AABB and Sphere Bounds with new BVH tree implement with go 1.18 generic

server/internal/bvh/bound.go

@@ -0,0 +1,59 @@
+package bvh
+
+import (
+	"golang.org/x/exp/constraints"
+	"math"
+)
+
+type AABB[I constraints.Signed | constraints.Float, V interface {
+	Add(V) V
+	Sub(V) V
+	Max(V) V
+	Min(V) V
+	Less(V) bool
+	More(V) bool
+	Sum() I
+}] struct{ Upper, Lower V }
+
+func (aabb AABB[I, V]) WithIn(point V) bool {
+	return aabb.Lower.Less(point) && aabb.Upper.More(point)
+}
+func (aabb AABB[I, V]) Touch(other AABB[I, V]) bool {
+	return aabb.Lower.Less(other.Upper) && other.Lower.Less(aabb.Upper) &&
+		aabb.Upper.More(other.Lower) && other.Upper.More(aabb.Lower)
+}
+func (aabb AABB[I, V]) Union(other AABB[I, V]) AABB[I, V] {
+	return AABB[I, V]{Upper: aabb.Upper.Max(other.Upper), Lower: aabb.Lower.Min(other.Lower)}
+}
+func (aabb AABB[I, V]) Surface() I { return aabb.Upper.Sub(aabb.Lower).Sum() * 2 }
+
+type Sphere[I constraints.Float, V interface {
+	Add(V) V
+	Sub(V) V
+	Mul(I) V
+	Max(V) V
+	Min(V) V
+	Less(V) bool
+	More(V) bool
+	Norm() I
+	Sum() I
+}] struct {
+	Center V
+	R      I
+}
+
+func (s Sphere[I, V]) WithIn(point V) bool {
+	return s.Center.Sub(point).Norm() < s.R
+}
+func (s Sphere[I, V]) Touch(other Sphere[I, V]) bool {
+	return s.Center.Sub(other.Center).Norm() < s.R+other.R
+}
+func (s Sphere[I, V]) Union(other Sphere[I, V]) Sphere[I, V] {
+	d := other.Center.Sub(s.Center).Norm()
+	r1r2d := (s.R - other.R) / d
+	return Sphere[I, V]{
+		Center: s.Center.Mul(1 + r1r2d).Add(other.Center.Mul(1 - r1r2d)),
+		R:      d + s.R + other.R,
+	}
+}
+func (s Sphere[I, V]) Surface() I { return I(2 * math.Pi * s.R) }