Home

Dynamic

package cas.cs4tb3.mellowd;

import java.util.List;

The Dynamic changes the volume. In MIDI this translates to the velocity with which the note is played. It works out very nicely because to play a piano sound louder the player would hit the key “harder” (which really corresponds to faster) producing a louder sound but also giving the note more power. This is exactly how MIDI velocity works.

public enum Dynamic {

Each dynamic has an associated MIDI velocity, for example pppp (pianissimo) corresponds to the MIDI velocity 8.

    pppp(8 ),
    ppp (20),
    pp  (31),
    p   (42),
    mp  (53),
    mf  (64),
    f   (80),
    ff  (96),
    fff (112),
    ffff(127);

    private int velocity;

    Dynamic(int velocity) {
        this.velocity = velocity;
    }

getVelocity returns the MIDI velocity for this dynamic

    public int getVelocity() {
        return this.velocity;
    }

This method applies this dynamic to each sound in the playableSounds

    public void applyToAllSounds(PlayableSound[] playableSounds) {
        for (PlayableSound sound : playableSounds) {
            sound.setVelocity(this.getVelocity());
        }
    }

    public void graduallyApplyToAllSounds(Dynamic targetDynamic, TimingEnvironment timingEnv, List<PlayableSound> playableSounds) {

Calculate the total duration of the change

        long totalDuration = 0;
        for (PlayableSound sound : playableSounds) {
            totalDuration += timingEnv.ticksInBeat(sound.getDuration());
        }

We want a linear increase or drop from this volume to the targetDynamic.

        int velocityChange = targetDynamic.velocity - this.velocity;
        double changeSlope = velocityChange / (double) totalDuration;

Using the general equation of a line y = mx+b we have a function to get the velocity of each sound in the sequence. y is the velocity, m is the changeSlope, x is the ticks that have passed since the start of the phrase and b is the starting velocity.

        long stateTime = 0;
        for (PlayableSound sound : playableSounds) {
            sound.setVelocity((int) (changeSlope*stateTime + this.velocity));
            stateTime += timingEnv.ticksInBeat(sound.getDuration());
        }
    }
}

Table of Contents

src\main\antlr

src\main\java\cas\cs4tb3\mellowd

src\main\java\cas\cs4tb3\mellowd\compiler

src\main\java\cas\cs4tb3\mellowd\midi

src\main\java\cas\cs4tb3\mellowd\parser

src\main\java\cas\cs4tb3\mellowd\primitives

src\test\java\cas\cs4tb3\mellowd

src\test\resources\compilertest

src\test\resources\errortest

src\test\resources\parsertest

src\test\resources\testdata

Dynamic