All of vectorpoint coverage

govector_test.go

@@ -125,24 +125,47 @@ func TestIntersection(t *testing.T) {
 }
 
 func TestAngle(t *testing.T) {
-	v1 := Vector2d{10, 0}
-	v2 := Vector2d{0, 10}
-
-	a := Angle(v2, v1)
-
-	if math.Abs(float64(a))-math.Pi/2 > Epsilon {
-		t.Errorf("Angle Error")
+	cases := []struct {
+		v1       Vector2d
+		v2       Vector2d
+		expected float32
+	}{
+		{
+			v1:       Vector2d{10, 0},
+			v2:       Vector2d{0, 10},
+			expected: -math.Pi / 2,
+		},
+		{
+			v1:       Vector2d{5, 0},
+			v2:       Vector2d{10, 10},
+			expected: -math.Pi / 4,
+		},
+		{
+			v1:       Vector2d{0, 10},
+			v2:       Vector2d{0, -10},
+			expected: math.Pi,
+		},
+		// nan angles:
+		{
+			v1:       Vector2d{0, 0},
+			v2:       Vector2d{0, 0},
+			expected: 0,
+		},
+		// nan angles
+		{
+			v1:       Vector2d{0.0001, 0},
+			v2:       Vector2d{0, 0},
+			expected: math.Pi * Rad2deg,
+		},
 	}
+	var a float32
+	for _, c := range cases {
+		a = Angle(c.v2, c.v1)
 
-	v1 = Vector2d{5, 0}
-	v2 = Vector2d{10, 10}
-
-	a = Angle(v1, v2)
-
-	if math.Abs(float64(a))-math.Pi/4 > Epsilon {
-		t.Errorf("Angle Error")
+		if math.Abs(float64(a-c.expected)) > Epsilon {
+			t.Errorf("Angle Error; expected: %f, actual: %f", c.expected, a)
+		}
 	}
-
 }
 
 func TestRotate(t *testing.T) {
@@ -354,3 +377,65 @@ func TestOrientedSquare(t *testing.T) {
 		}
 	}
 }
+
+func TestPopPop(t *testing.T) {
+	v1 := Vector2d{10, 10}
+	if v1.PopPop() != float32(math.Sqrt(10*10+10*10)) {
+		t.Errorf("Incorrect Magnitude!")
+	}
+}
+
+func TestAASquareAtPoint(t *testing.T) {
+	p1 := Point2d{10, 10}
+	expected := AABB2d{
+		A: Point2d{5, 5},
+		B: Point2d{15, 15},
+	}
+	aabb := AASquareAtPoint(p1, 10)
+	if aabb != expected {
+		t.Errorf("incorrect AABB2d; expected: %+v, calculated: %+v ", expected, aabb)
+	}
+
+}
+
+func TestDistance(t *testing.T) {
+	if Distance(Point2d{0, 0}, Point2d{0, 0}) != 0.0 {
+		t.Error("incorectly calculating distance between two points at origin")
+	}
+	if Distance(Point2d{0, 0}, Point2d{10, 0}) != 10.0 {
+		t.Error("incorectly calculating distance between points on y axis")
+	}
+	if Distance(Point2d{0, 0}, Point2d{3, 4}) != 5.0 {
+		t.Error("incorectly calculating distance for pythagorean triple")
+	}
+}
+
+func TestAABBToRect(t *testing.T) {
+	r := AABB2d{
+		A: Point2d{5, 5},
+		B: Point2d{15, 15},
+	}
+	p := r.ToPolygon()
+	expected := Polygon2d{
+		Points: []Vector2d{
+			Vector2d{X: 0, Y: 0},
+			Vector2d{X: 0, Y: 10},
+			Vector2d{X: 10, Y: 10},
+			Vector2d{X: 10, Y: 0},
+		},
+		Origin: Point2d{X: 5, Y: 5},
+	}
+	if len(p.Points) != 4 {
+		t.Error("incorrect number of points")
+	}
+	// alright, this just feels cumbersome ... unfortunate that structs with
+	// slices can't be compared this way ...
+	if p.Origin != expected.Origin {
+		t.Error("just wrong")
+	}
+	for i, pp := range expected.Points {
+		if p.Points[i] != pp {
+			t.Error("just wrong")
+		}
+	}
+}

vectorpoint.go

@@ -140,6 +140,7 @@ func Distance(p1, p2 Point2d) float32 {
 	return p1.Sub(p2).Mag()
 }
 
+// returns radians
 func Angle(v1, v2 Vector2d) float32 {
 	x := (v1.Dot(v2) / (v1.Mag() * v2.Mag()))
 	angle := math.Acos(float64(x))