From 799caa12dffc2f3869b89ef3ae672abd5f719fc4 Mon Sep 17 00:00:00 2001
From: "prompt.ac/@jeffrey" <mail@aesthetic.computer>
Date: Tue, 15 Sep 2026 13:08:05 -0700
Subject: [PATCH] Start No Paint home visits fresh and keep lines inside the
 canvas

---
 system/public/aesthetic.computer/boot.mjs     |  3 +-
 .../public/aesthetic.computer/disks/line.mjs  | 14 +++++-
 system/tests/nopaint-line-bounds.test.mjs     | 43 +++++++++++++++++++
 3 files changed, 57 insertions(+), 3 deletions(-)
 create mode 100644 system/tests/nopaint-line-bounds.test.mjs

diff --git a/system/public/aesthetic.computer/boot.mjs b/system/public/aesthetic.computer/boot.mjs
index 192c76a771..82e10f4b3c 100644
--- a/system/public/aesthetic.computer/boot.mjs
+++ b/system/public/aesthetic.computer/boot.mjs
@@ -1145,7 +1145,8 @@ if (
   location.hostname === "nopaint.art" ||
   location.hostname === "www.nopaint.art"
 ) {
-  window.acSTARTING_PIECE = "nopaint";
+  // The front door starts a new canvas; rewritten session URLs resume.
+  window.acSTARTING_PIECE = location.pathname === "/" ? "nopaint~fresh" : "nopaint";
 }
 if (
   location.hostname === "oskiewar.com" ||
diff --git a/system/public/aesthetic.computer/disks/line.mjs b/system/public/aesthetic.computer/disks/line.mjs
index 9f493dec50..5c1feb2ecf 100644
--- a/system/public/aesthetic.computer/disks/line.mjs
+++ b/system/public/aesthetic.computer/disks/line.mjs
@@ -284,7 +284,17 @@ const nopaintProposal = Object.freeze({
           Math.round(start.y + (end.y - start.y) * t - sway * 0.65))),
       });
     });
-    const thickness = 1 + Math.floor(random() * 50);
+    const shortSide = Math.min(width, height);
+    const maxThickness = Math.max(1, Math.min(50, Math.floor(shortSide * 0.12)));
+    const thickness = 1 + Math.floor(random() * maxThickness);
+    // Keep the whole stroke visible, including rounded caps and a little
+    // breathing room. Scale the path inward so it keeps its shape at edges.
+    const inset = Math.min(Math.floor((shortSide - 1) / 2),
+      Math.ceil(thickness / 2) + Math.max(2, Math.round(shortSide * 0.04)));
+    const insetPoints = points.map(({ x, y }) => Object.freeze({
+      x: Math.round(inset + x / Math.max(1, width - 1) * (width - 1 - inset * 2)),
+      y: Math.round(inset + y / Math.max(1, height - 1) * (height - 1 - inset * 2)),
+    }));
     const alpha = 24 + Math.floor(random() * 169);
     const color = Object.freeze([base.color[0], base.color[1], base.color[2], alpha]);
     const durationFrames = 24 + Math.floor(random() * 97);
@@ -292,7 +302,7 @@ const nopaintProposal = Object.freeze({
       ...base,
       color,
       thickness,
-      points: Object.freeze(points),
+      points: Object.freeze(insetPoints),
       brush: Object.freeze({
         slug: "line",
         params: Object.freeze(color.map(String)),
diff --git a/system/tests/nopaint-line-bounds.test.mjs b/system/tests/nopaint-line-bounds.test.mjs
new file mode 100644
index 0000000000..751eb8755b
--- /dev/null
+++ b/system/tests/nopaint-line-bounds.test.mjs
@@ -0,0 +1,43 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import { nopaintProposal } from "../public/aesthetic.computer/disks/line.mjs";
+import { makeProposal, seededRandom } from "../public/aesthetic.computer/lib/nopaint-proposals.mjs";
+import { color, line, setBuffer } from "../public/aesthetic.computer/lib/graph.mjs";
+
+test("Line's entire raster stays inside the painting with a visible edge margin", () => {
+  const guard = 32;
+  for (const [width, height] of [[8, 8], [96, 32], [256, 256], [390, 676], [844, 312], [1200, 700]]) {
+    const surface = {
+      width: width + guard * 2,
+      height: height + guard * 2,
+      pixels: new Uint8ClampedArray((width + guard * 2) * (height + guard * 2) * 4),
+    };
+    for (let seed = 0; seed < 16; seed++) {
+      const random = seededRandom(seed);
+      const base = makeProposal(random, width, height);
+      // Include paths that reach both opposite corners before insetting.
+      const edgeBase = seed % 2 === 0
+        ? { ...base, x: 0, y: 0, w: width - 1, h: height - 1 }
+        : base;
+      const score = nopaintProposal.generate({ random, width, height, base: edgeBase });
+      surface.pixels.fill(0);
+      setBuffer(surface);
+      nopaintProposal.render({ ink: (rgba) => {
+        color(...rgba);
+        return { line: (x0, y0, x1, y1, thickness) =>
+          line(x0 + guard, y0 + guard, x1 + guard, y1 + guard, thickness) };
+      } }, score, 600);
+      let count = 0;
+      for (let index = 3; index < surface.pixels.length; index += 4) {
+        if (!surface.pixels[index]) continue;
+        count++;
+        const pixel = (index - 3) / 4;
+        const x = pixel % surface.width - guard;
+        const y = Math.floor(pixel / surface.width) - guard;
+        assert.ok(x > 0 && x < width - 1 && y > 0 && y < height - 1,
+          `${width}x${height}, seed ${seed}: stroke pixel ${x},${y} touches or crosses an edge`);
+      }
+      assert.ok(count > 0, "the proposal remains visible");
+    }
+  }
+});
-- 
2.51.2