feat: 扩展天文计算能力

- 新增日食、月食、本地可见性、中心线、半影区域、SVG 图示与沙罗周期信息 - 新增行星冲合、留、方照、物理星历、视直径、相位、亮肢角、轨道节点等计算 - 新增木星伽利略卫星位置、现象与接触事件计算 - 新增恒星星表、星座判定、自行修正与观测辅助能力 - 新增 coord、formula、orbit、sundial、lite/sun、lite/moon 等扩展包 - 完善农历年号、月相英文别名、视差角、大气质量、折射、日晷与双星计算 - 增加 NASA、JPL Horizons、IMCCE 等回归测试数据与基线测试 - 重构基础算法文件组织，补充大量公开 API 注释和语义回归测试 - 更新中文和英文 README，补充示例、精度说明、SVG 配图
2026-05-01 22:38:44 +08:00
parent 98ff574495
commit 3ffdbe0034
365 changed files with 63589 additions and 17508 deletions
@@ -0,0 +1,120 @@
+package basic
+
+import (
+	"bytes"
+	"compress/gzip"
+	_ "embed"
+	"encoding/binary"
+	"fmt"
+	"io"
+)
+
+// star_catalog.dat layout after gzip decompression:
+// magic[8] | version[1] | rawDataLen[4] | rawData | stringCount[2] |
+// repeated(stringLen[uvarint] + stringBytes) |
+// maxHR[2] | repeated(maxHR * 6 * stringIndex[2]) | repeated(maxHR * hip[4]).
+const starCatalogMagic = "STRCAT01"
+
+//go:embed star_catalog.dat
+var starCatalogCompressed []byte
+
+func initStarCatalogData() []byte {
+	reader, err := gzip.NewReader(bytes.NewReader(starCatalogCompressed))
+	if err != nil {
+		panic(err)
+	}
+	defer reader.Close()
+	payload, err := io.ReadAll(reader)
+	if err != nil {
+		panic(err)
+	}
+	data, detail, hip, err := decodeStarCatalogPayload(payload)
+	if err != nil {
+		panic(err)
+	}
+	hr2detail = detail
+	hr2hip = hip
+	return data
+}
+
+func decodeStarCatalogPayload(payload []byte) ([]byte, map[uint16][]string, map[uint16]uint32, error) {
+	reader := bytes.NewReader(payload)
+
+	var magic [len(starCatalogMagic)]byte
+	if _, err := io.ReadFull(reader, magic[:]); err != nil {
+		return nil, nil, nil, fmt.Errorf("read star catalog magic: %w", err)
+	}
+	if string(magic[:]) != starCatalogMagic {
+		return nil, nil, nil, fmt.Errorf("invalid star catalog magic %q", string(magic[:]))
+	}
+
+	version, err := reader.ReadByte()
+	if err != nil {
+		return nil, nil, nil, fmt.Errorf("read star catalog version: %w", err)
+	}
+	if version != 1 {
+		return nil, nil, nil, fmt.Errorf("unsupported star catalog version %d", version)
+	}
+
+	var rawLen uint32
+	if err := binary.Read(reader, binary.LittleEndian, &rawLen); err != nil {
+		return nil, nil, nil, fmt.Errorf("read star catalog data length: %w", err)
+	}
+	data := make([]byte, rawLen)
+	if _, err := io.ReadFull(reader, data); err != nil {
+		return nil, nil, nil, fmt.Errorf("read star catalog data: %w", err)
+	}
+
+	var stringCount uint16
+	if err := binary.Read(reader, binary.LittleEndian, &stringCount); err != nil {
+		return nil, nil, nil, fmt.Errorf("read star catalog string count: %w", err)
+	}
+	stringsTable := make([]string, int(stringCount)+1)
+	for i := 1; i < len(stringsTable); i++ {
+		length, err := binary.ReadUvarint(reader)
+		if err != nil {
+			return nil, nil, nil, fmt.Errorf("read star catalog string length: %w", err)
+		}
+		value := make([]byte, length)
+		if _, err := io.ReadFull(reader, value); err != nil {
+			return nil, nil, nil, fmt.Errorf("read star catalog string: %w", err)
+		}
+		stringsTable[i] = string(value)
+	}
+
+	var maxHR uint16
+	if err := binary.Read(reader, binary.LittleEndian, &maxHR); err != nil {
+		return nil, nil, nil, fmt.Errorf("read star catalog max HR: %w", err)
+	}
+	detail := make(map[uint16][]string)
+	for hr := uint16(1); hr <= maxHR; hr++ {
+		record := make([]string, 6)
+		hasValue := false
+		for i := range record {
+			var index uint16
+			if err := binary.Read(reader, binary.LittleEndian, &index); err != nil {
+				return nil, nil, nil, fmt.Errorf("read star catalog detail index: %w", err)
+			}
+			if int(index) >= len(stringsTable) {
+				return nil, nil, nil, fmt.Errorf("detail string index out of range: hr=%d index=%d", hr, index)
+			}
+			record[i] = stringsTable[index]
+			hasValue = hasValue || index != 0
+		}
+		if hasValue {
+			detail[hr] = record
+		}
+	}
+
+	hip := make(map[uint16]uint32)
+	for hr := uint16(1); hr <= maxHR; hr++ {
+		var value uint32
+		if err := binary.Read(reader, binary.LittleEndian, &value); err != nil {
+			return nil, nil, nil, fmt.Errorf("read star catalog HIP: %w", err)
+		}
+		if value != 0 {
+			hip[hr] = value
+		}
+	}
+	return data, detail, hip, nil
+}