initial commit

misc/blobs/blobs.typ

@@ -0,0 +1,67 @@
+#import "@preview/cetz:0.3.1": draw
+
+#let rand-consts = (
+  a: 1103515245,
+  c: 12345,
+  m: (1).bit-lshift(31)
+)
+#let random(seed) = {
+  let seed = calc.rem(rand-consts.a * seed + rand-consts.c, rand-consts.m)
+  let value = seed / rand-consts.m
+  return (seed, value)
+}
+
+#let draw-blob(
+  seed,
+  center,
+  radius,
+  n-pts: 8,
+  curviness: 0.4,
+  debug: false,
+  ..args
+) = {
+  let pts = ()
+  let angle-step = 360deg / n-pts
+  let seed = seed
+  let v
+
+  if debug {
+    draw.circle(center, radius: radius, stroke: (dash: "dashed"))
+  }
+  for i in range(n-pts) {
+    (seed, v) = random(seed)
+    let angle = angle-step * (i + v - 0.5)
+    
+    (seed, v) = random(seed)
+    let f = calc.rem(i, 2) * 2 - 1
+    let r = radius * (1 + f * v * curviness)
+
+    let dx = r * calc.cos(angle)
+    let dy = r * calc.sin(angle)
+    let pt = (center.first() + dx, center.last() + dy)
+    pts.push(pt)
+
+    if debug {
+      draw.circle(
+        pt,
+        radius: .1,
+        stroke: none,
+        fill: black
+      )
+      draw.line(
+        center,
+        (rel: center, to: (angle-step * i, radius)),
+        stroke: (dash: "dashed")
+      )
+    }
+  }
+
+  let name = args.named().at("name", default: none)
+  draw.group(name: name, {
+    draw.hobby(..pts, close: true, ..args)
+    if name != none {
+      draw.copy-anchors(name)
+      draw.anchor("center", center)
+    }
+  })
+}

misc/blobs/main.typ

@@ -0,0 +1,79 @@
+#import "@preview/cetz:0.3.1": canvas, draw
+#import "blobs.typ": draw-blob
+
+#set page(width: auto, height: auto, margin: 1cm)
+
+#canvas({
+  draw-blob(
+    2, (0, 0), 1.5,
+    stroke: green,
+    name: "blob1"
+  )
+
+  draw-blob(
+    8, (5, 0), 1.5,
+    n-pts: 10,
+    stroke: orange,
+    name: "blob2"
+  )
+
+  draw.circle(
+    "blob1.center",
+    radius: .05,
+    fill: black,
+    stroke: none,
+    name: "x"
+  )
+
+  draw.circle(
+    "blob2.center",
+    radius: .05,
+    fill: black,
+    stroke: none,
+    name: "y"
+  )
+
+  draw.content(
+    "x",
+    [$arrow(x)$],
+    anchor: "east",
+    padding: 3pt
+  )
+
+  draw.content(
+    "y",
+    [$arrow(y)$],
+    anchor: "west",
+    padding: 3pt
+  )
+
+  draw.content(
+    (-1.2, .8),
+    text(fill: green)[$RR^n$]
+  )
+
+  draw.content(
+    (4.6, 1.4),
+    text(fill: orange)[$RR^m$]
+  )
+
+  let mid = (2.5, .5)
+
+  draw.bezier-through(
+    "x.north-east", mid, "y.north-west",
+    stroke: blue + .5pt,
+    mark: (end: ">", fill: blue),
+    name: "arrow"
+  )
+  draw.content(
+    mid,
+    [$f$],
+    anchor: "south",
+    padding: 3pt
+  )
+
+  draw.content(
+    (2.5, -1),
+    text(fill: blue)[$f: RR^n -> RR^m$]
+  )
+})