Update adding new Rect.Intersects Method

This addes a new Rect.Intersects method which is around 5x faster then Rect.Intersect when used for basic collision checks.

geometry.go

@@ -622,6 +622,17 @@ func (r Rect) Intersect(s Rect) Rect {
 	return t
 }
 
+// Intersects returns whether or not the given Rect intersects at any point with this Rect.
+//
+// This function is overall about 5x faster then 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)
+}
+
 // IntersectCircle returns a minimal required Vector, such that moving the circle by that vector would stop the Circle
 // and the Rect intersecting.  This function returns a zero-vector if the Circle and Rect do not overlap, and if only
 // the perimeters touch.

geometry_test.go

@@ -1555,3 +1555,29 @@ func TestLine_String(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
+		}
+
+		// do a thing
+	}
+}
+
+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.IsIntersect(inter) {
+			// do a thing
+		}
+
+		// do a thing
+	}
+}