Initial commit

2026-07-14 11:11:36 +08:00
commit 656499cf94
604 changed files with 119518 additions and 0 deletions
@@ -0,0 +1,111 @@
+import '../contracts/danmaku.dart';
+
+
+const int kDefaultHeatmapMinComments = 50;
+
+
+const int kDefaultHeatmapBucketCount = 200;
+
+
+class DanmakuHeatmapData {
+  final List<double> buckets;
+  final int bucketCount;
+  final int totalComments;
+  final int maxCount;
+  final bool visible;
+
+  const DanmakuHeatmapData({
+    required this.buckets,
+    required this.bucketCount,
+    required this.totalComments,
+    required this.maxCount,
+    required this.visible,
+  });
+
+  static const empty = DanmakuHeatmapData(
+    buckets: <double>[],
+    bucketCount: 0,
+    totalComments: 0,
+    maxCount: 0,
+    visible: false,
+  );
+}
+
+
+DanmakuHeatmapData computeHeatmap({
+  required List<DanmakuComment> comments,
+  required double durationSec,
+  int bucketCount = kDefaultHeatmapBucketCount,
+  int minComments = kDefaultHeatmapMinComments,
+}) {
+  if (bucketCount <= 0) return DanmakuHeatmapData.empty;
+  if (durationSec <= 0) return DanmakuHeatmapData.empty;
+
+  final counts = List<int>.filled(bucketCount, 0);
+  int total = 0;
+  for (final c in comments) {
+    final t = c.time;
+    if (t < 0 || t > durationSec) continue;
+    var idx = (t / durationSec * bucketCount).floor();
+    if (idx >= bucketCount) idx = bucketCount - 1;
+    if (idx < 0) idx = 0;
+    counts[idx]++;
+    total++;
+  }
+
+  if (total < minComments) {
+    return DanmakuHeatmapData(
+      buckets: const <double>[],
+      bucketCount: bucketCount,
+      totalComments: total,
+      maxCount: 0,
+      visible: false,
+    );
+  }
+
+  var maxCount = 0;
+  for (final v in counts) {
+    if (v > maxCount) maxCount = v;
+  }
+  if (maxCount <= 0) {
+    return DanmakuHeatmapData(
+      buckets: const <double>[],
+      bucketCount: bucketCount,
+      totalComments: total,
+      maxCount: 0,
+      visible: false,
+    );
+  }
+
+  final buckets = List<double>.generate(
+    bucketCount,
+    (i) => counts[i] / maxCount,
+    growable: false,
+  );
+
+  return DanmakuHeatmapData(
+    buckets: buckets,
+    bucketCount: bucketCount,
+    totalComments: total,
+    maxCount: maxCount,
+    visible: true,
+  );
+}
+
+
+List<double> downsampleHeatmap(List<double> buckets, int targetCount) {
+  if (buckets.isEmpty || targetCount <= 0) return const <double>[];
+  if (targetCount >= buckets.length) return buckets;
+  final out = List<double>.filled(targetCount, 0.0);
+  final src = buckets.length;
+  for (var i = 0; i < targetCount; i++) {
+    final start = (i * src / targetCount).floor();
+    final end = ((i + 1) * src / targetCount).floor().clamp(start + 1, src);
+    var m = 0.0;
+    for (var j = start; j < end; j++) {
+      if (buckets[j] > m) m = buckets[j];
+    }
+    out[i] = m;
+  }
+  return out;
+}