o cleanup

tools/bsnes/lib/ruby/ruby_audio.cpp

@@ -0,0 +1,135 @@
+bool AudioInterface::init() {
+  if(!p) driver();
+  return p->init();
+}
+
+void AudioInterface::term() {
+  if(p) {
+    delete p;
+    p = 0;
+  }
+}
+
+bool AudioInterface::cap(Audio::Setting setting) {
+  if(setting == Audio::Volume) return true;
+  if(setting == Audio::Resample) return true;
+  if(setting == Audio::ResampleOutputFrequency) return true;
+  if(setting == Audio::ResampleInputFrequency) return true;
+
+  return p ? p->cap(setting) : false;
+}
+
+uintptr_t AudioInterface::get(Audio::Setting setting) {
+  if(setting == Audio::Volume) return volume;
+  if(setting == Audio::Resample) return resample_enabled;
+  if(setting == Audio::ResampleOutputFrequency) return r_outfreq;
+  if(setting == Audio::ResampleInputFrequency) return r_infreq;
+
+  return p ? p->get(setting) : false;
+}
+
+bool AudioInterface::set(Audio::Setting setting, uintptr_t param) {
+  if(setting == Audio::Volume) {
+    volume = param;
+    return true;
+  }
+
+  if(setting == Audio::Resample) {
+    resample_enabled = param;
+    return true;
+  }
+
+  if(setting == Audio::ResampleOutputFrequency) {
+    r_outfreq = max(1, param);
+    r_step = (double)r_infreq / (double)r_outfreq;
+    r_frac = 0;
+    return true;
+  }
+
+  if(setting == Audio::ResampleInputFrequency) {
+    r_infreq = max(1, param);
+    r_step = (double)r_infreq / (double)r_outfreq;
+    r_frac = 0;
+    return true;
+  }
+
+  return p ? p->set(setting, param) : false;
+}
+
+//4-tap hermite interpolation
+double AudioInterface::hermite(double mu1, double a, double b, double c, double d) {
+  const double tension = 0.0; //-1 = low, 0 = normal, 1 = high
+  const double bias    = 0.0; //-1 = left, 0 = even, 1 = right
+
+  double mu2, mu3, m0, m1, a0, a1, a2, a3;
+
+  mu2 = mu1 * mu1;
+  mu3 = mu2 * mu1;
+
+  m0  = (b - a) * (1 + bias) * (1 - tension) / 2;
+  m0 += (c - b) * (1 - bias) * (1 - tension) / 2;
+  m1  = (c - b) * (1 + bias) * (1 - tension) / 2;
+  m1 += (d - c) * (1 - bias) * (1 - tension) / 2;
+
+  a0 = +2 * mu3 - 3 * mu2 + 1;
+  a1 =      mu3 - 2 * mu2 + mu1;
+  a2 =      mu3 -     mu2;
+  a3 = -2 * mu3 + 3 * mu2;
+
+  return (a0 * b) + (a1 * m0) + (a2 * m1) + (a3 * c);
+}
+
+void AudioInterface::sample(uint16_t left, uint16_t right) {
+  int s_left  = (int16_t)left;
+  int s_right = (int16_t)right;
+
+  if(volume != 100) {
+    s_left  = sclamp<16>((double)s_left  * (double)volume / 100.0);
+    s_right = sclamp<16>((double)s_right * (double)volume / 100.0);
+  }
+
+  r_left [0] = r_left [1];
+  r_left [1] = r_left [2];
+  r_left [2] = r_left [3];
+  r_left [3] = s_left;
+
+  r_right[0] = r_right[1];
+  r_right[1] = r_right[2];
+  r_right[2] = r_right[3];
+  r_right[3] = s_right;
+
+  if(resample_enabled == false) {
+    if(p) p->sample(left, right);
+    return;
+  }
+
+  while(r_frac <= 1.0) {
+    int output_left  = sclamp<16>(hermite(r_frac, r_left [0], r_left [1], r_left [2], r_left [3]));
+    int output_right = sclamp<16>(hermite(r_frac, r_right[0], r_right[1], r_right[2], r_right[3]));
+    r_frac += r_step;
+    if(p) p->sample(output_left, output_right);
+  }
+
+  r_frac -= 1.0;
+}
+
+void AudioInterface::clear() {
+  r_frac = 0;
+  r_left [0] = r_left [1] = r_left [2] = r_left [3] = 0;
+  r_right[0] = r_right[1] = r_right[2] = r_right[3] = 0;
+  if(p) p->clear();
+}
+
+AudioInterface::AudioInterface() {
+  p = 0;
+  volume = 100;
+  resample_enabled = false;
+  r_outfreq = r_infreq = 1;
+  r_step = r_frac = 0;
+  r_left [0] = r_left [1] = r_left [2] = r_left [3] = 0;
+  r_right[0] = r_right[1] = r_right[2] = r_right[3] = 0;
+}
+
+AudioInterface::~AudioInterface() {
+  term();
+}