:roclet: improve algorithm, add an intermediate phase to clean up residual cell from previous layer, before grabing the free ones

packages/demo/demo.getBestRoundTrip.ts

@@ -0,0 +1,54 @@
+import "./menu";
+import { createCanvas } from "./canvas";
+import { getSnakeLength } from "@snk/types/snake";
+import { grid, snake } from "./sample";
+import { getColor } from "@snk/types/grid";
+import { getBestTunnel } from "@snk/compute/getBestTunnel";
+import type { Color } from "@snk/types/grid";
+import type { Point } from "@snk/types/point";
+
+const { canvas, ctx, draw, highlightCell } = createCanvas(grid);
+document.body.appendChild(canvas);
+
+const ones: Point[] = [];
+
+for (let x = 0; x < grid.width; x++)
+  for (let y = 0; y < grid.height; y++)
+    if (getColor(grid, x, y) === 1) ones.push({ x, y });
+
+const points = getBestTunnel(
+  grid,
+  ones[0].x,
+  ones[0].y,
+  3 as Color,
+  getSnakeLength(snake)
+);
+
+let k = 0;
+
+const onChange = () => {
+  ctx.clearRect(0, 0, 9999, 9999);
+
+  draw(grid, [] as any, []);
+
+  if (points) {
+    points.forEach(({ x, y }) => highlightCell(x, y));
+    highlightCell(points[k].x, points[k].y, "blue");
+  }
+};
+
+onChange();
+
+const inputK = document.createElement("input") as any;
+inputK.type = "range";
+inputK.value = 0;
+inputK.step = 1;
+inputK.min = 0;
+inputK.max = points ? points.length - 1 : 0;
+inputK.style.width = "90%";
+inputK.style.padding = "20px 0";
+inputK.addEventListener("input", () => {
+  k = +inputK.value;
+  onChange();
+});
+document.body.append(inputK);

packages/demo/demo.getPathTo.ts

@@ -0,0 +1,75 @@
+import "./menu";
+import { createCanvas } from "./canvas";
+import { snakeToCells } from "@snk/types/snake";
+import { grid, snake } from "./sample";
+import { getColor } from "@snk/types/grid";
+import { getPathTo } from "@snk/compute/getPathTo";
+import type { Point } from "@snk/types/point";
+
+const { canvas, ctx, draw, highlightCell } = createCanvas(grid);
+document.body.appendChild(canvas);
+
+const ones: Point[] = [];
+
+for (let x = 0; x < grid.width; x++)
+  for (let y = 0; y < grid.height; y++)
+    if (getColor(grid, x, y) === 1) ones.push({ x, y });
+
+const chains = ones.map((p) => {
+  const chain = getPathTo(grid, snake, p.x, p.y);
+  return chain && [...chain, snake];
+});
+
+let k = 0;
+let i = 0;
+
+const onChange = () => {
+  ctx.clearRect(0, 0, 9999, 9999);
+
+  const chain = chains[k];
+
+  if (chain) {
+    draw(grid, chain[i], []);
+    chain
+      .map(snakeToCells)
+      .flat()
+      .forEach(({ x, y }) => highlightCell(x, y));
+  } else draw(grid, snake, []);
+};
+
+onChange();
+
+const inputK = document.createElement("input") as any;
+inputK.type = "range";
+inputK.value = k;
+inputK.step = 1;
+inputK.min = 0;
+inputK.max = chains.length - 1;
+inputK.style.width = "90%";
+inputK.style.padding = "20px 0";
+inputK.addEventListener("input", () => {
+  k = +inputK.value;
+  i = inputI.value = 0;
+  inputI.max = chains[k] ? chains[k]!.length - 1 : 0;
+  onChange();
+});
+document.body.append(inputK);
+
+const inputI = document.createElement("input") as any;
+inputI.type = "range";
+inputI.value = 0;
+inputI.max = chains[k] ? chains[k]!.length - 1 : 0;
+inputI.step = 1;
+inputI.min = 0;
+inputI.style.width = "90%";
+inputI.style.padding = "20px 0";
+inputI.addEventListener("input", () => {
+  i = +inputI.value;
+  onChange();
+});
+document.body.append(inputI);
+
+window.addEventListener("click", (e) => {
+  if (e.target === document.body || e.target === document.body.parentElement)
+    inputK.focus();
+});

packages/demo/demo.json

@@ -1 +1,8 @@
-["getAvailableRoutes", "pruneLayer", "getBestRoute", "interactive"]
+[
+  "getAvailableRoutes",
+  "pruneLayer",
+  "getBestRoute",
+  "getBestRoundTrip",
+  "getPathTo",
+  "interactive"
+]

packages/demo/demo.pruneLayer.ts

@@ -3,10 +3,11 @@ import { createCanvas } from "./canvas";
 import { Color, copyGrid } from "@snk/types/grid";
 import { grid, snake } from "./sample";
 import { pruneLayer } from "@snk/compute/pruneLayer";
+import { getSnakeLength } from "@snk/types/snake";
 
 const colors = [1, 2, 3] as Color[];
 
-const snakeN = snake.length / 2;
+const snakeN = getSnakeLength(snake);
 
 const layers = [{ grid, chunk: [] as { x: number; y: number }[] }];
 let grid0 = copyGrid(grid);