439 lines
20 KiB
Go
439 lines
20 KiB
Go
|
package svg
|
|||
|
|
|
|||
|
|
import (
|
|||
|
|
"fmt"
|
|||
|
|
"html"
|
|||
|
|
"math"
|
|||
|
|
"strings"
|
|||
|
|
"time"
|
|||
|
|
|
|||
|
|
"b612.me/astro"
|
|||
|
|
"b612.me/astro/basic"
|
|||
|
|
"b612.me/astro/internal/svgchart"
|
|||
|
|
"b612.me/astro/internal/timenote"
|
|||
|
|
)
|
|||
|
|
|
|||
|
|
const (
|
|||
|
|
transitLocalDefaultWidth = 960
|
|||
|
|
transitLocalDefaultHeight = 680
|
|||
|
|
)
|
|||
|
|
|
|||
|
|
// TransitLocalSVGOptions 控制站心凌日日面图。
|
|||
|
|
// TransitLocalSVGOptions controls a topocentric planetary-transit solar-disk chart.
|
|||
|
|
type TransitLocalSVGOptions struct {
|
|||
|
|
// Width 和 Height 是 SVG 画布尺寸；宽度小于 640 或高度小于 480 时使用 960x680 默认值。
|
|||
|
|
// Width and Height are SVG canvas dimensions. Width values below 640 and height values below 480 use the 960x680 defaults.
|
|||
|
|
Width int
|
|||
|
|
Height int
|
|||
|
|
// Step 是行星轨迹采样步长；非正值使用两分钟。
|
|||
|
|
// Step is the planet-track sampling step. Non-positive values use two minutes.
|
|||
|
|
Step time.Duration
|
|||
|
|
// Language 为 "en"（不区分大小写）时使用英文，否则使用中文。
|
|||
|
|
// Language uses English for "en" (case-insensitive) and Chinese otherwise.
|
|||
|
|
Language string
|
|||
|
|
// Location 控制显示的事件时刻；nil 使用 date.Location()。
|
|||
|
|
// Location controls displayed event times. Nil uses date.Location().
|
|||
|
|
Location *time.Location
|
|||
|
|
// TimeScale 选择图中时刻的时标：零值 UTC；TimeScaleUT1 要求 Location 为 nil 或 UTC，否则返回 false。
|
|||
|
|
// TimeScale selects the label scale: the zero value is UTC; TimeScaleUT1 requires Location to be nil or UTC, otherwise the renderer returns false.
|
|||
|
|
TimeScale astro.TimeScale
|
|||
|
|
// 空文本字段使用本地化的自动标签。
|
|||
|
|
// Empty text fields use localized automatic labels.
|
|||
|
|
Title string
|
|||
|
|
FooterNote string
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// TransitLocalSVG 绘制距 date 最近一次水星或金星凌日在观测地（经度 lon、纬度 lat，东经北纬为正，海拔 height 米）
|
|||
|
|
// 的站心日面图：上北左东的天空视向，画出行星中心轨迹、各接触与凌甚时的行星圆面，以及接触时刻表。
|
|||
|
|
// 轨迹上太阳中心在视地平下（计入标准大气折射）的部分画成灰色虚线。该地几何上看不到凌日、找不到凌日或选项无效时返回 false。
|
|||
|
|
// TransitLocalSVG renders the topocentric solar-disk view of the Mercury or Venus transit closest to date, seen from
|
|||
|
|
// longitude lon and latitude lat (east and north positive) at height metres: north up and east left as on the sky, with
|
|||
|
|
// the planet-centre track, the planet disk at each contact and at greatest, and a contact table. Track parts where the
|
|||
|
|
// Sun's centre is below the apparent horizon (standard refraction) are drawn grey and dashed. It returns false when the
|
|||
|
|
// site sees no geometric transit, no transit is found or the options are invalid.
|
|||
|
|
func TransitLocalSVG(planet TransitPlanet, date time.Time, lon, lat, height float64, options TransitLocalSVGOptions) (string, bool) {
|
|||
|
|
transit, ok := closestPlanetTransit(planet, date)
|
|||
|
|
if !ok {
|
|||
|
|
return "", false
|
|||
|
|
}
|
|||
|
|
if options.TimeScale == astro.TimeScaleUT1 {
|
|||
|
|
if options.Location != nil && options.Location != time.UTC {
|
|||
|
|
return "", false
|
|||
|
|
}
|
|||
|
|
options.Location = time.UTC
|
|||
|
|
}
|
|||
|
|
local := basic.PlanetTransitLocal(transit, basic.Observer{Longitude: lon, Latitude: lat, Height: height})
|
|||
|
|
if !local.Valid {
|
|||
|
|
return "", false
|
|||
|
|
}
|
|||
|
|
if options.Step <= 0 {
|
|||
|
|
options.Step = 2 * time.Minute
|
|||
|
|
}
|
|||
|
|
frames := basic.PlanetTransitLocalFrames(transit, local, options.Step.Hours()/24)
|
|||
|
|
if len(frames) < 2 {
|
|||
|
|
return "", false
|
|||
|
|
}
|
|||
|
|
options = normalizeTransitLocalSVGOptions(date, options)
|
|||
|
|
return renderTransitLocalSVG(planet, local, frames, options), true
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
func normalizeTransitLocalSVGOptions(date time.Time, options TransitLocalSVGOptions) TransitLocalSVGOptions {
|
|||
|
|
if options.Width < 640 {
|
|||
|
|
options.Width = transitLocalDefaultWidth
|
|||
|
|
}
|
|||
|
|
if options.Height < 480 {
|
|||
|
|
options.Height = transitLocalDefaultHeight
|
|||
|
|
}
|
|||
|
|
if strings.EqualFold(options.Language, "en") {
|
|||
|
|
options.Language = "en"
|
|||
|
|
} else {
|
|||
|
|
options.Language = "zh"
|
|||
|
|
}
|
|||
|
|
if options.Location == nil {
|
|||
|
|
options.Location = date.Location()
|
|||
|
|
}
|
|||
|
|
return options
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// transitLocalEvent 是日面上标注的一个接触或凌甚。
|
|||
|
|
type transitLocalEvent struct {
|
|||
|
|
label, name string
|
|||
|
|
contact basic.PlanetTransitLocalContact
|
|||
|
|
separation float64
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
func transitLocalEvents(local basic.PlanetTransitLocalResult, language string) []transitLocalEvent {
|
|||
|
|
names := []string{"一触", "二触", "凌甚", "三触", "四触"}
|
|||
|
|
if language == "en" {
|
|||
|
|
names = []string{"C1", "C2", "Greatest", "C3", "C4"}
|
|||
|
|
}
|
|||
|
|
external := local.SunSemidiameterArcsec + local.PlanetSemidiameterArcsec
|
|||
|
|
internal := local.SunSemidiameterArcsec - local.PlanetSemidiameterArcsec
|
|||
|
|
candidates := []transitLocalEvent{
|
|||
|
|
{"C1", names[0], local.ExternalIngress, external},
|
|||
|
|
{"C2", names[1], local.InternalIngress, internal},
|
|||
|
|
{"G", names[2], local.Greatest, local.MinimumSeparationArcsec},
|
|||
|
|
{"C3", names[3], local.InternalEgress, internal},
|
|||
|
|
{"C4", names[4], local.ExternalEgress, external},
|
|||
|
|
}
|
|||
|
|
events := candidates[:0]
|
|||
|
|
for _, event := range candidates {
|
|||
|
|
if event.contact.Valid {
|
|||
|
|
events = append(events, event)
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
return events
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// transitLocalSunUp 判断太阳中心几何高度 altitude 是否在视地平上（标准大气折射）。
|
|||
|
|
func transitLocalSunUp(altitude float64) bool {
|
|||
|
|
return altitude > -basic.RefractionFromApparentAltitude(0, transitMapRefractionPressureHPa, transitMapRefractionTemperatureC)
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
func transitDisplayTime(value time.Time, scale astro.TimeScale, location *time.Location) time.Time {
|
|||
|
|
if value.IsZero() {
|
|||
|
|
return value
|
|||
|
|
}
|
|||
|
|
if scale == astro.TimeScaleUT1 {
|
|||
|
|
return basic.UT1FromUTC(value)
|
|||
|
|
}
|
|||
|
|
return value.In(location)
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
func renderTransitLocalSVG(
|
|||
|
|
planet TransitPlanet,
|
|||
|
|
local basic.PlanetTransitLocalResult,
|
|||
|
|
frames []basic.PlanetTransitLocalFrame,
|
|||
|
|
options TransitLocalSVGOptions,
|
|||
|
|
) string {
|
|||
|
|
width, height := float64(options.Width), float64(options.Height)
|
|||
|
|
at := func(jd float64) time.Time {
|
|||
|
|
return transitDisplayTime(basic.JD2DateByZone(jd, time.UTC, false), options.TimeScale, options.Location)
|
|||
|
|
}
|
|||
|
|
title := options.Title
|
|||
|
|
if title == "" {
|
|||
|
|
date := at(local.Greatest.JD).Format("2006-01-02")
|
|||
|
|
if options.Language == "en" {
|
|||
|
|
title = fmt.Sprintf("%s Transit of %s, Local Circumstances", date, transitMapPlanetName(planet, "en"))
|
|||
|
|
} else {
|
|||
|
|
title = fmt.Sprintf("%s %s凌日站心图", date, transitMapPlanetName(planet, "zh"))
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
site := transitLocalSiteText(local.Observer, options.Language)
|
|||
|
|
summary := transitLocalSummaryText(local, 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><radialGradient id="transit-sun" cx="40%" cy="34%" r="64%"><stop offset="0%" stop-color="#fff8bb"/><stop offset="58%" stop-color="#ffd55f"/><stop offset="100%" stop-color="#f5a623"/></radialGradient></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"/>`, width-44, height-36)
|
|||
|
|
titleText := title
|
|||
|
|
if options.Title != "" {
|
|||
|
|
titleText = svgchart.EllipsizeText(title, width-52, 24)
|
|||
|
|
}
|
|||
|
|
fmt.Fprintf(&b, `<text x="%.3f" y="47" fill="#111111" font-family="Georgia, 'Times New Roman', serif" font-size="24" font-weight="700" text-anchor="middle">%s</text>`,
|
|||
|
|
width/2, html.EscapeString(titleText))
|
|||
|
|
for index, line := range []string{site, summary} {
|
|||
|
|
fmt.Fprintf(&b, `<text x="%.3f" y="%.3f" fill="#333" font-family="Georgia, 'Times New Roman', serif" font-size="13" text-anchor="middle">%s</text>`,
|
|||
|
|
width/2, 72+float64(index)*19, html.EscapeString(line))
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// 日面区占左侧，接触表占右侧。
|
|||
|
|
panelWidth := 300.0
|
|||
|
|
top, bottom := 112.0, height-86
|
|||
|
|
diskLeft, diskRight := 46.0, width-panelWidth-60
|
|||
|
|
cx, cy := (diskLeft+diskRight)/2, (top+bottom)/2
|
|||
|
|
extent := local.SunSemidiameterArcsec + 2.2*local.PlanetSemidiameterArcsec + 60
|
|||
|
|
scale := math.Min((diskRight-diskLeft)/2, (bottom-top)/2) / extent
|
|||
|
|
mapX := func(x float64) float64 { return cx - x*scale } // 东在左
|
|||
|
|
mapY := func(y float64) float64 { return cy - y*scale }
|
|||
|
|
sunRadius := local.SunSemidiameterArcsec * scale
|
|||
|
|
fmt.Fprintf(&b, `<circle class="transit-sun" cx="%.3f" cy="%.3f" r="%.3f" fill="url(#transit-sun)" stroke="#c78211" stroke-width="1.4"/>`, cx, cy, sunRadius)
|
|||
|
|
writeTransitLocalAxes(&b, cx, cy, sunRadius, options.Language)
|
|||
|
|
writeTransitLocalTrack(&b, frames, mapX, mapY)
|
|||
|
|
|
|||
|
|
events := transitLocalEvents(local, options.Language)
|
|||
|
|
planetRadius := math.Max(local.PlanetSemidiameterArcsec*scale, 2)
|
|||
|
|
table := &svgchart.LabelTable{}
|
|||
|
|
for _, event := range events {
|
|||
|
|
x, y := transitLocalEventPosition(frames, event.contact.JD, mapX, mapY)
|
|||
|
|
fill, stroke := "#1d1d1d", "#000000"
|
|||
|
|
if !transitLocalSunUp(event.contact.SunAltitudeDeg) {
|
|||
|
|
fill, stroke = "#9a9a9a", "#6d6d6d"
|
|||
|
|
}
|
|||
|
|
fmt.Fprintf(&b, `<circle class="transit-planet-%s" cx="%.3f" cy="%.3f" r="%.3f" fill="%s" fill-opacity="0.92" stroke="%s" stroke-width="0.8"/>`,
|
|||
|
|
strings.ToLower(event.label), x, y, planetRadius, fill, stroke)
|
|||
|
|
table.Reserve(x-planetRadius, y-planetRadius, 2*planetRadius, 2*planetRadius)
|
|||
|
|
}
|
|||
|
|
for _, event := range events {
|
|||
|
|
x, y := transitLocalEventPosition(frames, event.contact.JD, mapX, mapY)
|
|||
|
|
// 标签放在远离日心的一侧，避开日面内的轨迹与圆面。
|
|||
|
|
dx, dy := x-cx, y-cy
|
|||
|
|
norm := math.Hypot(dx, dy)
|
|||
|
|
if norm < 1e-6 {
|
|||
|
|
dx, dy, norm = 0, -1, 1
|
|||
|
|
}
|
|||
|
|
text := event.name + " " + at(event.contact.JD).Format("15:04:05")
|
|||
|
|
var placement svgchart.LabelPlacement
|
|||
|
|
placed := false
|
|||
|
|
// 相邻接触相隔仅数分钟时近处位次全被占，逐圈外推并画引线，不得丢标签。
|
|||
|
|
for ring := 0; ring < 6 && !placed; ring++ {
|
|||
|
|
offset := planetRadius + 12 + float64(ring)*16
|
|||
|
|
candidates := []svgchart.LabelPlacement{}
|
|||
|
|
for _, turn := range []float64{0, 0.5, -0.5, 1, -1} {
|
|||
|
|
ux := dx/norm*math.Cos(turn) - dy/norm*math.Sin(turn)
|
|||
|
|
uy := dx/norm*math.Sin(turn) + dy/norm*math.Cos(turn)
|
|||
|
|
anchor := "start"
|
|||
|
|
if ux < -0.3 {
|
|||
|
|
anchor = "end"
|
|||
|
|
} else if ux < 0.3 {
|
|||
|
|
anchor = "middle"
|
|||
|
|
}
|
|||
|
|
candidate := svgchart.LabelPlacement{X: x + ux*offset, Y: y + uy*offset + 4, Anchor: anchor}
|
|||
|
|
// 标签平移进白色图框内、接触表左侧，不能伸出画面。
|
|||
|
|
box := svgchart.LabelTextBox(candidate.X, candidate.Y, 11, text, anchor)
|
|||
|
|
candidate.X += math.Max(0, 30-box.X) - math.Max(0, box.X+box.Width-(width-panelWidth-44))
|
|||
|
|
candidate.Y += math.Max(0, top-8-box.Y) - math.Max(0, box.Y+box.Height-(height-30))
|
|||
|
|
candidates = append(candidates, candidate)
|
|||
|
|
}
|
|||
|
|
placement, placed = table.Place(text, 11, candidates)
|
|||
|
|
if placed && transitLocalLabelGap(placement, text, x, y) > planetRadius+16 {
|
|||
|
|
// 引线连到标签框上离接触点最近的位置。
|
|||
|
|
box := svgchart.LabelTextBox(placement.X, placement.Y, 11, text, placement.Anchor)
|
|||
|
|
endX := math.Max(box.X, math.Min(x, box.X+box.Width))
|
|||
|
|
endY := math.Max(box.Y, math.Min(y, box.Y+box.Height))
|
|||
|
|
fmt.Fprintf(&b, `<line class="transit-event-leader" x1="%.3f" y1="%.3f" x2="%.3f" y2="%.3f" stroke="#555" stroke-width="0.7" opacity="0.7"/>`,
|
|||
|
|
x, y, endX, endY)
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
if !placed {
|
|||
|
|
continue
|
|||
|
|
}
|
|||
|
|
fmt.Fprintf(&b, `<text class="transit-event-label" x="%.3f" y="%.3f" fill="#222" stroke="#ffffff" stroke-width="2.6" paint-order="stroke" font-family="Arial, sans-serif" font-size="11" text-anchor="%s">%s</text>`,
|
|||
|
|
placement.X, placement.Y, placement.Anchor, html.EscapeString(text))
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
writeTransitLocalContactTable(&b, local, events, at, width-panelWidth-36, top+10, panelWidth, options.Language)
|
|||
|
|
writeTransitLocalFooter(&b, local, options, width, height)
|
|||
|
|
b.WriteString(`</svg>`)
|
|||
|
|
return b.String()
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// transitLocalLabelGap 是接触点到标签框的最近距离。
|
|||
|
|
func transitLocalLabelGap(placement svgchart.LabelPlacement, text string, x, y float64) float64 {
|
|||
|
|
box := svgchart.LabelTextBox(placement.X, placement.Y, 11, text, placement.Anchor)
|
|||
|
|
return math.Hypot(x-math.Max(box.X, math.Min(x, box.X+box.Width)), y-math.Max(box.Y, math.Min(y, box.Y+box.Height)))
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
func transitLocalSiteText(observer basic.Observer, language string) string {
|
|||
|
|
ew, ns := "E", "N"
|
|||
|
|
if language != "en" {
|
|||
|
|
ew, ns = "东经", "北纬"
|
|||
|
|
}
|
|||
|
|
lon, lat := observer.Longitude, observer.Latitude
|
|||
|
|
if lon < 0 {
|
|||
|
|
ew = map[bool]string{true: "W", false: "西经"}[language == "en"]
|
|||
|
|
lon = -lon
|
|||
|
|
}
|
|||
|
|
if lat < 0 {
|
|||
|
|
ns = map[bool]string{true: "S", false: "南纬"}[language == "en"]
|
|||
|
|
lat = -lat
|
|||
|
|
}
|
|||
|
|
if language == "en" {
|
|||
|
|
return fmt.Sprintf("Site %.4f°%s %.4f°%s, height %.0f m", lon, ew, lat, ns, observer.Height)
|
|||
|
|
}
|
|||
|
|
return fmt.Sprintf("观测地 %s %.4f° %s %.4f°，海拔 %.0f 米", ew, lon, ns, lat, observer.Height)
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
func transitLocalSummaryText(local basic.PlanetTransitLocalResult, language string) string {
|
|||
|
|
kind := map[bool]string{true: "完整凌日", false: "掠凌（无内切接触）"}[local.HasInternal]
|
|||
|
|
visible := map[bool]string{true: "可见", false: "全程太阳在地平下"}[local.Visible]
|
|||
|
|
if language == "en" {
|
|||
|
|
kind = map[bool]string{true: "full transit", false: "grazing transit (no internal contacts)"}[local.HasInternal]
|
|||
|
|
visible = map[bool]string{true: "visible", false: "Sun below the horizon throughout"}[local.Visible]
|
|||
|
|
return fmt.Sprintf("Topocentric %s, %s | minimum separation %.1f″ | Sun %.1f″ | planet %.2f″",
|
|||
|
|
kind, visible, local.MinimumSeparationArcsec, local.SunSemidiameterArcsec, local.PlanetSemidiameterArcsec)
|
|||
|
|
}
|
|||
|
|
return fmt.Sprintf("站心%s，%s | 最小角距 %.1f″ | 太阳视半径 %.1f″ | 行星视半径 %.2f″",
|
|||
|
|
kind, visible, local.MinimumSeparationArcsec, local.SunSemidiameterArcsec, local.PlanetSemidiameterArcsec)
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// writeTransitLocalAxes 画过日心的南北、东西虚线与方向字。
|
|||
|
|
func writeTransitLocalAxes(b *strings.Builder, cx, cy, radius float64, language string) {
|
|||
|
|
reach := radius + 18
|
|||
|
|
fmt.Fprintf(b, `<line x1="%.3f" y1="%.3f" x2="%.3f" y2="%.3f" stroke="#8b6a2b" stroke-width="0.8" stroke-dasharray="3 4" stroke-opacity="0.7"/>`, cx, cy-reach, cx, cy+reach)
|
|||
|
|
fmt.Fprintf(b, `<line x1="%.3f" y1="%.3f" x2="%.3f" y2="%.3f" stroke="#8b6a2b" stroke-width="0.8" stroke-dasharray="3 4" stroke-opacity="0.7"/>`, cx-reach, cy, cx+reach, cy)
|
|||
|
|
labels := [4]string{"北", "南", "东", "西"}
|
|||
|
|
if language == "en" {
|
|||
|
|
labels = [4]string{"N", "S", "E", "W"}
|
|||
|
|
}
|
|||
|
|
for index, item := range []struct{ x, y float64 }{
|
|||
|
|
{cx, cy - reach - 6}, {cx, cy + reach + 16}, {cx - reach - 12, cy + 5}, {cx + reach + 12, cy + 5},
|
|||
|
|
} {
|
|||
|
|
fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#6b5222" font-family="Georgia, 'Times New Roman', serif" font-size="13" text-anchor="middle">%s</text>`,
|
|||
|
|
item.x, item.y, labels[index])
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// writeTransitLocalTrack 画行星中心轨迹：太阳在视地平上的段为实线，地平下为灰色虚线。
|
|||
|
|
func writeTransitLocalTrack(b *strings.Builder, frames []basic.PlanetTransitLocalFrame, mapX, mapY func(float64) float64) {
|
|||
|
|
start := 0
|
|||
|
|
for index := 1; index <= len(frames); index++ {
|
|||
|
|
if index < len(frames) && transitLocalSunUp(frames[index].SunAltitudeDeg) == transitLocalSunUp(frames[start].SunAltitudeDeg) {
|
|||
|
|
continue
|
|||
|
|
}
|
|||
|
|
// 段尾取下一段首点，相邻两段首尾相接。
|
|||
|
|
end := index
|
|||
|
|
if end == len(frames) {
|
|||
|
|
end--
|
|||
|
|
}
|
|||
|
|
class, color, dash := "transit-track", "#24518a", "none"
|
|||
|
|
if !transitLocalSunUp(frames[start].SunAltitudeDeg) {
|
|||
|
|
class, color, dash = "transit-track-below-horizon", "#8a8a8a", "5 4"
|
|||
|
|
}
|
|||
|
|
fmt.Fprintf(b, `<path class="%s" d="`, class)
|
|||
|
|
for position := start; position <= end; position++ {
|
|||
|
|
command := "L"
|
|||
|
|
if position == start {
|
|||
|
|
command = "M"
|
|||
|
|
}
|
|||
|
|
fmt.Fprintf(b, `%s %.3f %.3f `, command, mapX(frames[position].PlanetXArcsec), mapY(frames[position].PlanetYArcsec))
|
|||
|
|
}
|
|||
|
|
fmt.Fprintf(b, `" fill="none" stroke="%s" stroke-width="1.4" stroke-dasharray="%s" stroke-linecap="round"/>`, color, dash)
|
|||
|
|
start = index
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// transitLocalEventPosition 取时刻最接近 jd 的采样帧位置；接触与凌甚时刻本身在采样里。
|
|||
|
|
func transitLocalEventPosition(frames []basic.PlanetTransitLocalFrame, jd float64, mapX, mapY func(float64) float64) (float64, float64) {
|
|||
|
|
best := 0
|
|||
|
|
for index := range frames {
|
|||
|
|
if math.Abs(frames[index].JD-jd) < math.Abs(frames[best].JD-jd) {
|
|||
|
|
best = index
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
return mapX(frames[best].PlanetXArcsec), mapY(frames[best].PlanetYArcsec)
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
func writeTransitLocalContactTable(
|
|||
|
|
b *strings.Builder,
|
|||
|
|
local basic.PlanetTransitLocalResult,
|
|||
|
|
events []transitLocalEvent,
|
|||
|
|
at func(float64) time.Time,
|
|||
|
|
x, y, width float64,
|
|||
|
|
language string,
|
|||
|
|
) {
|
|||
|
|
heading := [4]string{"接触时刻", "时刻", "太阳高度", "方位"}
|
|||
|
|
if language == "en" {
|
|||
|
|
heading = [4]string{"Contacts", "Time", "Sun alt.", "Az."}
|
|||
|
|
}
|
|||
|
|
fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#111" font-family="Georgia, 'Times New Roman', serif" font-size="15" font-weight="700">%s</text>`, x, y, heading[0])
|
|||
|
|
columns := []float64{x, x + 78, x + 176, x + 252}
|
|||
|
|
rowY := y + 26
|
|||
|
|
for index, text := range []string{"", heading[1], heading[2], heading[3]} {
|
|||
|
|
fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#555" font-family="Arial, sans-serif" font-size="11">%s</text>`, columns[index], rowY, text)
|
|||
|
|
}
|
|||
|
|
fmt.Fprintf(b, `<line x1="%.3f" y1="%.3f" x2="%.3f" y2="%.3f" stroke="#bbb" stroke-width="0.8"/>`, x, rowY+6, x+width-8, rowY+6)
|
|||
|
|
for _, event := range events {
|
|||
|
|
rowY += 22
|
|||
|
|
fill := "#222"
|
|||
|
|
if !transitLocalSunUp(event.contact.SunAltitudeDeg) {
|
|||
|
|
fill = "#8a8a8a"
|
|||
|
|
}
|
|||
|
|
cells := []string{
|
|||
|
|
event.name,
|
|||
|
|
at(event.contact.JD).Format("15:04:05"),
|
|||
|
|
fmt.Sprintf("%+.1f°", event.contact.SunAltitudeDeg),
|
|||
|
|
fmt.Sprintf("%.1f°", event.contact.SunAzimuthDeg),
|
|||
|
|
}
|
|||
|
|
for index, text := range cells {
|
|||
|
|
fmt.Fprintf(b, `<text class="transit-contact-row" x="%.3f" y="%.3f" fill="%s" font-family="Arial, sans-serif" font-size="12">%s</text>`,
|
|||
|
|
columns[index], rowY, fill, html.EscapeString(text))
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
rowY += 30
|
|||
|
|
lines := []string{}
|
|||
|
|
duration := time.Duration((local.ExternalEgress.JD - local.ExternalIngress.JD) * 86400 * float64(time.Second)).Round(time.Second)
|
|||
|
|
if language == "en" {
|
|||
|
|
lines = append(lines, "Duration C1–C4 "+duration.String())
|
|||
|
|
} else {
|
|||
|
|
lines = append(lines, "一触至四触历时 "+duration.String())
|
|||
|
|
}
|
|||
|
|
for _, item := range []struct {
|
|||
|
|
jd float64
|
|||
|
|
zh, en string
|
|||
|
|
}{{local.Sunrise, "凌日中日出 ", "Sunrise during transit "}, {local.Sunset, "凌日中日落 ", "Sunset during transit "}} {
|
|||
|
|
if item.jd == 0 {
|
|||
|
|
continue
|
|||
|
|
}
|
|||
|
|
label := item.zh
|
|||
|
|
if language == "en" {
|
|||
|
|
label = item.en
|
|||
|
|
}
|
|||
|
|
lines = append(lines, label+at(item.jd).Format("15:04:05"))
|
|||
|
|
}
|
|||
|
|
for _, line := range lines {
|
|||
|
|
fmt.Fprintf(b, `<text x="%.3f" y="%.3f" fill="#333" font-family="Arial, sans-serif" font-size="12">%s</text>`, x, rowY, html.EscapeString(line))
|
|||
|
|
rowY += 19
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
func writeTransitLocalFooter(b *strings.Builder, local basic.PlanetTransitLocalResult, options TransitLocalSVGOptions, width, height float64) {
|
|||
|
|
note := options.FooterNote
|
|||
|
|
if note == "" {
|
|||
|
|
if options.Language == "en" {
|
|||
|
|
note = "Sky view, north up and east left. Topocentric contacts; Sun altitudes are geometric centre altitudes, grey parts have the Sun's centre below the apparent horizon (standard refraction)."
|
|||
|
|
} else {
|
|||
|
|
note = "天空视向，上北左东；站心接触时刻，太阳高度为日心几何高度，灰色部分太阳中心在视地平下（计入标准大气折射）。"
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
scaleNote := timenote.Scale(options.TimeScale, basic.JD2DateByZone(local.Greatest.JD, time.UTC, false), options.Location, options.Language)
|
|||
|
|
lines := svgchart.FooterLinesWithScale(svgchart.WrapText(note, width-80, 12), scaleNote, width-80, 12, 3)
|
|||
|
|
baselines, _ := svgchart.FooterBlock(len(lines), height, 12, svgchart.FooterLineHeight(12), svgchart.FooterBottomPadding(12)+18)
|
|||
|
|
for index, line := range lines {
|
|||
|
|
fmt.Fprintf(b, `<text x="40" y="%.3f" fill="#555" font-family="Georgia, 'Times New Roman', serif" font-size="12">%s</text>`,
|
|||
|
|
baselines[index], html.EscapeString(line))
|
|||
|
|
}
|
|||
|
|
}
|