feat: 完善日月食与月掩几何链路并扩展历法接口

- 新增日月食中心带、偏食带、阴影足迹、等时线、食分线及升落边界计算，支持极区与混合食拓扑 - 新增日食单时刻阴影求解器、站心状态查询、批量采样和 ΔT 覆盖接口 - 重构恒星与行星月掩路径，补充有限盘面接触、站心修正、掩带宽度、极区投影及升落边界 - 扩展 SVG 与 GeoJSON 输出，支持详细面板、全球/极区/地球投影、边界闭合、时间标记和拓扑签名 - 扩展日月食候选搜索、局地搜索、沙罗序列预计算与范围外推，补充系列锚点和成员一致性校验 - 补齐古历纪年、儒略历独有闰日、多公历候选、历法改革跨日及精确日期运算接口 - 优化 ΔT、章动、恒星时、月球地平线、事件根搜索和本地星历缓存，降低重复计算开销并提升边界稳定
2026-09-17 12:27:40 +08:00
parent 9ee2163cc7
commit 2bf8478639
428 changed files with 85981 additions and 7998 deletions
@@ -0,0 +1,119 @@
+package svg
+
+import (
+	"encoding/xml"
+	"io"
+	"strconv"
+	"strings"
+	"testing"
+	"time"
+
+	"b612.me/astro/eclipse"
+	"b612.me/astro/internal/svgmap"
+)
+
+func TestSolarSVGUsesAuthoritativeCentralBand(t *testing.T) {
+	zone := time.FixedZone("UTC+8", 8*3600)
+	for _, fixture := range []struct {
+		date     time.Time
+		lon, lat float64
+	}{
+		{time.Date(2012, 5, 21, 0, 0, 0, 0, zone), 120.4913, 27.4779},
+		{time.Date(2056, 7, 13, 0, 0, 0, 0, zone), -64.3737, -5.4978},
+		{time.Date(2164, 3, 23, 0, 0, 0, 0, zone), -120.575, 48.75},
+		{time.Date(2026, 8, 12, 0, 0, 0, 0, zone), -5.991755201, 45.070085755},
+	} {
+		t.Run(fixture.date.Format("2006-01-02"), func(t *testing.T) {
+			partial, ok := eclipse.SolarEclipsePartialFootprints(fixture.date, eclipse.SolarEclipsePartialFootprintOptions{Step: 2 * time.Minute, BoundaryPoints: 96})
+			if !ok {
+				t.Fatal("missing eclipse")
+			}
+			central, ok := eclipse.SolarEclipseCentralPath(fixture.date, eclipse.SolarEclipsePathOptions{Step: 2 * time.Minute})
+			if !ok {
+				t.Fatal("missing central path")
+			}
+			frame := svgmap.Frame{Width: 36000, Height: 18000, Projection: svgmap.ProjectionEquirectangular}
+			var builder strings.Builder
+			writeSolarEclipseCentralPath(&builder, central, partial.CentralBandFootprints, partial.CentralBandSegments, frame, partial.Eclipse.Type)
+			if !strings.Contains(builder.String(), `class="central-eclipse-band" data-source="besselian-critical-envelope"`) {
+				t.Fatal("old central fill used")
+			}
+			x, y, _ := frame.Project(fixture.lon, fixture.lat)
+			inside := false
+			for _, ring := range svgClosedPathRings(t, builder.String()) {
+				inside = inside || pointInLunarVisibilityPolygon(x, y, ring)
+			}
+			if !inside {
+				t.Fatal("rendered central band omits visible site")
+			}
+			full, ok := SolarEclipseMapSVG(fixture.date, SolarEclipseMapSVGOptions{Projection: EclipseMapProjectionEquirectangular})
+			if !ok || !strings.Contains(full, `class="central-eclipse-band" data-source="besselian-critical-envelope"`) {
+				t.Fatal("public SVG does not use core envelope")
+			}
+		})
+	}
+}
+
+func svgClosedPathRings(t *testing.T, value string) [][][2]float64 {
+	t.Helper()
+	decoder := xml.NewDecoder(strings.NewReader(value))
+	var rings [][][2]float64
+	for {
+		token, err := decoder.Token()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			t.Fatal(err)
+		}
+		tag, ok := token.(xml.StartElement)
+		if !ok || tag.Name.Local != "path" {
+			continue
+		}
+		for _, attribute := range tag.Attr {
+			if attribute.Name.Local != "d" || !strings.Contains(attribute.Value, "Z") {
+				continue
+			}
+			fields := strings.Fields(attribute.Value)
+			var ring [][2]float64
+			for index := 0; index < len(fields); {
+				if fields[index] == "Z" {
+					rings = append(rings, ring)
+					ring = nil
+					index++
+					continue
+				}
+				if (fields[index] != "M" && fields[index] != "L") || index+2 >= len(fields) {
+					t.Fatalf("unexpected path %q", attribute.Value)
+				}
+				x, err := strconv.ParseFloat(fields[index+1], 64)
+				if err != nil {
+					t.Fatal(err)
+				}
+				y, err := strconv.ParseFloat(fields[index+2], 64)
+				if err != nil {
+					t.Fatal(err)
+				}
+				ring = append(ring, [2]float64{x, y})
+				index += 3
+			}
+		}
+	}
+	return rings
+}
+
+func TestSolarPolarSVGUsesAuthoritativeCentralBand(t *testing.T) {
+	for _, day := range [][3]int{
+		{2003, 11, 23}, {2021, 12, 4}, {2039, 12, 15}, {2061, 10, 13}, {2981, 10, 19},
+	} {
+		date := time.Date(day[0], time.Month(day[1]), day[2], 0, 0, 0, 0, time.UTC)
+		t.Run(date.Format("2006-01-02"), func(t *testing.T) {
+			for _, projection := range []EclipseMapProjection{EclipseMapProjectionEquirectangular, EclipseMapProjectionSouthPolar} {
+				value, ok := SolarEclipseMapSVG(date, SolarEclipseMapSVGOptions{Projection: projection})
+				if !ok || !strings.Contains(value, `class="central-eclipse-band" data-source="besselian-critical-envelope"`) {
+					t.Fatalf("projection %s discarded the core central envelope", projection)
+				}
+			}
+		})
+	}
+}