feat(plugin-bartack): New plugin for bartacks

packages/plugin-bartack/src/bartack.js

@@ -0,0 +1,92 @@
+const name = (n, so) => `${so.prefix}${n}${so.suffix}`
+
+const drawBartack = (points, so, self) => {
+  let path = new self.Path().move(points.path1[0])
+  for (let i in points.path1) {
+    if (points.path1[i]) path = path.line(points.path1[i])
+    if (points.path2[i]) path = path.line(points.path2[i])
+  }
+
+  return path
+}
+
+const getPoints = (path, so, self) => {
+  let path1 = path.offset(so.width / 2)
+  let path2 = path.offset(so.width / -2)
+  let len1 = path1.length()
+  let len2 = path2.length()
+
+  // Make sure path1 is always the longest one
+  if (len2 > len1) {
+    let tmp = path2
+    path2 = path1
+    path1 = tmp
+    tmp = len2
+    len2 = len1
+    len1 = tmp
+  }
+
+  let points = {
+    path1: [path1.start()],
+    path2: [path2.start()]
+  }
+  let steps = Math.ceil((len1 / so.width) * so.density)
+  for (let i = 1; i < steps; i++) {
+    points.path1.push(path1.shiftFractionAlong((1 / steps) * i))
+    points.path2.push(path2.shiftFractionAlong((1 / steps) * i))
+  }
+
+  return points
+}
+
+const bartackPath = (path, so, self) =>
+  path ? drawBartack(getPoints(path, so, self), so, self) : null
+
+export default function bartack(so, self) {
+  const defaults = {
+    width: 3,
+    length: 15,
+    density: 3,
+    angle: 0,
+    prefix: '',
+    suffix: '',
+    anchor: false,
+    path: false,
+    from: false,
+    to: false,
+    start: 0,
+    end: 1,
+    bartackAlong: false,
+    bartackFractionAlong: false
+  }
+  so = { ...defaults, ...so }
+
+  let guide = false
+
+  if (so.anchor)
+    // Anchor + angle + length
+    guide = new self.Path().move(so.anchor).line(so.anchor.shift(so.angle, so.length))
+  else if (so.from && so.to)
+    // From to
+    guide = new self.Path().move(so.from).line(so.to)
+  else if (so.path) {
+    // Along path
+    let start = false
+    let end = false
+    if (so.bartackAlong) {
+      if (so.start > 0) start = so.path.shiftAlong(so.start)
+      if (end < so.path.length) end = so.path.shiftAlong(so.end)
+    } else if (so.bartackFractionAlong) {
+      if (so.start > 0) start = so.path.shiftFractionAlong(so.start)
+      if (so.end < 1) end = so.path.shiftFractionAlong(so.end)
+    }
+    if (start && end) guide = so.path.split(start).pop().split(end).shift()
+    else if (start) guide = so.path.split(start).pop()
+    else if (end) guide = so.path.split(end).shift()
+    else guide = so.path.clone()
+  }
+
+  self.paths[name('bartack', so)] = bartackPath(guide, so, self).attr('class', 'stroke-sm bartack')
+
+  return true
+}