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created line.go and moved tests and funcs

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This commit is contained in:
Derek McQuay 2016-08-27 19:10:42 -07:00
parent ace4f45155
commit 3850bdc592
5 changed files with 97 additions and 91 deletions
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45
line.go Normal file
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@ -0,0 +1,45 @@
package rect
import (
"fmt"
"math"
)
type line struct {
pt1, pt2 Point
}
func lineHelper(l line) (float64, float64, float64) {
a := l.pt2.Y - l.pt1.Y
b := l.pt1.X - l.pt2.X
c := a*l.pt1.X + b*l.pt1.Y
return a, b, c
}
func lineIntersection(l1, l2 line) (Point, error) {
a1, b1, c1 := lineHelper(l1)
a2, b2, c2 := lineHelper(l2)
det := a1*b2 - a2*b1
if det != 0 {
x := ((b2*c1 - b1*c2) / det)
y := ((a1*c2 - a2*c1) / det)
minx1, maxx1 := math.Min(l1.pt1.X, l1.pt2.X), math.Max(l1.pt1.X, l1.pt2.X)
miny1, maxy1 := math.Min(l1.pt1.Y, l1.pt2.Y), math.Max(l1.pt1.Y, l1.pt2.Y)
minx2, maxx2 := math.Min(l2.pt1.X, l2.pt2.X), math.Max(l2.pt1.X, l2.pt2.X)
miny2, maxy2 := math.Min(l2.pt1.Y, l2.pt2.Y), math.Max(l2.pt1.Y, l2.pt2.Y)
if minx1 <= x && x <= maxx1 && miny1 <= y && y <= maxy1 {
if minx2 <= x && x <= maxx2 && miny2 <= y && y <= maxy2 {
return Point{x, y}, nil
}
}
}
return Point{}, fmt.Errorf("lines do not intersect")
}
func lineOnLine(l1, l2 line) bool {
if onLine(l1.pt1, l1.pt2, l2.pt1) && onLine(l1.pt1, l1.pt2, l2.pt2) {
return true
}
return false
}

49
line_test.go Normal file
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@ -0,0 +1,49 @@
package rect
import "testing"
func TestOnLine(t *testing.T) {
var onLineTest = []struct {
p []Point
expected bool
}{
{[]Point{Point{1, 1}, Point{3, 3}, Point{2, 2}}, true},
{[]Point{Point{1, 1}, Point{3, 3}, Point{4, 4}}, false},
{[]Point{Point{-1, -1}, Point{-3, -3}, Point{-4, -4}}, false},
{[]Point{Point{-1, -1}, Point{-3, -3}, Point{-2, -2}}, true},
}
for _, rt := range onLineTest {
actual := onLine(rt.p[0], rt.p[1], rt.p[2])
if actual != rt.expected {
t.Errorf(
"failed onLine:\n\texpected: %t\n\t actual: %t",
rt.expected,
actual,
)
}
}
}
func TestLineIntersection(t *testing.T) {
var lineIntersectionTest = []struct {
l []line
expected Point
}{
{[]line{line{Point{0, 0}, Point{2, 2}}, line{Point{2, 0}, Point{0, 2}}}, Point{1, 1}},
{[]line{line{Point{0, 0}, Point{-2, -2}}, line{Point{-2, 0}, Point{0, -2}}}, Point{-1, -1}},
{[]line{line{Point{0, 0}, Point{-2, -2}}, line{Point{1, 0}, Point{1, -7}}}, Point{0, 0}},
{[]line{line{Point{5, 8}, Point{8, 5}}, line{Point{3, 7}, Point{7, 3}}}, Point{0, 0}},
}
for _, rt := range lineIntersectionTest {
actual, _ := lineIntersection(rt.l[0], rt.l[1])
if actual != rt.expected {
t.Errorf(
"failed lineIntersection:\n\texpected: %v\n\t actual: %v",
rt.expected,
actual,
)
}
}
}

44
point.go
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@ -1,18 +1,11 @@
package rect
import (
"fmt"
"math"
)
import "math"
type Point struct {
X, Y float64
}
type line struct {
pt1, pt2 Point
}
func distance(p1, p2 Point) float64 {
return math.Sqrt(math.Pow((p1.X-p2.X), 2) + math.Pow((p1.Y-p2.Y), 2))
}
@ -27,38 +20,3 @@ func onLine(rp1, rp2, p Point) bool {
}
return false
}
func lineHelper(l line) (float64, float64, float64) {
a := l.pt2.Y - l.pt1.Y
b := l.pt1.X - l.pt2.X
c := a*l.pt1.X + b*l.pt1.Y
return a, b, c
}
func lineIntersection(l1, l2 line) (Point, error) {
a1, b1, c1 := lineHelper(l1)
a2, b2, c2 := lineHelper(l2)
det := a1*b2 - a2*b1
if det != 0 {
x := ((b2*c1 - b1*c2) / det)
y := ((a1*c2 - a2*c1) / det)
minx1, maxx1 := math.Min(l1.pt1.X, l1.pt2.X), math.Max(l1.pt1.X, l1.pt2.X)
miny1, maxy1 := math.Min(l1.pt1.Y, l1.pt2.Y), math.Max(l1.pt1.Y, l1.pt2.Y)
minx2, maxx2 := math.Min(l2.pt1.X, l2.pt2.X), math.Max(l2.pt1.X, l2.pt2.X)
miny2, maxy2 := math.Min(l2.pt1.Y, l2.pt2.Y), math.Max(l2.pt1.Y, l2.pt2.Y)
if minx1 <= x && x <= maxx1 && miny1 <= y && y <= maxy1 {
if minx2 <= x && x <= maxx2 && miny2 <= y && y <= maxy2 {
return Point{x, y}, nil
}
}
}
return Point{}, fmt.Errorf("lines do not intersect")
}
func lineOnLine(l1, l2 line) bool {
if onLine(l1.pt1, l1.pt2, l2.pt1) && onLine(l1.pt1, l1.pt2, l2.pt2) {
return true
}
return false
}

46
point_test.go
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@ -27,49 +27,3 @@ func TestDistance(t *testing.T) {
}
}
func TestOnLine(t *testing.T) {
var onLineTest = []struct {
p []Point
expected bool
}{
{[]Point{Point{1, 1}, Point{3, 3}, Point{2, 2}}, true},
{[]Point{Point{1, 1}, Point{3, 3}, Point{4, 4}}, false},
{[]Point{Point{-1, -1}, Point{-3, -3}, Point{-4, -4}}, false},
{[]Point{Point{-1, -1}, Point{-3, -3}, Point{-2, -2}}, true},
}
for _, rt := range onLineTest {
actual := onLine(rt.p[0], rt.p[1], rt.p[2])
if actual != rt.expected {
t.Errorf(
"failed onLine:\n\texpected: %t\n\t actual: %t",
rt.expected,
actual,
)
}
}
}
func TestLineIntersection(t *testing.T) {
var lineIntersectionTest = []struct {
l []line
expected Point
}{
{[]line{line{Point{0, 0}, Point{2, 2}}, line{Point{2, 0}, Point{0, 2}}}, Point{1, 1}},
{[]line{line{Point{0, 0}, Point{-2, -2}}, line{Point{-2, 0}, Point{0, -2}}}, Point{-1, -1}},
{[]line{line{Point{0, 0}, Point{-2, -2}}, line{Point{1, 0}, Point{1, -7}}}, Point{0, 0}},
{[]line{line{Point{5, 8}, Point{8, 5}}, line{Point{3, 7}, Point{7, 3}}}, Point{0, 0}},
}
for _, rt := range lineIntersectionTest {
actual, _ := lineIntersection(rt.l[0], rt.l[1])
if actual != rt.expected {
t.Errorf(
"failed lineIntersection:\n\texpected: %v\n\t actual: %v",
rt.expected,
actual,
)
}
}
}

4
rectangle_test.go
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@ -16,7 +16,7 @@ func TestIsRect(t *testing.T) {
{Rectangle{P1: Point{0, 0}, P2: Point{0, 0}, P3: Point{0, 0}, P4: Point{0, 0}}, false},
}
for _, rt := range isRectTests {
actual := rt.r.IsRect()
actual := rt.r.isRect()
if actual != rt.expected {
t.Errorf(
"failed isRect:\n\texpected: %t\n\t actual: %t",
@ -41,7 +41,7 @@ func TestSize(t *testing.T) {
{Rectangle{P1: Point{0, 0}, P2: Point{0, 100}, P3: Point{100, 0}, P4: Point{100, 100}}, 10000},
}
for _, rt := range isRectTests {
actual := rt.r.Size()
actual := rt.r.size()
if actual != rt.expected {
t.Errorf(
"failed size:\n\texpected: %f\n\t actual: %f",