module Graphics.FreeGame.Data.Font
( Font
, loadFont
, Metrics(..)
, Graphics.FreeGame.Data.Font.metrics
, fontBoundingBox
, charToBitmap
, RenderedChar(..)
, text
, renderCharacters
) where
import Control.Applicative
import Control.Monad.IO.Class
import Data.Array.Repa as R
import Data.Array.Repa.Eval
import Data.Vect
import Data.IORef
import qualified Data.Map as M
import Data.Word
import Graphics.FreeGame.Base
import Graphics.FreeGame.Types
import Graphics.FreeGame.Data.Bitmap
import Graphics.FreeGame.Internal.Finalizer
import Graphics.Rendering.FreeType.Internal
import qualified Graphics.Rendering.FreeType.Internal.GlyphSlot as GS
import qualified Graphics.Rendering.FreeType.Internal.Vector as V
import Graphics.Rendering.FreeType.Internal.Bitmap as B
import Graphics.Rendering.FreeType.Internal.PrimitiveTypes as PT
import Graphics.Rendering.FreeType.Internal.Face as F
import Graphics.Rendering.FreeType.Internal.Library as L
import Graphics.Rendering.FreeType.Internal.BBox as BB
import Foreign.Marshal.Alloc
import Foreign.C.Types
import Foreign.C.String
import Foreign.Storable
import System.IO.Unsafe
import Unsafe.Coerce
data Font = Font FT_Face Metrics BoundingBox (IORef (M.Map (Float, Char) RenderedChar))
loadFont :: FilePath -> IO Font
loadFont path = alloca $ \p -> do
e <- withCString path $ \str -> ft_New_Face freeType str 0 p
failFreeType e
f <- peek p
b <- peek (bbox f)
asc <- peek (ascender f)
desc <- peek (descender f)
u <- fromIntegral <$> peek (units_per_EM f)
let m = Metrics (fromIntegral asc/u) (fromIntegral desc/u)
box = BoundingBox (Vec2 (fromIntegral (xMin b)/u) (fromIntegral (yMin b)/u))
(Vec2 (fromIntegral (xMax b)/u) (fromIntegral (yMin b)/u))
Font f m box <$> newIORef M.empty
metrics :: Font -> Metrics
metrics (Font _ m _ _) = m
fontBoundingBox :: Font -> BoundingBox
fontBoundingBox (Font _ _ b _) = b
text :: Font -> Float -> String -> Picture
text font siz str = PictureWithFinalizer $ Pictures <$> renderCharacters font siz str
failFreeType :: Monad m => CInt -> m ()
failFreeType 0 = return ()
failFreeType e = fail $ "FreeType Error:" Prelude.++ show e
freeType :: FT_Library
freeType = unsafePerformIO $ alloca $ \p -> do
failFreeType =<< ft_Init_FreeType p
peek p
data RenderedChar = RenderedChar
{ charBitmap :: Bitmap
, charOffset :: Vec2
,charAdvance :: Float
}
data Metrics = Metrics
{ metricsAscent :: Float
, metricsDescent :: Float
}
resolutionDPI :: Int
resolutionDPI = 300
charToBitmap :: Font -> Float -> Char -> FinalizerT IO RenderedChar
charToBitmap (Font face _ _ refCache) pixel ch = do
cache <- liftIO $ readIORef refCache
case M.lookup (siz, ch) cache of
Nothing -> do
d <- liftIO render
liftIO $ writeIORef refCache $ M.insert (siz, ch) d cache
finalizer $ modifyIORef refCache $ M.delete (siz, ch)
return d
Just d -> return d
where
siz = pixel * 72 / fromIntegral resolutionDPI
render = do
let dpi = fromIntegral resolutionDPI
failFreeType =<< ft_Set_Char_Size face 0 (floor $ siz * 64) dpi dpi
ix <- ft_Get_Char_Index face (fromIntegral $ fromEnum ch)
failFreeType =<< ft_Load_Glyph face ix ft_LOAD_DEFAULT
slot <- peek $ glyph face
failFreeType =<< ft_Render_Glyph slot ft_RENDER_MODE_NORMAL
bmp <- peek $ GS.bitmap slot
left <- fmap fromIntegral $ peek $ GS.bitmap_left slot
top <- fmap fromIntegral $ peek $ GS.bitmap_top slot
let h = fromIntegral $ B.rows bmp
w = fromIntegral $ B.width bmp
mv <- newMVec (w * h)
fillChunkedIOP (w * h) (unsafeWriteMVec mv) $ const $ return
$ fmap unsafeCoerce . peekElemOff (buffer bmp)
adv <- peek $ GS.advance slot
ar :: R.Array U DIM2 Word8 <- unsafeFreezeMVec (Z:.h:.w) mv
let pix (crd:.0) = R.index ar crd
pix (_:._) = 255
result <- computeP (fromFunction (Z:.h:.w:.4) pix) >>= makeStableBitmap
return $ RenderedChar result (Vec2 left (top)) (fromIntegral (V.x adv) / 64)
renderCharacters :: Font -> Float -> String -> FinalizerT IO [Picture]
renderCharacters font pixel str = render str 0 where
render [] _ = return []
render (c:cs) pen = do
RenderedChar b (Vec2 x y) adv <- charToBitmap font pixel c
let (w,h) = bitmapSize b
offset = Vec2 (pen + x + fromIntegral w / 2) (y + fromIntegral h / 2)
(Translate offset (Bitmap b):) <$> render cs (pen + adv)