summaryrefslogtreecommitdiff
path: root/vendor/github.com/golang/geo/s2/cap_test.go
diff options
context:
space:
mode:
Diffstat (limited to 'vendor/github.com/golang/geo/s2/cap_test.go')
-rw-r--r--vendor/github.com/golang/geo/s2/cap_test.go718
1 files changed, 718 insertions, 0 deletions
diff --git a/vendor/github.com/golang/geo/s2/cap_test.go b/vendor/github.com/golang/geo/s2/cap_test.go
new file mode 100644
index 0000000..a8ab810
--- /dev/null
+++ b/vendor/github.com/golang/geo/s2/cap_test.go
@@ -0,0 +1,718 @@
+/*
+Copyright 2014 Google Inc. All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package s2
+
+import (
+ "math"
+ "testing"
+
+ "github.com/golang/geo/r3"
+ "github.com/golang/geo/s1"
+)
+
+const (
+ tinyRad = 1e-10
+)
+
+var (
+ emptyCap = EmptyCap()
+ fullCap = FullCap()
+ defaultCap = EmptyCap()
+
+ zeroHeight = 0.0
+ fullHeight = 2.0
+ emptyHeight = -1.0
+
+ xAxisPt = Point{r3.Vector{1, 0, 0}}
+ yAxisPt = Point{r3.Vector{0, 1, 0}}
+
+ xAxis = CapFromPoint(xAxisPt)
+ yAxis = CapFromPoint(yAxisPt)
+ xComp = xAxis.Complement()
+
+ hemi = CapFromCenterHeight(PointFromCoords(1, 0, 1), 1)
+ concave = CapFromCenterAngle(PointFromLatLng(LatLngFromDegrees(80, 10)), s1.Angle(150.0)*s1.Degree)
+ tiny = CapFromCenterAngle(PointFromCoords(1, 2, 3), s1.Angle(tinyRad))
+)
+
+func TestCapBasicEmptyFullValid(t *testing.T) {
+ tests := []struct {
+ got Cap
+ empty, full, valid bool
+ }{
+ {Cap{}, false, false, false},
+
+ {emptyCap, true, false, true},
+ {emptyCap.Complement(), false, true, true},
+ {fullCap, false, true, true},
+ {fullCap.Complement(), true, false, true},
+ {defaultCap, true, false, true},
+
+ {xComp, false, true, true},
+ {xComp.Complement(), true, false, true},
+
+ {tiny, false, false, true},
+ {concave, false, false, true},
+ {hemi, false, false, true},
+ {tiny, false, false, true},
+ }
+ for _, test := range tests {
+ if e := test.got.IsEmpty(); e != test.empty {
+ t.Errorf("%v.IsEmpty() = %t; want %t", test.got, e, test.empty)
+ }
+ if f := test.got.IsFull(); f != test.full {
+ t.Errorf("%v.IsFull() = %t; want %t", test.got, f, test.full)
+ }
+ if v := test.got.IsValid(); v != test.valid {
+ t.Errorf("%v.IsValid() = %t; want %t", test.got, v, test.valid)
+ }
+ }
+}
+
+func TestCapCenterHeightRadius(t *testing.T) {
+ if xAxis == xAxis.Complement().Complement() {
+ t.Errorf("the complement of the complement is not the original. %v == %v",
+ xAxis, xAxis.Complement().Complement())
+ }
+
+ if fullCap.Height() != fullHeight {
+ t.Error("full Caps should be full height")
+ }
+ if fullCap.Radius().Degrees() != 180.0 {
+ t.Error("radius of x-axis cap should be 180 degrees")
+ }
+
+ if emptyCap.center != defaultCap.center {
+ t.Error("empty Caps should be have the same center as the default")
+ }
+ if emptyCap.Height() != defaultCap.Height() {
+ t.Error("empty Caps should be have the same height as the default")
+ }
+
+ if yAxis.Height() != zeroHeight {
+ t.Error("y-axis cap should not be empty height")
+ }
+
+ if xAxis.Height() != zeroHeight {
+ t.Error("x-axis cap should not be empty height")
+ }
+ if xAxis.Radius().Radians() != zeroHeight {
+ t.Errorf("radius of x-axis cap got %f want %f", xAxis.Radius().Radians(), emptyHeight)
+ }
+
+ hc := Point{hemi.center.Mul(-1.0)}
+ if hc != hemi.Complement().center {
+ t.Error("hemi center and its complement should have the same center")
+ }
+ if hemi.Height() != 1.0 {
+ t.Error("hemi cap should be 1.0 in height")
+ }
+}
+
+func TestCapContains(t *testing.T) {
+ tests := []struct {
+ c1, c2 Cap
+ want bool
+ }{
+ {emptyCap, emptyCap, true},
+ {fullCap, emptyCap, true},
+ {fullCap, fullCap, true},
+ {emptyCap, xAxis, false},
+ {fullCap, xAxis, true},
+ {xAxis, fullCap, false},
+ {xAxis, xAxis, true},
+ {xAxis, emptyCap, true},
+ {hemi, tiny, true},
+ {hemi, CapFromCenterAngle(xAxisPt, s1.Angle(math.Pi/4-epsilon)), true},
+ {hemi, CapFromCenterAngle(xAxisPt, s1.Angle(math.Pi/4+epsilon)), false},
+ {concave, hemi, true},
+ {concave, CapFromCenterHeight(Point{concave.center.Mul(-1.0)}, 0.1), false},
+ }
+ for _, test := range tests {
+ if got := test.c1.Contains(test.c2); got != test.want {
+ t.Errorf("%v.Contains(%v) = %t; want %t", test.c1, test.c2, got, test.want)
+ }
+ }
+}
+
+func TestCapContainsPoint(t *testing.T) {
+ // We don't use the standard epsilon in this test due different compiler
+ // math optimizations that are permissible (FMA vs no FMA) that yield
+ // slightly different floating point results between gccgo and gc.
+ const epsilon = 1e-14
+ tangent := tiny.center.Cross(r3.Vector{3, 2, 1}).Normalize()
+ tests := []struct {
+ c Cap
+ p Point
+ want bool
+ }{
+ {xAxis, xAxisPt, true},
+ {xAxis, Point{r3.Vector{1, 1e-20, 0}}, false},
+ {yAxis, xAxis.center, false},
+ {xComp, xAxis.center, true},
+ {xComp.Complement(), xAxis.center, false},
+ {tiny, Point{tiny.center.Add(tangent.Mul(tinyRad * 0.99))}, true},
+ {tiny, Point{tiny.center.Add(tangent.Mul(tinyRad * 1.01))}, false},
+ {hemi, PointFromCoords(1, 0, -(1 - epsilon)), true},
+ {hemi, xAxisPt, true},
+ {hemi.Complement(), xAxisPt, false},
+ {concave, PointFromLatLng(LatLngFromDegrees(-70*(1-epsilon), 10)), true},
+ {concave, PointFromLatLng(LatLngFromDegrees(-70*(1+epsilon), 10)), false},
+ // This test case is the one where the floating point values end up
+ // different in the 15th place and beyond.
+ {concave, PointFromLatLng(LatLngFromDegrees(-50*(1-epsilon), -170)), true},
+ {concave, PointFromLatLng(LatLngFromDegrees(-50*(1+epsilon), -170)), false},
+ }
+ for _, test := range tests {
+ if got := test.c.ContainsPoint(test.p); got != test.want {
+ t.Errorf("%v.ContainsPoint(%v) = %t, want %t", test.c, test.p, got, test.want)
+ }
+ }
+}
+
+func TestCapInteriorIntersects(t *testing.T) {
+ tests := []struct {
+ c1, c2 Cap
+ want bool
+ }{
+ {emptyCap, emptyCap, false},
+ {emptyCap, xAxis, false},
+ {fullCap, emptyCap, false},
+ {fullCap, fullCap, true},
+ {fullCap, xAxis, true},
+ {xAxis, fullCap, false},
+ {xAxis, xAxis, false},
+ {xAxis, emptyCap, false},
+ {concave, hemi.Complement(), true},
+ }
+ for _, test := range tests {
+ if got := test.c1.InteriorIntersects(test.c2); got != test.want {
+ t.Errorf("%v.InteriorIntersects(%v); got %t want %t", test.c1, test.c2, got, test.want)
+ }
+ }
+}
+
+func TestCapInteriorContains(t *testing.T) {
+ if hemi.InteriorContainsPoint(Point{r3.Vector{1, 0, -(1 + epsilon)}}) {
+ t.Errorf("hemi (%v) should not contain point just past half way(%v)", hemi,
+ Point{r3.Vector{1, 0, -(1 + epsilon)}})
+ }
+}
+
+func TestCapExpanded(t *testing.T) {
+ cap50 := CapFromCenterAngle(xAxisPt, 50.0*s1.Degree)
+ cap51 := CapFromCenterAngle(xAxisPt, 51.0*s1.Degree)
+
+ if !emptyCap.Expanded(s1.Angle(fullHeight)).IsEmpty() {
+ t.Error("Expanding empty cap should return an empty cap")
+ }
+ if !fullCap.Expanded(s1.Angle(fullHeight)).IsFull() {
+ t.Error("Expanding a full cap should return an full cap")
+ }
+
+ if !cap50.Expanded(0).ApproxEqual(cap50) {
+ t.Error("Expanding a cap by 0° should be equal to the original")
+ }
+ if !cap50.Expanded(1 * s1.Degree).ApproxEqual(cap51) {
+ t.Error("Expanding 50° by 1° should equal the 51° cap")
+ }
+
+ if cap50.Expanded(129.99 * s1.Degree).IsFull() {
+ t.Error("Expanding 50° by 129.99° should not give a full cap")
+ }
+ if !cap50.Expanded(130.01 * s1.Degree).IsFull() {
+ t.Error("Expanding 50° by 130.01° should give a full cap")
+ }
+}
+
+func TestCapRadiusToHeight(t *testing.T) {
+ tests := []struct {
+ got s1.Angle
+ want float64
+ }{
+ // Above/below boundary checks.
+ {s1.Angle(-0.5), emptyHeight},
+ {s1.Angle(0), 0},
+ {s1.Angle(math.Pi), fullHeight},
+ {s1.Angle(2 * math.Pi), fullHeight},
+ // Degree tests.
+ {-7.0 * s1.Degree, emptyHeight},
+ {-0.0 * s1.Degree, 0},
+ {0.0 * s1.Degree, 0},
+ {12.0 * s1.Degree, 0.0218523992661943},
+ {30.0 * s1.Degree, 0.1339745962155613},
+ {45.0 * s1.Degree, 0.2928932188134525},
+ {90.0 * s1.Degree, 1.0},
+ {179.99 * s1.Degree, 1.9999999847691292},
+ {180.0 * s1.Degree, fullHeight},
+ {270.0 * s1.Degree, fullHeight},
+ // Radians tests.
+ {-1.0 * s1.Radian, emptyHeight},
+ {-0.0 * s1.Radian, 0},
+ {0.0 * s1.Radian, 0},
+ {1.0 * s1.Radian, 0.45969769413186},
+ {math.Pi / 2.0 * s1.Radian, 1.0},
+ {2.0 * s1.Radian, 1.4161468365471424},
+ {3.0 * s1.Radian, 1.9899924966004454},
+ {math.Pi * s1.Radian, fullHeight},
+ {4.0 * s1.Radian, fullHeight},
+ }
+ for _, test := range tests {
+ // float64Eq comes from s2latlng_test.go
+ if got := radiusToHeight(test.got); !float64Eq(got, test.want) {
+ t.Errorf("radiusToHeight(%v) = %v; want %v", test.got, got, test.want)
+ }
+ }
+}
+
+func TestCapRectBounds(t *testing.T) {
+ const epsilon = 1e-13
+ var tests = []struct {
+ desc string
+ have Cap
+ latLoDeg float64
+ latHiDeg float64
+ lngLoDeg float64
+ lngHiDeg float64
+ isFull bool
+ }{
+ {
+ "Cap that includes South Pole.",
+ CapFromCenterAngle(PointFromLatLng(LatLngFromDegrees(-45, 57)), s1.Degree*50),
+ -90, 5, -180, 180, true,
+ },
+ {
+ "Cap that is tangent to the North Pole.",
+ CapFromCenterAngle(PointFromCoords(1, 0, 1), s1.Radian*(math.Pi/4.0+1e-16)),
+ 0, 90, -180, 180, true,
+ },
+ {
+ "Cap that at 45 degree center that goes from equator to the pole.",
+ CapFromCenterAngle(PointFromCoords(1, 0, 1), s1.Degree*(45+5e-15)),
+ 0, 90, -180, 180, true,
+ },
+ {
+ "The eastern hemisphere.",
+ CapFromCenterAngle(Point{r3.Vector{0, 1, 0}}, s1.Radian*(math.Pi/2+2e-16)),
+ -90, 90, -180, 180, true,
+ },
+ {
+ "A cap centered on the equator.",
+ CapFromCenterAngle(PointFromLatLng(LatLngFromDegrees(0, 50)), s1.Degree*20),
+ -20, 20, 30, 70, false,
+ },
+ {
+ "A cap centered on the North Pole.",
+ CapFromCenterAngle(PointFromLatLng(LatLngFromDegrees(90, 123)), s1.Degree*10),
+ 80, 90, -180, 180, true,
+ },
+ }
+
+ for _, test := range tests {
+ r := test.have.RectBound()
+ if !float64Near(s1.Angle(r.Lat.Lo).Degrees(), test.latLoDeg, epsilon) {
+ t.Errorf("%s: %v.RectBound(), Lat.Lo not close enough, got %0.20f, want %0.20f",
+ test.desc, test.have, s1.Angle(r.Lat.Lo).Degrees(), test.latLoDeg)
+ }
+ if !float64Near(s1.Angle(r.Lat.Hi).Degrees(), test.latHiDeg, epsilon) {
+ t.Errorf("%s: %v.RectBound(), Lat.Hi not close enough, got %0.20f, want %0.20f",
+ test.desc, test.have, s1.Angle(r.Lat.Hi).Degrees(), test.latHiDeg)
+ }
+ if !float64Near(s1.Angle(r.Lng.Lo).Degrees(), test.lngLoDeg, epsilon) {
+ t.Errorf("%s: %v.RectBound(), Lng.Lo not close enough, got %0.20f, want %0.20f",
+ test.desc, test.have, s1.Angle(r.Lng.Lo).Degrees(), test.lngLoDeg)
+ }
+ if !float64Near(s1.Angle(r.Lng.Hi).Degrees(), test.lngHiDeg, epsilon) {
+ t.Errorf("%s: %v.RectBound(), Lng.Hi not close enough, got %0.20f, want %0.20f",
+ test.desc, test.have, s1.Angle(r.Lng.Hi).Degrees(), test.lngHiDeg)
+ }
+ if got := r.Lng.IsFull(); got != test.isFull {
+ t.Errorf("%s: RectBound(%v).isFull() = %t, want %t", test.desc, test.have, got, test.isFull)
+ }
+ }
+
+ // Empty and full caps.
+ if !EmptyCap().RectBound().IsEmpty() {
+ t.Errorf("RectBound() on EmptyCap should be empty.")
+ }
+
+ if !FullCap().RectBound().IsFull() {
+ t.Errorf("RectBound() on FullCap should be full.")
+ }
+}
+
+func TestCapAddPoint(t *testing.T) {
+ const epsilon = 1e-14
+ tests := []struct {
+ have Cap
+ p Point
+ want Cap
+ }{
+ // Cap plus its center equals itself.
+ {xAxis, xAxisPt, xAxis},
+ {yAxis, yAxisPt, yAxis},
+
+ // Cap plus opposite point equals full.
+ {xAxis, Point{r3.Vector{-1, 0, 0}}, fullCap},
+ {yAxis, Point{r3.Vector{0, -1, 0}}, fullCap},
+
+ // Cap plus orthogonal axis equals half cap.
+ {xAxis, Point{r3.Vector{0, 0, 1}}, CapFromCenterAngle(xAxisPt, s1.Angle(math.Pi/2.0))},
+ {xAxis, Point{r3.Vector{0, 0, -1}}, CapFromCenterAngle(xAxisPt, s1.Angle(math.Pi/2.0))},
+
+ // The 45 degree angled hemisphere plus some points.
+ {
+ hemi,
+ PointFromCoords(0, 1, -1),
+ CapFromCenterAngle(Point{r3.Vector{1, 0, 1}},
+ s1.Angle(120.0)*s1.Degree),
+ },
+ {
+ hemi,
+ PointFromCoords(0, -1, -1),
+ CapFromCenterAngle(Point{r3.Vector{1, 0, 1}},
+ s1.Angle(120.0)*s1.Degree),
+ },
+ {
+ hemi,
+ PointFromCoords(-1, -1, -1),
+ CapFromCenterAngle(Point{r3.Vector{1, 0, 1}},
+ s1.Angle(math.Acos(-math.Sqrt(2.0/3.0)))),
+ },
+ {hemi, Point{r3.Vector{0, 1, 1}}, hemi},
+ {hemi, Point{r3.Vector{1, 0, 0}}, hemi},
+ }
+
+ for _, test := range tests {
+ got := test.have.AddPoint(test.p)
+ if !got.ApproxEqual(test.want) {
+ t.Errorf("%v.AddPoint(%v) = %v, want %v", test.have, test.p, got, test.want)
+ }
+
+ if !got.ContainsPoint(test.p) {
+ t.Errorf("%v.AddPoint(%v) did not contain added point", test.have, test.p)
+ }
+ }
+}
+
+func TestCapAddCap(t *testing.T) {
+ tests := []struct {
+ have Cap
+ other Cap
+ want Cap
+ }{
+ // Identity cases.
+ {emptyCap, emptyCap, emptyCap},
+ {fullCap, fullCap, fullCap},
+
+ // Anything plus empty equals itself.
+ {fullCap, emptyCap, fullCap},
+ {emptyCap, fullCap, fullCap},
+ {xAxis, emptyCap, xAxis},
+ {emptyCap, xAxis, xAxis},
+ {yAxis, emptyCap, yAxis},
+ {emptyCap, yAxis, yAxis},
+
+ // Two halves make a whole.
+ {xAxis, xComp, fullCap},
+
+ // Two zero-height orthogonal axis caps make a half-cap.
+ {xAxis, yAxis, CapFromCenterAngle(xAxisPt, s1.Angle(math.Pi/2.0))},
+ }
+
+ for _, test := range tests {
+ got := test.have.AddCap(test.other)
+ if !got.ApproxEqual(test.want) {
+ t.Errorf("%v.AddCap(%v) = %v, want %v", test.have, test.other, got, test.want)
+ }
+ }
+}
+
+func TestCapContainsCell(t *testing.T) {
+ faceRadius := math.Atan(math.Sqrt2)
+ for face := 0; face < 6; face++ {
+ // The cell consisting of the entire face.
+ rootCell := CellFromCellID(CellIDFromFace(face))
+
+ // A leaf cell at the midpoint of the v=1 edge.
+ edgeCell := CellFromPoint(Point{faceUVToXYZ(face, 0, 1-epsilon)})
+
+ // A leaf cell at the u=1, v=1 corner
+ cornerCell := CellFromPoint(Point{faceUVToXYZ(face, 1-epsilon, 1-epsilon)})
+
+ // Quick check for full and empty caps.
+ if !fullCap.ContainsCell(rootCell) {
+ t.Errorf("Cap(%v).ContainsCell(%v) = %t; want = %t", fullCap, rootCell, false, true)
+ }
+
+ // Check intersections with the bounding caps of the leaf cells that are adjacent to
+ // cornerCell along the Hilbert curve. Because this corner is at (u=1,v=1), the curve
+ // stays locally within the same cube face.
+ first := cornerCell.id.Advance(-3)
+ last := cornerCell.id.Advance(4)
+ for id := first; id < last; id = id.Next() {
+ c := CellFromCellID(id).CapBound()
+ if got, want := c.ContainsCell(cornerCell), id == cornerCell.id; got != want {
+ t.Errorf("Cap(%v).ContainsCell(%v) = %t; want = %t", c, cornerCell, got, want)
+ }
+ }
+
+ for capFace := 0; capFace < 6; capFace++ {
+ // A cap that barely contains all of capFace.
+ center := unitNorm(capFace)
+ covering := CapFromCenterAngle(center, s1.Angle(faceRadius+epsilon))
+ if got, want := covering.ContainsCell(rootCell), capFace == face; got != want {
+ t.Errorf("Cap(%v).ContainsCell(%v) = %t; want = %t", covering, rootCell, got, want)
+ }
+ if got, want := covering.ContainsCell(edgeCell), center.Vector.Dot(edgeCell.id.Point().Vector) > 0.1; got != want {
+ t.Errorf("Cap(%v).ContainsCell(%v) = %t; want = %t", covering, edgeCell, got, want)
+ }
+ if got, want := covering.ContainsCell(edgeCell), covering.IntersectsCell(edgeCell); got != want {
+ t.Errorf("Cap(%v).ContainsCell(%v) = %t; want = %t", covering, edgeCell, got, want)
+ }
+ if got, want := covering.ContainsCell(cornerCell), capFace == face; got != want {
+ t.Errorf("Cap(%v).ContainsCell(%v) = %t; want = %t", covering, cornerCell, got, want)
+ }
+
+ // A cap that barely intersects the edges of capFace.
+ bulging := CapFromCenterAngle(center, s1.Angle(math.Pi/4+epsilon))
+ if bulging.ContainsCell(rootCell) {
+ t.Errorf("Cap(%v).ContainsCell(%v) = %t; want = %t", bulging, rootCell, true, false)
+ }
+ if got, want := bulging.ContainsCell(edgeCell), capFace == face; got != want {
+ t.Errorf("Cap(%v).ContainsCell(%v) = %t; want = %t", bulging, edgeCell, got, want)
+ }
+ if bulging.ContainsCell(cornerCell) {
+ t.Errorf("Cap(%v).ContainsCell(%v) = %t; want = %t", bulging, cornerCell, true, false)
+ }
+ }
+ }
+}
+
+func TestCapIntersectsCell(t *testing.T) {
+ faceRadius := math.Atan(math.Sqrt2)
+ for face := 0; face < 6; face++ {
+ // The cell consisting of the entire face.
+ rootCell := CellFromCellID(CellIDFromFace(face))
+
+ // A leaf cell at the midpoint of the v=1 edge.
+ edgeCell := CellFromPoint(Point{faceUVToXYZ(face, 0, 1-epsilon)})
+
+ // A leaf cell at the u=1, v=1 corner
+ cornerCell := CellFromPoint(Point{faceUVToXYZ(face, 1-epsilon, 1-epsilon)})
+
+ // Quick check for full and empty caps.
+ if emptyCap.IntersectsCell(rootCell) {
+ t.Errorf("Cap(%v).IntersectsCell(%v) = %t; want = %t", emptyCap, rootCell, true, false)
+ }
+
+ // Check intersections with the bounding caps of the leaf cells that are adjacent to
+ // cornerCell along the Hilbert curve. Because this corner is at (u=1,v=1), the curve
+ // stays locally within the same cube face.
+ first := cornerCell.id.Advance(-3)
+ last := cornerCell.id.Advance(4)
+ for id := first; id < last; id = id.Next() {
+ c := CellFromCellID(id).CapBound()
+ if got, want := c.IntersectsCell(cornerCell), id.immediateParent().Contains(cornerCell.id); got != want {
+ t.Errorf("Cap(%v).IntersectsCell(%v) = %t; want = %t", c, cornerCell, got, want)
+ }
+ }
+
+ antiFace := (face + 3) % 6
+ for capFace := 0; capFace < 6; capFace++ {
+ // A cap that barely contains all of capFace.
+ center := unitNorm(capFace)
+ covering := CapFromCenterAngle(center, s1.Angle(faceRadius+epsilon))
+ if got, want := covering.IntersectsCell(rootCell), capFace != antiFace; got != want {
+ t.Errorf("Cap(%v).IntersectsCell(%v) = %t; want = %t", covering, rootCell, got, want)
+ }
+ if got, want := covering.IntersectsCell(edgeCell), covering.ContainsCell(edgeCell); got != want {
+ t.Errorf("Cap(%v).IntersectsCell(%v) = %t; want = %t", covering, edgeCell, got, want)
+ }
+ if got, want := covering.IntersectsCell(cornerCell), center.Vector.Dot(cornerCell.id.Point().Vector) > 0; got != want {
+ t.Errorf("Cap(%v).IntersectsCell(%v) = %t; want = %t", covering, cornerCell, got, want)
+ }
+
+ // A cap that barely intersects the edges of capFace.
+ bulging := CapFromCenterAngle(center, s1.Angle(math.Pi/4+epsilon))
+ if got, want := bulging.IntersectsCell(rootCell), capFace != antiFace; got != want {
+ t.Errorf("Cap(%v).IntersectsCell(%v) = %t; want = %t", bulging, rootCell, got, want)
+ }
+ if got, want := bulging.IntersectsCell(edgeCell), center.Vector.Dot(edgeCell.id.Point().Vector) > 0.1; got != want {
+ t.Errorf("Cap(%v).IntersectsCell(%v) = %t; want = %t", bulging, edgeCell, got, want)
+ }
+ if bulging.IntersectsCell(cornerCell) {
+ t.Errorf("Cap(%v).IntersectsCell(%v) = %t; want = %t", bulging, cornerCell, true, false)
+ }
+
+ // A singleton cap.
+ singleton := CapFromCenterAngle(center, 0)
+ if got, want := singleton.IntersectsCell(rootCell), capFace == face; got != want {
+ t.Errorf("Cap(%v).IntersectsCell(%v) = %t; want = %t", singleton, rootCell, got, want)
+ }
+ if singleton.IntersectsCell(edgeCell) {
+ t.Errorf("Cap(%v).IntersectsCell(%v) = %t; want = %t", singleton, edgeCell, true, false)
+ }
+ if singleton.IntersectsCell(cornerCell) {
+ t.Errorf("Cap(%v).IntersectsCell(%v) = %t; want = %t", singleton, cornerCell, true, false)
+ }
+ }
+ }
+}
+
+func TestCapCentroid(t *testing.T) {
+ // Empty and full caps.
+ if got, want := EmptyCap().Centroid(), (Point{}); !got.ApproxEqual(want) {
+ t.Errorf("Centroid of EmptyCap should be zero point, got %v", want)
+ }
+ if got, want := FullCap().Centroid().Norm(), 1e-15; got > want {
+ t.Errorf("Centroid of FullCap should have a Norm of 0, got %v", want)
+ }
+
+ // Random caps.
+ for i := 0; i < 100; i++ {
+ center := randomPoint()
+ height := randomUniformFloat64(0.0, 2.0)
+ c := CapFromCenterHeight(center, height)
+ got := c.Centroid()
+ want := center.Mul((1.0 - height/2.0) * c.Area())
+ if delta := got.Sub(want).Norm(); delta > 1e-15 {
+ t.Errorf("%v.Sub(%v).Norm() = %v, want %v", got, want, delta, 1e-15)
+ }
+ }
+}
+
+func TestCapUnion(t *testing.T) {
+ // Two caps which have the same center but one has a larger radius.
+ a := CapFromCenterAngle(PointFromLatLng(LatLngFromDegrees(50.0, 10.0)), s1.Degree*0.2)
+ b := CapFromCenterAngle(PointFromLatLng(LatLngFromDegrees(50.0, 10.0)), s1.Degree*0.3)
+ if !b.Contains(a) {
+ t.Errorf("%v.Contains(%v) = false, want true", b, a)
+ }
+ if got := b.ApproxEqual(a.Union(b)); !got {
+ t.Errorf("%v.ApproxEqual(%v) = %v, want true", b, a.Union(b), got)
+ }
+
+ // Two caps where one is the full cap.
+ if got := a.Union(FullCap()); !got.IsFull() {
+ t.Errorf("%v.Union(%v).IsFull() = %v, want true", a, got, got.IsFull())
+ }
+
+ // Two caps where one is the empty cap.
+ if got := a.Union(EmptyCap()); !a.ApproxEqual(got) {
+ t.Errorf("%v.Union(EmptyCap) = %v, want %v", a, got, a)
+ }
+
+ // Two caps which have different centers, one entirely encompasses the other.
+ c := CapFromCenterAngle(PointFromLatLng(LatLngFromDegrees(51.0, 11.0)), s1.Degree*1.5)
+ if !c.Contains(a) {
+ t.Errorf("%v.Contains(%v) = false, want true", c, a)
+ }
+ if got := a.Union(c).center; !got.ApproxEqual(c.center) {
+ t.Errorf("%v.Union(%v).center = %v, want %v", a, c, got, c.center)
+ }
+ if got := a.Union(c); !float64Eq(float64(got.Radius()), float64(c.Radius())) {
+ t.Errorf("%v.Union(%v).Radius = %v, want %v", a, c, got.Radius(), c.Radius())
+ }
+
+ // Two entirely disjoint caps.
+ d := CapFromCenterAngle(PointFromLatLng(LatLngFromDegrees(51.0, 11.0)), s1.Degree*0.1)
+ if d.Contains(a) {
+ t.Errorf("%v.Contains(%v) = true, want false", d, a)
+ }
+ if d.Intersects(a) {
+ t.Errorf("%v.Intersects(%v) = true, want false", d, a)
+ }
+
+ // Check union and reverse direction are the same.
+ aUnionD := a.Union(d)
+ if !aUnionD.ApproxEqual(d.Union(a)) {
+ t.Errorf("%v.Union(%v).ApproxEqual(%v.Union(%v)) = false, want true", a, d, d, a)
+ }
+ if got, want := LatLngFromPoint(aUnionD.center).Lat.Degrees(), 50.4588; !float64Near(got, want, 0.001) {
+ t.Errorf("%v.Center.Lat = %v, want %v", aUnionD, got, want)
+ }
+ if got, want := LatLngFromPoint(aUnionD.center).Lng.Degrees(), 10.4525; !float64Near(got, want, 0.001) {
+ t.Errorf("%v.Center.Lng = %v, want %v", aUnionD, got, want)
+ }
+ if got, want := aUnionD.Radius().Degrees(), 0.7425; !float64Near(got, want, 0.001) {
+ t.Errorf("%v.Radius = %v, want %v", aUnionD, got, want)
+ }
+
+ // Two partially overlapping caps.
+ e := CapFromCenterAngle(PointFromLatLng(LatLngFromDegrees(50.3, 10.3)), s1.Degree*0.2)
+ aUnionE := a.Union(e)
+ if e.Contains(a) {
+ t.Errorf("%v.Contains(%v) = false, want true", e, a)
+ }
+ if !e.Intersects(a) {
+ t.Errorf("%v.Intersects(%v) = false, want true", e, a)
+ }
+ if !aUnionE.ApproxEqual(e.Union(a)) {
+ t.Errorf("%v.Union(%v).ApproxEqual(%v.Union(%v)) = false, want true", a, e, e, a)
+ }
+ if got, want := LatLngFromPoint(aUnionE.center).Lat.Degrees(), 50.1500; !float64Near(got, want, 0.001) {
+ t.Errorf("%v.Center.Lat = %v, want %v", aUnionE, got, want)
+ }
+ if got, want := LatLngFromPoint(aUnionE.center).Lng.Degrees(), 10.1495; !float64Near(got, want, 0.001) {
+ t.Errorf("%v.Center.Lng = %v, want %v", aUnionE, got, want)
+ }
+ if got, want := aUnionE.Radius().Degrees(), 0.3781; !float64Near(got, want, 0.001) {
+ t.Errorf("%v.Radius = %v, want %v", aUnionE, got, want)
+ }
+
+ p1 := Point{r3.Vector{0, 0, 1}}
+ p2 := Point{r3.Vector{0, 1, 0}}
+ // Two very large caps, whose radius sums to in excess of 180 degrees, and
+ // whose centers are not antipodal.
+ f := CapFromCenterAngle(p1, s1.Degree*150)
+ g := CapFromCenterAngle(p2, s1.Degree*150)
+ if !f.Union(g).IsFull() {
+ t.Errorf("%v.Union(%v).IsFull() = false, want true", f, g)
+ }
+
+ // Two non-overlapping hemisphere caps with antipodal centers.
+ hemi := CapFromCenterHeight(p1, 1)
+ if !hemi.Union(hemi.Complement()).IsFull() {
+ t.Errorf("%v.Union(%v).Complement().IsFull() = false, want true", hemi, hemi.Complement())
+ }
+}
+
+func TestCapEqual(t *testing.T) {
+ tests := []struct {
+ a, b Cap
+ want bool
+ }{
+ {EmptyCap(), EmptyCap(), true},
+ {EmptyCap(), FullCap(), false},
+ {FullCap(), FullCap(), true},
+ {
+ CapFromCenterAngle(PointFromCoords(0, 0, 1), s1.Degree*150),
+ CapFromCenterAngle(PointFromCoords(0, 0, 1), s1.Degree*151),
+ false,
+ },
+ {xAxis, xAxis, true},
+ {xAxis, yAxis, false},
+ {xComp, xAxis.Complement(), true},
+ }
+
+ for _, test := range tests {
+ if got := test.a.Equal(test.b); got != test.want {
+ t.Errorf("%v.Equal(%v) = %t, want %t", test.a, test.b, got, test.want)
+ }
+ }
+}