public void TestChangeColor()
{
var turtle = new Turtle(new Vector(0, 0), 0.0, ImmutableStack<Turtle.TurtleState>.Empty, dummy, Colors.Black);
var colorChanged = turtle.ChangeColor(Colors.Green);
Assert.AreEqual(colorChanged.DrawColor, Colors.Green);
}
public void TestRotate()
{
var turtle = new Turtle(new Vector(0, 0), 0.0, ImmutableStack<Turtle.TurtleState>.Empty, dummy, Colors.Black);
var rotated = turtle.Rotate(Math.PI / 2);
var expected = Math.PI / 2;
var actual = rotated.Angle;
Assert.AreEqual(expected, actual);
}
public void TestForward()
{
var turtle = new Turtle(new Vector(0, 0), 0.0, ImmutableStack<Turtle.TurtleState>.Empty, dummy, Colors.Black);
var forward = turtle.Forward(15);
var expected = new Vector(15, 0);
var actual = forward.Position;
Assert.AreEqual(expected, actual);
}
public void TestPop()
{
var state = new Turtle.TurtleState(new Vector(2, 2), Math.PI / 4, Colors.Black);
var stack = ImmutableStack<Turtle.TurtleState>.Empty.Push(state);
var turtle = new Turtle(new Vector(0, 0), 0.0, stack, dummy, Colors.Black);
var popped = turtle.Pop();
Assert.AreEqual(popped.Position, state.Position);
Assert.AreEqual(popped.Angle, state.Angle);
Assert.AreEqual(popped.DrawColor, state.DrawColor);
}
public void TestPush()
{
var turtle = new Turtle(new Vector(0, 0), 0.0, ImmutableStack<Turtle.TurtleState>.Empty, dummy, Colors.Black);
var pushed = turtle.Push();
var first = pushed.Stack.Peek();
var pos = first.Position;
var angle = first.Angle;
var color = first.DrawColor;
Assert.AreEqual(turtle.Position, pos);
Assert.AreEqual(turtle.Angle, angle);
Assert.AreEqual(turtle.DrawColor, color);
}
/// <summary>
/// Draws the L-System to a WriteableBitmap. First computes the state string,
/// then computes a starting turtle position and then does a fold over the
/// state string, interpreting the characters as turtle commands.
/// </summary>
/// <param name="image"></param>
public void Draw(WriteableBitmap image)
{
var state = this.Step();
var start = new Turtle(
StartPos,
0.0,
ImmutableStack<Turtle.TurtleState>.Empty,
(a, b, c, d, color) => image.DrawLine(a, b, c, d, color),
Colors.Black);
state.Aggregate(start, (t, c) => {
switch (c) {
case 'F': return t.Forward(this.Distance);
case '+': return t.Rotate(this.Angle);
case '-': return t.Rotate(-this.Angle);
case '[': return t.Push();
case ']': return t.Pop();
case '1': return t.ChangeColor(Color.FromRgb(140, 80, 60));
case '2': return t.ChangeColor(Color.FromRgb(24, 180, 24));
case '3': return t.ChangeColor(Color.FromRgb(48, 220, 48));
default: return t;
}
});
}
public void TestBadPop()
{
var turtle = new Turtle(new Vector(0, 0), 0.0, ImmutableStack<Turtle.TurtleState>.Empty, dummy, Colors.Black);
turtle.Pop();
}