Tutorials · Sound and Music · Chapter 10

Moods

Four more pieces of music

A music asset

1. In Assets, click Assets in the path bar, then choose Create → New folder, type music and press Enter: a folder at the project’s top.
2. Click the music folder in the tree. Its row lights up and the path bar reads Assets / music: Create now writes into it.
3. Choose Create → New data asset → Music. In the field under the bar, which reads music, the type’s name, type crypt over it and press Enter. music/crypt.data is written, and opens in the Inspector, which draws it in place of the selection: crypt.data, MusicGraph, with no tracks and no rules yet, and its own Revert and Save.

Four tracks

1. Press + beside Tracks: a track, 1, with Looping ticked, as a track comes. Type calm in its Name, drag crypt-calm.wav from Assets onto its Clip, and crypt-intro.wav onto its Intro.
2. Press + beside Tracks again: 2, a copy of calm. Name it danger, drop crypt-danger.wav on its Clip, and clear its Intro: click the slot and pick (none), under the search box of the list it opens.
3. Press + again: 3. Name it found, drop found.wav on its Clip, and untick Looping.
4. Press + again: 4, a copy of found. Name it caught and drop caught.wav on its Clip. Press Save.

The music asset’s Tracks

The pieces of music the asset can play, a row each. One plays at a time; a level opens on one, and a script asks for another by its name. The Inspector reads each row by its place and its name, 1 calm.

A track’s Name

What play_music, a rule and a level’s Track call it by.

A track’s Clip

The sound the track plays, and loops while Looping is ticked. The ▶ beside it plays it, as beside every clip slot.

Intro

A clip the track plays once before its Clip, running straight into it with no gap: the intro’s last sample, then the loop’s first. It plays every time the track starts, not only the first. Empty for none: click the slot and pick (none) to empty it.

A track’s Looping

Ticked, the track plays until another takes its place. Unticked, it plays once and stops, and the music is silent after it unless something waits for its end, as a rule’s AtEnd below does.

Six rules

1. Press + beside Rules: rule 1, which comes as a rule does, reading any to nothing, a CrossFade of 1 second. Type calm in its From and danger in its To, or pick each from the list beside it, and set its Seconds to 1.5.
2. Press +: rule 2, a copy. Set From to danger, To to calm, and Seconds to 3.
3. Press +: rule 3. Clear From, which then reads any; set To to caught and How to Immediate.
4. Press +: rule 4. Set From to caught, To to calm and How to AtEnd.
5. Press +: rule 5. Clear From; set To to found and How to Immediate.
6. Press +: rule 6. Set From to found, To to calm and How to AtEnd.
7. Set the Default Transition’s Seconds to 2, and leave the Playlist empty. Press Save.

The music asset’s Rules

How the music changes from one track to another, a row each. When a track is asked for, the rule whose From is the playing track and whose To is the one asked for decides; a rule whose From is empty stands for any track. With no rule for the pair, the Default Transition does.

A rule’s From

The track being left, by its name. Empty, it reads any, and the rule is for every track. The list beside it picks a name from the asset’s tracks.

A rule’s To

The track being asked for, by its name.

A rule’s How

Immediate cuts: the playing track stops and the new one starts, on the step it is asked for. CrossFade fades the playing track out as the new one comes in, over its Seconds. AtEnd lets the playing track reach the end of its pass, its loop or its one play, and starts the new one there, with no gap; the new track waits until then, and a track asked for in the meantime calls it off.

A CrossFade rule’s Seconds

How long the two tracks overlap, one fading out as the other comes in, from 0 to 30. The fade is straight in gain: halfway, each track is at half its own level.

Default Transition

The How for any change no rule names, with the same three choices. A new asset’s is a CrossFade of 1 second. No change the crypt makes in this chapter falls to it: the opening and the alcove start calm from no music, which a crossfade starts at once. Chapter 11 gives it a case.

The Default Transition’s Seconds

The overlap of the default crossfade: 2 here, set from the 1 it comes with.

The crypt’s level

1. Click the Levels tab and click The Crypt row.
2. Drag crypt.data from music in Assets onto the row’s Music button. A Track list appears beside it: pick calm.
3. Leave the Title row’s Music as it is: the castle’s loop.

A level’s Track, in the Levels panel

With a music asset as the level’s Music, the track the level opens on, picked from the asset’s tracks. A clip as the level’s Music has no Track.

What goes

1. Select Crypt, and remove its AudioSourceComponent with the bin icon at the right of its header.
2. Select alcove, and remove its AudioSourceComponent the same way, its trigger calm with it. Its Alcove stays.
3. Select mix. In Effects, Music, open slot 1, the Gain, and set it from -4 to -7 dB. Press Ctrl+S.

The ghost’s moods

1. In Assets, double-click ghost.rgs. In the Code tab, replace everything in it with the script below, and press Ctrl+S.
2. Select ghost: its Ghost now shows Near 64, Far 96 and Close. Leave them.

/// The ghost, drifting its round through the flooded passage. Near the
/// knight it turns the crypt's music to danger, and once it is far from him
/// again, back to calm. A knight its Area touches is caught: the music cuts
/// to a sting, and he is sent back to where he started, in the entrance hall.
component Ghost : Area {
    /// Where a knight the ghost touches is sent back to: his start in the
    /// entrance hall.
    back_to: Vec2,
    /// How near the knight the ghost turns the music to danger.
    #[suffix("u")]
    near: f32 = 64.0,
    /// How far from him it turns the music back to calm. Farther than near,
    /// so a ghost drifting along the edge does not turn it back and forth.
    #[suffix("u")]
    far: f32 = 96.0,
    /// Whether it has turned the music to danger, or to the sting that waits
    /// for calm, so that it asks for each change once and not on every step.
    #[readonly]
    close: bool = false,

    fn loop() {
        let knight = nearest("knight");
        if knight != node(0) {
            let apart = position().distance(position_of(knight));
            // danger and calm are tracks of the crypt's music asset, the
            // level's Music: its rules say how one turns into the other.
            if !close && apart < near {
                play_music("danger");
                close = true;
            } else if close && apart > far {
                play_music("calm");
                close = false;
            }
        }
    }

    fn on_enter(other: NodeId) {
        if in_group(other, "knight") {
            // The sting cuts in at once, whatever is playing.
            play_music("caught");
            // Still close: once he is far from the ghost, it asks for calm,
            // which waits for the sting's end.
            close = true;
            move_node(other, back_to);
        }
    }
}

play_music, by a track’s name

With a music asset as the level’s Music, a name that is one of its tracks asks for that track, and the asset’s rule for the change says how it comes in. Asking for the track already playing leaves it playing. A name the asset does not have plays a trigger of that name on the script’s own node, as chapter 5’s did.

nearest and position_of

nearest("knight") is the nearest other node in the group knight, or node(0), nobody, when there is none; position_of is where a node stood as the step began. With the ghost’s own position(), .distance(...) is how far apart they are.

Near and Far, the ghost’s

How near the knight turns the music to danger, and how far from him it turns back to calm, in world units, u. Far is farther than Near, so a ghost drifting along the edge of Near does not turn the music back and forth.

Close, the ghost’s

Whether it has asked for danger, or for the sting, so that it asks for each change once. #[readonly] shows it and keeps it out of your hands: the script writes it.

/// The alcove at the end of the crypt, where the music box plays. As the
/// knight comes in, the crypt's music stops, and the box is heard alone. As he
/// leaves, the crypt's music comes back.
component Alcove : Area {
    fn on_enter(other: NodeId) {
        if in_group(other, "knight") {
            stop_music();
        }
    }

    fn on_exit(other: NodeId) {
        if in_group(other, "knight") {
            // calm is a track of the crypt's music asset, the level's Music.
            // Asked for while the box's found phrase plays, it waits for the
            // phrase's end.
            play_music("calm");
        }
    }
}

The box, found

1. Select music_box. Press Add component and choose AreaComponent. In its Shape, set Size to 32, 32 and Offset to 0, 16: the floor in front of the box.
2. In Assets, click Assets in the path bar, so the script is written at the project’s top, then click Create, choose New script, type music_box and press Enter. Replace everything in music_box.rgs with the script below, and press Ctrl+S.
3. Select music_box, press Add component and choose MusicBox. Press Ctrl+S.

/// The music box, at the end of the crypt. Its tune leads the knight to it.
/// Once he reaches it, it falls silent, and the crypt's music plays its found
/// phrase, once.
component MusicBox : Area {
    /// Whether he has reached it, so that it is found once.
    #[readonly]
    found: bool = false,

    fn on_enter(other: NodeId) {
        if in_group(other, "knight") && !found {
            // Its tune, its own Audio Source's Autoplay, stops.
            stop_sound();
            // A track of the crypt's music asset, whose Looping is unticked:
            // it plays once and stops.
            play_music("found");
            found = true;
        }
    }
}

Heard

The Sound tab’s Music band, with a music asset

Track is the track playing, or coming in. Fading out names the track a crossfade takes out, and how far through the fade is. A row for each track sounding says where it is, playing, fading out, or waiting to take over at the end of the pass, and its gain. Next names a track waiting for the end of this pass, as an AtEnd does. In Voices, a music voice is Heard at its share of the crossfade, the gain above, and not at how loud its music is: part way in, as in the picture, calm’s row still reads over danger’s, while danger, the louder music, is heard over calm.

Who decides what you hear

The moods

Check it works