Twin Perimeter

1"use client";
2 
3import type { CSSProperties } from "react";
4 
5import { cx } from "@/components/ui/cellforge-core";
6import { resolveDmxColorTokens } from "@/components/ui/cellforge-core";
7import { useCellForgePhases } from "@/components/ui/cellforge-hooks";
8import { styleOpacity, stylePx } from "@/components/ui/cellforge-core";
9import { remapOpacityToTriplet } from "@/components/ui/cellforge-core";
10import { dmxBloomRootActive, dmxDotBloomParts } from "@/components/ui/cellforge-core";
11import { useCyclePhase } from "@/components/ui/cellforge-hooks";
12import { usePrefersReducedMotion } from "@/components/ui/cellforge-hooks";
13import type { CellForgeCommonProps } from "@/components/ui/cellforge-core";
14 
15export type CellAngle20Props = CellForgeCommonProps;
16 
17const MATRIX_SIZE = 7;
18const BASE_OPACITY = 0.08;
19const HIGH_OPACITY = 0.94;
20const CENTER_DIM = 0.2;
21 
22const TRIANGLE_CELLS = new Set([
23  "1,3",
24  "2,2",
25  "2,4",
26  "3,1",
27  "3,3",
28  "3,5",
29  "4,0",
30  "4,2",
31  "4,4",
32  "4,6"
33]);
34 
35/** Same perimeter ring as CellTriangle1 — center is not on this loop. */
36const PERIMETER_PATH: ReadonlyArray<readonly [number, number]> = [
37  [1, 3],
38  [2, 2],
39  [3, 1],
40  [4, 0],
41  [4, 2],
42  [4, 4],
43  [4, 6],
44  [3, 5],
45  [2, 4]
46];
47 
48const PATH_LEN = PERIMETER_PATH.length;
49const TRAIL_SPAN = 3.35;
50const HALF = PATH_LEN / 2;
51 
52function isWithinTriangleMask(row: number, col: number): boolean {
53  if (row < 0 || row >= MATRIX_SIZE || col < 0 || col >= MATRIX_SIZE) {
54    return false;
55  }
56 
57  return TRIANGLE_CELLS.has(`${row},${col}`);
58}
59 
60function pathIndex(row: number, col: number): number | null {
61  for (let i = 0; i < PATH_LEN; i += 1) {
62    const [pr, pc] = PERIMETER_PATH[i]!;
63    if (pr === row && pc === col) {
64      return i;
65    }
66  }
67  return null;
68}
69 
70function modF(n: number, m: number): number {
71  return ((n % m) + m) % m;
72}
73 
74function behindAlongPath(s: number, i: number, L: number): number {
75  return modF(s - i, L);
76}
77 
78function smoothstep01(edge0: number, edge1: number, x: number): number {
79  if (edge1 <= edge0) {
80    return x >= edge1 ? 1 : 0;
81  }
82  const t = Math.max(0, Math.min(1, (x - edge0) / (edge1 - edge0)));
83  return t * t * (3 - 2 * t);
84}
85 
86function glowAlongPath(s: number, idx: number | null, L: number): number {
87  if (idx === null) {
88    return BASE_OPACITY;
89  }
90  const d = behindAlongPath(s, idx, L);
91  const g = 1 - smoothstep01(0, TRAIL_SPAN, d);
92  return BASE_OPACITY + g * (HIGH_OPACITY - BASE_OPACITY);
93}
94 
95/**
96// … truncated