044f2f4381
- 新增半解析、旧模型、自定义与多源堆叠星历实例,提供 Context、Instance、SPK 读取及状态与视位置计算 - 统一太阳、月球和行星实例接口,扩展黄经穿越、留、相位、最近角距、偕日可见、任意高度升落、轨道节点及凌日等天象查询 - 完善日月食、月掩与凌日的月缘剖面、有限盘面接触、站心修正、局地可见性、全球路径和地图输出 - 新增 SVG、GeoJSON、KML 天象输出及凌日、月掩和月缘地形相关缓存与几何求解 - 新增恒星星表导入与查询,支持 CSV、Hipparcos、BSC5、Stellarium 等格式及名称、交叉标识、锥面检索和星等过滤 - 补充 IAU 2006、地球定向、折射消光、大气观测、轨道传播及半解析行星/月球数据支持 - 将默认未来民用时标切换为 TimeScaleLeapHour,更新 2027–2400 农历速查表、中文日期解析和时区边界处理 - 增加事件基线、跨模型回归、几何边界、月缘地形和输出契约测试,完善中英文手册、示例资源、NOTICE 与忽略规则
630 lines
31 KiB
Go
630 lines
31 KiB
Go
package svg
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import (
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"errors"
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"fmt"
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"html"
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"math"
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"strings"
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"time"
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"b612.me/astro"
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"b612.me/astro/internal/svgasset"
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"b612.me/astro/internal/svgchart"
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"b612.me/astro/internal/timenote"
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"b612.me/astro/moon"
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)
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const (
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limbProfileSVGDefaultWidth = 920
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limbProfileSVGDefaultHeight = 620
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limbProfileSVGMinimumWidth = 640
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limbProfileSVGMinimumHeight = 480
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limbProfileSVGMaxRows = 12
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// limbProfilePanelGap 栏间距须容下上栏的时刻、位置角两行刻度与下栏上沿的两行接触编号。
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limbProfilePanelGap = 56.0
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// limbProfileInsetMinHeight 缩略图(含标题)的最小高度,接触表按它限行。
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limbProfileInsetMinHeight = 120.0
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)
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// ErrInvalidStarOccultationLimbProfileSVGOptions 表示精密月掩剖面图选项无效 / invalid precise occultation profile chart options.
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var ErrInvalidStarOccultationLimbProfileSVGOptions = errors.New("invalid stellar occultation limb profile SVG options")
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// ErrEmptyStarOccultationLimbProfile 表示剖面没有采样,恒星全程在月缘起伏带外 / the profile has no samples; the star stays outside the relief band.
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var ErrEmptyStarOccultationLimbProfile = errors.New("stellar occultation limb profile has no samples")
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// ErrInvalidStarOccultationLimbProfile 表示剖面数据不是 StarOccultationLimbProfile 能给出的形态 / malformed limb profile data.
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var ErrInvalidStarOccultationLimbProfile = errors.New("invalid stellar occultation limb profile")
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// StarOccultationLimbProfileSVGOptions 控制精密恒星月掩的月缘剖面图 / options for the precise stellar occultation profile chart.
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type StarOccultationLimbProfileSVGOptions struct {
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// Width、Height 为画布尺寸,非正值用默认 / canvas size; non-positive uses defaults.
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Width int
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Height int
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// Title 为空时自动生成 / empty uses an automatic title.
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Title string
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// Language 为 "en" 时英文,否则中文 / "en" for English, otherwise Chinese.
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Language string
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// Location 控制显示时刻,nil 为 UTC+8 / display zone; nil uses UTC+8.
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Location *time.Location
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// TimeScale 为 TimeScaleUT1 时改用 UT1 时刻,此时 Location 须为 nil 或 UTC / label time scale.
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TimeScale astro.TimeScale
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}
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// StarOccultationLimbProfileSVG 渲染精密恒星月掩剖面:横轴时刻、纵轴相对参考圆月面高度(km),给出遮挡区间与全部掩入复现 / precise stellar occultation limb profile chart.
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func StarOccultationLimbProfileSVG(profile moon.StarOccultationLimbProfileResult, options StarOccultationLimbProfileSVGOptions) (string, error) {
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if options.Width > 0 && options.Width < limbProfileSVGMinimumWidth {
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return "", fmt.Errorf("%w: width must be zero or at least %d", ErrInvalidStarOccultationLimbProfileSVGOptions, limbProfileSVGMinimumWidth)
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}
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if options.Height > 0 && options.Height < limbProfileSVGMinimumHeight {
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return "", fmt.Errorf("%w: height must be zero or at least %d", ErrInvalidStarOccultationLimbProfileSVGOptions, limbProfileSVGMinimumHeight)
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}
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if options.TimeScale == astro.TimeScaleUT1 && options.Location != nil && options.Location != time.UTC {
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return "", fmt.Errorf("occultation SVG: UT1 labels do not take a non-UTC location")
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}
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samples := 0
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for _, segment := range profile.Segments {
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samples += len(segment)
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}
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if samples < 2 || profile.Occultation.Greatest.IsZero() {
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return "", ErrEmptyStarOccultationLimbProfile
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}
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if err := validateStarOccultationLimbProfile(profile); err != nil {
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return "", err
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}
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if options.Width <= 0 {
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options.Width = limbProfileSVGDefaultWidth
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}
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if options.Height <= 0 {
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options.Height = limbProfileSVGDefaultHeight
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}
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if options.TimeScale == astro.TimeScaleUT1 {
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options.Location = time.UTC
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profile = moon.StarOccultationLimbProfileInUT1(profile)
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}
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if options.Location == nil {
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options.Location = time.FixedZone("UTC+8", starOccultationSVGDefaultZone)
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}
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if strings.EqualFold(options.Language, starOccultationSVGLanguageEnglish) {
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options.Language = starOccultationSVGLanguageEnglish
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} else {
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options.Language = starOccultationSVGLanguageChinese
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}
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return renderStarOccultationLimbProfileSVG(profile, options), nil
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}
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type limbProfilePoint struct {
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t time.Time
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limbKM, starKM float64
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positionAngle float64
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// skyX、skyY 为恒星相对月心的天空平面坐标(km,向东、向北为正)。
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skyX, skyY float64
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}
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// limbProfileHeights 把角量换算成月面上相对参考球的高度(km),恒星与月缘用同一比例。
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func limbProfileHeights(segment []moon.StarOccultationLimbSample, referenceKM float64) []limbProfilePoint {
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points := make([]limbProfilePoint, 0, len(segment))
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for _, sample := range segment {
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scale := referenceKM / sample.MeanRadiusArcsec
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points = append(points, limbProfilePoint{
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t: sample.Time,
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limbKM: (sample.LimbRadiusArcsec - sample.MeanRadiusArcsec) * scale,
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starKM: (sample.SeparationArcsec - sample.MeanRadiusArcsec) * scale,
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positionAngle: sample.PositionAngleDeg,
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skyX: sample.SeparationArcsec * scale * math.Sin(sample.PositionAngleDeg*math.Pi/180),
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skyY: sample.SeparationArcsec * scale * math.Cos(sample.PositionAngleDeg*math.Pi/180),
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})
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}
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return points
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}
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func limbProfileText(language, zh, en string) string {
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if language == starOccultationSVGLanguageEnglish {
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return en
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}
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return zh
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}
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func renderStarOccultationLimbProfileSVG(profile moon.StarOccultationLimbProfileResult, options StarOccultationLimbProfileSVGOptions) string {
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info := profile.Occultation
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width, height := float64(options.Width), float64(options.Height)
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language := options.Language
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segments := make([][]limbProfilePoint, 0, len(profile.Segments))
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minKM, maxKM := math.Inf(1), math.Inf(-1)
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for _, segment := range profile.Segments {
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points := limbProfileHeights(segment, limbProfileReferenceKM(profile))
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if len(points) < 2 {
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continue
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}
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for _, point := range points {
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minKM = math.Min(minKM, math.Min(point.limbKM, point.starKM))
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maxKM = math.Max(maxKM, math.Max(point.limbKM, point.starKM))
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}
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segments = append(segments, points)
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}
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if !(maxKM > minKM) {
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minKM, maxKM = -1, 1
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}
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padKM := (maxKM - minKM) * 0.08
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minKM, maxKM = minKM-padKM, maxKM+padKM
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title := options.Title
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if title == "" {
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target := info.TargetID
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if target == "" {
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target = limbProfileText(language, "恒星", "star")
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}
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date := info.Greatest.In(options.Location).Format("2006-01-02")
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title = date + limbProfileText(language, " 精密月掩月缘剖面 · "+target, " Limb Profile · Occultation of "+target)
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}
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site := starOccultationFormatCoordinates(info.Observer.Longitude, info.Observer.Latitude)
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summary := fmt.Sprintf(limbProfileText(language, "观测点 %s | 椭球高 %.0f 米 | 遮挡 %d 段 | 采样 %s", "Site %s | elevation %.0f m | %d hidden interval(s) | step %s"),
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site, info.Observer.Height, len(profile.Hidden), profile.Step)
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direction := limbProfileDirectionText(segments, profile.Hidden, language)
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const top = 136.0
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tableWidth := 260.0
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left, right := 70.0, width-tableWidth-48
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chartTop, chartBottom := top, height-122
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panels := len(segments)
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if panels < 1 {
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panels = 1
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}
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panelHeight := (chartBottom - chartTop - limbProfilePanelGap*float64(panels-1)) / float64(panels)
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var b strings.Builder
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fmt.Fprintf(&b, `<svg xmlns="http://www.w3.org/2000/svg" width="%d" height="%d" viewBox="0 0 %d %d" role="img" aria-label="%s">`,
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options.Width, options.Height, options.Width, options.Height, html.EscapeString(title))
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b.WriteString(`<defs>`)
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b.WriteString(svgasset.MoonFaceSymbol())
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b.WriteString(`<marker id="limb-profile-arrow" viewBox="0 0 10 10" refX="8" refY="5" markerWidth="6" markerHeight="6" orient="auto-start-reverse"><path d="M 0 0 L 10 5 L 0 10 z" fill="#d0473b"/></marker>`)
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b.WriteString(`</defs>`)
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b.WriteString(`<rect width="100%" height="100%" fill="#efefed"/>`)
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fmt.Fprintf(&b, `<rect x="22" y="18" width="%.3f" height="%.3f" fill="#ffffff" stroke="#c9c9c6" stroke-width="1.2"/>`, width-44, height-36)
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fmt.Fprintf(&b, `<text x="%.3f" y="46" fill="#111111" font-family="Georgia, 'Times New Roman', serif" font-size="%d" font-weight="700" text-anchor="middle">%s</text>`,
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width/2, starOccultationTitleFontSize(title, width), html.EscapeString(svgchart.EllipsizeText(title, width-80, float64(starOccultationTitleFontSize(title, width)))))
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fmt.Fprintf(&b, `<text x="%.3f" y="76" fill="#222222" font-family="Georgia, 'Times New Roman', serif" font-size="13" text-anchor="middle">%s</text>`,
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width/2, html.EscapeString(svgchart.EllipsizeText(summary, width-80, 13)))
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fmt.Fprintf(&b, `<text x="%.3f" y="98" fill="#3b4143" font-family="Georgia, 'Times New Roman', serif" font-size="12" text-anchor="middle">%s</text>`,
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width/2, html.EscapeString(svgchart.EllipsizeText(direction, width-80, 12)))
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for index, points := range segments {
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y0 := chartTop + float64(index)*(panelHeight+limbProfilePanelGap)
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writeLimbProfilePanel(&b, points, profile.Hidden, left, right, y0, y0+panelHeight, minKM, maxKM, options)
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}
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// 接触表与图例让出缩略图的最小高度:图例占 84 px,表头 28 px,每行 19 px。
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maxRows := int((chartBottom + 30 - limbProfileInsetMinHeight - 18 - top - 28 - 84) / 19)
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if maxRows < 2 {
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maxRows = 2
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}
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if maxRows > limbProfileSVGMaxRows {
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maxRows = limbProfileSVGMaxRows
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}
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legendBottom := writeLimbProfileContacts(&b, profile, right+28, top, width-48, maxRows, options)
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writeLimbProfileInset(&b, segments, info, limbProfileReferenceKM(profile), right+28, legendBottom+18, width-48, chartBottom+30, language)
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writeLimbProfileFooter(&b, info, limbProfileReferenceKM(profile), left, height-66, width-left-40, options)
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b.WriteString(`</svg>`)
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return b.String()
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}
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func writeLimbProfilePanel(b *strings.Builder, points []limbProfilePoint, hidden []moon.OccultationInterval,
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left, right, top, bottom, minKM, maxKM float64, options StarOccultationLimbProfileSVGOptions) {
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start, end := points[0].t, points[len(points)-1].t
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span := end.Sub(start).Seconds()
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if span <= 0 {
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span = 1
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}
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x := func(t time.Time) float64 { return left + (right-left)*t.Sub(start).Seconds()/span }
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y := func(km float64) float64 { return bottom - (bottom-top)*(km-minKM)/(maxKM-minKM) }
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fmt.Fprintf(b, `<rect x="%.3f" y="%.3f" width="%.3f" height="%.3f" fill="#fafaf8" stroke="#9a9a96" stroke-width="0.8"/>`, left, top, right-left, bottom-top)
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for _, interval := range hidden {
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if interval.End.Before(start) || interval.Start.After(end) {
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continue
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}
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x0, x1 := x(laterTime(interval.Start, start)), x(earlierTime(interval.End, end))
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fmt.Fprintf(b, `<rect x="%.3f" y="%.3f" width="%.3f" height="%.3f" fill="#3b4a5a" fill-opacity="0.16"/>`, x0, top, math.Max(x1-x0, 0.6), bottom-top)
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}
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if minKM < 0 && maxKM > 0 {
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fmt.Fprintf(b, `<line x1="%.3f" y1="%.3f" x2="%.3f" y2="%.3f" stroke="#b8b8b4" stroke-dasharray="4 3" stroke-width="0.8"/>`, left, y(0), right, y(0))
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}
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var limb, star strings.Builder
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for index, point := range points {
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command := "L"
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if index == 0 {
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command = "M"
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}
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fmt.Fprintf(&limb, "%s%.2f %.2f ", command, x(point.t), y(point.limbKM))
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fmt.Fprintf(&star, "%s%.2f %.2f ", command, x(point.t), y(point.starKM))
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}
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fmt.Fprintf(b, `<path d="%s" fill="none" stroke="#6f5a3a" stroke-width="1.3"/>`, strings.TrimSpace(limb.String()))
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fmt.Fprintf(b, `<path d="%s" fill="none" stroke="#9b3f36" stroke-width="1.1" stroke-dasharray="5 2"/>`, strings.TrimSpace(star.String()))
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font := `font-family="Georgia, 'Times New Roman', serif"`
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// 横轴按整刻度标时刻,下方配该时刻的位置角;刻度线贯穿剖面框作网格。
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step := limbProfileTickStep(span, right-left)
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majors := limbProfileTicks(start, end, step, options.Location)
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for _, tick := range majors {
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tx := x(tick)
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fmt.Fprintf(b, `<line x1="%.3f" y1="%.3f" x2="%.3f" y2="%.3f" stroke="#e2e2de" stroke-width="0.6"/>`, tx, top, tx, bottom)
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fmt.Fprintf(b, `<line x1="%.3f" y1="%.3f" x2="%.3f" y2="%.3f" stroke="#9a9a96" stroke-width="0.8"/>`, tx, bottom, tx, bottom+3)
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// 标签夹进剖面框,靠近两端时不越出框线,也不压住框外的 PA 轴标题。
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label := tick.In(options.Location).Format(limbProfileTickLayout(step))
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labelX := limbProfileClampLabel(tx, svgchart.EstimatedTextWidth(label, 10), left, right)
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fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#4f595b" %s font-size="10" text-anchor="middle">%s</text>`, labelX, bottom+14, font, label)
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angle := limbProfileFormatAngle(limbProfilePositionAngleAt(points, tick))
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angleX := limbProfileClampLabel(tx, svgchart.EstimatedTextWidth(angle, 9), left, right)
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fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#6f5a3a" %s font-size="9" text-anchor="middle">%s</text>`, angleX, bottom+26, font, angle)
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}
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fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#6f5a3a" %s font-size="9" text-anchor="end">PA</text>`, left-4, bottom+26, font)
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minor := step / 6
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if step%time.Minute != 0 {
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minor = step / 5
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}
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major := make(map[int64]bool, len(majors))
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for _, tick := range majors {
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major[tick.UnixNano()] = true
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}
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for _, tick := range limbProfileTicks(start, end, minor, options.Location) {
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if major[tick.UnixNano()] {
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continue
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}
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fmt.Fprintf(b, `<line x1="%.3f" y1="%.3f" x2="%.3f" y2="%.3f" stroke="#b8b8b4" stroke-width="0.6"/>`, x(tick), bottom, x(tick), bottom+2)
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}
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for _, label := range limbProfileContactLabels(hidden, start, end, x, left, right) {
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labelY := top - 4 - float64(label.row)*11
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fmt.Fprintf(b, `<line x1="%.3f" y1="%.3f" x2="%.3f" y2="%.3f" stroke="#3b4a5a" stroke-width="0.8"/>`, label.x, labelY+2, label.contactX, top+6)
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fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#3b4a5a" %s font-size="10" font-weight="700" text-anchor="middle">%d</text>`, label.x, labelY, font, label.number)
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}
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if ratio := limbProfileExaggeration(points, right-left, bottom-top, maxKM-minKM); ratio > 1.5 {
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fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#747c7d" %s font-size="10" text-anchor="end">%s</text>`, right-6, top+14, font,
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html.EscapeString(fmt.Sprintf(limbProfileText(options.Language, "纵向放大约 %.0f 倍", "vertical ×%.0f"), ratio)))
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} else if ratio > 0 && ratio < 1/1.5 {
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fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#747c7d" %s font-size="10" text-anchor="end">%s</text>`, right-6, top+14, font,
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html.EscapeString(fmt.Sprintf(limbProfileText(options.Language, "横向放大约 %.0f 倍", "horizontal ×%.0f"), 1/ratio)))
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}
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fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#4f595b" %s font-size="10" text-anchor="end">%+.1f</text>`, left-4, top+9, font, maxKM)
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fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#4f595b" %s font-size="10" text-anchor="end">%+.1f</text>`, left-4, bottom, font, minKM)
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}
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const limbProfileContactLabelGap = 14.0
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type limbProfileContactLabel struct {
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number int
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row int
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x, contactX float64
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}
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// limbProfileContactLabels 接触编号两行排位后逐行自右向左回推,使其落在 [left, right] 内且同行间距不小于 14 px。
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func limbProfileContactLabels(hidden []moon.OccultationInterval, start, end time.Time, x func(time.Time) float64, left, right float64) []limbProfileContactLabel {
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var labels []limbProfileContactLabel
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rows := [2][]int{}
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rowEnd := [2]float64{math.Inf(-1), math.Inf(-1)}
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number := 0
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for _, interval := range hidden {
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for _, contact := range []time.Time{interval.Start, interval.End} {
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number++
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if contact.Before(start) || contact.After(end) {
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continue
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}
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cx := x(contact)
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row := 0
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if rowEnd[1] < rowEnd[0] {
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row = 1
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}
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if cx-rowEnd[0] >= limbProfileContactLabelGap {
|
||
row = 0
|
||
}
|
||
labelX := math.Max(cx, rowEnd[row]+limbProfileContactLabelGap)
|
||
rowEnd[row] = labelX
|
||
rows[row] = append(rows[row], len(labels))
|
||
labels = append(labels, limbProfileContactLabel{number: number, row: row, x: labelX, contactX: cx})
|
||
}
|
||
}
|
||
halfWidth := func(label limbProfileContactLabel) float64 {
|
||
return svgchart.EstimatedTextWidth(fmt.Sprint(label.number), 10) / 2
|
||
}
|
||
for _, indices := range rows {
|
||
if len(indices) == 0 {
|
||
continue
|
||
}
|
||
limit := math.Inf(1)
|
||
for k := len(indices) - 1; k >= 0; k-- {
|
||
label := &labels[indices[k]]
|
||
label.x = math.Min(label.x, math.Min(limit, right-halfWidth(*label)))
|
||
limit = label.x - limbProfileContactLabelGap
|
||
}
|
||
// 一行塞不下时均分整行,间距小于 14 px 也不越框。
|
||
first, last := labels[indices[0]], labels[indices[len(indices)-1]]
|
||
if low, high := left+halfWidth(first), right-halfWidth(last); first.x < low && len(indices) > 1 {
|
||
for k, index := range indices {
|
||
labels[index].x = low + (high-low)*float64(k)/float64(len(indices)-1)
|
||
}
|
||
} else if first.x < low {
|
||
labels[indices[0]].x = low
|
||
}
|
||
}
|
||
return labels
|
||
}
|
||
|
||
func laterTime(a, b time.Time) time.Time {
|
||
if a.After(b) {
|
||
return a
|
||
}
|
||
return b
|
||
}
|
||
|
||
func earlierTime(a, b time.Time) time.Time {
|
||
if a.Before(b) {
|
||
return a
|
||
}
|
||
return b
|
||
}
|
||
|
||
// writeLimbProfileContacts 返回图例底边,供缩略图接在下方。
|
||
func writeLimbProfileContacts(b *strings.Builder, profile moon.StarOccultationLimbProfileResult, left, top, right float64, maxRows int, options StarOccultationLimbProfileSVGOptions) float64 {
|
||
language := options.Language
|
||
font := `font-family="Georgia, 'Times New Roman', serif"`
|
||
fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#111111" %s font-size="13" font-weight="700">%s</text>`, left, top+4, font,
|
||
html.EscapeString(limbProfileText(language, "掩入 / 复现", "Disappearances / reappearances")))
|
||
rows := make([][2]string, 0, 2*len(profile.Hidden))
|
||
for _, interval := range profile.Hidden {
|
||
rows = append(rows,
|
||
[2]string{fmt.Sprintf("%d %s", len(rows)+1, limbProfileText(language, "掩入", "Disappears")), interval.Start.In(options.Location).Format("15:04:05.00")},
|
||
[2]string{fmt.Sprintf("%d %s", len(rows)+2, limbProfileText(language, "复现", "Reappears")), interval.End.In(options.Location).Format("15:04:05.00")})
|
||
}
|
||
if len(rows) == 0 {
|
||
rows = append(rows, [2]string{limbProfileText(language, "未发生遮挡", "Not occulted"), ""})
|
||
}
|
||
overflow := 0
|
||
if len(rows) > maxRows {
|
||
overflow = len(rows) - (maxRows - 1)
|
||
rows = rows[:maxRows-1]
|
||
}
|
||
for index, row := range rows {
|
||
baseline := top + 28 + float64(index)*19
|
||
fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#3b4143" %s font-size="12">%s</text>`, left, baseline, font, html.EscapeString(row[0]))
|
||
fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#222222" %s font-size="12" text-anchor="end">%s</text>`, right, baseline, font, row[1])
|
||
}
|
||
if overflow > 0 {
|
||
fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#747c7d" %s font-size="11">%s</text>`, left, top+28+float64(len(rows))*19, font,
|
||
html.EscapeString(fmt.Sprintf(limbProfileText(language, "另有 %d 个接触未列出", "%d more contacts not listed"), overflow)))
|
||
}
|
||
listed := len(rows)
|
||
if overflow > 0 {
|
||
listed++
|
||
}
|
||
legendTop := top + 40 + float64(listed)*19
|
||
fmt.Fprintf(b, `<line x1="%.3f" y1="%.3f" x2="%.3f" y2="%.3f" stroke="#6f5a3a" stroke-width="1.3"/>`, left, legendTop, left+22, legendTop)
|
||
fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#3b4143" %s font-size="11">%s</text>`, left+28, legendTop+4, font,
|
||
html.EscapeString(limbProfileText(language, "恒星方向月缘高度", "Limb height toward the star")))
|
||
fmt.Fprintf(b, `<line x1="%.3f" y1="%.3f" x2="%.3f" y2="%.3f" stroke="#9b3f36" stroke-width="1.1" stroke-dasharray="5 2"/>`, left, legendTop+18, left+22, legendTop+18)
|
||
fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#3b4143" %s font-size="11">%s</text>`, left+28, legendTop+22, font,
|
||
html.EscapeString(limbProfileText(language, "恒星距参考圆月面(km)", "Star above the mean limb (km)")))
|
||
fmt.Fprintf(b, `<rect x="%.3f" y="%.3f" width="22" height="10" fill="#3b4a5a" fill-opacity="0.16"/>`, left, legendTop+31)
|
||
fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#3b4143" %s font-size="11">%s</text>`, left+28, legendTop+40, font,
|
||
html.EscapeString(limbProfileText(language, "恒星被遮挡", "Star hidden")))
|
||
return legendTop + 44
|
||
}
|
||
|
||
func writeLimbProfileFooter(b *strings.Builder, info moon.StarOccultationInfo, referenceKM, left, baseline, maxWidth float64, options StarOccultationLimbProfileSVGOptions) {
|
||
note := limbProfileText(options.Language,
|
||
"纵轴为月面上相对参考球 %.1f km 的高度;月缘按剖面表插值,短于采样步长的遮挡可能漏检。",
|
||
"Heights are relative to the %.1f km reference sphere; the limb is interpolated from the profile table and events shorter than the step may be missed.")
|
||
note = fmt.Sprintf(note, referenceKM)
|
||
lines := svgchart.TruncateTextLines(svgchart.WrapTextBalanced(note, maxWidth, 10), maxWidth, 10, 2)
|
||
lines = append(lines, svgchart.EllipsizeText(timenote.Scale(options.TimeScale, info.Greatest, options.Location, options.Language), maxWidth, 10))
|
||
font := `font-family="Georgia, 'Times New Roman', serif"`
|
||
for index, line := range lines {
|
||
fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#747c7d" %s font-size="10">%s</text>`, left, baseline+float64(index)*14, font, html.EscapeString(line))
|
||
}
|
||
}
|
||
|
||
// limbProfileTrackKM 返回恒星在天空平面上走过的弦长(km,按月面尺度)。
|
||
func limbProfileTrackKM(points []limbProfilePoint) float64 {
|
||
first, last := points[0], points[len(points)-1]
|
||
return math.Hypot(last.skyX-first.skyX, last.skyY-first.skyY)
|
||
}
|
||
|
||
// limbProfileExaggeration 纵向放大倍数:横向每像素代表的月面距离与纵向之比。
|
||
func limbProfileExaggeration(points []limbProfilePoint, widthPX, heightPX, spanKM float64) float64 {
|
||
if widthPX <= 0 || heightPX <= 0 || spanKM <= 0 {
|
||
return 0
|
||
}
|
||
return (limbProfileTrackKM(points) / widthPX) / (spanKM / heightPX)
|
||
}
|
||
|
||
// limbProfileCompass 把位置角换成八方位名。
|
||
func limbProfileCompass(positionAngle float64, language string) string {
|
||
zh := []string{"北", "东北", "东", "东南", "南", "西南", "西", "西北"}
|
||
en := []string{"N", "NE", "E", "SE", "S", "SW", "W", "NW"}
|
||
index := int(math.Floor(math.Mod(positionAngle+22.5+720, 360) / 45))
|
||
if language == starOccultationSVGLanguageEnglish {
|
||
return en[index]
|
||
}
|
||
return zh[index]
|
||
}
|
||
|
||
func limbProfileDirectionText(segments [][]limbProfilePoint, hidden []moon.OccultationInterval, language string) string {
|
||
if len(segments) == 0 {
|
||
return ""
|
||
}
|
||
first := segments[0][0]
|
||
lastSegment := segments[len(segments)-1]
|
||
last := lastSegment[len(lastSegment)-1]
|
||
if len(segments) == 1 {
|
||
return fmt.Sprintf(limbProfileText(language,
|
||
"恒星沿月缘自 PA %s(%s)移向 PA %s(%s),横向约 %.0f km;PA 自天北向东量",
|
||
"The star runs along the limb from PA %s (%s) to PA %s (%s), about %.0f km; PA measured from north through east"),
|
||
limbProfileFormatAngle(first.positionAngle), limbProfileCompass(first.positionAngle, language),
|
||
limbProfileFormatAngle(last.positionAngle), limbProfileCompass(last.positionAngle, language), limbProfileTrackKM(segments[0]))
|
||
}
|
||
// 深掩时取首次掩入与最后复现时刻的位置角,而非两栏端点。
|
||
immersion, emersion := first.positionAngle, last.positionAngle
|
||
if len(hidden) > 0 {
|
||
immersion = limbProfilePositionAngleAt(segments[0], hidden[0].Start)
|
||
emersion = limbProfilePositionAngleAt(lastSegment, hidden[len(hidden)-1].End)
|
||
}
|
||
return fmt.Sprintf(limbProfileText(language,
|
||
"恒星于 PA %s(%s)掩入、PA %s(%s)复现;上下两栏分别为掩入侧与复现侧,PA 自天北向东量",
|
||
"The star disappears at PA %s (%s) and reappears at PA %s (%s); panels show the two sides; PA measured from north through east"),
|
||
limbProfileFormatAngle(immersion), limbProfileCompass(immersion, language),
|
||
limbProfileFormatAngle(emersion), limbProfileCompass(emersion, language))
|
||
}
|
||
|
||
// limbProfileFormatAngle 按一位小数格式化位置角,舍入到 360.0° 时归一为 0.0°。
|
||
func limbProfileFormatAngle(positionAngle float64) string {
|
||
rounded := math.Round(positionAngle*10) / 10
|
||
if rounded >= 360 {
|
||
rounded -= 360
|
||
}
|
||
return fmt.Sprintf("%.1f°", rounded)
|
||
}
|
||
|
||
// writeLimbProfileInset 画掩甚时刻的站心月相缩略图(上北左东),加粗放大的月缘段并用箭头标出恒星运动方向。
|
||
func writeLimbProfileInset(b *strings.Builder, segments [][]limbProfilePoint, info moon.StarOccultationInfo, referenceKM, left, top, right, bottom float64, language string) {
|
||
size := math.Min(right-left, bottom-top-26)
|
||
if size < 60 || len(segments) == 0 {
|
||
return
|
||
}
|
||
font := `font-family="Georgia, 'Times New Roman', serif"`
|
||
fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#111111" %s font-size="12" font-weight="700">%s</text>`, left, top+10, font,
|
||
html.EscapeString(svgchart.EllipsizeText(limbProfileText(language, "月缘位置(上北左东)", "On the limb (N up, E left)"), right-left, 12)))
|
||
radius := size/2 - 16
|
||
cx, cy := left+(right-left)/2, top+26+size/2
|
||
writeLocalOccultationMoon(b, cx, cy, radius, "limb-profile-moon",
|
||
localOccultationMoonAppearanceAt(info.Greatest, info.Observer), "limb-profile-moon-phase")
|
||
fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#4f595b" %s font-size="10" text-anchor="middle">%s</text>`, cx, cy-radius-4, font, limbProfileText(language, "北", "N"))
|
||
fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#4f595b" %s font-size="10" text-anchor="end">%s</text>`, cx-radius-4, cy+4, font, limbProfileText(language, "东", "E"))
|
||
limbPoint := func(positionAngle, scale float64) (float64, float64) {
|
||
angle := positionAngle * math.Pi / 180
|
||
return cx - scale*math.Sin(angle), cy - scale*math.Cos(angle)
|
||
}
|
||
for _, points := range segments {
|
||
first, last := points[0], points[len(points)-1]
|
||
x0, y0 := limbPoint(first.positionAngle, radius)
|
||
x1, y1 := limbPoint(last.positionAngle, radius)
|
||
sweep := 0
|
||
if signedPositionAngleStep(first.positionAngle, last.positionAngle) < 0 {
|
||
sweep = 1
|
||
}
|
||
fmt.Fprintf(b, `<path d="M%.2f %.2f A%.2f %.2f 0 0 %d %.2f %.2f" fill="none" stroke="#e0a32e" stroke-width="3.6"/>`, x0, y0, radius, radius, sweep, x1, y1)
|
||
}
|
||
// 恒星轨迹按真实比例画在月盘坐标里,深掩时两段之间连成穿过月面的弦。
|
||
kmToPX := radius / referenceKM
|
||
firstPoint := segments[0][0]
|
||
lastSegment := segments[len(segments)-1]
|
||
lastPoint := lastSegment[len(lastSegment)-1]
|
||
fmt.Fprintf(b, `<line x1="%.2f" y1="%.2f" x2="%.2f" y2="%.2f" stroke="#d0473b" stroke-width="1.6" marker-end="url(#limb-profile-arrow)"/>`,
|
||
cx-firstPoint.skyX*kmToPX, cy-firstPoint.skyY*kmToPX, cx-lastPoint.skyX*kmToPX, cy-lastPoint.skyY*kmToPX)
|
||
}
|
||
|
||
// signedPositionAngleStep 返回自 from 到 to 的位置角变化(度),取 (−180, 180];负值为顺时针(向西)。
|
||
func signedPositionAngleStep(from, to float64) float64 {
|
||
delta := math.Mod(to-from+540, 360) - 180
|
||
return delta
|
||
}
|
||
|
||
// limbProfileTickStep 选使相邻时刻标签不重叠的最小整刻度步长。
|
||
func limbProfileTickStep(spanSeconds, widthPX float64) time.Duration {
|
||
for _, step := range []time.Duration{5 * time.Second, 10 * time.Second, 15 * time.Second, 20 * time.Second, 30 * time.Second,
|
||
time.Minute, 2 * time.Minute, 5 * time.Minute, 10 * time.Minute, 15 * time.Minute, 30 * time.Minute, time.Hour} {
|
||
if widthPX*step.Seconds()/spanSeconds >= 56 {
|
||
return step
|
||
}
|
||
}
|
||
return 2 * time.Hour
|
||
}
|
||
|
||
func limbProfileTickLayout(step time.Duration) string {
|
||
if step%time.Minute == 0 {
|
||
return "15:04"
|
||
}
|
||
return "15:04:05"
|
||
}
|
||
|
||
// limbProfilePositionAngleAt 在相邻样本间线性插值位置角,跨 0° 时按最短方向。
|
||
func limbProfilePositionAngleAt(points []limbProfilePoint, at time.Time) float64 {
|
||
for index := 1; index < len(points); index++ {
|
||
if points[index].t.Before(at) {
|
||
continue
|
||
}
|
||
previous, next := points[index-1], points[index]
|
||
span := next.t.Sub(previous.t).Seconds()
|
||
if span <= 0 {
|
||
return next.positionAngle
|
||
}
|
||
fraction := at.Sub(previous.t).Seconds() / span
|
||
return math.Mod(previous.positionAngle+fraction*signedPositionAngleStep(previous.positionAngle, next.positionAngle)+360, 360)
|
||
}
|
||
return points[len(points)-1].positionAngle
|
||
}
|
||
|
||
// limbProfileTicks 返回 [start, end] 内按显示时区本地时钟对齐 step 的全部刻度;每个刻度按它自身所在时刻的时区偏移判断,跨夏令时切换也落在当地整刻度上。
|
||
func limbProfileTicks(start, end time.Time, step time.Duration, location *time.Location) []time.Time {
|
||
// ceil 返回不早于 at、在当地时钟上是 step 整数倍的第一个时刻;结果若落到另一偏移下,按结果的偏移重算一次。
|
||
ceil := func(at time.Time) time.Time {
|
||
withOffset := func(at time.Time, offset int) time.Time {
|
||
shift := time.Duration(offset) * time.Second
|
||
tick := at.Add(shift).Truncate(step).Add(-shift)
|
||
if tick.Before(at) {
|
||
tick = tick.Add(step)
|
||
}
|
||
return tick
|
||
}
|
||
_, offset := at.In(location).Zone()
|
||
tick := withOffset(at, offset)
|
||
if _, actual := tick.In(location).Zone(); actual != offset {
|
||
tick = withOffset(at, actual)
|
||
}
|
||
return tick
|
||
}
|
||
var ticks []time.Time
|
||
for tick := ceil(start); !tick.After(end) && len(ticks) < 1000; tick = ceil(tick.Add(step)) {
|
||
ticks = append(ticks, tick)
|
||
}
|
||
return ticks
|
||
}
|
||
|
||
// limbProfileClampLabel 返回中锚标签的 x,使宽 width 的标签整体落在 [left, right] 内。
|
||
func limbProfileClampLabel(x, width, left, right float64) float64 {
|
||
return math.Max(left+width/2, math.Min(right-width/2, x))
|
||
}
|
||
|
||
// limbProfileReferenceKM 剖面结果声明的参考月球半径,旧结果未填时用 1737.4 km。
|
||
func limbProfileReferenceKM(profile moon.StarOccultationLimbProfileResult) float64 {
|
||
if profile.ReferenceRadiusKM > 0 && !math.IsInf(profile.ReferenceRadiusKM, 0) {
|
||
return profile.ReferenceRadiusKM
|
||
}
|
||
return 1737.4
|
||
}
|
||
|
||
// validateStarOccultationLimbProfile 拒绝 StarOccultationLimbProfile 给不出的数据:至多两栏、每栏至少两个样本且时间递增、角量有限、遮挡区间有序。
|
||
func validateStarOccultationLimbProfile(profile moon.StarOccultationLimbProfileResult) error {
|
||
if len(profile.Segments) > 2 {
|
||
return fmt.Errorf("%w: at most two segments, got %d", ErrInvalidStarOccultationLimbProfile, len(profile.Segments))
|
||
}
|
||
finiteValue := func(value float64) bool { return !math.IsNaN(value) && !math.IsInf(value, 0) }
|
||
if !finiteValue(profile.ReferenceRadiusKM) || profile.ReferenceRadiusKM < 0 {
|
||
return fmt.Errorf("%w: reference radius must be finite and non-negative", ErrInvalidStarOccultationLimbProfile)
|
||
}
|
||
for index, segment := range profile.Segments {
|
||
if len(segment) < 2 {
|
||
return fmt.Errorf("%w: segment %d has fewer than two samples", ErrInvalidStarOccultationLimbProfile, index)
|
||
}
|
||
for sampleIndex, sample := range segment {
|
||
if !finiteValue(sample.SeparationArcsec) || !finiteValue(sample.LimbRadiusArcsec) ||
|
||
!finiteValue(sample.MeanRadiusArcsec) || sample.MeanRadiusArcsec <= 0 || !finiteValue(sample.PositionAngleDeg) {
|
||
return fmt.Errorf("%w: segment %d sample %d has non-finite geometry", ErrInvalidStarOccultationLimbProfile, index, sampleIndex)
|
||
}
|
||
if sampleIndex > 0 && !sample.Time.After(segment[sampleIndex-1].Time) {
|
||
return fmt.Errorf("%w: segment %d samples must increase in time", ErrInvalidStarOccultationLimbProfile, index)
|
||
}
|
||
}
|
||
}
|
||
for index, interval := range profile.Hidden {
|
||
if !interval.End.After(interval.Start) || (index > 0 && interval.Start.Before(profile.Hidden[index-1].End)) {
|
||
return fmt.Errorf("%w: hidden intervals must be ordered", ErrInvalidStarOccultationLimbProfile)
|
||
}
|
||
}
|
||
return nil
|
||
}
|