feat: 完善日月食与月掩几何链路并扩展历法接口
- 新增日月食中心带、偏食带、阴影足迹、等时线、食分线及升落边界计算，支持极区与混合食拓扑 - 新增日食单时刻阴影求解器、站心状态查询、批量采样和 ΔT 覆盖接口 - 重构恒星与行星月掩路径，补充有限盘面接触、站心修正、掩带宽度、极区投影及升落边界 - 扩展 SVG 与 GeoJSON 输出，支持详细面板、全球/极区/地球投影、边界闭合、时间标记和拓扑签名 - 扩展日月食候选搜索、局地搜索、沙罗序列预计算与范围外推，补充系列锚点和成员一致性校验 - 补齐古历纪年、儒略历独有闰日、多公历候选、历法改革跨日及精确日期运算接口 - 优化 ΔT、章动、恒星时、月球地平线、事件根搜索和本地星历缓存，降低重复计算开销并提升边界稳定
This commit is contained in:
@@ -0,0 +1,179 @@
|
||||
// Package solarclosure 把被地平线切断的日食偏食足迹闭合到地平圈，并把零食分包络与
|
||||
// 日升日落相位线并集成一块可见域。
|
||||
//
|
||||
// Package solarclosure closes horizon-cut solar-eclipse footprints onto the horizon and
|
||||
// unions the zero-magnitude envelope with the rise/set phase lines into one visibility region.
|
||||
package solarclosure
|
||||
|
||||
import (
|
||||
"math"
|
||||
|
||||
"b612.me/astro/internal/geodata"
|
||||
)
|
||||
|
||||
// Footprint 是一个瞬时足迹的闭合输入。
|
||||
type Footprint struct {
|
||||
// Boundaries 是物理边界分段；反经线或无效投影会拆成多段。
|
||||
Boundaries [][]geodata.GeoPoint
|
||||
// HorizonEnds 是未闭合边界两端的地平擦地点，顺序任意，使用时按 Boundaries 走向排序。
|
||||
HorizonEnds []geodata.GeoPoint
|
||||
// Subsolar 是该时刻的太阳直射点，缺少精确擦地点时用它采样地平圈近似补口。
|
||||
Subsolar geodata.GeoPoint
|
||||
// Closed 表示 Boundaries 自身闭合，不需要补口。
|
||||
Closed bool
|
||||
}
|
||||
|
||||
// Terminator 返回以太阳直射点为圆心的地平圈采样点。
|
||||
func Terminator(subsolar geodata.GeoPoint) []geodata.GeoPoint {
|
||||
return geodata.SphericalCircle(subsolar, 90, 360)
|
||||
}
|
||||
|
||||
// HorizonEnds 按 Boundaries 走向排序两个地平擦地点；点数不是 2 或首段为空时返回 nil。
|
||||
func HorizonEnds(footprint Footprint) []geodata.GeoPoint {
|
||||
if len(footprint.HorizonEnds) != 2 || len(footprint.Boundaries) == 0 ||
|
||||
len(footprint.Boundaries[0]) == 0 {
|
||||
return nil
|
||||
}
|
||||
points := []geodata.GeoPoint{footprint.HorizonEnds[0], footprint.HorizonEnds[1]}
|
||||
if pointDistanceKM(points[0], footprint.Boundaries[0][0]) >
|
||||
pointDistanceKM(points[1], footprint.Boundaries[0][0]) {
|
||||
points[0], points[1] = points[1], points[0]
|
||||
}
|
||||
return points
|
||||
}
|
||||
|
||||
// ExactHorizon 报告足迹能否用两个精确擦地点闭合。
|
||||
func ExactHorizon(footprint Footprint) bool {
|
||||
return len(HorizonEnds(footprint)) == 2
|
||||
}
|
||||
|
||||
// Curve 返回足迹的物理边界折线，重复的闭合点已去掉。
|
||||
func Curve(footprint Footprint) []geodata.GeoPoint {
|
||||
return openRing(geodata.JoinPolylineSegments(footprint.Boundaries))
|
||||
}
|
||||
|
||||
// Ring 返回足迹的填充环与补口后的物理边界折线；ok 为假表示边界点不足以成环。
|
||||
// exact 为假或缺少擦地点时按 Subsolar 地平圈的最短弧近似补口。
|
||||
func Ring(footprint Footprint, exact bool) (ring, boundary []geodata.GeoPoint, ok bool) {
|
||||
curve := Curve(footprint)
|
||||
// 单点开放边界既不能补口也不该报错：调用方按退化区域丢弃。
|
||||
if len(curve) == 1 && !footprint.Closed {
|
||||
return curve, curve, true
|
||||
}
|
||||
minimumPoints := 3
|
||||
if !footprint.Closed {
|
||||
minimumPoints = 2
|
||||
}
|
||||
if len(curve) < minimumPoints {
|
||||
return nil, nil, false
|
||||
}
|
||||
if footprint.Closed {
|
||||
return append([]geodata.GeoPoint(nil), curve...), curve, true
|
||||
}
|
||||
ring, boundary = closeOpen(footprint, curve, exact)
|
||||
if len(openRing(ring)) < 3 {
|
||||
return nil, nil, false
|
||||
}
|
||||
return ring, boundary, true
|
||||
}
|
||||
|
||||
// HorizonRing 补出已拼接的开放边界 curve 的填充环与物理边界折线，不做点数校验。
|
||||
func HorizonRing(footprint Footprint, curve []geodata.GeoPoint) (ring, boundary []geodata.GeoPoint) {
|
||||
return closeOpen(footprint, curve, true)
|
||||
}
|
||||
|
||||
// SnapDistanceKM 是并集线网的节点吸附尺度：比这更近的交点按同一个物理节点处理。
|
||||
const SnapDistanceKM = 25
|
||||
|
||||
// BandPolygons 以零食分连续包络和日升日落相位线为线网、瞬时足迹为覆盖面，
|
||||
// 返回偏食可见域的并集；ok 为假表示线网无法成面。
|
||||
// exact 为真时瞬时足迹按精确擦地点补口，为假时按 Subsolar 地平圈近似补口。
|
||||
func BandPolygons(
|
||||
contours, phaseLines [][]geodata.GeoPoint,
|
||||
footprints []Footprint,
|
||||
exact bool,
|
||||
snapDistanceKM float64,
|
||||
) ([][]geodata.GeoPoint, bool) {
|
||||
boundaryLines := make([][]geodata.GeoPoint, 0, len(contours)+len(phaseLines))
|
||||
boundaryLines = append(boundaryLines, contours...)
|
||||
boundaryLines = append(boundaryLines, phaseLines...)
|
||||
fillPolygons := make([][]geodata.GeoPoint, 0, len(footprints))
|
||||
coveragePaths := make([][]geodata.GeoPoint, 0, len(footprints)*2)
|
||||
for _, footprint := range footprints {
|
||||
for _, segment := range footprint.Boundaries {
|
||||
if len(segment) > 0 {
|
||||
coveragePaths = append(coveragePaths, segment)
|
||||
}
|
||||
}
|
||||
if ring, _, ok := Ring(footprint, exact); ok && len(ring) >= 3 {
|
||||
fillPolygons = append(fillPolygons, ring)
|
||||
}
|
||||
}
|
||||
polygons, err := geodata.VisibleLineworkPolygons(
|
||||
boundaryLines, fillPolygons, coveragePaths, snapDistanceKM,
|
||||
)
|
||||
if err != nil || len(polygons) == 0 {
|
||||
return nil, false
|
||||
}
|
||||
for polygonIndex := range polygons {
|
||||
for pointIndex := range polygons[polygonIndex] {
|
||||
polygons[polygonIndex][pointIndex].Longitude =
|
||||
normalizeLongitude(polygons[polygonIndex][pointIndex].Longitude)
|
||||
}
|
||||
}
|
||||
return polygons, true
|
||||
}
|
||||
|
||||
// closeOpen 用精确擦地点闭合开放边界；擦地点缺失或 exact 为假时改用 Subsolar 地平圈的近似弧。
|
||||
func closeOpen(footprint Footprint, curve []geodata.GeoPoint, exact bool) ([]geodata.GeoPoint, []geodata.GeoPoint) {
|
||||
if len(curve) == 0 {
|
||||
return nil, nil
|
||||
}
|
||||
ends := []geodata.GeoPoint(nil)
|
||||
if exact {
|
||||
ends = HorizonEnds(footprint)
|
||||
}
|
||||
if len(ends) != 2 {
|
||||
ring := append([]geodata.GeoPoint(nil), curve...)
|
||||
arc := geodata.ShortestCircleArc(Terminator(footprint.Subsolar), curve[len(curve)-1], curve[0])
|
||||
if len(arc) > 1 {
|
||||
ring = append(ring, arc[1:]...)
|
||||
}
|
||||
return ring, curve
|
||||
}
|
||||
boundary := make([]geodata.GeoPoint, 0, len(curve)+2)
|
||||
boundary = append(boundary, ends[0])
|
||||
boundary = append(boundary, curve...)
|
||||
boundary = append(boundary, ends[1])
|
||||
ring := make([]geodata.GeoPoint, 0, len(curve)+3)
|
||||
ring = append(ring, curve...)
|
||||
ring = append(ring, ends[1])
|
||||
arc := geodata.ShortestCircleArc(Terminator(footprint.Subsolar), ends[1], ends[0])
|
||||
if len(arc) > 1 {
|
||||
ring = append(ring, arc[1:]...)
|
||||
}
|
||||
return ring, boundary
|
||||
}
|
||||
|
||||
func openRing(points []geodata.GeoPoint) []geodata.GeoPoint {
|
||||
if len(points) > 1 && geodata.SameGeoPoint(points[0], points[len(points)-1]) {
|
||||
return points[:len(points)-1]
|
||||
}
|
||||
return points
|
||||
}
|
||||
|
||||
func normalizeLongitude(value float64) float64 {
|
||||
value = math.Mod(value+180, 360)
|
||||
if value < 0 {
|
||||
value += 360
|
||||
}
|
||||
return value - 180
|
||||
}
|
||||
|
||||
func pointDistanceKM(first, second geodata.GeoPoint) float64 {
|
||||
lat1, lat2 := first.Latitude*math.Pi/180, second.Latitude*math.Pi/180
|
||||
dlat := lat2 - lat1
|
||||
dlon := math.Remainder((second.Longitude-first.Longitude)*math.Pi/180, 2*math.Pi)
|
||||
h := math.Sin(dlat/2)*math.Sin(dlat/2) + math.Cos(lat1)*math.Cos(lat2)*math.Sin(dlon/2)*math.Sin(dlon/2)
|
||||
return 6371.0088 * 2 * math.Asin(math.Sqrt(math.Max(0, math.Min(1, h))))
|
||||
}
|
||||
Reference in New Issue
Block a user