Function TestMatrix

util_test.go:192–277

(t *testing.T)

}

func TestMatrix(t *testing.T) {
	p := Point{3, 4}
	test.T(t, Identity.Translate(2.0, 2.0).Dot(p), Point{5.0, 6.0})
	test.T(t, Identity.Scale(2.0, 2.0).Dot(p), Point{6.0, 8.0})
	test.T(t, Identity.Scale(1.0, -1.0).Dot(p), Point{3.0, -4.0})
	test.T(t, Identity.ScaleAbout(2.0, -1.0, 2.0, 2.0).Dot(p), Point{4.0, 0.0})
	test.T(t, Identity.Shear(1.0, 0.0).Dot(p), Point{7.0, 4.0})
	test.T(t, Identity.ShearAbout(1.0, 0.0, 2.0, 2.0).Dot(p), Point{5.0, 4.0})
	test.T(t, Identity.Rotate(90.0).Dot(p), p.Rot90CCW())
	test.T(t, Identity.RotateAbout(90.0, 5.0, 5.0).Dot(p), p.Rot(90.0*math.Pi/180.0, Point{5.0, 5.0}))
	test.T(t, Identity.ReflectX().Dot(p), Point{-3.0, 4.0})
	test.T(t, Identity.ReflectY().Dot(p), Point{3.0, -4.0})
	test.T(t, Identity.ReflectXAbout(1.5).Dot(p), Point{0.0, 4.0})
	test.T(t, Identity.ReflectYAbout(2.0).Dot(p), Point{3.0, 0.0})
	test.T(t, Identity.Rotate(90.0).T().Dot(p), p.Rot90CW())
	test.T(t, Identity.Scale(2.0, 4.0).Inv(), Identity.Scale(0.5, 0.25))
	test.T(t, Identity.Rotate(90.0).Inv(), Identity.Rotate(-90.0))
	test.T(t, Identity.Rotate(90.0).Scale(2.0, 1.0), Identity.Scale(1.0, 2.0).Rotate(90.0))

	lambda1, lambda2, v1, v2 := Identity.Rotate(-90.0).Scale(2.0, 1.0).Rotate(90.0).Eigen()
	test.Float(t, lambda1, 1.0)
	test.Float(t, lambda2, 2.0)
	test.T(t, v1, Point{1.0, 0.0})
	test.T(t, v2, Point{0.0, 1.0})

	halfSqrt2 := 1.0 / math.Sqrt(2.0)
	lambda1, lambda2, v1, v2 = Identity.Shear(1.0, 1.0).Eigen()
	test.Float(t, lambda1, 0.0)
	test.Float(t, lambda2, 2.0)
	test.T(t, v1, Point{-halfSqrt2, halfSqrt2})
	test.T(t, v2, Point{halfSqrt2, halfSqrt2})

	lambda1, lambda2, v1, v2 = Identity.Shear(1.0, 0.0).Eigen()
	test.Float(t, lambda1, 1.0)
	test.Float(t, lambda2, 1.0)
	test.T(t, v1, Point{1.0, 0.0})
	test.T(t, v2, Point{1.0, 0.0})

	lambda1, lambda2, v1, v2 = Identity.Scale(math.NaN(), math.NaN()).Eigen()
	test.Float(t, lambda1, math.NaN())
	test.Float(t, lambda2, math.NaN())
	test.T(t, v1, Point{0.0, 0.0})
	test.T(t, v2, Point{0.0, 0.0})

	tx, ty, phi, sx, sy, theta := Identity.Rotate(-90.0).Scale(2.0, 1.0).Rotate(90.0).Translate(0.0, 10.0).Decompose()
	test.Float(t, tx, 0.0)
	test.Float(t, ty, 20.0)
	test.Float(t, phi, -90.0)
	test.Float(t, sx, 2.0)
	test.Float(t, sy, 1.0)
	test.Float(t, theta, 90.0)

	test.T(t, Identity.Translate(1.0, 1.0).IsTranslation(), true)
	test.T(t, Identity.Rotate(90.0).IsTranslation(), false)
	test.T(t, Identity.Scale(-1.0, 1.0).IsTranslation(), false)
	test.T(t, Identity.Scale(2.0, 2.0).IsTranslation(), false)
	test.T(t, Identity.Scale(2.0, 1.0).IsTranslation(), false)
	test.T(t, Identity.Shear(2.0, -1.0).IsTranslation(), false)