Akso - Audio DSP Platform

tri_4_p

$\text{[math]}$

Quadrature triangle LFO, unipolar, pitch input, phase reset

Author: Are Leistad

License: BSD

Github: drj/lfo/quad_triangle.axo

IO Variants: 2

Variant: 1

Inlets

frac32.bipolar Pitch input

bool32.rising Reset phase

Outlets

frac32.positive 0 deg triangle wave

frac32.positive 90 deg triangle wave

frac32.positive 180 deg triangle wave

frac32.positive 270 triangle wave

Parameters

frac32.s.map.lfopitch pitch

Declaration

uint32_t phase;
uint32_t old_reset;
__attribute__((always_inline)) __STATIC_INLINE int32_t ___ABS(int32_t op1) {
  int32_t result;
  __ASM volatile("movs  %0, %1\n"
                 "it    mi\n"
                 "rsbmi %0, %0, #0"
                 : "=r"(result)
                 : "r"(op1));
  return (result);
};

Init

phase = 0;
old_reset = 0;

Control Rate

if (inlet_reset && !old_reset) {
  phase = 0;
} else {
  int32_t freq;
  MTOFEXTENDED(param_pitch + inlet_pitch, freq);
  phase += freq >> 2;
}
old_reset = inlet_reset;

int32_t saw;

saw = (phase >> 4) - (1 << 27);
outlet_0 = (1 << 27) - ___ABS(saw);

saw = ((phase - 0x40000000) >> 4) - (1 << 27);
outlet_90 = (1 << 27) - ___ABS(saw);

outlet_180 = (1 << 27) - outlet_0;

outlet_270 = (1 << 27) - outlet_90;

Variant: 2

Inlets

frac32.bipolar Pitch input

bool32.rising Reset phase

Outlets

frac32.bipolar 0 deg triangle wave

frac32.bipolar 90 deg triangle wave

frac32.bipolar 180 deg triangle wave

frac32.bipolar 270 triangle wave

Parameters

frac32.s.map.lfopitch pitch

Declaration

uint32_t phase;
uint32_t old_reset;
__attribute__((always_inline)) __STATIC_INLINE int32_t ___ABS(int32_t op1) {
  int32_t result;
  __ASM volatile("movs  %0, %1\n"
                 "it    mi\n"
                 "rsbmi %0, %0, #0"
                 : "=r"(result)
                 : "r"(op1));
  return (result);
};

Init

phase = 0;
old_reset = 0;

Control Rate

if (inlet_reset && !old_reset) {
  phase = 0;
} else {
  int32_t freq;
  MTOFEXTENDED(param_pitch + inlet_pitch, freq);
  phase += freq >> 2;
}
old_reset = inlet_reset;

int32_t saw;

saw = (phase >> 4) - (1 << 27);
outlet_0 = (1 << 27) - ___ABS(saw << 1);

saw = ((phase - 0x40000000) >> 4) - (1 << 27);
outlet_90 = (1 << 27) - ___ABS(saw << 1);

outlet_180 = -outlet_0;

outlet_270 = -outlet_90;