regl-line2d

Draw polyline with regl.

Remake on gl-line2d:

• GPU join calculation.
• Bevel, round and rectangular joins.
• Dash patterns.
• Self-overlapping and sharp angles cases.
• Multiline rendering.
• Float64 precision.
• <polyline>-compatible API

Demo.

Usage

let regl = require('regl')({extensions: 'angle_instanced_arrays'})
let line2d = require('regl-line2d')(regl)

// draw red triangle
line2d.render({ thickness: 4, points: [0,0, 1,1, 1,0], close: true, color: 'red' })

line2d.render(options|list?)

Draw line or multiple lines and update options, once per frame at most.

Option	Default	Description
positions, points, data	[]	Point coordinates, eg. [0,0, 1,1, 0,2, 1,-1] or [[0,0], [1,1], [0,2], [1,-1]].
color, colors, stroke	black	CSS color string or an array with 0..1 values, eg. 'red' or [0, 0, 0, 1].
fill	null	Fill area enclosed by line with defined color.
opacity	1	Line transparency regardless of color.
thickness, lineWidth, width, strokeWidth	1	Line width in px.
dashes, dash, dasharray	null	Array with dash lengths in px, altering color/space pairs, ie. [2,10, 5,10, ...]. null corresponds to solid line.
join, type	bevel	Join style: 'rect', 'round', 'bevel'. Applied to caps too.
miterLimit	1	Max ratio of the join length to the thickness.
close, closed, closePath	false	Connect last point with the first point with a segment.
overlay	false	Enable overlay of line segments.
range, dataBox	null	Visible data range.
viewport, viewBox	null	Area within canvas, an array [left, top, right, bottom] or an object {x, y, w, h} or {left, top, bottom, right}.

To render multiple lines pass an array with options for every line as list:

line2d.render([
  {thickness: 2, points: [0,0, 1,1], color: 'blue'},
  {thickness: 2, points: [0,1, 1,0], color: 'blue'}
])

null argument will destroy line2d instance and dispose resources.

line2d.update(options|list)

Update line(s) not incurring redraw.

line2d.draw(id?)

Draw lines from last updated options. id integer can specify a single line from the list to redraw.

line2d.destroy()

Dispose line2d and associated resources.

Related

• regl-scatter2d
• regl-error2d

Similar

• regl-line-builder
• instanced-lines-demos

License

(c) 2017 Dima Yv. MIT License

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