amy.c: Preserve one-frame fade-out.

shorepine · Mar 19, 2024 · fe3ad6b · fe3ad6b
1 parent aa3bc38
commit fe3ad6b
Show file tree

Hide file tree

Showing 3 changed files with 8 additions and 3 deletions.
diff --git a/src/amy.c b/src/amy.c
@@ -1049,7 +1049,11 @@ void hold_and_modify(uint16_t osc) {
  msynth[osc].pan = combine_controls(ctrl_inputs, synth[osc].pan_coefs);
  // amp is a special case - coeffs apply in log domain.
  // Also, we advance one frame by writing both last_amp and amp (=next amp)
- msynth[osc].last_amp = combine_controls_mult(ctrl_inputs, synth[osc].amp_coefs);
+ float new_last_amp = combine_controls_mult(ctrl_inputs, synth[osc].amp_coefs);
+ // Prevent hard-off on transition to release by updating last_amp only for nonzero new_last_amp.
+ if (new_last_amp > 0) {
+ msynth[osc].last_amp = new_last_amp;
+ }
  ctrl_inputs[COEF_EG0] = S2F(compute_breakpoint_scale(osc, 0, AMY_BLOCK_SIZE));
  ctrl_inputs[COEF_EG1] = S2F(compute_breakpoint_scale(osc, 1, AMY_BLOCK_SIZE));
  msynth[osc].amp = combine_controls_mult(ctrl_inputs, synth[osc].amp_coefs);

diff --git a/src/oscillators.c b/src/oscillators.c
@@ -445,7 +445,7 @@ SAMPLE render_sine(SAMPLE* buf, uint16_t osc) {
  PHASOR step = F2P(freq / (float)AMY_SAMPLE_RATE); // cycles per sec / samples per sec -> cycles per sample
  SAMPLE amp = F2S(msynth[osc].amp);
  SAMPLE last_amp = F2S(msynth[osc].last_amp);
- //fprintf(stderr, "render_sine: time %f osc %d freq %f amp %f\n", total_samples / (float)AMY_SAMPLE_RATE, osc, AMY_SAMPLE_RATE * P2F(step), S2F(amp));
+ //fprintf(stderr, "render_sine: time %f osc %d freq %f last_amp %f amp %f\n", total_samples / (float)AMY_SAMPLE_RATE, osc, AMY_SAMPLE_RATE * P2F(step), S2F(last_amp), S2F(amp));
  SAMPLE max_value;
  synth[osc].phase = render_lut(buf, synth[osc].phase, step, last_amp, amp, synth[osc].lut, &max_value);
  msynth[osc].last_amp = msynth[osc].amp;

diff --git a/test.py b/test.py
@@ -406,7 +406,8 @@ def main(argv):
  #TestSawDownOsc().test()
  #TestGuitar().test()
  #TestFilter().test()
- TestAlgo().test()
+ #TestAlgo().test()
+ TestBleep().test()
  amy.send(debug=0)
  print("tests done.")