|stb-truetype-0.1.1: A wrapper around Sean Barrett's TrueType rasterizer library.||Contents||Index|
This is a wrapper around Sean Barrett's TrueType font rasterizer code.
The original can be found at http://nothings.org/stb/stb_truetype.h.
The version of stb-truetype used here is 0.2.
Note: it seems that compound glyphs are not implemented yet!
|data TrueType |
|A TrueType font file (containing maybe multiple font sets) loaded into memory.
|data Offset |
|A font offset inside a TrueType font file.
|data Font |
|data Glyph |
|A glyph inside a font.
|loadTTF :: FilePath -> IO TrueType|
|withTTF :: FilePath -> (TrueType -> IO a) -> IO a|
|enumerateFonts :: TrueType -> IO [Offset]|
|Enumerates the fonts found in a TrueType file. Often there is only one,
but there may be more.
|initFont :: TrueType -> Offset -> IO Font|
|findGlyph :: Font -> Char -> IO (Maybe Glyph)|
|Note: this is cached.
|type Unscaled = Int|
|data HorizontalMetrics a |
|advanceWidth :: a|
|leftSideBearing :: a|
|data VerticalMetrics a |
|ascent is the coordinate above the baseline the font extends; descent
is the coordinate below the baseline the font extends (i.e. it is typically negative)
lineGap is the spacing between one row's descent and the next row's ascent...
so you should advance the vertical position by ascent - descent + lineGap
|ascent :: a|
|descent :: a|
|lineGap :: a|
|data BoundingBox a |
|The convention is BBox (x0,y0) (x1,y1).
|lineAdvance :: Num a => VerticalMetrics a -> a|
|As calculated by (ascent - descent + lineGap).
|verticalSize :: Num a => VerticalMetrics a -> a|
|As calculated by (ascent - descent).
|scaleForPixelHeight :: VerticalMetrics Unscaled -> Float -> Float|
|getFontVerticalMetrics :: Font -> IO (VerticalMetrics Unscaled)|
|getGlyphHorizontalMetrics :: Font -> Glyph -> IO (HorizontalMetrics Unscaled)|
|getGlyphKernAdvance :: Font -> Glyph -> Glyph -> IO Unscaled|
|This is not yet implemented in stb_truetype; it always returns 0.
|getGlyphBoundingBox :: Font -> Glyph -> IO (BoundingBox Unscaled)|
|type Scaling = (Float, Float)|
|data Bitmap |
|A 8-bit grayscale bitmap.
|newBitmap :: (Int, Int) -> IO Bitmap|
|withBitmap :: Bitmap -> (Int -> Int -> Ptr Word8 -> IO a) -> IO a|
|flipBitmap :: Bitmap -> IO Bitmap|
|Flips the bitmap vertically (leaving the original unchanged)
|type BitmapOfs = (Int, Int)|
|An offset (for example the pivot of the glyph)
|getGlyphBitmapBox :: Font -> Glyph -> Scaling -> IO (BoundingBox Int)|
Returns the size of the bitmap (in pixels) needed to
render the glyph with the given scaling.
The box is centered around the glyph origin; so the
bitmap width is x1-x0, height is y1-y0, and location to place
the bitmap top left is (leftSideBearing*scale,y0).
Note that the bitmap uses y-increases-down, but the shape uses
y-increases-up, so the results of getGlyphBitmapBox and
getGlyphBoundingBox are inverted.
|newGlyphBitmap :: Font -> Glyph -> Scaling -> IO (Bitmap, BitmapOfs)|
|Creates a new bitmap just enough to fit the glyph with the given scaling,
and renders the glyph into it. The offset returned is the offset
in pixel space from the glyph origin to the top-left of the bitmap
(so it's almost always negative).
|renderGlyphIntoBitmap' :: Font -> Glyph -> Scaling -> Bitmap -> BitmapOfs -> IO ()|
|The offset is the top-left corner of the bounding box of the glyph,
and must be nonnegative (otherwise nothing will happen).
|renderGlyphIntoBitmap :: Font -> Glyph -> Scaling -> Bitmap -> BitmapOfs -> IO ()|
|The offset is the origin of the glyph. If the glyph extends from the
bitmap in the positive direction, it is clipped; however, if it extends
in the negative direction, no drawing will happen!
|bitmapArray :: Bitmap -> IO (UArray (Int, Int) Word8)|
|NOTE: because of the way Haskell indexes rectangular arrays,
the resulting array is indexed with (y,x), as opposed to what
you would expect.
|bitmapFloatArray :: Bitmap -> IO (UArray (Int, Int) Float)|
|Cached glyph storage
|data CachedBitmap |
|Note: the metrics are scaled!
|data BitmapCache |
|bmcVerticalMetrics :: BitmapCache -> VerticalMetrics Float|
|Note: these metrics are scaled!
|bmcScaling :: BitmapCache -> Scaling|
|newBitmapCache :: Font -> Bool -> (Float, Float) -> IO BitmapCache|
|Creates a new cache where glyph bitmaps with the given scaling
will be stored. The second argument is whether the resulting bitmaps
should be flipped vertically or not (this is useful with OpenGL).
|getCachedBitmap :: BitmapCache -> Char -> IO (Maybe CachedBitmap)|
|Fetches a rendered glyph bitmap from the cache (rendering it first if
it was not present in the cache before).
|Produced by Haddock version 2.4.1|