StringArt

a bundled profile photograph wound from one continuous thread over 200 rim pins, where each chord is chosen greedily for the darkness it still covers, and the winding builds up live (StringArt, step, thread)

Run

swift run --package-path Examples Example-Images-StringArt

Imports

OllinSamplePhotos

Source

Examples/Images/StringArt/Sketch.swift

import Ollin
import OllinSamplePhotos

/// String art: a profile knitted out of one continuous thread.
///
/// `StringArt` rings the canvas with 200 pins and winds a single thread
/// between them, chord after chord, each one chosen greedily for the
/// darkness it still covers. Dark regions collect many crossings, light
/// regions few, and the straight lines add up to a shaded picture. The
/// canvas never clears (`noClear()`): every frame winds a few more chords
/// onto the accumulation, so the face knits itself over the first seconds.
///
/// The winding is deterministic (no seed involved), and `art.thread` holds
/// the whole piece so far as one open polyline: draw it with `drawPolyline`
/// in a clearing sketch and the vector exports write a single continuous
/// line, exactly the thing a pen plotter loves most.
///
/// The picture is one of the bundled sample photographs, a woman in profile
/// on a plain ground: bold tonal masses, which is what the technique reads
/// best, since every chord crosses the whole disk.
@main
final class StringArt: Sketch {
    private var art: Ollin.StringArt!

    override func setup() {
        noClear()
        let picture = SamplePhoto.profile.load().resized(width: 340, height: 340)
        art = Ollin.StringArt(of: picture, center: center,
                              radius: 470, pins: 200, chords: 3200, ink: 0.08)
    }

    override func draw() {
        if frameCount == 1 {
            background(Color(hex: 0xF6F1E7))
            noStroke()
            fill(Color(hex: 0x3A3C46))
            for pin in art.pins { drawCircle(center: pin, radius: 2.4) }
        }

        noFill()
        stroke(Color(hex: 0x20222B).withAlpha(0.35))
        strokeWeight(1.0)
        for chord in art.step(8) {
            drawLine(chord.from, chord.to)
        }

        // The caption stays word-for-word stable: the canvas never clears,
        // so changing text would smear over itself.
        drawCaption("one continuous thread over 200 pins")
    }
}