// ============================================================
//  MORPHING MEDALLION — circles slowly become stars
//
//  std.shapes supplies the two outlines, std.pathops aligns their
//  different point counts, and std.mathx controls the transition.
// ============================================================

import std.shapes.ellipsepath as ellipsepath
import std.shapes.starpath as starpath
import std.pathops.morphpaths as morphpaths
import std.mathx.easeinout as easeinout
import std.stitchcraft.sewrun as sewrun

let layers = 10       // [4:1:16] nested outlines
let inner = 8         // [4:1:14] inner circle radius, mm
let outer = 36        // [24:1:42] outer star radius, mm
let points = 7        // [4:1:12] star points

lock 0
stitchlen 1.8

let circleform = ellipsepath(inner, inner)
let starform = starpath(points, outer, outer * 0.42)

for i = 0 to layers - 1 [
  // `u` progresses from 0 (circle) to 1 (star); easing slows both endpoints.
  let u = easeinout(i / (layers - 1))
  // morphpaths first aligns the two point lists, then interpolates them.
  let outline = morphpaths(circleform, starform, u)

  // Cycle through three thread colours while each outline remains a separate run.
  color 2 + mod(i, 3)
  sewrun(outline, 1.8)
  trim
]