Render smoother findmydevice history paths

2026-06-17 19:42:59 +09:00
parent 8bbe43b8c4
commit 938868ea64
3 changed files with 173 additions and 79 deletions
@@ -221,6 +221,136 @@ if (isset($historyData[0])) {
    }
 }

+function pathDistanceM(array $a, array $b): float
+{
+    $earth = 6371000;
+    $lat1 = deg2rad((float)$a['lat']);
+    $lat2 = deg2rad((float)$b['lat']);
+    $dLat = $lat2 - $lat1;
+    $dLng = deg2rad((float)$b['lng'] - (float)$a['lng']);
+    $h = sin($dLat / 2) ** 2 + cos($lat1) * cos($lat2) * sin($dLng / 2) ** 2;
+    return 2 * $earth * asin(min(1, sqrt($h)));
+}
+
+function pointLineDistanceM(array $point, array $start, array $end): float
+{
+    $latScale = 111320;
+    $lngScale = 111320 * cos(deg2rad((float)$point['lat']));
+    $px = (float)$point['lng'] * $lngScale;
+    $py = (float)$point['lat'] * $latScale;
+    $sx = (float)$start['lng'] * $lngScale;
+    $sy = (float)$start['lat'] * $latScale;
+    $ex = (float)$end['lng'] * $lngScale;
+    $ey = (float)$end['lat'] * $latScale;
+    $dx = $ex - $sx;
+    $dy = $ey - $sy;
+
+    if ($dx == 0.0 && $dy == 0.0) {
+        return sqrt(($px - $sx) ** 2 + ($py - $sy) ** 2);
+    }
+
+    $t = max(0, min(1, (($px - $sx) * $dx + ($py - $sy) * $dy) / ($dx ** 2 + $dy ** 2)));
+    $cx = $sx + $t * $dx;
+    $cy = $sy + $t * $dy;
+
+    return sqrt(($px - $cx) ** 2 + ($py - $cy) ** 2);
+}
+
+function douglasPeucker(array $points, float $epsilon): array
+{
+    $count = count($points);
+    if ($count <= 2) {
+        return $points;
+    }
+
+    $maxDistance = 0.0;
+    $index = 0;
+    $last = $count - 1;
+    for ($i = 1; $i < $last; $i++) {
+        $distance = pointLineDistanceM($points[$i], $points[0], $points[$last]);
+        if ($distance > $maxDistance) {
+            $index = $i;
+            $maxDistance = $distance;
+        }
+    }
+
+    if ($maxDistance > $epsilon) {
+        $left = douglasPeucker(array_slice($points, 0, $index + 1), $epsilon);
+        $right = douglasPeucker(array_slice($points, $index), $epsilon);
+        return array_merge(array_slice($left, 0, -1), $right);
+    }
+
+    return [$points[0], $points[$last]];
+}
+
+function smoothPath(array $path): array
+{
+    $count = count($path);
+    if ($count < 5) {
+        return $path;
+    }
+
+    $smoothed = [];
+    for ($i = 0; $i < $count; $i++) {
+        if ($i === 0 || $i === $count - 1) {
+            $smoothed[] = $path[$i];
+            continue;
+        }
+
+        $prev = $path[$i - 1];
+        $cur = $path[$i];
+        $next = $path[$i + 1];
+        $smoothed[] = [
+            'lat' => ((float)$prev['lat'] + ((float)$cur['lat'] * 2) + (float)$next['lat']) / 4,
+            'lng' => ((float)$prev['lng'] + ((float)$cur['lng'] * 2) + (float)$next['lng']) / 4,
+            'time' => $cur['time'],
+        ];
+    }
+
+    return $smoothed;
+}
+
+function renderPath(array $path, int $renderLimit = 1200): array
+{
+    $count = count($path);
+    if ($count <= 2) {
+        return $path;
+    }
+
+    $filtered = [];
+    $last = null;
+    foreach ($path as $point) {
+        if ($last === null || pathDistanceM($last, $point) >= 8) {
+            $filtered[] = $point;
+            $last = $point;
+        }
+    }
+    if (count($filtered) < 2) {
+        $filtered = [$path[0], $path[$count - 1]];
+    }
+
+    $epsilon = 6.0;
+    $render = $filtered;
+    do {
+        $render = douglasPeucker($filtered, $epsilon);
+        $epsilon *= 1.45;
+    } while (count($render) > $renderLimit && $epsilon < 500);
+
+    if (count($render) > $renderLimit) {
+        $sampled = [];
+        $lastIndex = count($render) - 1;
+        for ($i = 0; $i < $renderLimit; $i++) {
+            $sampled[] = $render[(int)round($i * $lastIndex / max(1, $renderLimit - 1))];
+        }
+        $render = $sampled;
+    }
+
+    return smoothPath($render);
+}
+
+$historyRawCount = count($path);
+$path = renderPath($path);
+
 $lang = $_GET['lang'] ?? 'en';

 $activityMap = [
@@ -503,5 +633,7 @@ echo json_encode([
    'connection' => $connectionMap[$lang][$connectionState] ?? $connectionState ?? null,
    'sensors' => $sensorSections,
    'history' => $includeHistory ? $path : null,
+    'historyRawCount' => $includeHistory ? $historyRawCount : null,
+    'historyRenderCount' => $includeHistory ? count($path) : null,
 ], JSON_UNESCAPED_UNICODE);
 ?>