ichigo/geom/polygon_test.go

package geom

import (
	"image"
	"testing"
)

func TestPolygonContains(t *testing.T) {
	square5 := []image.Point{
		{X: 0, Y: 0},
		{X: 0, Y: 5},
		{X: 5, Y: 5},
		{X: 5, Y: 0},
	}
	pentagon := []image.Point{
		{X: -5, Y: -4},
		{X: -7, Y: 2},
		{X: 0, Y: 7},
		{X: 7, Y: 2},
		{X: 5, Y: -4},
	}
	hexagon := []image.Point{
		{X: 8, Y: 0},
		{X: 0, Y: 8},
		{X: 8, Y: 16},
		{X: 23, Y: 16},
		{X: 31, Y: 8},
		{X: 23, Y: 0},
	}

	tests := []struct {
		polygon []image.Point
		point   image.Point
		want    bool
	}{
		{square5, image.Pt(2, 3), true},
		{square5, image.Pt(0, 0), true},
		{square5, image.Pt(5, 5), true},
		{square5, image.Pt(-5, 0), false},
		{square5, image.Pt(0, -5), false},
		{square5, image.Pt(6, 6), false},

		{pentagon, image.Pt(0, 0), true},
		{pentagon, image.Pt(8, 0), false},
		{pentagon, image.Pt(1, 1), true},
		{pentagon, image.Pt(-1, -1), true},
		{pentagon, image.Pt(-10000, 10000), false},

		{hexagon, image.Pt(0, 0), false},
		{hexagon, image.Pt(16, 8), true},
		{hexagon, image.Pt(0, 8), true},
		{hexagon, image.Pt(-1, 8), false},
		{hexagon, image.Pt(31, 8), true},
		{hexagon, image.Pt(32, 8), false},
		{hexagon, image.Pt(10000, 10000), false},
	}

	for _, test := range tests {
		if got, want := PolygonContains(test.polygon, test.point), test.want; got != want {
			t.Errorf("PolygonContains(%v, %v) = %v, want %v", test.polygon, test.point, got, want)
		}
	}
}