osctest.cpp

#include "userosc.h"

typedef struct State {
  float w0;
  float phase;
  uint8_t flags;
} State;

enum {
  k_flags_none = 0,
  k_flag_reset = 1<<0,
};

static State s_state;

void OSC_INIT(uint32_t platform, uint32_t api)
{
  s_state.w0    = 0.f;
  s_state.phase = 0.f;
  s_state.flags = k_flags_none;
}

void OSC_CYCLE(const user_osc_param_t * const params,
               int32_t *yn,
               const uint32_t frames)
{
  const uint8_t flags = s_state.flags;
  s_state.flags = k_flags_none;
    
  const float w0 = s_state.w0 = osc_w0f_for_note((params->pitch)>>8, params->pitch & 0xFF);
  float phase = (flags & k_flag_reset) ? 0.f : s_state.phase;
  
  q31_t * __restrict y = (q31_t *)yn;
  const q31_t * y_e = y + frames;
  
  for (; y != y_e; ) {
    float sig = (phase - 0.5f <= 0.f) ? 1.f : -1.f;

    *(y++) = f32_to_q31(sig);

    phase += w0;
    phase -= (uint32_t)phase;
  }
  s_state.phase = phase;
}

void OSC_NOTEON(const user_osc_param_t * const params)
{
  s_state.flags |= k_flag_reset;
}

void OSC_NOTEOFF(const user_osc_param_t * const params)
{
  (void)params;
}

void OSC_PARAM(uint16_t index, uint16_t value)
{
}