lang/laantas-script/GlyphsBase.hs

162 lines
4.5 KiB
Haskell

module GlyphsBase (module GlyphsBase, module Svg) where
import Svg hiding (shiftX, shiftY, shift, width, size)
import qualified Svg
import Prelude hiding (Word)
import Data.Foldable
import Numeric
import Prelude hiding (Word)
data Glyph = G {path :: Segs, size :: SizeInfo}
data SizeInfo = SI {
width :: Double, -- ^ total width
right :: Double, -- ^ attachment point for e.g. a
center :: Double -- ^ attachment point for e.g. á
}
simpleG :: Segs -> Double -> Glyph
simpleG path width =
G {path, size = SI {width, right = width, center = width/2}}
-- | base amounts
charHeight', lineHeight', spaceWidth', gap' :: Double
charHeight' = 13
lineHeight' = 15
spaceWidth' = 4
gap' = 1.5
withSize :: MonadReader Env m => (Double -> a) -> m a
withSize f = asks \E {size} -> f size
-- | multiplied by size
charHeight, lineHeight, spaceWidth, margin, gap :: MonadReader Env m => m Double
charHeight = withSize (* charHeight')
lineHeight = withSize (* lineHeight')
spaceWidth = withSize (* spaceWidth')
margin = asks \E {stroke} -> stroke
gap = withSize (* gap')
data Segs = P [M Text] | Shift !Double !Double Segs | Segs :<>: Segs
instance Semigroup Segs where
P [] <> s = s
s <> P [] = s
P ss <> P ts = P $ ss <> ts
s <> t = s :<>: t
instance Monoid Segs where
mempty = P []
mappend = (<>)
joinSegs :: Segs -> M Text
joinSegs (P ps) = fmap mconcat $ sequence ps
joinSegs (Shift dx dy segs) = do
E {size} <- ask
localS (Svg.shift (size * dx, size * dy)) $ joinSegs segs
joinSegs (ss1 :<>: ss2) = liftM2 (<>) (joinSegs ss1) (joinSegs ss2)
localS :: MonadState s m => (s -> s) -> m a -> m a
localS f m = do old <- get; modify f; res <- m; put old; pure res
shiftX, shiftY :: Double -> Segs -> Segs
shiftX dx = Shift dx 0
shiftY dy = Shift 0 dy
space :: M ()
space = do
swidth <- spaceWidth
modify \s@(S {x}) -> s {x = x + swidth}
data TextSize = T {width, height :: !Double}
run :: M a -> Env -> (a, TextSize)
run m e@(E {size}) =
let (res, S {..}) = runState (runReaderT m e) s in
(res, T {width = textWidth, height = textHeight})
where
margin' = runReader margin e
ascHeight = size * 3
s = S {x = margin', y = margin' + ascHeight,
textWidth = 0, textHeight = 0, firstOnLine = True}
type Word = [EGlyph]
type EGlyph = (Glyph, [Diacritic])
type Diacritic' a = SizeInfo -> (Segs, a)
type Diacritic = Diacritic' Double
simpleDia :: Segs -> Diacritic
simpleDia ss (SI {width}) = (ss, width)
doGlyphs :: [Word] -> Env -> Element
doGlyphs gs e = wrap $ run act e where
act = do
E {stroke, color} <- ask
let gattrs = [Stroke_ <<- color, Stroke_width_ <<- toPx stroke,
Stroke_linecap_ <<- "round", Stroke_linejoin_ <<- "round",
Fill_ <<- "none"]
g_ gattrs . mconcat <$> traverse placeWord gs <* newline
wrap (content, T {width, height}) =
let sattrs = [Height_ <<- toPx height, Width_ <<- toPx width] in
doctype <> svg11_ content `with` sattrs
liftDia :: Diacritic -> Diacritic' SizeInfo
liftDia f sz = let (x, w) = f sz in (x, sz {width = w} :: SizeInfo)
glyphWidth :: EGlyph -> M Double
glyphWidth (G {size}, ss) =
let SI {width} = foldl (\x f -> snd $ liftDia f x) size ss in
(+) <$> withSize (* width) <*> gap
totalWidth :: Double -> M Double
totalWidth width = (+) <$> withSize (* width) <*> gap
wordWidth :: Word -> M Double
wordWidth = fmap sum . traverse glyphWidth
placeWord :: Word -> M Element
placeWord w = do
wwidth <- wordWidth w
margin' <- margin
S {x, firstOnLine} <- get
E {width} <- ask
let space' = if firstOnLine then pure () else space
e <- if x > margin' && x + wwidth > width then do
newline *> placeWord w
else do
mconcat <$> (space' *> traverse placeGlyph w)
modify \s -> s {firstOnLine = False}
pure e
placeGlyph :: EGlyph -> M Element
placeGlyph (G {path = path1, size}, dias) = do
let (segs', width') = placeDias size dias
path <- joinSegs $ path1 <> segs'
width <- totalWidth width'
modify \s@(S {x}) -> s {x = x + width}
pure $ path_ [D_ <<- path]
placeDias :: SizeInfo -> [Diacritic] -> (Segs, Double)
placeDias sz =
unlift . flip runState sz . fmap fold . traverse (state . liftDia)
where unlift (x, SI {width}) = (x, width)
newline :: M ()
newline = do
lh <- lineHeight
m <- margin
modify \s@(S {x, y, textWidth, textHeight}) ->
s {x = m, y = y + lh,
textWidth = textWidth `max` (x + m),
textHeight = textHeight + lh,
firstOnLine = True}
toPx :: Double -> Text
toPx x = pack (showFFloat (Just 4) x "px")