// Check that the value doesn't change until the time is advanced.
public void testGetValue() {
SynthesisTime time = new SynthesisTime();
time.setSampleRate(44100.0);
MockCachedFrequencyProvider mock = new MockCachedFrequencyProvider();
assertEquals(0, mock.getLogFrequency(time), TOLERANCE);
assertEquals(0, mock.getLogFrequency(time), TOLERANCE);
assertEquals(0, mock.getLogFrequency(time), TOLERANCE);
time.advance();
assertEquals(1, mock.getLogFrequency(time), TOLERANCE);
assertEquals(1, mock.getLogFrequency(time), TOLERANCE);
time.advance();
assertEquals(2, mock.getLogFrequency(time), TOLERANCE);
assertEquals(2, mock.getLogFrequency(time), TOLERANCE);
assertEquals(2, mock.getLogFrequency(time), TOLERANCE);
assertEquals(2, mock.getLogFrequency(time), TOLERANCE);
}
/** Gets one value from the synthesizer. */
public synchronized double computeValue(SynthesisTime time) {
// How many samples have passed?
double deltaTime = time.getAbsoluteTime() - previousTime_;
previousTime_ = time.getAbsoluteTime();
// First, skip over however many samples we've passed in the buffer.
int bufferSamples = (int) (deltaTime * sampleRateInHz_ + 0.5);
// If everything in the buffer would be skipped, don't do extra work.
if (bufferSamples > buffer_.length) {
bufferSamples = buffer_.length;
}
// Clear all of the ones we've passed.
for (int i = 0; i < bufferSamples; ++i) {
buffer_[bufferIndex_++] = 0.0;
if (bufferIndex_ >= buffer_.length) {
bufferIndex_ = 0;
}
}
double output = buffer_[bufferIndex_];
// If the instrument has been retriggered, find the right sample.
if (pressed_) {
pressed_ = false;
int key = Note.getKeyforLog12TET(frequency_.getLogFrequency(time));
int velocity = 255;
initSample(key, velocity);
} else {
if (currentSample_ != null) {
// Advance by deltaTime in the current sample.
currentSampleIndex_ += deltaTime * currentSample_.getSample().getRate();
if (currentSample_.getSampleMode() == SampleMode.NO_LOOP) {
if (currentSampleIndex_ > currentSample_.getEnd()) {
// We're off the end of the sample.
currentSample_ = null;
}
} else {
if (currentSampleIndex_ >= currentSample_.getEndLoop()) {
double distanceFromLoopStart = currentSampleIndex_ - currentSample_.getStartLoop();
double loopLength = currentSample_.getEndLoop() - currentSample_.getStartLoop();
currentSampleIndex_ =
currentSample_.getStartLoop() + (distanceFromLoopStart % loopLength);
}
}
}
}
// Okay, now get the new data from the current sample.
if (currentSample_ != null) {
int firstSample = (int) currentSampleIndex_;
double weight = 1.0 - (currentSampleIndex_ - firstSample);
if (weight == 1.0) {
output += currentSample_.getSample().getSample(firstSample);
} else {
output +=
weight * currentSample_.getSample().getSample(firstSample)
+ (1.0 - weight) * currentSample_.getSample().getSample(firstSample + 1);
}
}
return output;
}
