Copyright | (c) 2011 Michael Sloan |
---|---|

License | BSD-style (see LICENSE) |

Maintainer | Michael Sloan <mgsloan at gmail> |

Safe Haskell | None |

Language | Haskell2010 |

Stateful domain specific language for diagram paths, modelled after the classic "turtle" graphics language.

- type Turtle = TurtleT Identity
- type TurtleT = StateT TurtleState
- runTurtle :: Turtle a -> TurtleState
- runTurtleT :: Monad m => TurtleT m a -> m TurtleState
- drawTurtle :: Renderable (Path R2) b => Turtle a -> Diagram b R2
- drawTurtleT :: (Monad m, Functor m, Renderable (Path R2) b) => TurtleT m a -> m (Diagram b R2)
- sketchTurtle :: Turtle a -> Path R2
- sketchTurtleT :: (Functor m, Monad m) => TurtleT m a -> m (Path R2)
- forward :: Monad m => Double -> TurtleT m ()
- backward :: Monad m => Double -> TurtleT m ()
- left :: Monad m => Double -> TurtleT m ()
- right :: Monad m => Double -> TurtleT m ()
- heading :: Monad m => TurtleT m Double
- setHeading :: Monad m => Double -> TurtleT m ()
- towards :: Monad m => P2 -> TurtleT m ()
- isDown :: Monad m => TurtleT m Bool
- pos :: Monad m => TurtleT m P2
- setPos :: Monad m => P2 -> TurtleT m ()
- setPenWidth :: Monad m => Double -> TurtleT m ()
- setPenColor :: Monad m => Colour Double -> TurtleT m ()
- penUp :: Monad m => TurtleT m ()
- penDown :: Monad m => TurtleT m ()
- penHop :: Monad m => TurtleT m ()
- closeCurrent :: Monad m => TurtleT m ()

# Documentation

type TurtleT = StateT TurtleState Source

# Turtle control commands

runTurtle :: Turtle a -> TurtleState Source

Run the turtle, yielding the final turtle state.

runTurtleT :: Monad m => TurtleT m a -> m TurtleState Source

A more general way to run the turtle. Returns a computation in the
underlying monad `m`

yielding the final turtle state.

drawTurtle :: Renderable (Path R2) b => Turtle a -> Diagram b R2 Source

Run the turtle, yielding a diagram.

drawTurtleT :: (Monad m, Functor m, Renderable (Path R2) b) => TurtleT m a -> m (Diagram b R2) Source

A more general way to run the turtle. Returns a computation in
the underlying monad `m`

yielding the final diagram.

sketchTurtle :: Turtle a -> Path R2 Source

Run the turtle, ignoring any pen style commands and yielding a 2D path.

sketchTurtleT :: (Functor m, Monad m) => TurtleT m a -> m (Path R2) Source

A more general way to run the turtle. Returns a computation in
the underlying monad `m`

, ignoring any pen style commands and
yielding a 2D path.

# Motion commands

forward :: Monad m => Double -> TurtleT m () Source

Move the turtle forward, along the current heading.

backward :: Monad m => Double -> TurtleT m () Source

Move the turtle backward, directly away from the current heading.

left :: Monad m => Double -> TurtleT m () Source

Modify the current heading to the left by the specified angle in degrees.

right :: Monad m => Double -> TurtleT m () Source

Modify the current heading to the right by the specified angle in degrees.

# State accessors / setters

setHeading :: Monad m => Double -> TurtleT m () Source

Set the current turtle angle, in degrees.

isDown :: Monad m => TurtleT m Bool Source

Queries whether the pen is currently drawing a path or not.

setPenWidth :: Monad m => Double -> TurtleT m () Source

Sets the pen size

# Drawing control

closeCurrent :: Monad m => TurtleT m () Source

Closes the current path , to the starting position of the current trail. Has no effect when the pen position is up.