Bevy dialogue system

When to use

Load this when lines, choices, or speaker ids advance. Rendering the line is bevy-ui-text.

ECS shape

• Components: a line id and a speaker id that you define.
• Resources: run-wide tables live in a resource (bevy-data-resources), not an autoload.
• Systems: mutate those components on Update or the fixed timestep. Use .chain() when damage must land before death.
• Messages: one-shot facts (hit, pickup, quest advance) go through bevy-events-messaging. This file does not add a new event type name.

Engine counterparts

Godot idea	Bevy idiom
Line table	A resource of ids and strings.
Current line	A component that stores the line index.
Portrait	An image handle via bevy-asset-scenes. Layout is bevy-ui-layout.

Scope

Dialogue data is a resource of lines plus a component that stores the current line index. Rich text rendering belongs on bevy-ui-text.

[dependencies]
bevy = "0.20"

#[derive(Clone)]
struct LineDef {
    speaker: &'static str,
    text: &'static str,
    next: Option<usize>,
}

#[derive(Resource)]
struct DialogueTable {
    lines: Vec<LineDef>,
}

#[derive(Component)]
struct LineMark {
    index: usize,
    open: bool,
}

fn advance_line(
    keys: Res<ButtonInput<KeyCode>>,
    table: Res<DialogueTable>,
    mut marks: Query<&mut LineMark>,
) {
    if !keys.just_pressed(KeyCode::Space) {
        return;
    }
    for mut mark in &mut marks {
        if !mark.open {
            continue;
        }
        let Some(line) = table.lines.get(mark.index) else {
            mark.open = false;
            continue;
        };
        match line.next {
            Some(next) => mark.index = next,
            None => mark.open = false,
        }
    }
}