module Lib
( someFunc
) where
import qualified Graphics.UI.Threepenny as UI
import Graphics.UI.Threepenny.Core
import Safe
import Data.List
someFunc :: IO ()
someFunc = startGUI defaultConfig setup
class PrintType a where
printType :: a -> b
black = "#000000"
blue = "#66CCFF"
circle :: String -> UI.Point -> Double -> UI.Canvas -> UI ()
circle color p r c = do
c # set' UI.fillStyle (UI.htmlColor color)
c # UI.beginPath
c # UI.arc p r (pi) pi
c # UI.closePath
c # UI.fill
wrapper :: Int -> Int -> UI Element
wrapper width height =
UI.canvas
# set UI.height height
# set UI.width width
# set style [("border", "solid black 1px")]
data MouseState = MouseUp | MouseDown deriving Eq
newtype Reversed a = Reversed [a]
mouseState :: MonadIO m => Element -> m (Behavior MouseState)
mouseState e = MouseUp `stepper` unionWith undefined (MouseDown <$ UI.mousedown e) (MouseUp <$ UI.mouseup e)
currentStroke :: MonadIO m => Element -> m (Behavior (Reversed (Int, Int)))
currentStroke e = do
mouseIsDown <- (fmap . fmap) (const . (== MouseDown)) $ mouseState e
let mouseDownMove = fmap (\x (Reversed xs) -> Reversed (x:xs)) $ filterApply mouseIsDown $ UI.mousemove e
let mouseUpClear = fmap (const $ const $ Reversed []) $ UI.mouseup e
accumB (Reversed []) (unionWith undefined mouseDownMove mouseUpClear)
mouseStroke :: MonadIO m => Element -> m (Event (Reversed (Int, Int)))
mouseStroke e = do
l <- currentStroke e
return $ l <@ UI.mouseup e
smooth :: Double -> [UI.Point] -> [UI.Point]
smooth smoothFact x = scanl1 (\(xl, xr) (yl, yr) -> (smoothFact * xl + (1 smoothFact) * yl, smoothFact * xr + (1 smoothFact) * yr)) x
thin :: Double -> [UI.Point] -> [UI.Point]
thin dist [] = []
thin dist (x@(lx, ly):xs) = x : thin dist (dropWhile (\(rx, ry) -> (lx rx) ** 2 + (ly ry) ** 2 < dist ** 2) xs)
data Curvature = CUp | CDown | CLeft | CRight deriving (Eq, Ord, Show)
mapBetween :: (a -> a -> b) -> [a] -> [b]
mapBetween f x | length x < 2 = []
mapBetween f x = zipWith f x (tail x)
mapBetween4 :: (a -> a -> a -> a -> b) -> [a] -> [b]
mapBetween4 f x | length x < 4 = []
mapBetween4 f x = zipWith4 f x tx ttx tttx
where
tx = tail x
ttx = tail tx
tttx = tail ttx
direction :: UI.Point -> UI.Point -> Curvature
direction (lx, ly) (rx, ry) =
if abs (lx rx) < abs (ly ry)
then if ly < ry then CDown else CUp
else if lx < rx then CRight else CLeft
directions :: [UI.Point] -> [Curvature]
directions = map head . group . mapBetween direction
toPoint :: (Int, Int) -> UI.Point
toPoint (x, y) = (fromIntegral x, fromIntegral y)
withAngles :: [UI.Point] -> [(UI.Point, Double)]
withAngles = mapBetween (\(lx, ly) (rx, ry) -> ((rx, ry), atan2 (ly ry) (rx lx)))
corners :: Double -> Double -> [UI.Point] -> [UI.Point]
corners sameLimit changeLimit =
map fst . filter snd .
mapBetween4 (\(_, a0) (_, a1) (p, a2) (_, a3) -> (p, abs (a0 a1) < sameLimit && abs (a2 a3) < sameLimit && abs (a1 a2) > changeLimit)) .
withAngles
data Grid = Grid { gridLeftTop :: UI.Point, gridRightDown :: UI.Point }
makeGrid :: [UI.Point] -> Maybe Grid
makeGrid [] = Nothing
makeGrid l = Just $ Grid (left, top) (right, down)
where
xs = map fst l
ys = map snd l
left = minimum xs
right = maximum xs
top = minimum ys
down = maximum ys
locateInRange :: Double -> Double -> Int -> Double -> Maybe Int
locateInRange down up numBracket val = if down <= val && val <= up then Just (min (floor ((val down) / (up down) * (fromIntegral numBracket))) numBracket) else Nothing
locateInGrid :: Grid -> Int -> Int -> UI.Point -> Maybe (Int, Int)
locateInGrid (Grid (left, top) (right, down)) numCol numRow (x, y) = do
x' <- locateInRange left right numCol x
y' <- locateInRange top down numRow y
return (x', y')
setup :: Window -> UI ()
setup w = do
return w # set UI.title "Ordinary"
wrap <- wrapper 1024 640
smoothFactIn <- UI.input
getBody w #+ [row [element wrap, column [string "smooth by", element smoothFactIn]]]
smoothFact <- stepper 0.5 $ filterJust $ fmap (readMay :: String -> Maybe Double) $ UI.valueChange smoothFactIn
stroke <- mouseStroke wrap
unEvent <- onEvent stroke $
\(Reversed x) -> do
let points = map toPoint $ reverse x
mapM (\p -> circle blue p 5 wrap) points
smoothFactCur <- currentValue smoothFact
let processedPoints = thin 20 $ smooth smoothFactCur points
mapM (\p -> circle black p 5 wrap) $ processedPoints
mapM (\p -> circle black p 20 wrap) $ corners (pi/6) (pi/3) processedPoints
return ()