b612
16c62a97d5
- 新增时标、ΔT 模型、质心时间与 UT1 支持 - 改进日月食、月掩、行星事件及路径边界计算 - 完善恒星三维自行与动态距离传播 - 扩展 SVG、GeoJSON、KML 输出与底层距离换算工具 - 整理中英文手册、示例资源及回归测试
853 lines
36 KiB
Go
853 lines
36 KiB
Go
package svg
|
||
|
||
import (
|
||
"b612.me/astro/internal/timenote"
|
||
"errors"
|
||
"fmt"
|
||
"html"
|
||
"math"
|
||
"strings"
|
||
"time"
|
||
|
||
"b612.me/astro"
|
||
"b612.me/astro/internal/svgasset"
|
||
"b612.me/astro/internal/svgchart"
|
||
"b612.me/astro/moon"
|
||
)
|
||
|
||
const (
|
||
localStarOccultationSVGDefaultWidth = 920
|
||
localStarOccultationSVGDefaultHeight = 720
|
||
localStarOccultationSVGMinimumWidth = 640
|
||
localStarOccultationSVGMinimumHeight = 520
|
||
localStarOccultationSVGDefaultStep = 2 * time.Minute
|
||
)
|
||
|
||
// ErrInvalidLocalStarOccultationSVGOptions 表示本地图表选项无效。
|
||
// ErrInvalidLocalStarOccultationSVGOptions reports invalid local chart options.
|
||
var ErrInvalidLocalStarOccultationSVGOptions = errors.New("invalid local stellar occultation SVG options")
|
||
|
||
// ErrInvalidLocalStarOccultationInfo 表示固定地点事件数据格式错误。
|
||
// ErrInvalidLocalStarOccultationInfo reports malformed fixed-site event data.
|
||
var ErrInvalidLocalStarOccultationInfo = errors.New("invalid local stellar occultation info")
|
||
|
||
// LocalStarOccultationSVGOptions 控制固定地点月球与恒星盘面图。
|
||
// LocalStarOccultationSVGOptions controls a fixed-site Moon-star disk chart.
|
||
type LocalStarOccultationSVGOptions struct {
|
||
// Width 和 Height 是 SVG 画布尺寸；非正值使用默认值。
|
||
// Width and Height are SVG canvas dimensions. Values <= 0 use defaults.
|
||
Width int
|
||
Height int
|
||
// Step 是月心恒星轨迹请求采样步长；零值使用两分钟，负值无效，正值小于一秒时提升到一秒。长事件可能增大实际步长，以保持基础轨迹在有界采样预算内。
|
||
// Step is the requested Moon-centered stellar-track sampling step. Zero uses two minutes; negative values are invalid. Positive values below one second are raised to one second, and long events may use a larger effective step to keep the base track within its bounded sample budget.
|
||
Step time.Duration
|
||
// 空文本字段使用本地化的自动标签。
|
||
// Empty text fields use localized automatic labels.
|
||
Title string
|
||
SummaryText string
|
||
GreatestText string
|
||
OverviewTitle string
|
||
PhasePanelsTitle string
|
||
ContactsTitle string
|
||
DirectionText string
|
||
FooterNote string
|
||
// Language 为 "en" 时使用英文，其他值使用中文。
|
||
// Language uses English for "en" and Chinese for every other value.
|
||
Language string
|
||
// Location 控制显示的事件时刻；nil 使用 UTC+8。
|
||
// Location controls displayed event times. Nil uses UTC+8.
|
||
Location *time.Location
|
||
// TimeScale 选择图中时刻的时标：零值 UTC；TimeScaleUT1 改用 UT1 时刻，此时 Location 必须是
|
||
// nil 或 UTC（否则渲染器返回错误），并在图注里声明尺度。
|
||
// TimeScale selects the label scale: the zero value is UTC; TimeScaleUT1 uses UT1 labels, requires
|
||
// Location to be nil or UTC (otherwise the renderer returns an error) and declares the scale.
|
||
TimeScale astro.TimeScale
|
||
}
|
||
|
||
type localStarOccultationSVGLayout struct {
|
||
width float64
|
||
height float64
|
||
margin float64
|
||
overviewLeft float64
|
||
overviewRight float64
|
||
overviewTop float64
|
||
overviewBottom float64
|
||
panelX float64
|
||
panelWidth float64
|
||
stageTop float64
|
||
stageBottom float64
|
||
footerY float64
|
||
headerMaxLines int
|
||
}
|
||
|
||
type localStarOccultationEventFrame struct {
|
||
label string
|
||
name string
|
||
time time.Time
|
||
frame moon.StarOccultationDiagramFrame
|
||
appearance localOccultationMoonAppearance
|
||
}
|
||
|
||
// FindLocalStarOccultationSVGs 搜索固定观测地点，并渲染请求时间窗口内的每次点光源恒星月掩。不会加载内嵌星表；空切片表示没有本地事件。
|
||
// FindLocalStarOccultationSVGs searches one fixed observing site and renders every point-source stellar occultation in the requested time window. It does not load the embedded star catalog; an empty slice means no local event.
|
||
func FindLocalStarOccultationSVGs(
|
||
start, end time.Time,
|
||
star moon.StarCoordinate,
|
||
longitude, latitude, height float64,
|
||
searchOptions moon.OccultationSearchOptions,
|
||
options LocalStarOccultationSVGOptions,
|
||
) ([]string, error) {
|
||
if err := validateLocalStarOccultationSVGOptions(options); err != nil {
|
||
return nil, err
|
||
}
|
||
events, err := moon.FindStarOccultations(start, end, star, longitude, latitude, height, searchOptions)
|
||
if err != nil {
|
||
return nil, err
|
||
}
|
||
diagrams := make([]string, 0, len(events))
|
||
for _, event := range events {
|
||
diagram, renderErr := LocalStarOccultationSVG(event, star, options)
|
||
if renderErr != nil {
|
||
return nil, renderErr
|
||
}
|
||
diagrams = append(diagrams, diagram)
|
||
}
|
||
return diagrams, nil
|
||
}
|
||
|
||
// LocalStarOccultationSVG 渲染已求解的固定地点恒星月掩的月心轨迹及掩始、掩甚、掩终阶段面板；不会运行事件搜索或加载星表。
|
||
// LocalStarOccultationSVG renders an already solved fixed-site stellar occultation as a Moon-centered track with immersion, greatest, and emersion stage panels. It does not run the event search or load the star catalog.
|
||
func LocalStarOccultationSVG(
|
||
info moon.StarOccultationInfo,
|
||
star moon.StarCoordinate,
|
||
options LocalStarOccultationSVGOptions,
|
||
) (string, error) {
|
||
if options.TimeScale == astro.TimeScaleUT1 && options.Location != nil && options.Location != time.UTC {
|
||
return "", fmt.Errorf("occultation SVG: UT1 labels do not take a non-UTC location")
|
||
}
|
||
if err := validateLocalStarOccultationInfo(info, star); err != nil {
|
||
return "", err
|
||
}
|
||
if err := validateLocalStarOccultationSVGOptions(options); err != nil {
|
||
return "", err
|
||
}
|
||
if options.TimeScale == astro.TimeScaleUT1 {
|
||
options.Location = time.UTC
|
||
}
|
||
|
||
options = normalizeLocalStarOccultationSVGOptions(options)
|
||
diagram := moon.StarOccultationDiagram(info, star, moon.StarOccultationDiagramOptions{
|
||
StepDays: options.Step.Hours() / 24,
|
||
})
|
||
if len(diagram.Frames) == 0 {
|
||
return "", fmt.Errorf("%w: diagram geometry is unavailable", ErrInvalidLocalStarOccultationInfo)
|
||
}
|
||
if options.TimeScale == astro.TimeScaleUT1 {
|
||
info = moon.StarOccultationInfoInUT1(info)
|
||
}
|
||
return renderLocalStarOccultationSVG(info, diagram, options), nil
|
||
}
|
||
|
||
func validateLocalStarOccultationSVGOptions(options LocalStarOccultationSVGOptions) error {
|
||
if options.Width > 0 && options.Width < localStarOccultationSVGMinimumWidth {
|
||
return fmt.Errorf("%w: width must be zero or at least %d", ErrInvalidLocalStarOccultationSVGOptions, localStarOccultationSVGMinimumWidth)
|
||
}
|
||
if options.Height > 0 && options.Height < localStarOccultationSVGMinimumHeight {
|
||
return fmt.Errorf("%w: height must be zero or at least %d", ErrInvalidLocalStarOccultationSVGOptions, localStarOccultationSVGMinimumHeight)
|
||
}
|
||
if options.Step < 0 {
|
||
return fmt.Errorf("%w: step cannot be negative", ErrInvalidLocalStarOccultationSVGOptions)
|
||
}
|
||
return nil
|
||
}
|
||
|
||
func validateLocalStarOccultationInfo(info moon.StarOccultationInfo, star moon.StarCoordinate) error {
|
||
if err := star.Validate(); err != nil {
|
||
return fmt.Errorf("%w: %v", ErrInvalidLocalStarOccultationInfo, err)
|
||
}
|
||
if info.TargetID != "" && star.ID != "" && info.TargetID != star.ID {
|
||
return fmt.Errorf("%w: event target %q does not match star %q", ErrInvalidLocalStarOccultationInfo, info.TargetID, star.ID)
|
||
}
|
||
if err := info.Observer.Validate(); err != nil {
|
||
return fmt.Errorf("%w: %v", ErrInvalidLocalStarOccultationInfo, err)
|
||
}
|
||
if !info.ContactsComplete || info.Immersion.IsZero() || info.Greatest.IsZero() || info.Emersion.IsZero() {
|
||
return fmt.Errorf("%w: complete immersion, greatest, and emersion times are required", ErrInvalidLocalStarOccultationInfo)
|
||
}
|
||
if info.Greatest.Before(info.Immersion) || info.Emersion.Before(info.Greatest) {
|
||
return fmt.Errorf("%w: event times must be ordered", ErrInvalidLocalStarOccultationInfo)
|
||
}
|
||
if info.Type != moon.OccultationTotal && info.Type != moon.OccultationGrazing {
|
||
return fmt.Errorf("%w: unsupported point-source geometry %q", ErrInvalidLocalStarOccultationInfo, info.Type)
|
||
}
|
||
if !starOccultationFinite(info.MinimumSeparationArcsec) || info.MinimumSeparationArcsec < 0 ||
|
||
!starOccultationFinite(info.MoonSemidiameterArcsec) || info.MoonSemidiameterArcsec <= 0 ||
|
||
!starOccultationFinite(info.PositionAngleDeg) ||
|
||
!starOccultationFinite(info.MoonAltitudeAtGreatest) ||
|
||
!starOccultationFinite(info.MoonAzimuthAtGreatest) {
|
||
return fmt.Errorf("%w: event geometry must be finite", ErrInvalidLocalStarOccultationInfo)
|
||
}
|
||
return nil
|
||
}
|
||
|
||
func normalizeLocalStarOccultationSVGOptions(options LocalStarOccultationSVGOptions) LocalStarOccultationSVGOptions {
|
||
if options.Width <= 0 {
|
||
options.Width = localStarOccultationSVGDefaultWidth
|
||
}
|
||
if options.Height <= 0 {
|
||
options.Height = localStarOccultationSVGDefaultHeight
|
||
}
|
||
if options.Step <= 0 {
|
||
options.Step = localStarOccultationSVGDefaultStep
|
||
}
|
||
if options.Location == nil {
|
||
options.Location = time.FixedZone("UTC+8", starOccultationSVGDefaultZone)
|
||
}
|
||
if strings.EqualFold(options.Language, starOccultationSVGLanguageEnglish) {
|
||
options.Language = starOccultationSVGLanguageEnglish
|
||
} else {
|
||
options.Language = starOccultationSVGLanguageChinese
|
||
}
|
||
return options
|
||
}
|
||
|
||
func renderLocalStarOccultationSVG(
|
||
info moon.StarOccultationInfo,
|
||
diagram moon.StarOccultationDiagramResult,
|
||
options LocalStarOccultationSVGOptions,
|
||
) string {
|
||
title := localStarOccultationSVGTitle(info, options)
|
||
headerLines := localStarOccultationSVGHeaderLines(info, options)
|
||
// 页眉字号 14/13，省略号按较大的 14 估算；行数上限只与画布高度有关，先按空页眉取上限。
|
||
headerLimit := localStarOccultationSVGLayoutFor(options, 72).headerMaxLines
|
||
headerLines = svgchart.TruncateTextLines(headerLines, float64(options.Width)-80, 14, headerLimit)
|
||
headerBottom := 72.0 + float64(len(headerLines))*19
|
||
layout := localStarOccultationSVGLayoutFor(options, headerBottom)
|
||
events := localStarOccultationSVGEventFrames(info, diagram.Frames, options.Language)
|
||
|
||
var b strings.Builder
|
||
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">`,
|
||
options.Width, options.Height, options.Width, options.Height, html.EscapeString(title))
|
||
b.WriteString(`<defs>`)
|
||
b.WriteString(svgasset.MoonFaceSymbol())
|
||
b.WriteString(`<marker id="local-occultation-arrow" viewBox="0 0 10 10" refX="8" refY="5" markerWidth="5" markerHeight="5" orient="auto-start-reverse"><path d="M 0 0 L 10 5 L 0 10 z" fill="#9b3f36"/></marker>`)
|
||
b.WriteString(`</defs>`)
|
||
b.WriteString(`<rect width="100%" height="100%" fill="#efefed"/>`)
|
||
fmt.Fprintf(&b, `<rect x="22" y="18" width="%.3f" height="%.3f" fill="#ffffff" stroke="#c9c9c6" stroke-width="1.2"/>`, layout.width-44, layout.height-36)
|
||
titleSize := starOccultationTitleFontSize(title, layout.width)
|
||
titleText := title
|
||
if options.Title != "" {
|
||
titleText = svgchart.EllipsizeText(title, layout.width-80, float64(titleSize))
|
||
}
|
||
fmt.Fprintf(&b, `<text x="%.3f" y="44" fill="#111111" font-family="Georgia, 'Times New Roman', serif" font-size="%d" font-weight="700" text-anchor="middle">%s</text>`,
|
||
layout.width/2, titleSize, html.EscapeString(titleText))
|
||
fmt.Fprintf(&b, `<line x1="%.3f" y1="57" x2="%.3f" y2="57" stroke="#555" stroke-width="1"/>`, layout.width/2-78, layout.width/2+78)
|
||
for index, line := range headerLines {
|
||
fontSize, fill := 13, "#3b4143"
|
||
if index == 0 {
|
||
fontSize, fill = 14, "#222222"
|
||
}
|
||
fmt.Fprintf(&b, `<text x="%.3f" y="%.3f" fill="%s" font-family="Georgia, 'Times New Roman', serif" font-size="%d" text-anchor="middle">%s</text>`,
|
||
layout.width/2, 82+float64(index)*19, fill, fontSize, html.EscapeString(line))
|
||
}
|
||
|
||
writeLocalStarOccultationOverview(&b, diagram, events, layout, options)
|
||
writeLocalStarOccultationContacts(&b, events, layout, options)
|
||
writeLocalStarOccultationStages(&b, events, layout, options)
|
||
writeLocalStarOccultationFooter(&b, layout, options, info.Greatest)
|
||
b.WriteString(`</svg>`)
|
||
return b.String()
|
||
}
|
||
|
||
func localStarOccultationSVGLayoutFor(options LocalStarOccultationSVGOptions, headerBottom float64) localStarOccultationSVGLayout {
|
||
width := float64(options.Width)
|
||
height := float64(options.Height)
|
||
margin := math.Max(30, math.Min(44, width*0.05))
|
||
gap := math.Max(18, math.Min(24, width*0.025))
|
||
panelWidth := math.Max(188, math.Min(236, width*0.25))
|
||
overviewLeft := margin
|
||
overviewRight := width - margin - panelWidth - gap
|
||
// 页脚末行按 9px 字号留 12 px 底边留白，预留高度与页脚起始位置随之上移，
|
||
// 否则英文默认说明会被截到只剩一行、时标声明整行消失。
|
||
footerSpace := 74.0
|
||
stageHeight := math.Max(132, math.Min(170, height*0.23))
|
||
stageBottom := height - footerSpace
|
||
stageTop := stageBottom - stageHeight
|
||
overviewTop := headerBottom + 26
|
||
overviewBottom := stageTop - 20
|
||
return localStarOccultationSVGLayout{
|
||
width: width,
|
||
height: height,
|
||
margin: margin,
|
||
overviewLeft: overviewLeft,
|
||
overviewRight: overviewRight,
|
||
overviewTop: overviewTop,
|
||
overviewBottom: overviewBottom,
|
||
panelX: overviewRight + gap,
|
||
panelWidth: panelWidth,
|
||
stageTop: stageTop,
|
||
stageBottom: stageBottom,
|
||
footerY: height - 49,
|
||
headerMaxLines: localOccultationHeaderLineLimit(height, footerSpace, stageHeight),
|
||
}
|
||
}
|
||
|
||
func writeLocalStarOccultationOverview(
|
||
b *strings.Builder,
|
||
diagram moon.StarOccultationDiagramResult,
|
||
events []localStarOccultationEventFrame,
|
||
layout localStarOccultationSVGLayout,
|
||
options LocalStarOccultationSVGOptions,
|
||
) {
|
||
overviewTitle := occultationTitleText(localStarOccultationSVGOverviewTitle(options), options.OverviewTitle != "",
|
||
layout.panelX-layout.overviewLeft-12, 14)
|
||
fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#161a1b" font-family="Georgia, 'Times New Roman', serif" font-size="14" font-weight="700">%s</text>`,
|
||
layout.overviewLeft, layout.overviewTop-10, html.EscapeString(overviewTitle))
|
||
cx := (layout.overviewLeft + layout.overviewRight) / 2
|
||
cy := (layout.overviewTop+layout.overviewBottom)/2 + 4
|
||
extent := localStarOccultationSVGExtent(diagram.Frames)
|
||
availableWidth := layout.overviewRight - layout.overviewLeft - 74
|
||
availableHeight := layout.overviewBottom - layout.overviewTop - 50
|
||
scale := math.Min(availableWidth/(2*extent), availableHeight/(2*extent))
|
||
if !starOccultationFinite(scale) || scale <= 0 {
|
||
scale = 1
|
||
}
|
||
mapX := func(value float64) float64 { return cx - value*scale }
|
||
mapY := func(value float64) float64 { return cy - value*scale }
|
||
moonRadius := localStarOccultationSVGMaximumMoonRadius(diagram.Frames) * scale
|
||
|
||
table := &svgchart.LabelTable{}
|
||
table.ReserveText(layout.overviewLeft, layout.overviewTop-10, 14, overviewTitle, "start")
|
||
table.Reserve(layout.panelX-12, layout.overviewTop-16, layout.width-(layout.panelX-12), layout.height-layout.overviewTop)
|
||
table.Reserve(cx-moonRadius, cy-moonRadius, 2*moonRadius, 2*moonRadius)
|
||
writeLocalStarOccultationAxes(b, cx, cy, moonRadius, options.Language, table)
|
||
writeLocalOccultationMoon(b, cx, cy, moonRadius, "overview-moon",
|
||
localOccultationMoonAppearanceAt(diagram.Occultation.Greatest, diagram.Occultation.Observer),
|
||
"local-star-occultation-moon-overview")
|
||
writeLocalStarOccultationLunarPath(b, diagram.Frames, mapX, mapY, extent, options.Language)
|
||
writeLocalStarOccultationTrack(b, diagram.Frames, mapX, mapY)
|
||
overviewLabels := make([]localOccultationOverviewLabel, 0, len(events))
|
||
for _, event := range events {
|
||
x := mapX(event.frame.StarXArcsec)
|
||
y := mapY(event.frame.StarYArcsec)
|
||
writeLocalStarOccultationStar(b, x, y, event.frame.BehindMoon, "overview-star", event.label)
|
||
overviewLabels = append(overviewLabels, localOccultationOverviewLabel{
|
||
text: localStarOccultationSVGEventName(event.label, options.Language),
|
||
x: x,
|
||
y: y,
|
||
})
|
||
}
|
||
writeLocalOccultationOverviewLabels(b, overviewLabels, table, cx, cy, moonRadius, "#792d28")
|
||
}
|
||
|
||
func localStarOccultationSVGExtent(frames []moon.StarOccultationDiagramFrame) float64 {
|
||
extent := 1.0
|
||
for _, frame := range frames {
|
||
extent = math.Max(extent, frame.MoonRadiusArcsec)
|
||
extent = math.Max(extent, math.Abs(frame.StarXArcsec))
|
||
extent = math.Max(extent, math.Abs(frame.StarYArcsec))
|
||
}
|
||
return extent * 1.28
|
||
}
|
||
|
||
func localStarOccultationSVGMaximumMoonRadius(frames []moon.StarOccultationDiagramFrame) float64 {
|
||
radius := 1.0
|
||
for _, frame := range frames {
|
||
radius = math.Max(radius, frame.MoonRadiusArcsec)
|
||
}
|
||
return radius
|
||
}
|
||
|
||
func writeLocalStarOccultationTrack(
|
||
b *strings.Builder,
|
||
frames []moon.StarOccultationDiagramFrame,
|
||
mapX, mapY func(float64) float64,
|
||
) {
|
||
if len(frames) < 2 {
|
||
return
|
||
}
|
||
var path strings.Builder
|
||
for index, frame := range frames {
|
||
command := "L"
|
||
if index == 0 {
|
||
command = "M"
|
||
}
|
||
fmt.Fprintf(&path, "%s %.3f %.3f ", command, mapX(frame.StarXArcsec), mapY(frame.StarYArcsec))
|
||
}
|
||
fmt.Fprintf(b, `<path class="local-star-track" d="%s" fill="none" stroke="#9b3f36" stroke-width="1.7" stroke-dasharray="5 4" opacity="0.82" marker-end="url(#local-occultation-arrow)"/>`, strings.TrimSpace(path.String()))
|
||
}
|
||
|
||
func writeLocalStarOccultationLunarPath(
|
||
b *strings.Builder,
|
||
frames []moon.StarOccultationDiagramFrame,
|
||
mapX, mapY func(float64) float64,
|
||
extent float64,
|
||
language string,
|
||
) {
|
||
unitX, unitY, ok := localStarOccultationSVGLunarPathDirection(frames)
|
||
if !ok {
|
||
return
|
||
}
|
||
lineExtent := extent * 0.92
|
||
startX := mapX(-unitX * lineExtent)
|
||
startY := mapY(-unitY * lineExtent)
|
||
endX := mapX(unitX * lineExtent)
|
||
endY := mapY(unitY * lineExtent)
|
||
if !starOccultationFinite(startX) || !starOccultationFinite(startY) ||
|
||
!starOccultationFinite(endX) || !starOccultationFinite(endY) {
|
||
return
|
||
}
|
||
|
||
fmt.Fprintf(b, `<line class="lunar-path-line" x1="%.3f" y1="%.3f" x2="%.3f" y2="%.3f" stroke="#506975" stroke-width="1.1" stroke-dasharray="7 4" opacity="0.86"/>`,
|
||
startX, startY, endX, endY)
|
||
labelX, labelY, anchor := startX, startY, "end"
|
||
if endX < startX {
|
||
labelX, labelY = endX, endY
|
||
}
|
||
fmt.Fprintf(b, `<text class="lunar-path-label" x="%.3f" y="%.3f" fill="#405966" stroke="#ffffff" stroke-width="3" paint-order="stroke" font-family="Georgia, 'Times New Roman', serif" font-size="12" text-anchor="%s">%s</text>`,
|
||
labelX-6, labelY-6, anchor, html.EscapeString(localStarOccultationSVGLunarPathLabel(language)))
|
||
}
|
||
|
||
// 恒星轨迹相对固定月心测量，因此其切线与月球站心视运动反向。参考线没有箭头，因此归一化轨迹切线就是图表使用的月掩路径轴。
|
||
// The star track is measured relative to a fixed lunar center, so its tangent is antiparallel to the Moon's topocentric apparent motion. A reference line has no arrow, therefore the normalized track tangent is the same lunar-path axis used by the chart.
|
||
func localStarOccultationSVGLunarPathDirection(frames []moon.StarOccultationDiagramFrame) (float64, float64, bool) {
|
||
if len(frames) < 2 {
|
||
return 0, 0, false
|
||
}
|
||
greatest := -1
|
||
for index, frame := range frames {
|
||
if localStarOccultationSVGFrameHasLabel(frame, "Greatest") {
|
||
greatest = index
|
||
break
|
||
}
|
||
}
|
||
left, right := 0, len(frames)-1
|
||
if greatest > 0 && greatest+1 < len(frames) {
|
||
left, right = greatest-1, greatest+1
|
||
} else if greatest == 0 {
|
||
left, right = 0, 1
|
||
} else if greatest == len(frames)-1 {
|
||
left, right = len(frames)-2, len(frames)-1
|
||
}
|
||
dx := frames[right].StarXArcsec - frames[left].StarXArcsec
|
||
dy := frames[right].StarYArcsec - frames[left].StarYArcsec
|
||
length := math.Hypot(dx, dy)
|
||
if !starOccultationFinite(length) || length == 0 {
|
||
return 0, 0, false
|
||
}
|
||
return dx / length, dy / length, true
|
||
}
|
||
|
||
func localStarOccultationSVGLunarPathLabel(language string) string {
|
||
if language == starOccultationSVGLanguageEnglish {
|
||
return "Lunar path"
|
||
}
|
||
return "白道"
|
||
}
|
||
|
||
func writeLocalStarOccultationAxes(b *strings.Builder, cx, cy, radius float64, language string, table *svgchart.LabelTable) {
|
||
north, east, west, south := "北", "东", "西", "南"
|
||
if language == starOccultationSVGLanguageEnglish {
|
||
north, east, west, south = "N", "E", "W", "S"
|
||
}
|
||
labels := []struct {
|
||
x, y float64
|
||
anchor string
|
||
text string
|
||
}{
|
||
{cx, cy - radius - 15, "middle", north},
|
||
{cx - radius - 18, cy + 4, "middle", east},
|
||
{cx + radius + 18, cy + 4, "middle", west},
|
||
{cx, cy + radius + 24, "middle", south},
|
||
}
|
||
for _, label := range labels {
|
||
if table != nil {
|
||
table.ReserveText(label.x, label.y, 12, label.text, label.anchor)
|
||
}
|
||
fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#293235" font-family="Georgia, 'Times New Roman', serif" font-size="12" font-weight="700" text-anchor="%s">%s</text>`,
|
||
label.x, label.y, label.anchor, html.EscapeString(label.text))
|
||
}
|
||
}
|
||
|
||
func writeLocalStarOccultationStar(b *strings.Builder, x, y float64, hidden bool, class, label string) {
|
||
fill, stroke, dash := "#fff7d6", "#9b3028", ""
|
||
if hidden {
|
||
fill, stroke, dash = "none", "#7d3430", ` stroke-dasharray="2 2"`
|
||
}
|
||
fmt.Fprintf(b, `<g class="%s" data-label="%s">`, html.EscapeString(class), html.EscapeString(label))
|
||
fmt.Fprintf(b, `<circle cx="%.3f" cy="%.3f" r="4.2" fill="%s" stroke="%s" stroke-width="1.4"%s/>`, x, y, fill, stroke, dash)
|
||
fmt.Fprintf(b, `<line x1="%.3f" y1="%.3f" x2="%.3f" y2="%.3f" stroke="%s" stroke-width="1"/>`, x-6, y, x+6, y, stroke)
|
||
fmt.Fprintf(b, `<line x1="%.3f" y1="%.3f" x2="%.3f" y2="%.3f" stroke="%s" stroke-width="1"/>`, x, y-6, x, y+6, stroke)
|
||
b.WriteString(`</g>`)
|
||
}
|
||
func writeLocalStarOccultationContacts(
|
||
b *strings.Builder,
|
||
events []localStarOccultationEventFrame,
|
||
layout localStarOccultationSVGLayout,
|
||
options LocalStarOccultationSVGOptions,
|
||
) {
|
||
fmt.Fprintf(b, `<line x1="%.3f" y1="%.3f" x2="%.3f" y2="%.3f" stroke="#d0d3d1" stroke-width="1"/>`,
|
||
layout.panelX-12, layout.overviewTop-12, layout.panelX-12, layout.overviewBottom)
|
||
contactsTitle := occultationTitleText(localStarOccultationSVGContactsTitle(options), options.ContactsTitle != "",
|
||
layout.width-layout.panelX-layout.margin, 14)
|
||
fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#161a1b" font-family="Georgia, 'Times New Roman', serif" font-size="14" font-weight="700">%s</text>`,
|
||
layout.panelX, layout.overviewTop-10, html.EscapeString(contactsTitle))
|
||
available := layout.overviewBottom - layout.overviewTop - 10
|
||
rowHeight := math.Min(86, available/math.Max(1, float64(len(events))))
|
||
for index, event := range events {
|
||
y := layout.overviewTop + 17 + float64(index)*rowHeight
|
||
if index > 0 {
|
||
fmt.Fprintf(b, `<line x1="%.3f" y1="%.3f" x2="%.3f" y2="%.3f" stroke="#e0e1df" stroke-width="0.8"/>`,
|
||
layout.panelX, y-13, layout.panelX+layout.panelWidth, y-13)
|
||
}
|
||
fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#1c2528" font-family="Arial, sans-serif" font-size="12" font-weight="700">%s</text>`,
|
||
layout.panelX, y, html.EscapeString(event.name))
|
||
fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#1c2528" font-family="Arial, sans-serif" font-size="11" text-anchor="end">%s</text>`,
|
||
layout.panelX+layout.panelWidth, y, html.EscapeString(event.time.In(options.Location).Format("15:04:05.0")))
|
||
fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#536063" font-family="Arial, sans-serif" font-size="10">PA %.1f° | %s %.1f°</text>`,
|
||
layout.panelX, y+18, event.frame.PositionAngleDeg, localStarOccultationSVGAltitudeLabel(options.Language), event.frame.MoonAltitudeDeg)
|
||
fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#6b7577" font-family="Arial, sans-serif" font-size="10">%s %.1f° | %s</text>`,
|
||
layout.panelX, y+34, localStarOccultationSVGAzimuthLabel(options.Language), event.frame.MoonAzimuthDeg,
|
||
html.EscapeString(localStarOccultationSVGVisibilityText(event.frame.MoonAltitudeDeg >= 0, options.Language)))
|
||
}
|
||
}
|
||
|
||
func writeLocalStarOccultationStages(
|
||
b *strings.Builder,
|
||
events []localStarOccultationEventFrame,
|
||
layout localStarOccultationSVGLayout,
|
||
options LocalStarOccultationSVGOptions,
|
||
) {
|
||
phaseTitle := occultationTitleText(localStarOccultationSVGPhasePanelsTitle(options), options.PhasePanelsTitle != "",
|
||
layout.width-2*layout.margin, 14)
|
||
fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#161a1b" font-family="Georgia, 'Times New Roman', serif" font-size="14" font-weight="700">%s</text>`,
|
||
layout.margin, layout.stageTop+13, html.EscapeString(phaseTitle))
|
||
if len(events) == 0 {
|
||
return
|
||
}
|
||
usableWidth := layout.width - 2*layout.margin
|
||
columnWidth := usableWidth / float64(len(events))
|
||
maxMoonRadius := localStarOccultationSVGMaximumMoonRadiusFromEvents(events)
|
||
radius := math.Min(46, math.Max(31, (layout.stageBottom-layout.stageTop-53)/2))
|
||
scale := radius / maxMoonRadius
|
||
cy := layout.stageTop + 34 + radius
|
||
for index, event := range events {
|
||
cx := layout.margin + columnWidth*(float64(index)+0.5)
|
||
writeLocalOccultationMoon(b, cx, cy, event.frame.MoonRadiusArcsec*scale, "stage-moon",
|
||
event.appearance, fmt.Sprintf("local-star-occultation-moon-stage-%d", index))
|
||
x := cx - event.frame.StarXArcsec*scale
|
||
y := cy - event.frame.StarYArcsec*scale
|
||
writeLocalStarOccultationStar(b, x, y, event.frame.BehindMoon, "stage-star", event.label)
|
||
fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#1c2528" font-family="Arial, sans-serif" font-size="11" font-weight="700" text-anchor="middle">%s</text>`,
|
||
cx, cy+radius+19, html.EscapeString(event.name))
|
||
fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#667174" font-family="Arial, sans-serif" font-size="10" text-anchor="middle">%s</text>`,
|
||
cx, cy+radius+34, html.EscapeString(event.time.In(options.Location).Format("15:04:05.0")))
|
||
}
|
||
}
|
||
|
||
func localStarOccultationSVGMaximumMoonRadiusFromEvents(events []localStarOccultationEventFrame) float64 {
|
||
radius := 1.0
|
||
for _, event := range events {
|
||
radius = math.Max(radius, event.frame.MoonRadiusArcsec)
|
||
}
|
||
return radius
|
||
}
|
||
|
||
func writeLocalStarOccultationFooter(
|
||
b *strings.Builder,
|
||
layout localStarOccultationSVGLayout,
|
||
options LocalStarOccultationSVGOptions,
|
||
instant time.Time,
|
||
) {
|
||
directionLines, footerLines := localOccultationFooterLines(
|
||
localStarOccultationSVGDirectionText(options),
|
||
localStarOccultationSVGFooterNote(options),
|
||
timenote.Scale(options.TimeScale, instant, options.Location, options.Language),
|
||
layout.footerY, layout.width, layout.height)
|
||
for index, line := range directionLines {
|
||
fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#4f595b" font-family="Georgia, 'Times New Roman', serif" font-size="10">%s</text>`,
|
||
layout.margin, layout.footerY+float64(index)*14-8, html.EscapeString(line))
|
||
}
|
||
for index, line := range footerLines {
|
||
fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#747c7d" font-family="Georgia, 'Times New Roman', serif" font-size="9">%s</text>`,
|
||
layout.margin, layout.footerY+float64(len(directionLines))*14+float64(index)*12-6, html.EscapeString(line))
|
||
}
|
||
}
|
||
|
||
func localStarOccultationSVGEventFrames(
|
||
info moon.StarOccultationInfo,
|
||
frames []moon.StarOccultationDiagramFrame,
|
||
language string,
|
||
) []localStarOccultationEventFrame {
|
||
times := map[string]time.Time{
|
||
"Immersion": info.Immersion,
|
||
"Greatest": info.Greatest,
|
||
"Emersion": info.Emersion,
|
||
}
|
||
labels := []string{"Immersion", "Greatest", "Emersion"}
|
||
result := make([]localStarOccultationEventFrame, 0, len(labels))
|
||
for _, label := range labels {
|
||
for _, frame := range frames {
|
||
if localStarOccultationSVGFrameHasLabel(frame, label) {
|
||
result = append(result, localStarOccultationEventFrame{
|
||
label: label,
|
||
name: localStarOccultationSVGEventName(label, language),
|
||
time: times[label],
|
||
frame: frame,
|
||
appearance: localOccultationMoonAppearanceAt(times[label], info.Observer),
|
||
})
|
||
break
|
||
}
|
||
}
|
||
}
|
||
return result
|
||
}
|
||
|
||
func localStarOccultationSVGFrameHasLabel(frame moon.StarOccultationDiagramFrame, label string) bool {
|
||
if frame.Label == label {
|
||
return true
|
||
}
|
||
for _, current := range frame.Labels {
|
||
if current == label {
|
||
return true
|
||
}
|
||
}
|
||
return false
|
||
}
|
||
|
||
func localStarOccultationSVGHeaderLines(info moon.StarOccultationInfo, options LocalStarOccultationSVGOptions) []string {
|
||
lines := make([]string, 0, 4)
|
||
for _, item := range []struct {
|
||
value string
|
||
custom bool
|
||
}{
|
||
{localStarOccultationSVGSummaryText(info, options), options.SummaryText != ""},
|
||
{localStarOccultationSVGGreatestText(info, options), options.GreatestText != ""},
|
||
} {
|
||
lines = append(lines, occultationWrappedTextLines(item.value, item.custom, float64(options.Width)-80, 13)...)
|
||
}
|
||
return lines
|
||
}
|
||
|
||
// localOccultationFooterLines 排布本地图页脚：时标声明并进补充说明后一起均衡折行，方向说明占用上方余高，两块都按行数上限截断。
|
||
func localOccultationFooterLines(
|
||
directionText, noteText, scaleNote string,
|
||
footerY, width, height float64,
|
||
) ([]string, []string) {
|
||
maxWidth := width - 80
|
||
direction := svgchart.WrapTextBalanced(directionText, maxWidth, 10)
|
||
// 默认把时标声明并进说明一起均衡折行；说明太长折不下时改成"说明截断 + 声明独占最后一行"。
|
||
mergedLines := svgchart.WrapTextBalanced(strings.TrimSpace(noteText+" "+scaleNote), maxWidth, 9)
|
||
notesOnly := svgchart.WrapTextBalanced(strings.TrimSpace(noteText), maxWidth, 9)
|
||
noteAbove, noteBelow := svgchart.EstimatedTextExtents(9)
|
||
noteHeight := noteAbove + float64(len(mergedLines)-1)*12 + noteBelow
|
||
direction = svgchart.TruncateTextLines(direction, maxWidth, 10,
|
||
svgchart.BaselineLineLimit(10, 14, footerY-8, height-svgchart.FooterBottomPadding(9)-noteHeight))
|
||
noteFirst := footerY + float64(len(direction))*14 - 6
|
||
maxNoteLines := svgchart.BaselineLineLimit(9, 12, noteFirst, height-svgchart.FooterBottomPadding(9))
|
||
noteLines := mergedLines
|
||
if len(mergedLines) > maxNoteLines {
|
||
noteLines = svgchart.FooterLinesWithScale(notesOnly, scaleNote, maxWidth, 9, maxNoteLines)
|
||
} else {
|
||
noteLines = svgchart.TruncateTextLines(mergedLines, maxWidth, 9, maxNoteLines)
|
||
}
|
||
return direction, noteLines
|
||
}
|
||
|
||
// localOccultationHeaderLineLimit 由版式的页脚预留与阶段区高度推出页眉行数上限，总览区被压到 120 px 以下时圆盘与方向标记会跑出画布。
|
||
func localOccultationHeaderLineLimit(height, footerSpace, stageHeight float64) int {
|
||
const (
|
||
stageGap = 20.0
|
||
overviewTopGap = 26.0
|
||
overviewMin = 120.0
|
||
headerStart = 72.0
|
||
)
|
||
limit := int(math.Floor((height - footerSpace - stageHeight - stageGap - overviewMin - overviewTopGap - headerStart) / 19))
|
||
if limit < 1 {
|
||
return 1
|
||
}
|
||
return limit
|
||
}
|
||
|
||
func localStarOccultationSVGTitle(info moon.StarOccultationInfo, options LocalStarOccultationSVGOptions) string {
|
||
if options.Title != "" {
|
||
return options.Title
|
||
}
|
||
target := info.TargetID
|
||
if target == "" {
|
||
if options.Language == starOccultationSVGLanguageEnglish {
|
||
target = "star"
|
||
} else {
|
||
target = "恒星"
|
||
}
|
||
}
|
||
date := info.Greatest.In(options.Location).Format("2006-01-02")
|
||
if options.Language == starOccultationSVGLanguageEnglish {
|
||
return fmt.Sprintf("%s Local Lunar Occultation of %s", date, target)
|
||
}
|
||
return fmt.Sprintf("%s 指定地点月掩%s", date, target)
|
||
}
|
||
|
||
func localStarOccultationSVGSummaryText(info moon.StarOccultationInfo, options LocalStarOccultationSVGOptions) string {
|
||
if options.SummaryText != "" {
|
||
return options.SummaryText
|
||
}
|
||
coordinates := starOccultationFormatCoordinates(info.Observer.Longitude, info.Observer.Latitude)
|
||
duration := localStarOccultationSVGFormatDuration(info.Emersion.Sub(info.Immersion), options.Language)
|
||
if options.Language == starOccultationSVGLanguageEnglish {
|
||
return fmt.Sprintf("Site %s | elevation %.0f m | %s | duration %s", coordinates, info.Observer.Height,
|
||
localStarOccultationSVGTypeName(info.Type, options.Language), duration)
|
||
}
|
||
return fmt.Sprintf("观测点 %s | 椭球高 %.0f 米 | %s | 掩星历时 %s", coordinates, info.Observer.Height,
|
||
localStarOccultationSVGTypeName(info.Type, options.Language), duration)
|
||
}
|
||
|
||
func localStarOccultationSVGGreatestText(info moon.StarOccultationInfo, options LocalStarOccultationSVGOptions) string {
|
||
if options.GreatestText != "" {
|
||
return options.GreatestText
|
||
}
|
||
value := info.Greatest.In(options.Location)
|
||
zone := starOccultationLocationLabel(value, options.Location)
|
||
if options.Language == starOccultationSVGLanguageEnglish {
|
||
return fmt.Sprintf("Greatest %s %s | minimum separation %.2f arcsec | Moon altitude %+.1f° azimuth %.1f°",
|
||
value.Format("2006-01-02 15:04:05.0"), zone, info.MinimumSeparationArcsec, info.MoonAltitudeAtGreatest, info.MoonAzimuthAtGreatest)
|
||
}
|
||
return fmt.Sprintf("掩甚 %s %s | 最小角距 %.2f 角秒 | 月球高度 %+.1f° 方位 %.1f°",
|
||
value.Format("2006-01-02 15:04:05.0"), zone, info.MinimumSeparationArcsec, info.MoonAltitudeAtGreatest, info.MoonAzimuthAtGreatest)
|
||
}
|
||
|
||
func localStarOccultationSVGOverviewTitle(options LocalStarOccultationSVGOptions) string {
|
||
if options.OverviewTitle != "" {
|
||
return options.OverviewTitle
|
||
}
|
||
if options.Language == starOccultationSVGLanguageEnglish {
|
||
return "Topocentric star track"
|
||
}
|
||
return "站心恒星轨迹"
|
||
}
|
||
|
||
func localStarOccultationSVGPhasePanelsTitle(options LocalStarOccultationSVGOptions) string {
|
||
if options.PhasePanelsTitle != "" {
|
||
return options.PhasePanelsTitle
|
||
}
|
||
if options.Language == starOccultationSVGLanguageEnglish {
|
||
return "Contact stages"
|
||
}
|
||
return "掩始、掩甚与掩终视圆"
|
||
}
|
||
|
||
func localStarOccultationSVGContactsTitle(options LocalStarOccultationSVGOptions) string {
|
||
if options.ContactsTitle != "" {
|
||
return options.ContactsTitle
|
||
}
|
||
if options.Language == starOccultationSVGLanguageEnglish {
|
||
return "Local contacts"
|
||
}
|
||
return "本地接触时刻"
|
||
}
|
||
|
||
func localStarOccultationSVGDirectionText(options LocalStarOccultationSVGOptions) string {
|
||
if options.DirectionText != "" {
|
||
return options.DirectionText
|
||
}
|
||
if options.Language == starOccultationSVGLanguageEnglish {
|
||
return "Moon fixed at center; east is left and north is up. The blue-gray dashed line is the local lunar path; the red dashed line is the star track."
|
||
}
|
||
return "月球固定在中心；图上左东右西，向上为北。灰蓝虚线为掩甚附近的站心白道，红色虚线为恒星相对月心轨迹。"
|
||
}
|
||
|
||
func localStarOccultationSVGFooterNote(options LocalStarOccultationSVGOptions) string {
|
||
if options.FooterNote != "" {
|
||
return options.FooterNote
|
||
}
|
||
if options.Language == starOccultationSVGLanguageEnglish {
|
||
return "The star is a point source; immersion and emersion occur where it crosses the topocentric apparent lunar limb. Lunar texture is schematic."
|
||
}
|
||
return "恒星按点光源绘制；掩始和掩终是恒星穿越站心月球视圆外缘的时刻，月面纹理仅作方向辅助。"
|
||
}
|
||
|
||
func localStarOccultationSVGEventName(label, language string) string {
|
||
if language == starOccultationSVGLanguageEnglish {
|
||
switch label {
|
||
case "Immersion":
|
||
return "Immersion"
|
||
case "Greatest":
|
||
return "Greatest"
|
||
case "Emersion":
|
||
return "Emersion"
|
||
}
|
||
}
|
||
switch label {
|
||
case "Immersion":
|
||
return "掩始"
|
||
case "Greatest":
|
||
return "掩甚"
|
||
case "Emersion":
|
||
return "掩终"
|
||
default:
|
||
return label
|
||
}
|
||
}
|
||
|
||
func localStarOccultationSVGTypeName(eventType moon.OccultationType, language string) string {
|
||
if language == starOccultationSVGLanguageEnglish {
|
||
if eventType == moon.OccultationGrazing {
|
||
return "grazing"
|
||
}
|
||
return "total"
|
||
}
|
||
if eventType == moon.OccultationGrazing {
|
||
return "擦边掩星"
|
||
}
|
||
return "全掩"
|
||
}
|
||
|
||
func localStarOccultationSVGFormatDuration(duration time.Duration, language string) string {
|
||
if duration < 0 {
|
||
duration = -duration
|
||
}
|
||
duration = duration.Round(100 * time.Millisecond)
|
||
hours := int(duration / time.Hour)
|
||
duration -= time.Duration(hours) * time.Hour
|
||
minutes := int(duration / time.Minute)
|
||
duration -= time.Duration(minutes) * time.Minute
|
||
seconds := float64(duration) / float64(time.Second)
|
||
if language == starOccultationSVGLanguageEnglish {
|
||
if hours > 0 {
|
||
return fmt.Sprintf("%dh %02dm %04.1fs", hours, minutes, seconds)
|
||
}
|
||
return fmt.Sprintf("%dm %04.1fs", minutes, seconds)
|
||
}
|
||
if hours > 0 {
|
||
return fmt.Sprintf("%d时%02d分%04.1f秒", hours, minutes, seconds)
|
||
}
|
||
return fmt.Sprintf("%d分%04.1f秒", minutes, seconds)
|
||
}
|
||
|
||
func localStarOccultationSVGAltitudeLabel(language string) string {
|
||
if language == starOccultationSVGLanguageEnglish {
|
||
return "alt"
|
||
}
|
||
return "高度"
|
||
}
|
||
|
||
func localStarOccultationSVGAzimuthLabel(language string) string {
|
||
if language == starOccultationSVGLanguageEnglish {
|
||
return "az"
|
||
}
|
||
return "方位"
|
||
}
|
||
|
||
func localStarOccultationSVGVisibilityText(visible bool, language string) string {
|
||
if language == starOccultationSVGLanguageEnglish {
|
||
if visible {
|
||
return "above horizon"
|
||
}
|
||
return "below horizon"
|
||
}
|
||
if visible {
|
||
return "地平线上"
|
||
}
|
||
return "地平线下"
|
||
}
|