cga/Graphics/Diagram/Types.hs
2014-10-10 17:40:08 +02:00

88 lines
1.9 KiB
Haskell

{-# OPTIONS_HADDOCK ignore-exports #-}
module Graphics.Diagram.Types where
import Algebra.VectorTypes
import Diagrams.Backend.Cairo
import Diagrams.Prelude
import MyPrelude
type MeshString = String
-- |Represents a Cairo Diagram. This allows us to create multiple
-- diagrams with different algorithms but based on the same
-- coordinates and common properties.
data Diag = Diag {
mkDiag :: DiagProp
-> [PT]
-> Diagram Cairo R2
}
-- |Holds the properties for a Diagram, like thickness of 2d points etc.
-- This can also be seen as a context when merging multiple diagrams.
data DiagProp = MkProp {
-- |The thickness of the dots.
t :: Double,
-- |The dimensions of the x-axis.
dX :: Coord,
-- |The dimensions of the y-axis.
dY :: Coord,
-- |Algorithm to use.
alg :: Int,
-- |If we want to show the grid.
gd :: Bool,
-- |If we want to show the coordinates as text.
ct :: Bool,
-- |Square size used to show the grid and x/y-axis.
sqS :: Double
}
instance Def DiagProp where
def = defaultProp
instance Monoid Diag where
mempty = Diag (\_ _ -> mempty)
mappend d1 d2 = Diag g
where
g p vt = mkDiag d1 p vt <> mkDiag d2 p vt
mconcat = foldr mappend mempty
-- |The default properties of the Diagram.
defaultProp :: DiagProp
defaultProp = MkProp 2 (0,500) (0,500) 0 False False 50
-- |Extract the lower bound of the x-axis dimension.
xlD :: DiagProp -> Double
xlD = fst . dX
-- |Extract the upper bound of the x-axis dimension.
xuD :: DiagProp -> Double
xuD = snd . dX
-- |Extract the lower bound of the y-axis dimension.
ylD :: DiagProp -> Double
ylD = fst . dY
-- |Extract the upper bound of the y-axis dimension.
yuD :: DiagProp -> Double
yuD = snd . dY
-- |Returns the specified diagram if True is passed,
-- otherwise returns the empty diagram. This is just for convenience
-- to avoid if else constructs.
maybeDiag :: Bool -> Diag -> Diag
maybeDiag b d
| b = d
| otherwise = mempty