Reactor.Graphics.Drawing

type Drawing = DrawingM Unit

DrawingM is usually too general; our drawing-contructing functions don't need to return anything. Internal implementation detail.

Usually, constructing a drawing will look something like this.

drawTwoPoints :: CoordinateSystem Point -> CoordinateSystem Point -> Drawing
drawTwoPoints blueXY redXY = do
  fill Color.blue400 $ tile blueXY
  fill Color.red400 $ tile redXY

newtype DrawingM a

A free monad for DrawingF that enables you to use do-notation when constructing drawings. Just an internal implementation detail.

Constructors

• DrawingM (Free DrawingF a)

Instances

• Functor DrawingM
• Apply DrawingM
• Applicative DrawingM
• Bind DrawingM
• Monad DrawingM
• (Semigroup a) => Semigroup (DrawingM a)
• (Monoid a) => Monoid (DrawingM a)
• MonadRec DrawingM

data DrawingF a

A DSL for constructing drawings. Currently, only filled shapes are supported. DrawingF is for internal use. You should construct a drawing by calling the different helper functions, like fill, instead of manually calling the DrawingF data contructors.

Constructors

• Filled Color Shape a

Instances

• (Functor m) => Functor DrawingF

fill :: Color -> Shape -> Drawing

Given a shape (e.g. a rectangle), draw it and fill it with the provided color.

drawGrid :: forall a. Grid a -> (a -> Maybe Color) -> Drawing

This function produces a drawing from a grid. For each cell in the grid, it calls the supplied (a -> Maybe Color) function to obtain its color. The cell is then drawn it using the fill and tile functions.

drawGridWithIndex :: forall a. Grid a -> (Coordinates -> a -> Maybe Color) -> Drawing

A function almost identical to drawGrid, only the function matching colors to grid cells is provided with an index of the cell in addition to the value of the cell.

data Shape

Constructors

• Rectangle (Int -> Coordinates) (Int -> { height :: Int, width :: Int })

tile :: Coordinates -> Shape

A 1-square tile on the given point in the grid.