Struct PolylineWidget 

pub struct PolylineWidget {
    pub points: Vec<Vec3>,
    pub colour: [f32; 4],
    pub line_width: f32,
    pub handle_colour: [f32; 4],
    pub hovered_point: Option<usize>,
    pub active_point: Option<usize>,
    /* private fields */
}

An interactive polyline widget with N draggable control points.

Unlike crate::SplineWidget, this uses straight line segments between points (no interpolation). Control points can be added and removed programmatically, and via double-click when ctx.double_clicked is set by the host.

Usage

let mut pw = PolylineWidget::new(vec![
    glam::Vec3::new(-2.0, 0.0, 0.0),
    glam::Vec3::new( 0.0, 1.0, 0.0),
    glam::Vec3::new( 2.0, 0.0, 0.0),
]);

// Each frame:
let result = pw.update(&ctx);
fd.scene.polylines.push(pw.polyline_item(PL_ID));
fd.scene.glyphs.push(pw.handle_glyphs(HANDLE_ID, &ctx));

Fields

points: Vec<Vec3>

Control point positions in world space.

colour: [f32; 4]

RGBA colour for the line segments.

line_width: f32

Line width in pixels.

handle_colour: [f32; 4]

RGBA colour for the drag handles.

hovered_point: Option<usize>

Index of the currently hovered control point.

active_point: Option<usize>

Index of the point actively being dragged.

Implementations

impl PolylineWidget

pub fn new(points: Vec<Vec3>) -> Self

Create a new polyline widget. Must have at least two points; extras are ignored if fewer are provided by adding a default second point.

pub fn is_active(&self) -> bool

True while a control point drag is in progress.

pub fn add_point(&mut self, pos: Vec3)

Append a point at the end of the polyline.

pub fn remove_point(&mut self, index: usize)

Remove the point at index. No-op if the polyline would drop below two points.

pub fn update(&mut self, ctx: &WidgetContext) -> WidgetResult

Process input for this frame. Returns Updated if state changed.

Double-click behavior (requires ctx.double_clicked):

• On a hovered control point: removes that point (minimum 2 enforced).
• On a line segment: inserts a new point at the projected position.

pub fn polyline_item(&self, id: u64) -> PolylineItem

Build a PolylineItem through all control points.

pub fn handle_glyphs(&self, id_base: u64, ctx: &WidgetContext) -> GlyphItem

Build a GlyphItem with sphere handles for each control point.

Hovered and active handles appear brighter (scalar = 1.0 vs 0.2). id_base is the pick ID for the first point; each subsequent point uses id_base + i.