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627 lines
12 KiB
C++
627 lines
12 KiB
C++
//
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// FILE: functionGenerator.cpp
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// AUTHOR: Rob Tillaart
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// VERSION: 0.3.0
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// PURPOSE: wave form generating functions (use with care)
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// URL: https://github.com/RobTillaart/FunctionGenerator
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#include "functionGenerator.h"
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funcgen::funcgen(float period, float amplitude, float phase, float yShift)
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{
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setPeriod(period);
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setAmplitude(amplitude);
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setPhase(phase);
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setYShift(yShift);
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setDutyCycle(50); // TODO param?
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}
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/////////////////////////////////////////////////////////////
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//
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// CONFIGURATION
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//
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void funcgen::setPeriod(float period)
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{
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_period = period;
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_freq1 = 1 / period;
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_freq2 = 2 * _freq1;
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_freq4 = 4 * _freq1;
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_freq0 = TWO_PI * _freq1;
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}
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float funcgen::getPeriod()
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{
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return _period;
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}
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void funcgen::setFrequency(float freq)
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{
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setPeriod(1.0 / freq);
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}
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float funcgen::getFrequency()
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{
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return _freq1;
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}
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void funcgen::setAmplitude(float ampl)
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{
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_amplitude = ampl;
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}
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float funcgen::getAmplitude()
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{
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return _amplitude;
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}
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void funcgen::setPhase(float phase)
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{
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_phase = phase;
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}
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float funcgen::getPhase()
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{
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return _phase;
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}
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void funcgen::setYShift(float yShift)
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{
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_yShift = yShift;
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}
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float funcgen::getYShift()
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{
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return _yShift;
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}
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void funcgen::setDutyCycle(float dutyCycle)
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{
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// negative dutyCycle? => 1-dc? or abs()?
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if (dutyCycle < 0) _dutyCycle = 0.0;
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else if (dutyCycle > 100) _dutyCycle = 1.0;
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else _dutyCycle = dutyCycle * 0.01;
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}
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float funcgen::getDutyCycle()
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{
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return _dutyCycle * 100.0;
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}
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void funcgen::setRandomSeed(uint32_t a, uint32_t b)
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{
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// prevent zero loops in random() function.
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if (a == 0) a = 123;
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if (b == 0) b = 456;
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_m_w = a;
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_m_z = b;
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}
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/////////////////////////////////////////////////////////////
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//
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// FUNCTIONS
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//
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float funcgen::line()
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{
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return _yShift + _amplitude;
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}
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float funcgen::zero()
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{
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return 0;
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}
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float funcgen::sawtooth(float t, uint8_t mode)
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{
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float rv;
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t += _phase;
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if (t >= 0.0)
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{
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t = fmod(t, _period);
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if (mode == 1) t = _period - t;
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rv = _amplitude * (-1.0 + t *_freq2);
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}
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else
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{
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t = -t;
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t = fmod(t, _period);
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if (mode == 1) t = _period - t;
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rv = _amplitude * ( 1.0 - t * _freq2);
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}
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rv += _yShift;
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return rv;
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}
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float funcgen::triangle(float t)
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{
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float rv;
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t += _phase;
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if (t < 0.0)
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{
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t = -t;
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}
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t = fmod(t, _period);
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if (t < (_period * _dutyCycle))
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{
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rv = _amplitude * (-1.0 + t * _freq2 / _dutyCycle);
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}
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else
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{
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// mirror math
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t = _period - t;
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rv = _amplitude * (-1.0 + t * _freq2 /(1 - _dutyCycle));
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}
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rv += _yShift;
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return rv;
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}
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float funcgen::square(float t)
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{
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float rv;
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t += _phase;
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if (t >= 0)
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{
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t = fmod(t, _period);
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if (t < (_period * _dutyCycle)) rv = _amplitude;
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else rv = -_amplitude;
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}
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else
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{
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t = -t;
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t = fmod(t, _period);
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if (t < (_period * _dutyCycle)) rv = -_amplitude;
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else rv = _amplitude;
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}
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rv += _yShift;
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return rv;
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}
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float funcgen::sinus(float t)
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{
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float rv;
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t += _phase;
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rv = _amplitude * sin(t * _freq0);
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rv += _yShift;
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return rv;
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}
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float funcgen::stair(float t, uint16_t steps, uint8_t mode)
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{
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t += _phase;
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if (t >= 0)
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{
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t = fmod(t, _period);
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if (mode == 1) t = _period - t;
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int level = steps * t / _period;
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return _yShift + _amplitude * (-1.0 + 2.0 * level / (steps - 1));
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}
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t = -t;
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t = fmod(t, _period);
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if (mode == 1) t = _period - t;
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int level = steps * t / _period;
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return _yShift + _amplitude * (1.0 - 2.0 * level / (steps - 1));
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}
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float funcgen::random()
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{
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float rv = _yShift + _amplitude * _random() * 0.2328306436E-9; // div 0xFFFFFFFF
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return rv;
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}
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// duty cycle variant takes more than twice as much time.
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float funcgen::random_DC()
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{
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static float rv = 0;
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float next = _yShift + _amplitude * _random() * 0.2328306436E-9; // div 0xFFFFFFFF
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rv += (next - rv) * _dutyCycle;
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return rv;
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}
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/////////////////////////////////////////////////////////////
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//
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// EXPERIMENTAL 0.2.7
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//
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float funcgen::sinusDiode(float t)
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{
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float rv = sinus(t);
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if (rv < _yShift) return _yShift;
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return rv;
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// float rv;
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// t += _phase;
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// rv = sin(t * _freq0);
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// if (rv < 0) return _yShift;
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// rv *= amplitude;
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// rv += _yShift;
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// return rv;
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}
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float funcgen::sinusRectified(float t)
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{
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// float rv = sinus(t);
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// if (rv < _yShift) return _yShift - rv;
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// return rv;
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float rv;
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t += _phase;
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rv = _amplitude * sin(t * _freq0);
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if (rv < 0) rv = -rv;
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rv += _yShift;
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return rv;
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}
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float funcgen::trapezium1(float t)
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{
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t += _phase + _period * _dutyCycle / 4; // zero point for t = 0
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if (t < 0)
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{
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t = -t;
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}
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t = fmod(t, _period);
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if (t < _period * 0.5 * _dutyCycle) // rising part
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{
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return _yShift + -_amplitude + 2 * _amplitude * (t * 2 / (_period * _dutyCycle));
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}
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else if (t < _period * 0.5) // high part
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{
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return _yShift + _amplitude;
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}
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else if (t < _period * (0.5 + 0.5 * _dutyCycle)) // falling part
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{
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return _yShift + _amplitude - 2 * _amplitude * ( (t * 2 - _period) / (_period * _dutyCycle));
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}
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else // low part
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{
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return _yShift + -_amplitude;
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}
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}
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float funcgen::trapezium2(float t)
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{
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t += _phase + _period * _dutyCycle / 4; // zero point for t = 0
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if (t < 0)
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{
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t = -t;
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}
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t = fmod(t, _period);
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if (t < _period * 0.25) // rising part
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{
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return _yShift + -_amplitude + 2 * _amplitude * (t * 4 / _period);
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}
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else if (t < _period * (0.25 + 0.5 * _dutyCycle)) // high part
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{
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return _yShift + _amplitude;
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}
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else if (t < _period * (0.5 + 0.5 * _dutyCycle)) // falling part
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{
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return _yShift + _amplitude - 2 * _amplitude * ((t - _period * (0.25 + 0.5 * _dutyCycle)) * 4 / _period);
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}
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else // low part
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{
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return _yShift + -_amplitude;
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}
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}
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/*
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// no DC version (50%
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float funcgen::trapezium(float t)
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{
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t += _phase;
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if (t < 0)
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{
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t = -t;
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}
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t = fmod(t, _period);
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if (t < _period * 0.25) // rising part
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{
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return -_amplitude + 2 * _amplitude * (t * 4 / _period);
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}
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else if (t < _period * 0.5) // high part
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{
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return _amplitude;
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}
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else if (t < _period * 0.75) // high part
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{
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return _amplitude - 2 * _amplitude * ((t - _period/2) * 4 / _period);
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}
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else // low part
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{
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return -_amplitude;
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}
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}
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*/
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//
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// EXPERIMENTAL HEARTBEAT
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// => setFrequency(72.0 / 60.0); // BPM/60 = BPS.
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float funcgen::heartBeat(float t)
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{
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int16_t out[32] = {
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0, 0, 1000, 2500,
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1000, 1000, -50, 10000,
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-2500, 2000, 2500, 3000,
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3000, 2000, 0, 0,
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0,0,0,0,
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0,0,0,0,
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0,0,0,0,
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0,0,0,0,
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};
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// use duty cycle to determine zero level duration.
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int pts = map(_dutyCycle * 100, 0, 100, 31, 15);
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return freeWave(t, out, pts);
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}
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/*
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// points need to be optimized,
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// 0.2.7 uses 160 bytes for the two arrays.
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// wrapper around freeWave?
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float funcgen::heartBeat(float t)
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{
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// based upon MultiMap in[] array is normalized to 0.0 - 1.0
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// Heart beat phase P Q R S T U
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float in[21] = { 0.0, 0.07, 0.13, 0.20, 0.27, 0.33, 0.40, 0.46, 0.53, 0.60, 0.66, 0.73, 0.80, 0.86, 0.93, 1.00 };
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float out[21] = { 0.0, 0.00, 0.10, 0.25, 0.10, 0.10, -0.05, 1.00, -0.25, 0.20, 0.25, 0.30, 0.30, 0.20, 0.00, 0.00 };
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t += _phase;
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t = fmod(t, _period);
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// normalize t to 0.0 - 1.0
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t *= _freq1;
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// search interval
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int idx = 0;
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while (t > in[idx]) idx++;
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if (t == in[idx]) return _yShift + _amplitude * out[idx];
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idx--;
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// interpolate.
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float factor = (t - in[idx]) / (in[idx+1] - in[idx]);
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return _yShift + _amplitude * (out[idx] + factor * (out[idx+1] - out[idx]));
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}
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*/
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float funcgen::freeWave(float t, int16_t * arr, int16_t size)
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{
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t += _phase;
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// normalize t to 0.0 - 1.0
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t = fmod(t, _period);
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t *= _freq1;
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// search interval, as arr is based upon N equidistant points,
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// we can easily calculate the points for direct access
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float factor = t * size;
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int idx = factor; // truncate to get index of output array.
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factor = factor - idx; // remainder is interpolate factor.
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// interpolate.
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return _yShift + _amplitude * 1e-4 * (arr[idx] + factor * (arr[idx+1] - arr[idx]));
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}
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/////////////////////////////////////////////////////////////
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//
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// PRIVATE
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//
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// An example of a simple pseudo-random number generator is the
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// Multiply-with-carry method invented by George Marsaglia.
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// two initializers (not null)
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uint32_t funcgen::_random()
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{
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_m_z = 36969L * (_m_z & 65535L) + (_m_z >> 16);
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_m_w = 18000L * (_m_w & 65535L) + (_m_w >> 16);
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return (_m_z << 16) + _m_w; /* 32-bit result */
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}
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/////////////////////////////////////////////////////////////
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//
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// INTEGER VERSIONS FOR 8 BIT DAC
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//
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// 8 bits version
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// t = 0..9999 period 10000 in millis, returns 0..255
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/*
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uint8_t ifgsaw(uint16_t t, uint16_t period = 1000)
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{
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return 255L * t / period;
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}
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uint8_t ifgtri(uint16_t t, uint16_t period = 1000)
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{
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if (t * 2 < period) return 510L * t / period;
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return 255L - 510L * t / period;
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}
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uint8_t ifgsqr(uint16_t t, uint16_t period = 1000)
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{
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if (t * 2 < period) return 510L * t / period;
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return 255L - 510L * t / period;
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}
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uint8_t ifgsin(uint16_t t, uint16_t period = 1000)
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{
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return sin(355L * t / period / 113); // LUT
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}
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uint8_t ifgstr(uint16_t t, uint16_t period = 1000, uint16_t steps = 8)
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{
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int level = 1L * steps * t / period;
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return 255L * level / (steps - 1);
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}
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*/
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/////////////////////////////////////////////////////////////
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//
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// SIMPLE float ONES
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//
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// t = 0..period
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// period = 0.001 ... 10000 ?
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/*
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float fgsaw(float t, float period = 1.0)
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{
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if (t >= 0) return -1.0 + 2 * t / period;
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return 1.0 + 2 * t / period;
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}
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float fgtri(float t, float period = 1.0)
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{
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if (t < 0) t = -t;
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if (t * 2 < period) return -1.0 + 4 * t / period;
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return 3.0 - 4 * t / period;
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}
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float fgsqr(float t, float period = 1.0)
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{
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if (t >= 0)
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{
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if ( 2 * t < period) return 1.0;
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return -1.0;
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}
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t = -t;
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if (2 * t < period) return -1.0;
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return 1.0;
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}
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float fgsin(float t, float period = 1.0)
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{
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return sin(TWO_PI * t / period);
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}
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float fgstr(float t, float period = 1.0, uint16_t steps = 8)
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{
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if (t >= 0)
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{
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int level = steps * t / period;
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return -1.0 + 2.0 * level / (steps - 1);
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}
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t = -t;
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int level = steps * t / period;
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return 1.0 - 2.0 * level / (steps - 1);
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}
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*/
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/////////////////////////////////////////////////////////////
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//
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// FULL floatS ONES
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//
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// SAWTOOTH
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float fgsaw(float t, float period = 1.0, float amplitude = 1.0, float phase = 0.0, float yShift = 0.0)
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{
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t += phase;
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if (t >= 0)
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{
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if (t >= period) t = fmod(t, period);
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return yShift + amplitude * (-1.0 + 2 * t / period);
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}
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t = -t;
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if (t >= period) t = fmod(t, period);
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return yShift + amplitude * ( 1.0 - 2 * t / period);
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}
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// TRIANGLE
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float fgtri(float t, float period = 1.0, float amplitude = 1.0, float phase = 0.0, float yShift = 0.0, float dutyCycle = 0.50)
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{
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t += phase;
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if (t < 0) t = -t;
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if (t >= period) t = fmod(t, period);
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// 50 % dutyCycle = faster
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// if (t * 2 < period) return yShift + amplitude * (-1.0 + 4 * t / period);
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// return yShift + amplitude * (3.0 - 4 * t / period);
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if (t < dutyCycle * period) return yShift + amplitude * (-1.0 + 2 * t / (dutyCycle * period));
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// return yShift + amplitude * (-1.0 + 2 / (1 - dutyCycle) - 2 * t / ((1 - dutyCycle) * period));
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return yShift + amplitude * (-1.0 + 2 / (1 - dutyCycle) * ( 1 - t / period));
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}
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// SQUARE
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float fgsqr(float t, float period = 1.0, float amplitude = 1.0, float phase = 0.0, float yShift = 0.0, float dutyCycle = 0.50)
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{
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t += phase;
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if (t >= 0)
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{
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if (t >= period) t = fmod(t, period);
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if (t < dutyCycle * period) return yShift + amplitude;
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return yShift - amplitude;
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}
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t = -t;
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if (t >= period) t = fmod(t, period);
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if (t < dutyCycle * period) return yShift - amplitude;
|
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return yShift + amplitude;
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}
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// SINUS
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float fgsin(float t, float period = 1.0, float amplitude = 1.0, float phase = 0.0, float yShift = 0.0)
|
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{
|
|
t += phase;
|
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float rv = yShift + amplitude * sin(TWO_PI * t / period);
|
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return rv;
|
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}
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|
|
// STAIR
|
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float fgstr(float t, float period = 1.0, float amplitude = 1.0, float phase = 0.0, float yShift = 0.0, uint16_t steps = 8)
|
|
{
|
|
t += phase;
|
|
if (t >= 0)
|
|
{
|
|
if (t >= period) t = fmod(t, period);
|
|
int level = steps * t / period;
|
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return yShift + amplitude * (-1.0 + 2.0 * level / (steps - 1));
|
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}
|
|
t = -t;
|
|
if (t >= period) t = fmod(t, period);
|
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int level = steps * t / period;
|
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return yShift + amplitude * (1.0 - 2.0 * level / (steps - 1));
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}
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// -- END OF FILE --
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