Graphics.Rendering.Chart.Geometry

Points and Vectors

data Rect

A rectangle is defined by two points.

Constructors

Rect Point Point

Instances

Show Rect

Methods

showsPrec :: Int -> Rect -> ShowS

show :: Rect -> String

showList :: [Rect] -> ShowS

data Point

A point in two dimensions.

Constructors

Point

Fields

• p_x :: Double
• p_y :: Double

Instances

Show Point

Methods

showsPrec :: Int -> Point -> ShowS

show :: Point -> String

showList :: [Point] -> ShowS

data Vector

A vector in two dimensions.

Constructors

Vector

Fields

• v_x :: Double
• v_y :: Double

Instances

Show Vector

Methods

showsPrec :: Int -> Vector -> ShowS

show :: Vector -> String

showList :: [Vector] -> ShowS

type RectSize = (Double, Double)

type Range = (Double, Double)

pointToVec :: Point -> Vector

Convert a Point to a Vector.

mkrect :: Point -> Point -> Point -> Point -> Rect

Create a rectangle based upon the coordinates of 4 points.

rectPath :: Rect -> Path

Make a path from a rectangle.

pvadd :: Point -> Vector -> Point

Add a point and a vector.

pvsub :: Point -> Vector -> Point

Subtract a vector from a point.

psub :: Point -> Point -> Vector

Subtract two points.

vangle :: Vector -> Double

Angle of a vector (counterclockwise from positive x-axis)

vlen :: Vector -> Double

Length/magnitude of a vector

vscale :: Double -> Vector -> Vector

Scale a vector by a constant.

within :: Point -> Rect -> Bool

Test if a point is within a rectangle.

intersectRect :: Limit Rect -> Limit Rect -> Limit Rect

Intersects the rectangles. If they intersect the intersection rectangle is returned. LMin is the empty rectangle / intersection and LMax is the infinite plane.

data RectEdge

Edge of a rectangle.

Constructors

E_Top

E_Bottom

E_Left

E_Right

data Limit a

Constructors

LMin

LValue a

LMax

Instances

Show a => Show (Limit a)

Methods

showsPrec :: Int -> Limit a -> ShowS

show :: Limit a -> String

showList :: [Limit a] -> ShowS

type PointMapFn x y = (Limit x, Limit y) -> Point

A function mapping between points.

Paths

data Path

The path type used by Charts.

A path can consist of several subpaths. Each is started by a MoveTo operation. All subpaths are open, except the last one, which may be closed using the Close operation. When filling a path all subpaths are closed implicitly.

Closing a subpath means that a line is drawn from the end point to the start point of the subpath.

If a Arc (or ArcNeg) is drawn a implicit line from the last end point of the subpath is drawn to the beginning of the arc. Another implicit line is drawn from the end of an arc to the beginning of the next path segment.

The beginning of a subpath is either (0,0) or set by a MoveTo instruction. If the first subpath is started with an arc the beginning of that subpath is the beginning of the arc.

Constructors

MoveTo Point Path

LineTo Point Path

Arc Point Double Double Double Path

ArcNeg Point Double Double Double Path

End

Close

Instances

Monoid Path

Paths are monoids. After a path is closed you can not append anything to it anymore. The empty path is open. Use close to close a path.

Methods

mempty :: Path

mappend :: Path -> Path -> Path

mconcat :: [Path] -> Path

lineTo :: Point -> Path

Move the paths pointer to the given location and draw a straight line while doing so.

moveTo :: Point -> Path

Move the paths pointer to the given location.

lineTo' :: Double -> Double -> Path

Short-cut for lineTo, if you don't want to create a Point.

moveTo' :: Double -> Double -> Path

Short-cut for moveTo, if you don't want to create a Point.

arc

Arguments

:: Point

Center point of the circle arc.

-> Double

Radius of the circle.

-> Double

Angle to start drawing at, in radians.

-> Double

Angle to stop drawing at, in radians.

-> Path

Draw the arc of a circle. A straight line connects the end of the previous path with the beginning of the arc. The zero angle points in direction of the positive x-axis. Angles increase in clock-wise direction. If the stop angle is smaller then the start angle it is increased by multiples of 2 * pi until is is greater or equal.

arc' :: Double -> Double -> Double -> Double -> Double -> Path

Short-cut for arc, if you don't want to create a Point.

arcNeg :: Point -> Double -> Double -> Double -> Path

Like arc, but draws from the stop angle to the start angle instead of between them.

arcNeg' :: Double -> Double -> Double -> Double -> Double -> Path

Short-cut for arcNeg, if you don't want to create a Point.

close :: Path

A closed empty path. Closes a path when appended.

foldPath

Arguments

:: Monoid m

=> (Point -> m)

MoveTo

-> (Point -> m)

LineTo

-> (Point -> Double -> Double -> Double -> m)

Arc

-> (Point -> Double -> Double -> Double -> m)

ArcNeg

-> m

Close

-> Path

Path to fold

-> m

Fold the given path to a monoid structure.

makeLinesExplicit :: Path -> Path

Enriches the path with explicit instructions to draw lines, that otherwise would be implicit. See Path for details about what lines in paths are implicit.

Matrices

transformP :: Matrix -> Point -> Point

Transform a point using the given matrix.

scaleP :: Vector -> Point -> Point

Scale a point.

rotateP :: Double -> Point -> Point

Rotate a point around the origin. The angle is given in radians.

translateP :: Vector -> Point -> Point

Translate a point.

data Matrix

Copied from Graphics.Rendering.Cairo.Matrix

Constructors

Matrix

Fields

• xx :: !Double
• yx :: !Double
• xy :: !Double
• yy :: !Double
• x0 :: !Double
• y0 :: !Double

Instances

Num Matrix

Copied from Graphics.Rendering.Cairo.Matrix

Methods

(+) :: Matrix -> Matrix -> Matrix

(-) :: Matrix -> Matrix -> Matrix

(*) :: Matrix -> Matrix -> Matrix

negate :: Matrix -> Matrix

abs :: Matrix -> Matrix

signum :: Matrix -> Matrix

fromInteger :: Integer -> Matrix

Show Matrix

Methods

showsPrec :: Int -> Matrix -> ShowS

show :: Matrix -> String

showList :: [Matrix] -> ShowS

identity :: Matrix

Copied from Graphics.Rendering.Cairo.Matrix

rotate :: Double -> Matrix -> Matrix

Copied from Graphics.Rendering.Cairo.Matrix Rotations angle is given in radians.

scale :: Vector -> Matrix -> Matrix

Copied and adopted from Graphics.Rendering.Cairo.Matrix

translate :: Vector -> Matrix -> Matrix

Copied and adopted from Graphics.Rendering.Cairo.Matrix

scalarMultiply :: Double -> Matrix -> Matrix

Copied from Graphics.Rendering.Cairo.Matrix

adjoint :: Matrix -> Matrix

Copied from Graphics.Rendering.Cairo.Matrix

invert :: Matrix -> Matrix

Copied from Graphics.Rendering.Cairo.Matrix