lin = long_lin >> 1; // reduce to 17.15 bit to support signed operations here after
long_x1 = long_lin-(32768); //(x-1) we have the decimal part in s15 now
long_x2 = (long_x1 * long_x1) >> 15 ; // (x-1)^2
long_x3 = (long_x2 * long_x1) >> 15 ; // (x-1)^3
log_output += ( (POLY_A0)
+ ((POLY_A1 * long_x1) >> 15)
+ ((POLY_A2 * long_x2) >> 15)
+ ((POLY_A3 * long_x3) >> 15) ) >> 3;
}
else
{
log_output=0;
}
return log_output;
}
void Application::hzToAddVal(float hz) {
setWavetableSampleAdvance((uint16_t)(hz * HZ_ADDVAL_FACTOR));
}
@ -561,41 +631,42 @@ void Application::midi_msg_send(uint8_t channel, uint8_t midi_cmd1, uint8_t midi
// The bigger is synth's pitch bend range the beter is the effect.
void Application::midi_application ()
{
double delta_loop_cc_val = 0;
double calculated_velocity = 0;
int16_t delta_loop_cc_val = 0;
int16_t calculated_velocity = 0;
// Calculate loop antena cc value for midi
new_midi_loop_cc_val = loop_hand_pos >> 1;
new_midi_loop_cc_val = min (new_midi_loop_cc_val, 127);
delta_loop_cc_val = (double)new_midi_loop_cc_val - (double)old_midi_loop_cc_val;
delta_loop_cc_val = (int16_t)new_midi_loop_cc_val - (int16_t)old_midi_loop_cc_val;
// Calculate log freq
if ((vPointerIncrement < 18) || (vPointerIncrement > 65518))
{
// Lowest note
double_log_freq = 0;
long_log_note = 0;
}
else if ((vPointerIncrement > 26315) && (vPointerIncrement < 39221))
{
// Highest note
double_log_freq = 127;
long_log_note = 127;
}
else if (vPointerIncrement < 32768)
{
// Positive frequencies
// Find note in the playing range
double_log_freq = (log (vPointerIncrement/17.152) / 0.057762265); // Precise note played in the logaritmic scale
// 16795 = log2U16 (C0 [8.1758] * HZ_ADDVAL_FACTOR [2.09785])
long_log_note = 12 * ((uint32_t) log2U16(vPointerIncrement) - 16795); // Precise note played in the logaritmic scale
}
else
{
// Negative frequencies
// Find note in the playing range
double_log_freq = (log ((65535-vPointerIncrement+1)/17.152) / 0.057762265); // Precise note played in the logaritmic scale
// 16795 = log2U16 (C0 [8.1758] * HZ_ADDVAL_FACTOR [2.09785])
long_log_note = 12 * ((uint32_t) log2U16(65535-vPointerIncrement+1) - 16795); // Precise note played in the logaritmic scale
}
// Calculate rod antena cc value for midi
new_midi_rod_cc_val = round (min(((double_log_freq * 128) * rod_cc_scale), 16383)); // 14 bit value !
new_midi_rod_cc_val = (uint16_t) min((long_log_note * rod_cc_scale) >> 12, 16383); // 14 bit value
// State machine for MIDI
switch (_midistate)
@ -637,7 +708,7 @@ void Application::midi_application ()
if (new_midi_loop_cc_val > midi_volume_trigger)
{
// Set key follow to the minimum in order to use closest note played as the center note
midi_key_follow = 0.5;
midi_key_follow = 2048;
// Calculate note and associated pitch bend
calculate_note_bend ();
@ -649,8 +720,8 @@ void Application::midi_application ()
// Calculate velocity
if (midi_timer != 0)
{
calculated_velocity = (64 * (127 - (double)midi_volume_trigger) / 127) + (VELOCITY_SENS * (double)midi_volume_trigger * delta_loop_cc_val / (double)midi_timer);
midi_velocity = min (round (abs (calculated_velocity)), 127);
calculated_velocity = ((127 - midi_volume_trigger) >> 1 ) + (VELOCITY_SENS * midi_volume_trigger * delta_loop_cc_val / midi_timer);
midi_velocity = min (abs (calculated_velocity), 127);
}
else
{
@ -710,12 +781,12 @@ void Application::midi_application ()
if ( flag_legato_on == 1)
{
// Set key follow so as next played note will be at limit of pitch bend range
midi_key_follow = (double)(midi_bend_range) - PLAYER_ACCURACY;
midi_key_follow = ((uint32_t) midi_bend_range * 4096) - PLAYER_ACCURACY;
}
else
{
// Set key follow to max so as no key follows
midi_key_follow = 127;
midi_key_follow = 520192; // 127*2^12
}
// Calculate note and associated pitch bend
@ -771,16 +842,16 @@ void Application::midi_application ()
void Application::calculate_note_bend ()
{
double double_log_bend;
double double_norm_log_bend;
int32_t long_log_bend;
int32_t long_norm_log_bend;
double_log_bend = double_log_freq - old_midi_note; // How far from last played midi chromatic note we are
long_log_bend = ((int32_t)long_log_note) - (((int32_t) old_midi_note) * 4096); // How far from last played midi chromatic note we are
// If too much far from last midi chromatic note played (midi_key_follow depends on pitch bend range)
if ((abs (double_log_bend) >= midi_key_follow) && (midi_key_follow != 127))
if ((abs (long_log_bend) >= midi_key_follow) && (midi_key_follow != 520192))
{
new_midi_note = round (double_log_freq); // Select the new midi chromatic note
double_log_bend = double_log_freq - new_midi_note; // calculate bend to reach precise note played
new_midi_note = (uint8_t) ((long_log_note + 2048) >> 12); // Select the new midi chromatic note - round to integer part by adding 1/2 before shifting
long_log_bend = ((int32_t) long_log_note) - (((int32_t) new_midi_note) * 4096); // calculate bend to reach precise note played
}
else
{
@ -791,16 +862,16 @@ void Application::calculate_note_bend ()
if (flag_pitch_bend_on == 1)
{
// use it to reach precise note played
double_norm_log_bend = (double_log_bend / midi_bend_range);
if (double_norm_log_bend > 1)
long_norm_log_bend = (long_log_bend / midi_bend_range);
if (long_norm_log_bend > 4096)
{
double_norm_log_bend = 1;
long_norm_log_bend = 4096;
}
else if (double_norm_log_bend < -1)
else if (long_norm_log_bend < -4096)
{
double_norm_log_bend = -1;
long_norm_log_bend = -4096;
}
new_midi_bend = 8192 + (8191 * double_norm_log_bend); // Calculate midi pitch bend
new_midi_bend = 8192 + ((long_norm_log_bend * 8191) >> 12); // Calculate midi pitch bend
}
else
{
@ -968,42 +1039,42 @@ void Application::set_parameters ()
case 0:
rod_midi_cc = 255; // Nothing
rod_midi_cc_lo = 255; // Nothing
rod_cc_scale = 1.0;
rod_cc_scale = 128;
break;
case 1:
rod_midi_cc = 8; // Balance
rod_midi_cc_lo = 255; // No least significant bits
rod_cc_scale = 1.0;
rod_cc_scale = 128;
break;
case 2:
rod_midi_cc = 10; // Pan
rod_midi_cc_lo = 255; // No least significant bits
rod_cc_scale = 1.0;
rod_cc_scale = 128;
break;
case 3:
rod_midi_cc = 16; // General Purpose 1 (14 Bits)
rod_midi_cc_lo = 48; // General Purpose 1 least significant bits
rod_cc_scale = 1.0;
rod_cc_scale = 128;
break;
case 4:
rod_midi_cc = 17; // General Purpose 2 (14 Bits)
rod_midi_cc_lo = 49; // General Purpose 2 least significant bits
rod_cc_scale = 1.0;
rod_cc_scale = 128;
break;
case 5:
rod_midi_cc = 18; // General Purpose 3 (7 Bits)
rod_midi_cc_lo = 255; // No least significant bits
rod_cc_scale = 1.0;
rod_cc_scale = 128;
break;
case 6:
rod_midi_cc = 19; // General Purpose 4 (7 Bits)
rod_midi_cc_lo = 255; // No least significant bits
rod_cc_scale = 1.0;
rod_cc_scale = 128;
break;
default:
rod_midi_cc = 74; // Cutoff (exists of both loop and rod)
rod_midi_cc_lo = 255; // No least significant bits
rod_cc_scale = 1.0;
rod_cc_scale = 128;
break;
}
break;

Write Preview
Loading…
Cancel
Save