[Test]
public void RenderCoordinateSystemCross()
{
    CreateLookAtCamera(Vector3D.One * 4.0f, Vector3D.Zero);
    new Line3D(-Vector3D.UnitX, Vector3D.UnitX * 3, Color.Red);
    new Line3D(-Vector3D.UnitY, Vector3D.UnitY * 3, Color.Green);
    new Line3D(-Vector3D.UnitZ, Vector3D.UnitZ * 3, Color.Blue);
}

[Test]
public void RenderCoordinateSystemCross()
{
    CreateLookAtCamera(Vector3D.One * 4.0f, Vector3D.Zero);
    new Line3D(-Vector3D.UnitX, Vector3D.UnitX * 3, Color.Red);
    new Line3D(-Vector3D.UnitY, Vector3D.UnitY * 3, Color.Green);
    new Line3D(-Vector3D.UnitZ, Vector3D.UnitZ * 3, Color.Blue);
}

[Test]
public void RenderGrid()
{
    const int GridSize = 10;
    const float GridScale = 0.5f;
    const float HalfGridSize = GridSize * 0.5f;
    var axisXz = new Vector2D(-HalfGridSize, -HalfGridSize);
    CreateLookAtCamera(Vector3D.One * 4.0f, Vector3D.Zero);
    for (int i = 0; i <= GridSize; i++, axisXz.X += 1, axisXz.Y += 1)
    {
        new Line3D(new Vector3D(-HalfGridSize * GridScale, axisXz.Y * GridScale, 0.0f),
            new Vector3D(HalfGridSize * GridScale, axisXz.Y * GridScale, 0.0f), Color.White);
        new Line3D(new Vector3D(axisXz.X * GridScale, -HalfGridSize * GridScale, 0.0f),
            new Vector3D(axisXz.X * GridScale, HalfGridSize * GridScale, 0.0f), Color.White);
    }
}

[Test]
public void RenderGrid()
{
    const int GridSize = 10;
    const float GridScale = 0.5f;
    const float HalfGridSize = GridSize * 0.5f;
    var axisXz = new Vector2D(-HalfGridSize, -HalfGridSize);
    CreateLookAtCamera(Vector3D.One * 4.0f, Vector3D.Zero);
    for (int i = 0; i <= GridSize; i++, axisXz.X += 1, axisXz.Y += 1)
    {
        new Line3D(new Vector3D(-HalfGridSize * GridScale, axisXz.Y * GridScale, 0.0f),
            new Vector3D(HalfGridSize * GridScale, axisXz.Y * GridScale, 0.0f), Color.White);
        new Line3D(new Vector3D(axisXz.X * GridScale, -HalfGridSize * GridScale, 0.0f),
            new Vector3D(axisXz.X * GridScale, HalfGridSize * GridScale, 0.0f), Color.White);
    }
}

[Test]
public void RenderRedLine()
{
    CreateLookAtCamera(Vector3D.UnitY, Vector3D.Zero);
    new Line3D(-Vector3D.UnitX, Vector3D.UnitX, Color.Red);
}

[Test]
public void RenderRedLine()
{
    CreateLookAtCamera(Vector3D.UnitY, Vector3D.Zero);
    new Line3D(-Vector3D.UnitX, Vector3D.UnitX, Color.Red);
}

[Test, CloseAfterFirstFrame]
public void CreateLine3D()
{
    CreateLookAtCamera(Vector3D.One * 4.0f, Vector3D.Zero);
    var entity = new Line3D(Vector3D.Zero, Vector3D.One, Color.Red);
    Assert.AreEqual(Vector3D.Zero, entity.StartPoint);
    Assert.AreEqual(Vector3D.One, entity.EndPoint);
}

[Test, CloseAfterFirstFrame]
public void CreateLine3D()
{
    CreateLookAtCamera(Vector3D.One * 4.0f, Vector3D.Zero);
    var entity = new Line3D(Vector3D.Zero, Vector3D.One, Color.Red);
    Assert.AreEqual(Vector3D.Zero, entity.StartPoint);
    Assert.AreEqual(Vector3D.One, entity.EndPoint);
}

[Test, CloseAfterFirstFrame]
public void SetLine3DPoints()
{
    CreateLookAtCamera(Vector3D.One * 4.0f, Vector3D.Zero);
    var entity = new Line3D(Vector3D.Zero, Vector3D.Zero, Color.Red)
    {
        StartPoint = Vector3D.UnitX,
        EndPoint = Vector3D.UnitY
    };
    Assert.AreEqual(Vector3D.UnitX, entity.StartPoint);
    Assert.AreEqual(Vector3D.UnitY, entity.EndPoint);
}

[Test, CloseAfterFirstFrame]
public void SetLine3DPoints()
{
    CreateLookAtCamera(Vector3D.One * 4.0f, Vector3D.Zero);
    var entity = new Line3D(Vector3D.Zero, Vector3D.Zero, Color.Red)
    {
        StartPoint = Vector3D.UnitX,
        EndPoint = Vector3D.UnitY
    };
    Assert.AreEqual(Vector3D.UnitX, entity.StartPoint);
    Assert.AreEqual(Vector3D.UnitY, entity.EndPoint);
}

[Test, CloseAfterFirstFrame]
public void SetLine3DPointList()
{
    CreateLookAtCamera(Vector3D.One * 4.0f, Vector3D.Zero);
    var entity = new Line3D(Vector3D.Zero, Vector3D.Zero, Color.Red)
    {
        Points = new List<Vector3D> { Vector3D.UnitZ, Vector3D.UnitY }
    };

[Test, CloseAfterFirstFrame]
public void SetLine3DPointList()
{
    CreateLookAtCamera(Vector3D.One * 4.0f, Vector3D.Zero);
    var entity = new Line3D(Vector3D.Zero, Vector3D.Zero, Color.Red)
    {
        Points = new List<Vector3D> { Vector3D.UnitZ, Vector3D.UnitY }
    };

[Test, CloseAfterFirstFrame]
public void RenderingHiddenLineDoesNotThrowException()
{
    Camera.Current.Position = Vector3D.UnitZ;
    new Line3D(-Vector3D.UnitX, Vector3D.UnitX, Color.Red) { IsVisible = false };
    Assert.DoesNotThrow(() => AdvanceTimeAndUpdateEntities());
}

[Test, CloseAfterFirstFrame]
public void RenderingHiddenLineDoesNotThrowException()
{
    Camera.Current.Position = Vector3D.UnitZ;
    new Line3D(-Vector3D.UnitX, Vector3D.UnitX, Color.Red) { IsVisible = false };
    Assert.DoesNotThrow(() => AdvanceTimeAndUpdateEntities());
}