Implement Rand (#51)

Addresses issue #20

Co-authored-by: Galih Fajar <[email protected]>

rand.go

@@ -0,0 +1,20 @@
+package govec
+
+import (
+	"math/rand"
+	"time"
+
+	"golang.org/x/exp/constraints"
+)
+
+// RandV2F returns a new random normalized V2F vector
+func RandV2F[T constraints.Float]() V2F[T] {
+	r := rand.New(rand.NewSource(time.Now().UnixNano()))
+	return V2F[T]{T(r.Float32()), T(r.Float32())}.Norm()
+}
+
+// RandV3F returns a new random normalized V3F vector
+func RandV3F[T constraints.Float]() V3F[T] {
+	r := rand.New(rand.NewSource(time.Now().UnixNano()))
+	return V3F[T]{T(r.Float32()), T(r.Float32()), T(r.Float32())}.Norm()
+}

rand_test.go

@@ -0,0 +1,62 @@
+package govec
+
+import (
+	"math"
+	"testing"
+)
+
+func Test_RandV2F(t *testing.T) {
+	t.Run("generate 2 different random f32 vectors, shouldn't be equal", func(t *testing.T) {
+		v1 := RandV2F[float32]()
+		v2 := RandV2F[float32]()
+
+		if v1.X == v2.X || v1.Y == v2.Y || v1.X == v1.Y || v2.X == v2.Y {
+			t.Errorf("Expected [%f, %f] not equal to each other or with [%f, %f]", v1.X, v1.Y, v2.X, v2.Y)
+		}
+	})
+
+	t.Run("generate 2 different random f64 vectors, shouldn't be equal", func(t *testing.T) {
+		v1 := RandV2F[float64]()
+		v2 := RandV2F[float64]()
+
+		if v1.X == v2.X || v1.Y == v2.Y || v1.X == v1.Y || v2.X == v2.Y {
+			t.Errorf("Expected [%f, %f] not equal to each other or with [%f, %f]", v1.X, v1.Y, v2.X, v2.Y)
+		}
+	})
+
+	t.Run("randomized vectors should be normalized", func(t *testing.T) {
+		v := RandV2F[float32]()
+
+		if !almostEqual[float64](math.Sqrt(float64((v.X*v.X)+(v.Y*v.Y))), 1.0, 1e-5) {
+			t.Errorf("Expected [%f, %f] to be normalized!", v.X, v.Y)
+		}
+	})
+}
+
+func Test_RandV3F(t *testing.T) {
+	t.Run("generate 2 different random f32 vectors, shouldn't be equal", func(t *testing.T) {
+		v1 := RandV3F[float32]()
+		v2 := RandV3F[float32]()
+
+		if v1.X == v2.X || v1.Y == v2.Y || v1.Z == v2.Z || v1.X == v1.Y || v1.X == v1.Z || v1.Y == v1.Z || v2.X == v2.Y || v2.X == v2.Z || v2.Y == v2.Z {
+			t.Errorf("Expected [%f, %f, %f] not equal to each other or with [%f, %f, %f]", v1.X, v1.Y, v1.Z, v2.X, v2.Y, v2.Z)
+		}
+	})
+
+	t.Run("generate 2 different random f64 vectors, shouldn't be equal", func(t *testing.T) {
+		v1 := RandV3F[float64]()
+		v2 := RandV3F[float64]()
+
+		if v1.X == v2.X || v1.Y == v2.Y || v1.Z == v2.Z || v1.X == v1.Y || v1.X == v1.Z || v1.Y == v1.Z || v2.X == v2.Y || v2.X == v2.Z || v2.Y == v2.Z {
+			t.Errorf("Expected [%f, %f, %f] not equal to each other or with [%f, %f, %f]", v1.X, v1.Y, v1.Z, v2.X, v2.Y, v2.Z)
+		}
+	})
+
+	t.Run("randomized vectors should be normalized", func(t *testing.T) {
+		v := RandV3F[float32]()
+
+		if !almostEqual[float64](math.Sqrt(float64((v.X*v.X)+(v.Y*v.Y)+(v.Z*v.Z))), 1.0, 1e-5) {
+			t.Errorf("Expected [%f, %f, %f] to be normalized!", v.X, v.Y, v.Z)
+		}
+	})
+}