/// <summary>
/// converts an L-System in to a collection of instantiations of objects using a stack of Turtle3D objects
/// Renderable characters are:
/// F - Draw Stem at current scale
/// F(x) - Draw stem of width (x)
/// L - Draw Leaf at current scale
/// </summary>
/// <param name="lsystem">string containing a parameterized and/or bracketed L-System</param>
void TreeBuilder(string lsystem)
{
turtles.Push(topTurtle);
for (int i = 0; i < lsystem.Length; i++)
{
//
float angle = 25f;
// Process the commands, many of them just set values on the top turtle of the stack
switch (lsystem[i])
{
case 'F': // Move forward & draw
GameObject segment = Instantiate(stem);
// If this is parameterized, we draw the stem with a scale
// factor in the non-Z directions: aka thickness of the stem
if (lsystem[i + 1] == '(')
{
string foo = lsystem.Substring(i + 2);
foo = foo.Substring(0, foo.IndexOf(')'));
float thickness = float.Parse(foo);
i += foo.Length;
DrawObject(segment, this.transform, new Vector3(thickness * topTurtle.scale.x, thickness * topTurtle.scale.y, topTurtle.scale.z));
topTurtle.Move();
}
else
{
MoveDraw(segment, this.transform);
}
break;
case 'L':
DrawObject(Instantiate(leaf), this.transform);
break;
case 'f': // Just move forward, no drawing
topTurtle.Move();
break;
case '+': // Rotate Right
if (lsystem[i + 1] == '(')
{
string foo = lsystem.Substring(i + 2);
foo = foo.Substring(0, foo.IndexOf(')'));
angle = float.Parse(foo);
i += foo.Length;
}
topTurtle.Turn(Quaternion.AngleAxis(angle, Vector3.up));
break;
case '-': //Rotate Left
if (lsystem[i + 1] == '(')
{
string foo = lsystem.Substring(i + 2);
foo = foo.Substring(0, foo.IndexOf(')'));
angle = float.Parse(foo);
i += foo.Length;
}
topTurtle.Turn(Quaternion.AngleAxis(-angle, Vector3.up));
break;
case '&': //Pitch down
if (lsystem[i + 1] == '(')
{
string foo = lsystem.Substring(i + 2);
foo = foo.Substring(0, foo.IndexOf(')'));
angle = float.Parse(foo);
i += foo.Length;
}
topTurtle.Turn(Quaternion.AngleAxis(angle, Vector3.right));
break;
case '^': // Pitch up
if (lsystem[i + 1] == '(')
{
string foo = lsystem.Substring(i + 2);
foo = foo.Substring(0, foo.IndexOf(')'));
angle = float.Parse(foo);
i += foo.Length;
}
topTurtle.Turn(Quaternion.AngleAxis(-angle, Vector3.right));
break;
case '\\': //Roll left
if (lsystem[i + 1] == '(')
{
string foo = lsystem.Substring(i + 2);
foo = foo.Substring(0, foo.IndexOf(')'));
angle = float.Parse(foo);
i += foo.Length;
}
topTurtle.Turn(Quaternion.AngleAxis(-137.5f, Vector3.forward));
break;
case '/': // Roll right
if (lsystem[i + 1] == '(')
{
string foo = lsystem.Substring(i + 2);
foo = foo.Substring(0, foo.IndexOf(')'));
angle = float.Parse(foo);
i += foo.Length;
}
topTurtle.Turn(Quaternion.AngleAxis(137.5f, Vector3.forward));
break;
case '[': //Push stack
turtles.Push(new Turtle3D(topTurtle));
break;
case ']': //Pop stack
topTurtle = turtles.Pop();
break;
case '!': // Shrink scale of turtle and all children
topTurtle.scale *= .85f;
break;
case '\'': // Color?
break;
}
}
topTurtle = turtles.Pop();
Debug.Log(turtles.Count);
}
// for if you want to copy somebody else
public Turtle3D(Turtle3D copy)
{
this.position = copy.position;
this.orientation = copy.orientation;
this.scale = copy.scale;
}