Merge pull request #290 from dusk125/master

Fixing #277: Rect.Intersect and Rect.Intersects now have consistent behavior

rectangle.go

@@ -222,10 +222,10 @@ func (r Rect) Intersect(s Rect) Rect {
 // This function is overall about 5x faster than Intersect, so it is better
 // to use if you have no need for the returned Rect from Intersect.
 func (r Rect) Intersects(s Rect) bool {
- return !(s.Max.X < r.Min.X ||
- s.Min.X > r.Max.X ||
- s.Max.Y < r.Min.Y ||
- s.Min.Y > r.Max.Y)
+ return !(s.Max.X <= r.Min.X ||
+ s.Min.X >= r.Max.X ||
+ s.Max.Y <= r.Min.Y ||
+ s.Min.Y >= r.Max.Y)
 }
 
 // IntersectCircle returns a minimal required Vector, such that moving the rect by that vector would stop the Circle

rectangle_test.go

@@ -329,28 +329,56 @@ func TestRect_IntersectionPoints(t *testing.T) {
  }
 }
 
-func BenchmarkRect_Intersect(b *testing.B) {
- root := pixel.R(10, 10, 50, 50)
- inter := pixel.R(11, 11, 15, 15)
-
- for i := 0; i < b.N; i++ {
- if root.Intersect(inter) != pixel.ZR {
- // do a thing
- }
+var rectIntTests = []struct {
+ name string
+ r1, r2 pixel.Rect
+ want pixel.Rect
+ intersect bool
+}{
+ {
+ name: "Nothing touching",
+ r1: pixel.R(0, 0, 10, 10),
+ r2: pixel.R(21, 21, 40, 40),
+ want: pixel.ZR,
+ },
+ {
+ name: "Edge touching",
+ r1: pixel.R(0, 0, 10, 10),
+ r2: pixel.R(10, 10, 20, 20),
+ want: pixel.ZR,
+ },
+ {
+ name: "Bit of overlap",
+ r1: pixel.R(0, 0, 10, 10),
+ r2: pixel.R(0, 9, 20, 20),
+ want: pixel.R(0, 9, 10, 10),
+ intersect: true,
+ },
+ {
+ name: "Fully overlapped",
+ r1: pixel.R(0, 0, 10, 10),
+ r2: pixel.R(0, 0, 10, 10),
+ want: pixel.R(0, 0, 10, 10),
+ intersect: true,
+ },
+}
 
- // do a thing
+func TestRect_Intersect(t *testing.T) {
+ for _, tt := range rectIntTests {
+ t.Run(tt.name, func(t *testing.T) {
+ if got := tt.r1.Intersect(tt.r2); !reflect.DeepEqual(got, tt.want) {
+ t.Errorf("Rect.Intersect() = %v, want %v", got, tt.want)
+ }
+ })
  }
 }
 
-func BenchmarkRect_IsIntersect(b *testing.B) {
- root := pixel.R(10, 10, 50, 50)
- inter := pixel.R(11, 11, 15, 15)
-
- for i := 0; i < b.N; i++ {
- if root.Intersects(inter) {
- // do a thing
- }
-
- // do a thing
+func TestRect_Intersects(t *testing.T) {
+ for _, tt := range rectIntTests {
+ t.Run(tt.name, func(t *testing.T) {
+ if got := tt.r1.Intersects(tt.r2); got != tt.intersect {
+ t.Errorf("Rect.Intersects() = %v, want %v", got, tt.want)
+ }
+ })
  }
 }