    module Graphics.Gloss.Data.Picture
            ( Picture       (..)
            , Point, Vector, Path

            -- * Aliases for Picture constructors
            , blank
            , polygon
            , line
            , circle, thickCircle
            , arc,    thickArc
            , text
            , bitmap
            , color
            , translate, rotate, scale
            , pictures

            -- * Compound shapes
            , lineLoop
            , circleSolid
            , arcSolid
            , sectorWire
            , rectanglePath
            , rectangleWire
            , rectangleSolid
            , rectangleUpperPath
            , rectangleUpperWire
            , rectangleUpperSolid)
    where
    import Graphics.Gloss.Rendering
    import Graphics.Gloss.Geometry.Angle

    -- Constructors ----------------------------------------------------------------
    -- NOTE: The docs here should be identical to the ones on the constructors.

    -- | A blank picture, with nothing in it.
    blank :: Picture
    blank   = Blank

    -- | A convex polygon filled with a solid color.
    polygon :: Path -> Picture
    polygon = Polygon

    -- | A line along an arbitrary path.
    line :: Path -> Picture
    line    = Line

    -- | A circle with the given radius.
    circle  :: Float  -> Picture
    circle  = Circle

    -- | A circle with the given thickness and radius.
    --   If the thickness is 0 then this is equivalent to `Circle`.
    thickCircle  :: Float -> Float -> Picture
    thickCircle = ThickCircle

    -- | A circular arc drawn counter-clockwise between two angles (in degrees)
    --   at the given radius.
    arc     :: Float -> Float -> Float -> Picture
    arc = Arc

    -- | A circular arc drawn counter-clockwise between two angles (in degrees),
    --   with the given radius  and thickness.
    --   If the thickness is 0 then this is equivalent to `Arc`.
    thickArc :: Float -> Float -> Float -> Float -> Picture
    thickArc = ThickArc

    -- | Some text to draw with a vector font.
    text :: String -> Picture
    text = Text

    -- | A bitmap image with a width, height and a Vector holding the
    --   32-bit RGBA bitmap data.
    --
    --  The boolean flag controls whether Gloss should cache the data
    --  between frames for speed.
    --  If you are programatically generating the image for
    --  each frame then use `False`.
    --  If you have loaded it from a file then use `True`.
    bitmap  :: Int -> Int -> BitmapData -> Bool -> Picture
    bitmap = Bitmap

    -- | A picture drawn with this color.
    color :: Color -> Picture -> Picture
    color = Color

    -- | A picture translated by the given x and y coordinates.
    translate :: Float -> Float -> Picture -> Picture
    translate = Translate

    -- | A picture rotated clockwise by the given angle (in degrees).
    rotate  :: Float -> Picture -> Picture
    rotate = Rotate

    -- | A picture scaled by the given x and y factors.
    scale   :: Float -> Float -> Picture -> Picture
    scale = Scale

    -- | A picture consisting of several others.
    pictures :: [Picture] -> Picture
    pictures = Pictures

    -- Other Shapes ---------------------------------------------------------------
    -- | A closed loop along a path.
    lineLoop :: Path -> Picture
    lineLoop []     = Line []
    lineLoop (x:xs) = Line ((x:xs) ++ [x])

    -- Circles and Arcs -----------------------------------------------------------
    -- | A solid circle with the given radius.
    circleSolid :: Float -> Picture
    circleSolid r
            = thickCircle (r/2) r

    -- | A solid arc, drawn counter-clockwise between two angles at the given radius.
    arcSolid  :: Float -> Float -> Float -> Picture
    arcSolid a1 a2 r
            = thickArc a1 a2 (r/2) r

    -- | A wireframe sector of a circle.
    --   An arc is draw counter-clockwise from the first to the second angle at
    --   the given radius. Lines are drawn from the origin to the ends of the arc.
    ---
    --   NOTE: We take the absolute value of the radius incase it's negative.
    --   It would also make sense to draw the sector flipped around the
    --   origin, but I think taking the absolute value will be less surprising
    --   for the user.
    --
    sectorWire :: Float -> Float -> Float -> Picture
    sectorWire a1 a2 r_
     = let r        = abs r_
       in  Pictures
            [ Arc a1 a2 r
            , Line [(0, 0), (r * cos (degToRad a1), r * sin (degToRad a1))]
            , Line [(0, 0), (r * cos (degToRad a2), r * sin (degToRad a2))] ]

    -- Rectangles -----------------------------------------------------------------
    -- NOTE: Only the first of these rectangle functions has haddocks on the
    --       arguments to reduce the amount of noise in the extracted docs.

    -- | A path representing a rectangle centered about the origin
    rectanglePath
            :: Float        -- ^ width of rectangle
            -> Float        -- ^ height of rectangle
            -> Path
    rectanglePath sizeX sizeY
     = let  sx      = sizeX / 2
            sy      = sizeY / 2
       in   [(-sx, -sy), (-sx, sy), (sx, sy), (sx, -sy)]

    -- | A wireframe rectangle centered about the origin.
    rectangleWire :: Float -> Float -> Picture
    rectangleWire sizeX sizeY
            = lineLoop $ rectanglePath sizeX sizeY

    -- | A wireframe rectangle in the y > 0 half of the x-y plane.
    rectangleUpperWire :: Float -> Float -> Picture
    rectangleUpperWire sizeX sizeY
            = lineLoop $ rectangleUpperPath sizeX sizeY

    -- | A path representing a rectangle in the y > 0 half of the x-y plane.
    rectangleUpperPath :: Float -> Float -> Path
    rectangleUpperPath sizeX sy
     = let  sx      = sizeX / 2
       in   [(-sx, 0), (-sx, sy), (sx, sy), (sx, 0)]

    -- | A solid rectangle centered about the origin.
    rectangleSolid :: Float -> Float -> Picture
    rectangleSolid sizeX sizeY
            = Polygon $ rectanglePath sizeX sizeY

    -- | A solid rectangle in the y > 0 half of the x-y plane.
    rectangleUpperSolid :: Float -> Float -> Picture
    rectangleUpperSolid sizeX sizeY
            = Polygon  $ rectangleUpperPath sizeX sizeY