Graphics.Rendering.MiniTypeset.FontTexture

Store font glyphs in OpenGL textures

TODO: add (optional) subpixel rendering support (pre-render say 4 versions of the same glyphs with fractional horizontal offsets)

Documentation

replacementCharacter :: Char

data BufLoc

The location of a glyph in a font texture collection

Constructors

BufLoc

Fields

• _locGlyph :: !Glyph
• _locBufIdx :: !Int

  which buffer

• _locBufXY :: !(Int, Int)

  position within the texture (buffer)

• _locBufSiz :: !(Int, Int)

  size of the bounding box

• _locBufOfs :: !(Int, Int)

  offset relative to the bounding box

• _locHM :: !(HorizontalMetrics Float)

  for convenience, we cache the glyph metrics

Instances

Show BufLoc

Defined in Graphics.Rendering.MiniTypeset.FontTexture

Methods

showsPrec :: Int -> BufLoc -> ShowS

show :: BufLoc -> String

showList :: [BufLoc] -> ShowS

data TexBuf

A single texture buffer

Constructors

TexBuf

Fields

• _bufTexObj :: !TextureObject
• _bufSize :: !(Int, Int)

Instances

Show TexBuf

Defined in Graphics.Rendering.MiniTypeset.FontTexture

Methods

showsPrec :: Int -> TexBuf -> ShowS

show :: TexBuf -> String

showList :: [TexBuf] -> ShowS

allocateTexBuf :: FontTexture -> IO TexBuf

data TexCursor

Constructors

TexCursor

Fields

• _curBufIdx :: !Int

  which buffer we are filling currently

• _curX :: !Int

  next X position

• _curY :: !Int

  current Y position

• _cutMaxHt :: !Int

  maximal bitmap height in this row

Instances

Show TexCursor

Defined in Graphics.Rendering.MiniTypeset.FontTexture

Methods

showsPrec :: Int -> TexCursor -> ShowS

show :: TexCursor -> String

showList :: [TexCursor] -> ShowS

zeroCursor :: TexCursor

data FontTexture

A font texture collection: possibly several textures containing bitmaps a given font with a given height.

Constructors

FontTexture

Fields

• _ftexFont :: !Font
• _ftexName :: !String
• _ftexHeight :: !(Float, Float)
• _ftexScaling :: !Scaling
• _ftexVM :: !(VerticalMetrics Float)
• _ftexChars :: !(UnicodeCache (Maybe BufLoc))
• _ftexBufSize :: !(Int, Int)
• _ftexCursor :: !(IORef TexCursor)
• _ftexBufs :: !(IORef [TexBuf])
• _ftexLGapFactor :: !Double

Instances

Show FontTexture

Defined in Graphics.Rendering.MiniTypeset.FontTexture

Methods

showsPrec :: Int -> FontTexture -> ShowS

show :: FontTexture -> String

showList :: [FontTexture] -> ShowS

scaleU :: Float -> Unscaled -> Float

defaultTextureSize :: (Int, Int)

newFontTexture :: Font -> Float -> String -> IO FontTexture

newFontTexture' :: Font -> (Float, Float) -> String -> (Int, Int) -> Double -> IO FontTexture

Creates a new (empty) font texture. We allow different horizontal and vertical scaling, but both are measured in pixel heights

lookupFontTexture :: FontTexture -> Char -> IO BufLoc

Finds a character in the font texture (rendering it first if necessary). If the glyph is not present in the font, we return the "replacement character" instead. If that doesn't exist either, then we return the "not defined glyph" (glyph #0)

mbLookupFontTexture :: FontTexture -> Char -> IO (Maybe BufLoc)

Finds a character in the font texture (rendering it first if necessary)

testRenderFullTextureQuad :: FontTexture -> Int -> IO ()

Renders the given font texture as a quad (useful for debugging)