feat: 扩展天文计算能力

- 新增日食、月食、本地可见性、中心线、半影区域、SVG 图示与沙罗周期信息 - 新增行星冲合、留、方照、物理星历、视直径、相位、亮肢角、轨道节点等计算 - 新增木星伽利略卫星位置、现象与接触事件计算 - 新增恒星星表、星座判定、自行修正与观测辅助能力 - 新增 coord、formula、orbit、sundial、lite/sun、lite/moon 等扩展包 - 完善农历年号、月相英文别名、视差角、大气质量、折射、日晷与双星计算 - 增加 NASA、JPL Horizons、IMCCE 等回归测试数据与基线测试 - 重构基础算法文件组织，补充大量公开 API 注释和语义回归测试 - 更新中文和英文 README，补充示例、精度说明、SVG 配图
2026-05-01 22:38:44 +08:00
parent 98ff574495
commit 3ffdbe0034
365 changed files with 63589 additions and 17508 deletions
@@ -0,0 +1,146 @@
+package svg
+
+import (
+	"math"
+	"time"
+
+	"b612.me/astro/basic"
+	eclipsecore "b612.me/astro/eclipse"
+)
+
+type LunarEclipseType = eclipsecore.LunarEclipseType
+
+type LunarEclipseContactPoint = eclipsecore.LunarEclipseContactPoint
+
+type LunarEclipseInfo = eclipsecore.LunarEclipseInfo
+
+const (
+	LunarEclipseNone      = eclipsecore.LunarEclipseNone
+	LunarEclipsePenumbral = eclipsecore.LunarEclipsePenumbral
+	LunarEclipsePartial   = eclipsecore.LunarEclipsePartial
+	LunarEclipseTotal     = eclipsecore.LunarEclipseTotal
+)
+
+func lunarEclipseInfoFromBasic(result basic.LunarEclipseResult, location *time.Location) LunarEclipseInfo {
+	return LunarEclipseInfo{
+		Type:               mapBasicLunarEclipseType(result.Type),
+		PenumbralMagnitude: result.PenumbralMagnitude,
+		UmbralMagnitude:    result.Magnitude,
+		PenumbralStart:     ttJDEToTime(result.PenumbralStart, location),
+		PartialStart:       ttJDEToTime(result.PartialStart, location),
+		TotalStart:         ttJDEToTime(result.TotalStart, location),
+		Maximum:            ttJDEToTime(result.Maximum, location),
+		TotalEnd:           ttJDEToTime(result.TotalEnd, location),
+		PartialEnd:         ttJDEToTime(result.PartialEnd, location),
+		PenumbralEnd:       ttJDEToTime(result.PenumbralEnd, location),
+		ContactPoints:      lunarEclipseContactPointsFromBasic(result, location),
+		HasPenumbral:       result.HasPenumbral,
+		HasPartial:         result.HasPartial,
+		HasTotal:           result.HasTotal,
+	}
+}
+
+func lunarEclipseContactPointsFromBasic(
+	result basic.LunarEclipseResult,
+	location *time.Location,
+) []LunarEclipseContactPoint {
+	if !result.HasPenumbral {
+		return nil
+	}
+
+	contacts := []LunarEclipseContactPoint{
+		lunarEclipseContactPoint("P1", result.PenumbralStart, location, false),
+	}
+	if result.HasPartial {
+		contacts = append(contacts, lunarEclipseContactPoint("U1", result.PartialStart, location, false))
+	}
+	if result.HasTotal {
+		contacts = append(contacts, lunarEclipseContactPoint("U2", result.TotalStart, location, true))
+	}
+	if result.HasTotal {
+		contacts = append(contacts, lunarEclipseContactPoint("U3", result.TotalEnd, location, true))
+	}
+	if result.HasPartial {
+		contacts = append(contacts, lunarEclipseContactPoint("U4", result.PartialEnd, location, false))
+	}
+	contacts = append(contacts, lunarEclipseContactPoint("P4", result.PenumbralEnd, location, false))
+	return contacts
+}
+
+func lunarEclipseContactPoint(
+	label string,
+	ttJDE float64,
+	location *time.Location,
+	internalContact bool,
+) LunarEclipseContactPoint {
+	moonCenterPA := lunarEclipseMoonCenterPositionAngle(ttJDE)
+	shadowCenterPA := normalizeDegree360(moonCenterPA + 180)
+	contactPA := shadowCenterPA
+	if internalContact {
+		contactPA = moonCenterPA
+	}
+	return LunarEclipseContactPoint{
+		Label:                     label,
+		Time:                      ttJDEToTime(ttJDE, location),
+		ContactPositionAngle:      contactPA,
+		ContactClockwiseAngle:     normalizeDegree360(360 - contactPA),
+		MoonCenterPositionAngle:   moonCenterPA,
+		ShadowCenterPositionAngle: shadowCenterPA,
+	}
+}
+
+func lunarEclipseMoonCenterPositionAngle(ttJDE float64) float64 {
+	shadowRA, shadowDec := lunarEclipseShadowCenterRaDec(ttJDE)
+	moonRA, moonDec := basic.HMoonTrueRaDec(ttJDE)
+	return lunarEclipsePositionAngle(shadowRA, shadowDec, moonRA, moonDec)
+}
+
+func lunarEclipseShadowCenterRaDec(ttJDE float64) (float64, float64) {
+	sunRA, sunDec := basic.HSunApparentRaDec(ttJDE)
+	return normalizeDegree360(sunRA + 180), -sunDec
+}
+
+func lunarEclipsePositionAngle(fromRA, fromDec, toRA, toDec float64) float64 {
+	dRA := (toRA - fromRA) * math.Pi / 180
+	fromDecRad := fromDec * math.Pi / 180
+	toDecRad := toDec * math.Pi / 180
+	angle := math.Atan2(
+		math.Sin(dRA),
+		math.Cos(fromDecRad)*math.Tan(toDecRad)-math.Sin(fromDecRad)*math.Cos(dRA),
+	) * 180 / math.Pi
+	return normalizeDegree360(angle)
+}
+
+func mapBasicLunarEclipseType(eclipseType basic.LunarEclipseType) LunarEclipseType {
+	switch eclipseType {
+	case basic.LunarEclipsePenumbral:
+		return LunarEclipsePenumbral
+	case basic.LunarEclipsePartial:
+		return LunarEclipsePartial
+	case basic.LunarEclipseTotal:
+		return LunarEclipseTotal
+	default:
+		return LunarEclipseNone
+	}
+}
+
+func ttJDEToTime(ttJDE float64, location *time.Location) time.Time {
+	if ttJDE == 0 {
+		return time.Time{}
+	}
+	utcJDE := basic.TD2UT(ttJDE, false)
+	return basic.JDE2DateByZone(utcJDE, location, false)
+}
+
+func timeToTTJDE(date time.Time) float64 {
+	utcJDE := basic.Date2JDE(date.UTC())
+	return basic.TD2UT(utcJDE, true)
+}
+
+func normalizeDegree360(angle float64) float64 {
+	angle = math.Mod(angle, 360)
+	if angle < 0 {
+		angle += 360
+	}
+	return angle
+}