Files
astro/internal/svgmap/seam_test.go
T
b612 16c62a97d5 feat: 完善时标与天象几何计算并扩展输出接口
- 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
2026-09-23 18:55:12 +08:00

93 lines
3.4 KiB
Go

package svgmap
import (
"math"
"testing"
)
// 居中经线对面的接缝同时是画面左右边缘:贴右边缘的分段必须落在窗口右端,
// 折回左端会让闭合边横穿整幅图。
func TestEquirectangularSeamKeepsBothWindowEdges(t *testing.T) {
frame := Frame{X: 52, Y: 168, Width: 610.8, Height: 305.4,
Projection: ProjectionEquirectangular, CenterLongitude: 176.271}
left := frame.CenterLongitude - 180
right := frame.CenterLongitude + 180
if x, _, _ := frame.Project(left, 0); math.Abs(x-frame.X) > 1e-9 {
t.Fatalf("seam at the left edge maps to x=%.6f, want %.6f", x, frame.X)
}
if x, _, _ := frame.Project(right, 0); math.Abs(x-(frame.X+frame.Width)) > 1e-9 {
t.Fatalf("the same seam in the adjacent world maps to x=%.6f, want %.6f", x, frame.X+frame.Width)
}
if x, _, _ := frame.Project(right-0.5, 0); x >= frame.X+frame.Width {
t.Fatalf("a point just west of the seam maps to x=%.6f, want inside the frame", x)
}
ring := make([]GeoPoint, 0, 40)
for longitude := -10.0; longitude <= 5; longitude += 5 {
ring = append(ring, GeoPoint{Longitude: longitude, Latitude: 0})
}
for latitude := 5.0; latitude <= 20; latitude += 5 {
ring = append(ring, GeoPoint{Longitude: 5, Latitude: latitude})
}
for longitude := 0.0; longitude >= -10; longitude -= 5 {
ring = append(ring, GeoPoint{Longitude: longitude, Latitude: 20})
}
for latitude := 15.0; latitude >= 5; latitude -= 5 {
ring = append(ring, GeoPoint{Longitude: -10, Latitude: latitude})
}
fragments := PolygonFragments(ring, frame.Clip())
if len(fragments) != 2 {
t.Fatalf("straddling ring fragments = %d, want 2", len(fragments))
}
for index, fragment := range fragments {
minX, maxX := math.Inf(1), math.Inf(-1)
for _, point := range fragment {
x, _, ok := frame.Project(point.Longitude, point.Latitude)
if !ok {
t.Fatalf("fragment %d dropped a point", index)
}
minX, maxX = math.Min(minX, x), math.Max(maxX, x)
}
if maxX-minX > frame.Width/2 {
t.Fatalf("fragment %d spans %.3f px, want one side of the seam only", index, maxX-minX)
}
}
}
// 绕极点一圈的环靠地图上边缘闭合,闭合边两端必须分贴左右边缘。
func TestEquirectangularPoleClosureUsesMapEdges(t *testing.T) {
frame := Frame{X: 52, Y: 168, Width: 610.8, Height: 305.4,
Projection: ProjectionEquirectangular, CenterLongitude: 176.271}
ring := make([]GeoPoint, 0, 36)
for longitude := -180.0; longitude < 180; longitude += 10 {
ring = append(ring, GeoPoint{Longitude: longitude, Latitude: 70})
}
fragments := PolygonFragments(ring, frame.Clip())
if len(fragments) != 1 {
t.Fatalf("cap ring fragments = %d, want 1", len(fragments))
}
left, right, top := false, false, false
for _, point := range fragments[0] {
if math.Abs(point.Latitude) < 89.999 {
continue
}
x, y, _ := frame.Project(point.Longitude, point.Latitude)
if math.Abs(y-frame.Y) > 1e-6 {
t.Fatalf("pole closure at y=%.3f, want the map top edge %.3f", y, frame.Y)
}
switch {
case math.Abs(x-frame.X) < 1e-6:
left = true
case math.Abs(x-(frame.X+frame.Width)) < 1e-6:
right = true
}
top = true
}
if !top || !left || !right {
t.Fatalf("pole closure left=%v right=%v top=%v, want the cap closed along both edges", left, right, top)
}
if fragments := PolygonFragments(ring, ClipView{Projection: ProjectionEquirectangular}); len(fragments) != 1 {
t.Fatalf("uncentred cap fragments = %d, want 1", len(fragments))
}
}