blob: 9fede027218c31e54a478cd6a40bd4e34fac577b [file] [log] [blame]
 // Copyright 2015 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. package image import ( "fmt" "testing" ) func TestRectangle(t *testing.T) { // in checks that every point in f is in g. in := func(f, g Rectangle) error { if !f.In(g) { return fmt.Errorf("f=%s, f.In(%s): got false, want true", f, g) } for y := f.Min.Y; y < f.Max.Y; y++ { for x := f.Min.X; x < f.Max.X; x++ { p := Point{x, y} if !p.In(g) { return fmt.Errorf("p=%s, p.In(%s): got false, want true", p, g) } } } return nil } rects := []Rectangle{ Rect(0, 0, 10, 10), Rect(10, 0, 20, 10), Rect(1, 2, 3, 4), Rect(4, 6, 10, 10), Rect(2, 3, 12, 5), Rect(-1, -2, 0, 0), Rect(-1, -2, 4, 6), Rect(-10, -20, 30, 40), Rect(8, 8, 8, 8), Rect(88, 88, 88, 88), Rect(6, 5, 4, 3), } // r.Eq(s) should be equivalent to every point in r being in s, and every // point in s being in r. for _, r := range rects { for _, s := range rects { got := r.Eq(s) want := in(r, s) == nil && in(s, r) == nil if got != want { t.Errorf("Eq: r=%s, s=%s: got %t, want %t", r, s, got, want) } } } // The intersection should be the largest rectangle a such that every point // in a is both in r and in s. for _, r := range rects { for _, s := range rects { a := r.Intersect(s) if err := in(a, r); err != nil { t.Errorf("Intersect: r=%s, s=%s, a=%s, a not in r: %v", r, s, a, err) } if err := in(a, s); err != nil { t.Errorf("Intersect: r=%s, s=%s, a=%s, a not in s: %v", r, s, a, err) } if isZero, overlaps := a == (Rectangle{}), r.Overlaps(s); isZero == overlaps { t.Errorf("Intersect: r=%s, s=%s, a=%s: isZero=%t same as overlaps=%t", r, s, a, isZero, overlaps) } largerThanA := [4]Rectangle{a, a, a, a} largerThanA[0].Min.X-- largerThanA[1].Min.Y-- largerThanA[2].Max.X++ largerThanA[3].Max.Y++ for i, b := range largerThanA { if b.Empty() { // b isn't actually larger than a. continue } if in(b, r) == nil && in(b, s) == nil { t.Errorf("Intersect: r=%s, s=%s, a=%s, b=%s, i=%d: intersection could be larger", r, s, a, b, i) } } } } // The union should be the smallest rectangle a such that every point in r // is in a and every point in s is in a. for _, r := range rects { for _, s := range rects { a := r.Union(s) if err := in(r, a); err != nil { t.Errorf("Union: r=%s, s=%s, a=%s, r not in a: %v", r, s, a, err) } if err := in(s, a); err != nil { t.Errorf("Union: r=%s, s=%s, a=%s, s not in a: %v", r, s, a, err) } if a.Empty() { // You can't get any smaller than a. continue } smallerThanA := [4]Rectangle{a, a, a, a} smallerThanA[0].Min.X++ smallerThanA[1].Min.Y++ smallerThanA[2].Max.X-- smallerThanA[3].Max.Y-- for i, b := range smallerThanA { if in(r, b) == nil && in(s, b) == nil { t.Errorf("Union: r=%s, s=%s, a=%s, b=%s, i=%d: union could be smaller", r, s, a, b, i) } } } } }