package nodebox.util.waves;

public abstract class AbstractWave {

public static final float PI = 3.14159265358979323846f;

public static final float TWO_PI = 2 * PI;

public static enum Type { SINE, TRIANGLE, SQUARE, SAWTOOTH };

private float period;

private float phase;

private float frequency;

protected float amplitude;

private float offset;

public AbstractWave(float period, float amplitude) {

this(period, 0f, amplitude, 0);

}

public AbstractWave(float period, float phase, float amplitude) {

this(period, phase, amplitude, 0);

}

public AbstractWave(float period, float phase, float amplitude, float offset) {

this.period = period;

this.frequency = TWO_PI / period;

this.amplitude = amplitude;

this.offset = offset;

setPhase(phase);

}

public float getPeriod() {

return period;

}

public float getFrequency() {

return frequency;

}

public float getAmplitude() {

return amplitude;

}

public float getOffset() {

return offset;

}

public float getPhase() {

return phase;

}

/**

* (Re)sets the starting position of the wave.

*

* @param phase the new starting phase

*/

public void setPhase(float phase) {

phase %= TWO_PI;

if (phase < 0) phase += TWO_PI;

this.phase = phase;

}

/**

* Calculates and returns the value at time unit t for the wave.

*

* @param t time coordinate on the wave continuum

* @return the new value

*/

public float getValueAt(float t) {

float time = adjustedTime(t);

float phase;

if (time % period == 0)

phase = this.phase;

else

phase = (this.phase + time * frequency) % TWO_PI;

if (phase < 0) phase += TWO_PI;

return computeValue(phase) + offset;

}

protected abstract float adjustedTime(float t);

/**

* Calculates and returns the value at phase for the wave.

*

* @param phase

* @return the new value

*/

protected abstract float computeValue(float phase);

}