Maintainer  diagramsdiscuss@googlegroups.com 

Safe Haskell  None 
This module defines the twodimensional vector space R^2, twodimensional transformations, and various predefined twodimensional shapes. This module reexports useful functionality from a group of more specific modules:
 Diagrams.TwoD.Types defines basic types for twodimensional diagrams, including types representing the 2D Euclidean vector space and various systems of angle measurement.
 Diagrams.TwoD.Align defines alignment combinators specialized to two dimensions (see Diagrams.Align for more general alignment).
 Diagrams.TwoD.Combinators defines ways of combining diagrams specialized to two dimensions (see also Diagrams.Combinators for more general combining).
 Diagrams.TwoD.Transform defines R^2specific transformations such as rotation by an angle, and scaling, translation, and reflection in the X and Y directions.
 Diagrams.TwoD.Ellipse defines circles and ellipses.
 Diagrams.TwoD.Arc defines circular arcs.
 Diagrams.TwoD.Path exports various operations on twodimensional paths when viewed as regions of the plane.
 Diagrams.TwoD.Polygons defines general algorithms for drawing various types of polygons.
 Diagrams.TwoD.Shapes defines other twodimensional shapes, e.g. various polygons.
 Diagrams.TwoD.Text defines primitive text diagrams.
 Diagrams.TwoD.Image allows importing external images into diagrams.
 Diagrams.TwoD.Vector defines some special 2D vectors and functions for converting between vectors and angles.
 Diagrams.TwoD.Size defines functions for working with the size of 2D objects.
 Diagrams.TwoD.Model defines some aids for visualizing diagrams' internal model (local origins, envelopes, etc.)
 data R2
 r2 :: (Double, Double) > R2
 unr2 :: R2 > (Double, Double)
 type P2 = Point R2
 p2 :: (Double, Double) > P2
 unp2 :: P2 > (Double, Double)
 type T2 = Transformation R2
 unitX :: R2
 unitY :: R2
 unit_X :: R2
 unit_Y :: R2
 direction :: Angle a => R2 > a
 fromDirection :: Angle a => a > R2
 e :: Angle a => a > R2
 tau :: Floating a => a
 class Num a => Angle a where
 newtype Turn = Turn {}
 type CircleFrac = Turn
 newtype Rad = Rad {}
 newtype Deg = Deg {}
 fullCircle :: Angle a => a
 convertAngle :: (Angle a, Angle b) => a > b
 stroke :: Renderable (Path R2) b => Path R2 > Diagram b R2
 stroke' :: (Renderable (Path R2) b, IsName a) => StrokeOpts a > Path R2 > Diagram b R2
 strokeT :: Renderable (Path R2) b => Trail R2 > Diagram b R2
 strokeT' :: (Renderable (Path R2) b, IsName a) => StrokeOpts a > Trail R2 > Diagram b R2
 strokeLine :: Renderable (Path R2) b => Trail' Line R2 > Diagram b R2
 strokeLoop :: Renderable (Path R2) b => Trail' Loop R2 > Diagram b R2
 strokeLocT :: Renderable (Path R2) b => Located (Trail R2) > Diagram b R2
 strokeLocLine :: Renderable (Path R2) b => Located (Trail' Line R2) > Diagram b R2
 strokeLocLoop :: Renderable (Path R2) b => Located (Trail' Loop R2) > Diagram b R2
 data FillRule
 fillRule :: HasStyle a => FillRule > a > a
 data StrokeOpts a = StrokeOpts {
 vertexNames :: [[a]]
 queryFillRule :: FillRule
 clipBy :: (HasStyle a, V a ~ R2) => Path R2 > a > a
 hrule :: (TrailLike t, V t ~ R2) => Double > t
 vrule :: (TrailLike t, V t ~ R2) => Double > t
 unitCircle :: (TrailLike t, V t ~ R2) => t
 circle :: (TrailLike t, V t ~ R2, Transformable t) => Double > t
 ellipse :: (TrailLike t, V t ~ R2, Transformable t) => Double > t
 ellipseXY :: (TrailLike t, V t ~ R2, Transformable t) => Double > Double > t
 arc :: (Angle a, TrailLike t, V t ~ R2) => a > a > t
 arc' :: (Angle a, TrailLike p, V p ~ R2) => Double > a > a > p
 arcCW :: (Angle a, TrailLike t, V t ~ R2) => a > a > t
 wedge :: (Angle a, TrailLike p, V p ~ R2) => Double > a > a > p
 polygon :: (TrailLike t, V t ~ R2) => PolygonOpts > t
 polyTrail :: PolygonOpts > Located (Trail R2)
 data PolygonOpts = PolygonOpts {}
 data PolyType
 data PolyOrientation
 data StarOpts
 star :: StarOpts > [P2] > Path R2
 regPoly :: (TrailLike t, V t ~ R2) => Int > Double > t
 triangle :: (TrailLike t, V t ~ R2) => Double > t
 eqTriangle :: (TrailLike t, V t ~ R2) => Double > t
 square :: (TrailLike t, Transformable t, V t ~ R2) => Double > t
 pentagon :: (TrailLike t, V t ~ R2) => Double > t
 hexagon :: (TrailLike t, V t ~ R2) => Double > t
 septagon :: (TrailLike t, V t ~ R2) => Double > t
 octagon :: (TrailLike t, V t ~ R2) => Double > t
 nonagon :: (TrailLike t, V t ~ R2) => Double > t
 decagon :: (TrailLike t, V t ~ R2) => Double > t
 hendecagon :: (TrailLike t, V t ~ R2) => Double > t
 dodecagon :: (TrailLike t, V t ~ R2) => Double > t
 unitSquare :: (TrailLike t, V t ~ R2) => t
 rect :: (TrailLike t, Transformable t, V t ~ R2) => Double > Double > t
 roundedRect :: (TrailLike t, V t ~ R2) => Double > Double > Double > t
 roundedRect' :: (TrailLike t, V t ~ R2) => Double > Double > RoundedRectOpts > t
 data RoundedRectOpts = RoundedRectOpts {}
 text :: Renderable Text b => String > Diagram b R2
 topLeftText :: Renderable Text b => String > Diagram b R2
 alignedText :: Renderable Text b => Double > Double > String > Diagram b R2
 baselineText :: Renderable Text b => String > Diagram b R2
 font :: HasStyle a => String > a > a
 fontSize :: HasStyle a => Double > a > a
 italic :: HasStyle a => a > a
 oblique :: HasStyle a => a > a
 bold :: HasStyle a => a > a
 image :: Renderable Image b => FilePath > Double > Double > Diagram b R2
 rotation :: Angle a => a > T2
 rotate :: (Transformable t, V t ~ R2, Angle a) => a > t > t
 rotateBy :: (Transformable t, V t ~ R2) => Turn > t > t
 rotationAbout :: Angle a => P2 > a > T2
 rotateAbout :: (Transformable t, V t ~ R2, Angle a) => P2 > a > t > t
 scalingX :: Double > T2
 scaleX :: (Transformable t, V t ~ R2) => Double > t > t
 scalingY :: Double > T2
 scaleY :: (Transformable t, V t ~ R2) => Double > t > t
 scaling :: (HasLinearMap v, Fractional (Scalar v)) => Scalar v > Transformation v
 scale :: (Transformable t, Fractional (Scalar (V t)), Eq (Scalar (V t))) => Scalar (V t) > t > t
 scaleToX :: (Enveloped t, Transformable t, V t ~ R2) => Double > t > t
 scaleToY :: (Enveloped t, Transformable t, V t ~ R2) => Double > t > t
 scaleUToX :: (Enveloped t, Transformable t, V t ~ R2) => Double > t > t
 scaleUToY :: (Enveloped t, Transformable t, V t ~ R2) => Double > t > t
 translationX :: Double > T2
 translateX :: (Transformable t, V t ~ R2) => Double > t > t
 translationY :: Double > T2
 translateY :: (Transformable t, V t ~ R2) => Double > t > t
 translation :: HasLinearMap v => v > Transformation v
 translate :: (Transformable t, HasLinearMap (V t)) => V t > t > t
 reflectionX :: T2
 reflectX :: (Transformable t, V t ~ R2) => t > t
 reflectionY :: T2
 reflectY :: (Transformable t, V t ~ R2) => t > t
 reflectionAbout :: P2 > R2 > T2
 reflectAbout :: (Transformable t, V t ~ R2) => P2 > R2 > t > t
 shearingX :: Double > T2
 shearX :: (Transformable t, V t ~ R2) => Double > t > t
 shearingY :: Double > T2
 shearY :: (Transformable t, V t ~ R2) => Double > t > t
 (===) :: (Juxtaposable a, V a ~ R2, Semigroup a) => a > a > a
 () :: (Juxtaposable a, V a ~ R2, Semigroup a) => a > a > a
 atAngle :: (Juxtaposable a, V a ~ R2, Semigroup a, Angle b) => b > a > a > a
 hcat :: (Juxtaposable a, HasOrigin a, Monoid' a, V a ~ R2) => [a] > a
 hcat' :: (Juxtaposable a, HasOrigin a, Monoid' a, V a ~ R2) => CatOpts R2 > [a] > a
 vcat :: (Juxtaposable a, HasOrigin a, Monoid' a, V a ~ R2) => [a] > a
 vcat' :: (Juxtaposable a, HasOrigin a, Monoid' a, V a ~ R2) => CatOpts R2 > [a] > a
 strutX :: (Backend b R2, Monoid' m) => Double > QDiagram b R2 m
 strutY :: (Backend b R2, Monoid' m) => Double > QDiagram b R2 m
 padX :: (Backend b R2, Monoid' m) => Double > QDiagram b R2 m > QDiagram b R2 m
 padY :: (Backend b R2, Monoid' m) => Double > QDiagram b R2 m > QDiagram b R2 m
 extrudeLeft :: (Semigroup m, Monoid m) => Double > QDiagram b R2 m > QDiagram b R2 m
 extrudeRight :: (Semigroup m, Monoid m) => Double > QDiagram b R2 m > QDiagram b R2 m
 extrudeBottom :: (Semigroup m, Monoid m) => Double > QDiagram b R2 m > QDiagram b R2 m
 extrudeTop :: (Semigroup m, Monoid m) => Double > QDiagram b R2 m > QDiagram b R2 m
 view :: (Backend b R2, Monoid' m) => P2 > R2 > QDiagram b R2 m > QDiagram b R2 m
 boundingRect :: (Enveloped t, Transformable t, TrailLike t, Monoid t, V t ~ R2, Enveloped a, V a ~ R2) => a > t
 bg :: Renderable (Path R2) b => Colour Double > Diagram b R2 > Diagram b R2
 alignL :: (Alignable a, V a ~ R2) => a > a
 alignR :: (Alignable a, V a ~ R2) => a > a
 alignT :: (Alignable a, V a ~ R2) => a > a
 alignB :: (Alignable a, V a ~ R2) => a > a
 alignTL :: (Alignable a, V a ~ R2) => a > a
 alignTR :: (Alignable a, V a ~ R2) => a > a
 alignBL :: (Alignable a, V a ~ R2) => a > a
 alignBR :: (Alignable a, V a ~ R2) => a > a
 alignX :: (Alignable a, V a ~ R2) => Double > a > a
 alignY :: (Alignable a, V a ~ R2) => Double > a > a
 centerX :: (Alignable a, V a ~ R2) => a > a
 centerY :: (Alignable a, V a ~ R2) => a > a
 centerXY :: (Alignable a, V a ~ R2) => a > a
 width :: (Enveloped a, V a ~ R2) => a > Double
 height :: (Enveloped a, V a ~ R2) => a > Double
 size2D :: (Enveloped a, V a ~ R2) => a > (Double, Double)
 sizeSpec2D :: (Enveloped a, V a ~ R2) => a > SizeSpec2D
 extentX :: (Enveloped a, V a ~ R2) => a > Maybe (Double, Double)
 extentY :: (Enveloped a, V a ~ R2) => a > Maybe (Double, Double)
 center2D :: (Enveloped a, V a ~ R2) => a > P2
 data SizeSpec2D
 mkSizeSpec :: Maybe Double > Maybe Double > SizeSpec2D
 sized :: (Transformable a, Enveloped a, V a ~ R2) => SizeSpec2D > a > a
 sizedAs :: (Transformable a, Enveloped a, V a ~ R2, Enveloped b, V b ~ R2) => b > a > a
 showOrigin :: (Renderable (Path R2) b, Backend b R2, Monoid' m) => QDiagram b R2 m > QDiagram b R2 m
 showOrigin' :: (Renderable (Path R2) b, Backend b R2, Monoid' m) => OriginOpts > QDiagram b R2 m > QDiagram b R2 m
 data OriginOpts = OriginOpts {}
 showLabels :: (Renderable Text b, Backend b R2) => QDiagram b R2 m > QDiagram b R2 Any
R^2
The twodimensional Euclidean vector space R^2. This type is intentionally abstract.
 To construct a vector, use
r2
, or&
(from Diagrams.Coordinates):
r2 (3,4) :: R2 3 & 4 :: R2
Note that Diagrams.Coordinates is not reexported by Diagrams.Prelude and must be explicitly imported.
 To construct the vector from the origin to a point
p
, usep
...
origin
 To convert a vector
v
into the point obtained by followingv
from the origin, use
.origin
.+^
v  To convert a vector back into a pair of components, use
unv2
orcoords
(from Diagrams.Coordinates). These are typically used in conjunction with theViewPatterns
extension:
foo (unr2 > (x,y)) = ... foo (coords > x :& y) = ...
Eq R2  
Fractional R2  
Num R2  
Ord R2  
Read R2  
Show R2  
Typeable R2  
Transformable R2  
HasBasis R2  
VectorSpace R2  
InnerSpace R2  
AdditiveGroup R2  
Coordinates R2  
Newtype R2 (Double, Double)  
Traced (FixedSegment R2)  
Traced (Trail R2)  
Traced (Path R2)  
Traced (Segment Closed R2)  
Renderable (Path R2) b => TrailLike (QDiagram b R2 Any) 
unr2 :: R2 > (Double, Double)Source
Convert a 2D vector back into a pair of components. See also coords
.
Points in R^2. This type is intentionally abstract.
 To construct a point, use
p2
, or&
(see Diagrams.Coordinates):
p2 (3,4) :: P2 3 & 4 :: P2
 To construct a point from a vector
v
, use
.origin
.+^
v  To convert a point
p
into the vector from the origin top
, usep
...
origin
 To convert a point back into a pair of coordinates, use
unp2
, orcoords
(from Diagrams.Coordinates). It's common to use these in conjunction with theViewPatterns
extension:
foo (unp2 > (x,y)) = ... foo (coords > x :& y) = ...
unp2 :: P2 > (Double, Double)Source
Convert a 2D point back into a pair of coordinates. See also coords
.
type T2 = Transformation R2Source
Transformations in R^2.
direction :: Angle a => R2 > aSource
Compute the direction of a vector, measured counterclockwise from the positive xaxis as a fraction of a full turn. The zero vector is arbitrarily assigned the direction 0.
fromDirection :: Angle a => a > R2Source
Convert an angle into a unit vector pointing in that direction.
A convenient synonym for fromDirection
.
Angles
The circle constant, the ratio of a circle's circumference to its
radius. Note that pi = tau/2
.
For more information and a wellreasoned argument why we should all be using tau instead of pi, see The Tau Manifesto, http://tauday.com/.
To hear what it sounds like (and to easily memorize the first 30 digits or so), try http://youtu.be/3174T359Q.
class Num a => Angle a whereSource
Type class for types that measure angles.
Convert to a turn, i.e. a fraction of a circle.
Convert from a turn, i.e. a fraction of a circle.
Newtype wrapper used to represent angles as fractions of a circle. For example, 1/3 turn = tau/3 radians = 120 degrees.
type CircleFrac = TurnSource
Deprecated synonym for Turn
, retained for backwards compatibility.
Newtype wrapper for representing angles in radians.
Newtype wrapper for representing angles in degrees.
fullCircle :: Angle a => aSource
Deprecated synonym for fullTurn
, retained for backwards compatibility.
convertAngle :: (Angle a, Angle b) => a > bSource
Convert between two angle representations.
Paths
Stroking
stroke :: Renderable (Path R2) b => Path R2 > Diagram b R2Source
Convert a path into a diagram. The resulting diagram has the names 0, 1, ... assigned to each of the path's vertices.
See also stroke'
, which takes an extra options record allowing
its behavior to be customized.
Note that a bug in GHC 7.0.1 causes a context stack overflow when
inferring the type of stroke
. The solution is to give a type
signature to expressions involving stroke
, or (recommended)
upgrade GHC (the bug is fixed in 7.0.2 onwards).
stroke' :: (Renderable (Path R2) b, IsName a) => StrokeOpts a > Path R2 > Diagram b R2Source
A variant of stroke
that takes an extra record of options to
customize its behavior. In particular:
 Names can be assigned to the path's vertices
StrokeOpts
is an instance of Default
, so stroke'
syntax may be used.
with
{
... }
strokeT :: Renderable (Path R2) b => Trail R2 > Diagram b R2Source
A composition of stroke
and pathFromTrail
for conveniently
converting a trail directly into a diagram.
Note that a bug in GHC 7.0.1 causes a context stack overflow when
inferring the type of stroke
and hence of strokeT
as well.
The solution is to give a type signature to expressions involving
strokeT
, or (recommended) upgrade GHC (the bug is fixed in 7.0.2
onwards).
strokeT' :: (Renderable (Path R2) b, IsName a) => StrokeOpts a > Trail R2 > Diagram b R2Source
A composition of stroke'
and pathFromTrail
for conveniently
converting a trail directly into a diagram.
strokeLine :: Renderable (Path R2) b => Trail' Line R2 > Diagram b R2Source
strokeLoop :: Renderable (Path R2) b => Trail' Loop R2 > Diagram b R2Source
strokeLocT :: Renderable (Path R2) b => Located (Trail R2) > Diagram b R2Source
A convenience function for converting a Located Trail
directly
into a diagram; strokeLocT = stroke . trailLike
.
strokeLocLine :: Renderable (Path R2) b => Located (Trail' Line R2) > Diagram b R2Source
A convenience function for converting a Located
line directly
into a diagram; strokeLocLine = stroke . trailLike . mapLoc wrapLine
.
strokeLocLoop :: Renderable (Path R2) b => Located (Trail' Loop R2) > Diagram b R2Source
A convenience function for converting a Located
loop directly
into a diagram; strokeLocLoop = stroke . trailLike . mapLoc wrapLoop
.
Enumeration of algorithms or "rules" for determining which points lie in the interior of a (possibly selfintersecting) closed path.
Winding  Interior points are those with a nonzero winding number. See http://en.wikipedia.org/wiki/Nonzerorule. 
EvenOdd  Interior points are those where a ray extended infinitely in a particular direction crosses the path an odd number of times. See http://en.wikipedia.org/wiki/Evenodd_rule. 
fillRule :: HasStyle a => FillRule > a > aSource
Specify the fill rule that should be used for determining which points are inside a path.
data StrokeOpts a Source
A record of options that control how a path is stroked.
StrokeOpts
is an instance of Default
, so a StrokeOpts
records can be created using
notation.
with
{ ... }
StrokeOpts  

Default (StrokeOpts a) 
Clipping
clipBy :: (HasStyle a, V a ~ R2) => Path R2 > a > aSource
Clip a diagram by the given path:
 Only the parts of the diagram which lie in the interior of the path will be drawn.
 The envelope of the diagram is unaffected.
Shapes
Rules
hrule :: (TrailLike t, V t ~ R2) => Double > tSource
Create a centered horizontal (LR) line of the given length.
hruleEx = vcat' with {sep = 0.2} (map hrule [1..5]) # centerXY # pad 1.1
vrule :: (TrailLike t, V t ~ R2) => Double > tSource
Create a centered vertical (TB) line of the given length.
vruleEx = hcat' with {sep = 0.2} (map vrule [1, 1.2 .. 2]) # centerXY # pad 1.1
Circleish things
unitCircle :: (TrailLike t, V t ~ R2) => tSource
A circle of radius 1, with center at the origin.
circle :: (TrailLike t, V t ~ R2, Transformable t) => Double > tSource
A circle of the given radius, centered at the origin. As a path, it begins at (r,0).
ellipse :: (TrailLike t, V t ~ R2, Transformable t) => Double > tSource
ellipse e
constructs an ellipse with eccentricity e
by
scaling the unit circle in the X direction. The eccentricity must
be within the interval [0,1).
ellipseXY :: (TrailLike t, V t ~ R2, Transformable t) => Double > Double > tSource
ellipseXY x y
creates an axisaligned ellipse, centered at the
origin, with radius x
along the xaxis and radius y
along the
yaxis.
arc :: (Angle a, TrailLike t, V t ~ R2) => a > a > tSource
Given a start angle s
and an end angle e
,
is the
path of a radius one arc counterclockwise between the two angles.
The origin of the arc is its center.
arc
s e
arc' :: (Angle a, TrailLike p, V p ~ R2) => Double > a > a > pSource
Given a radus r
, a start angle s
and an end angle e
,
is the path of a radius arc'
r s e(abs r)
arc between
the two angles. If a negative radius is given, the arc will
be clockwise, otherwise it will be counterclockwise. The origin
of the arc is its center.
wedge :: (Angle a, TrailLike p, V p ~ R2) => Double > a > a > pSource
Create a circular wedge of the given radius, beginning at the first angle and extending counterclockwise to the second.
General polygons
polygon :: (TrailLike t, V t ~ R2) => PolygonOpts > tSource
Generate the polygon described by the given options.
polyTrail :: PolygonOpts > Located (Trail R2)Source
Generate a polygon. See PolygonOpts
for more information.
data PolygonOpts Source
Options for specifying a polygon.
PolygonOpts  

Default PolygonOpts  The default polygon is a regular pentagon of radius 1, centered at the origin, aligned to the xaxis. 
Method used to determine the vertices of a polygon.
forall a . Angle a => PolyPolar [a] [Double]  A "polar" polygon.
To construct an ngon, use a list of n1 angles and n radii. Extra angles or radii are ignored. Cyclic polygons (with all vertices lying on a
circle) can be constructed using a second
argument of 
forall a . Angle a => PolySides [a] [Double]  A polygon determined by the distance between successive vertices and the angles formed by each three successive vertices. In other words, a polygon specified by "turtle graphics": go straight ahead x1 units; turn by angle a1; go straght ahead x2 units; turn by angle a2; etc. The polygon will be centered at the centroid of its vertices.
To construct an ngon, use a list of n2 angles and n1 edge lengths. Extra angles or lengths are ignored. 
PolyRegular Int Double  A regular polygon with the given number of sides (first argument) and the given radius (second argument). 
data PolyOrientation Source
Determine how a polygon should be oriented.
NoOrient  No special orientation; the first vertex will be at (1,0). This is the default. 
OrientH  Orient horizontally, so the bottommost edge is parallel to the xaxis. 
OrientV  Orient vertically, so the leftmost edge is parallel to the yaxis. 
OrientTo R2  Orient so some edge is facing in the direction of, that is, perpendicular to, the given vector. 
Star polygons
Options for creating "star" polygons, where the edges connect possibly nonadjacent vertices.
StarFun (Int > Int)  Specify the order in which the vertices should be connected by a function that maps each vertex index to the index of the vertex that should come next. Indexing of vertices begins at 0. 
StarSkip Int  Specify a star polygon by a "skip". A skip of 1 indicates a normal polygon, where edges go between successive vertices. A skip of 2 means that edges will connect every second vertex, skipping one in between. Generally, a skip of n means that edges will connect every nth vertex. 
star :: StarOpts > [P2] > Path R2Source
Create a generalized star polygon. The StarOpts
are used
to determine in which order the given vertices should be
connected. The intention is that the second argument of type
[P2]
could be generated by a call to polygon
, regPoly
, or
the like, since a list of vertices is TrailLike
. But of course
the list can be generated any way you like. A
is
returned (instead of any Path
R2
TrailLike
) because the resulting path
may have more than one component, for example if the vertices are
to be connected in several disjoint cycles.
Regular polygons
regPoly :: (TrailLike t, V t ~ R2) => Int > Double > tSource
Create a regular polygon. The first argument is the number of
sides, and the second is the length of the sides. (Compare to the
polygon
function with a PolyRegular
option, which produces
polygons of a given radius).
The polygon will be oriented with one edge parallel to the xaxis.
triangle :: (TrailLike t, V t ~ R2) => Double > tSource
An equilateral triangle, with sides of the given length and base parallel to the xaxis.
eqTriangle :: (TrailLike t, V t ~ R2) => Double > tSource
A synonym for triangle
, provided for backwards compatibility.
square :: (TrailLike t, Transformable t, V t ~ R2) => Double > tSource
A square with its center at the origin and sides of the given length, oriented parallel to the axes.
pentagon :: (TrailLike t, V t ~ R2) => Double > tSource
A regular pentagon, with sides of the given length and base parallel to the xaxis.
hexagon :: (TrailLike t, V t ~ R2) => Double > tSource
A regular hexagon, with sides of the given length and base parallel to the xaxis.
septagon :: (TrailLike t, V t ~ R2) => Double > tSource
A regular septagon, with sides of the given length and base parallel to the xaxis.
octagon :: (TrailLike t, V t ~ R2) => Double > tSource
A regular octagon, with sides of the given length and base parallel to the xaxis.
nonagon :: (TrailLike t, V t ~ R2) => Double > tSource
A regular nonagon, with sides of the given length and base parallel to the xaxis.
decagon :: (TrailLike t, V t ~ R2) => Double > tSource
A regular decagon, with sides of the given length and base parallel to the xaxis.
hendecagon :: (TrailLike t, V t ~ R2) => Double > tSource
A regular hendecagon, with sides of the given length and base parallel to the xaxis.
dodecagon :: (TrailLike t, V t ~ R2) => Double > tSource
A regular dodecagon, with sides of the given length and base parallel to the xaxis.
Other special polygons
unitSquare :: (TrailLike t, V t ~ R2) => tSource
A square with its center at the origin and sides of length 1, oriented parallel to the axes.
rect :: (TrailLike t, Transformable t, V t ~ R2) => Double > Double > tSource
rect w h
is an axisaligned rectangle of width w
and height
h
, centered at the origin.
Other shapes
roundedRect :: (TrailLike t, V t ~ R2) => Double > Double > Double > tSource
roundedRect w h r
generates a closed trail, or closed path
centered at the origin, of an axisaligned rectangle with width
w
, height h
, and circular rounded corners of radius r
. If
r
is negative the corner will be cut out in a reverse arc. If
the size of r
is larger than half the smaller dimension of w
and h
, then it will be reduced to fit in that range, to prevent
the corners from overlapping. The trail or path begins with the
right edge and proceeds counterclockwise. If you need to specify
a different radius for each corner individually, use
roundedRect'
instead.
roundedRectEx = pad 1.1 . centerXY $ hcat' with { sep = 0.2 } [ roundedRect 0.5 0.4 0.1 , roundedRect 0.5 0.4 (0.1) , roundedRect' 0.7 0.4 with { radiusTL = 0.2 , radiusTR = 0.2 , radiusBR = 0.1 } ]
roundedRect' :: (TrailLike t, V t ~ R2) => Double > Double > RoundedRectOpts > tSource
roundedRect'
works like roundedRect
but allows you to set the radius of
each corner indivually, using RoundedRectOpts
. The default corner radius is 0.
Each radius can also be negative, which results in the curves being reversed
to be inward instead of outward.
data RoundedRectOpts Source
Text
text :: Renderable Text b => String > Diagram b R2Source
Create a primitive text diagram from the given string, with center
alignment, equivalent to
.
alignedText
0.5 0.5
Note that it takes up no space, as text size information is not available.
topLeftText :: Renderable Text b => String > Diagram b R2Source
Create a primitive text diagram from the given string, origin at
the top left corner of the text's bounding box, equivalent to
.
alignedText
0 1
Note that it takes up no space.
alignedText :: Renderable Text b => Double > Double > String > Diagram b R2Source
Create a primitive text diagram from the given string, with the origin set to a point interpolated within the bounding box. The first parameter varies from 0 (left) to 1 (right), and the second parameter from 0 (bottom) to 1 (top).
The height of this box is determined by the font's potential ascent and descent, rather than the height of the particular string.
Note that it takes up no space.
baselineText :: Renderable Text b => String > Diagram b R2Source
Create a primitive text diagram from the given string, with the origin set to be on the baseline, at the beginning (although not bounding). This is the reference point of showText in the Cairo graphics library.
Note that it takes up no space.
font :: HasStyle a => String > a > aSource
Specify a font family to be used for all text within a diagram.
fontSize :: HasStyle a => Double > a > aSource
Set the font size, that is, the size of the font's emsquare as
measured within the current local vector space. The default size
is 1
.
Images
image :: Renderable Image b => FilePath > Double > Double > Diagram b R2Source
Take an external image from the specified file and turn it into a diagram with the specified width and height, centered at the origin. Note that the image's aspect ratio will be preserved; if the specified width and height have a different ratio than the image's aspect ratio, there will be extra space in one dimension.
Transformations
Rotation
rotation :: Angle a => a > T2Source
Create a transformation which performs a rotation about the local
origin by the given angle. See also rotate
.
rotate :: (Transformable t, V t ~ R2, Angle a) => a > t > tSource
Rotate about the local origin by the given angle. Positive angles
correspond to counterclockwise rotation, negative to
clockwise. The angle can be expressed using any type which is an
instance of Angle
. For example, rotate (1/4 ::
, Turn
)rotate (tau/4 ::
, and Rad
)rotate (90 ::
all represent the same transformation, namely, a
counterclockwise rotation by a right angle. To rotate about some
point other than the local origin, see Deg
)rotateAbout
.
Note that writing rotate (1/4)
, with no type annotation, will
yield an error since GHC cannot figure out which sort of angle
you want to use. In this common situation you can use
rotateBy
, which is specialized to take a Turn
argument.
rotationAbout :: Angle a => P2 > a > T2Source
rotationAbout p
is a rotation about the point p
(instead of
around the local origin).
rotateAbout :: (Transformable t, V t ~ R2, Angle a) => P2 > a > t > tSource
rotateAbout p
is like rotate
, except it rotates around the
point p
instead of around the local origin.
Scaling
scalingX :: Double > T2Source
Construct a transformation which scales by the given factor in the x (horizontal) direction.
scaleX :: (Transformable t, V t ~ R2) => Double > t > tSource
Scale a diagram by the given factor in the x (horizontal)
direction. To scale uniformly, use scale
.
scalingY :: Double > T2Source
Construct a transformation which scales by the given factor in the y (vertical) direction.
scaleY :: (Transformable t, V t ~ R2) => Double > t > tSource
Scale a diagram by the given factor in the y (vertical)
direction. To scale uniformly, use scale
.
scaling :: (HasLinearMap v, Fractional (Scalar v)) => Scalar v > Transformation v
Create a uniform scaling transformation.
scale :: (Transformable t, Fractional (Scalar (V t)), Eq (Scalar (V t))) => Scalar (V t) > t > t
Scale uniformly in every dimension by the given scalar.
scaleToX :: (Enveloped t, Transformable t, V t ~ R2) => Double > t > tSource
scaleToX w
scales a diagram in the x (horizontal) direction by
whatever factor required to make its width w
. scaleToX
should not be applied to diagrams with a width of 0, such as
vrule
.
scaleToY :: (Enveloped t, Transformable t, V t ~ R2) => Double > t > tSource
scaleToY h
scales a diagram in the y (vertical) direction by
whatever factor required to make its height h
. scaleToY
should not be applied to diagrams with a height of 0, such as
hrule
.
scaleUToX :: (Enveloped t, Transformable t, V t ~ R2) => Double > t > tSource
scaleUToX w
scales a diagram uniformly by whatever factor
required to make its width w
. scaleUToX
should not be
applied to diagrams with a width of 0, such as vrule
.
scaleUToY :: (Enveloped t, Transformable t, V t ~ R2) => Double > t > tSource
scaleUToY h
scales a diagram uniformly by whatever factor
required to make its height h
. scaleUToY
should not be applied
to diagrams with a height of 0, such as hrule
.
Translation
translationX :: Double > T2Source
Construct a transformation which translates by the given distance in the x (horizontal) direction.
translateX :: (Transformable t, V t ~ R2) => Double > t > tSource
Translate a diagram by the given distance in the x (horizontal) direction.
translationY :: Double > T2Source
Construct a transformation which translates by the given distance in the y (vertical) direction.
translateY :: (Transformable t, V t ~ R2) => Double > t > tSource
Translate a diagram by the given distance in the y (vertical) direction.
translation :: HasLinearMap v => v > Transformation v
Create a translation.
translate :: (Transformable t, HasLinearMap (V t)) => V t > t > t
Translate by a vector.
Reflection
Construct a transformation which flips a diagram from left to right, i.e. sends the point (x,y) to (x,y).
reflectX :: (Transformable t, V t ~ R2) => t > tSource
Flip a diagram from left to right, i.e. send the point (x,y) to (x,y).
Construct a transformation which flips a diagram from top to bottom, i.e. sends the point (x,y) to (x,y).
reflectY :: (Transformable t, V t ~ R2) => t > tSource
Flip a diagram from top to bottom, i.e. send the point (x,y) to (x,y).
reflectionAbout :: P2 > R2 > T2Source
reflectionAbout p v
is a reflection in the line determined by
the point p
and vector v
.
reflectAbout :: (Transformable t, V t ~ R2) => P2 > R2 > t > tSource
reflectAbout p v
reflects a diagram in the line determined by
the point p
and the vector v
.
Shears
shearingX :: Double > T2Source
shearingX d
is the linear transformation which is the identity on
y coordinates and sends (0,1)
to (d,1)
.
shearX :: (Transformable t, V t ~ R2) => Double > t > tSource
shearX d
performs a shear in the xdirection which sends
(0,1)
to (d,1)
.
shearingY :: Double > T2Source
shearingY d
is the linear transformation which is the identity on
x coordinates and sends (1,0)
to (1,d)
.
shearY :: (Transformable t, V t ~ R2) => Double > t > tSource
shearY d
performs a shear in the ydirection which sends
(1,0)
to (1,d)
.
Combinators
Combining multiple diagrams
(===) :: (Juxtaposable a, V a ~ R2, Semigroup a) => a > a > aSource
Place two diagrams (or other objects) vertically adjacent to one another, with the first diagram above the second. Since Haskell ignores whitespace in expressions, one can thus write
c === d
to place c
above d
. The local origin of the resulting
combined diagram is the same as the local origin of the first.
(===)
is associative and has mempty
as an identity. See the
documentation of beside
for more information.
() :: (Juxtaposable a, V a ~ R2, Semigroup a) => a > a > aSource
Place two diagrams (or other juxtaposable objects) horizontally
adjacent to one another, with the first diagram to the left of
the second. The local origin of the resulting combined diagram
is the same as the local origin of the first. (===)
is
associative and has mempty
as an identity. See the
documentation of beside
for more information.
atAngle :: (Juxtaposable a, V a ~ R2, Semigroup a, Angle b) => b > a > a > aSource
Place two diagrams (or other juxtaposable objects) adjacent to one
another, with the second diagram placed along a line at angle
th
from the first. The local origin of the resulting combined
diagram is the same as the local origin of the first.
See the documentation of beside
for more information.
hcat :: (Juxtaposable a, HasOrigin a, Monoid' a, V a ~ R2) => [a] > aSource
Lay out a list of juxtaposable objects in a row from left to right, so that their local origins lie along a single horizontal line, with successive envelopes tangent to one another.
vcat :: (Juxtaposable a, HasOrigin a, Monoid' a, V a ~ R2) => [a] > aSource
Lay out a list of juxtaposable objects in a column from top to bottom, so that their local origins lie along a single vertical line, with successive envelopes tangent to one another.
Spacing and envelopes
strutX :: (Backend b R2, Monoid' m) => Double > QDiagram b R2 mSource
strutX w
is an empty diagram with width w
, height 0, and a
centered local origin. Note that strutX (w)
behaves the same as
strutX w
.
strutY :: (Backend b R2, Monoid' m) => Double > QDiagram b R2 mSource
strutY h
is an empty diagram with height h
, width 0, and a
centered local origin. Note that strutY (h)
behaves the same as
strutY h
.
padX :: (Backend b R2, Monoid' m) => Double > QDiagram b R2 m > QDiagram b R2 mSource
padX s
"pads" a diagram in the xdirection, expanding its
envelope horizontally by a factor of s
(factors between 0 and 1
can be used to shrink the envelope). Note that the envelope will
expand with respect to the local origin, so if the origin is not
centered horizontally the padding may appear "uneven". If this
is not desired, the origin can be centered (using centerX
)
before applying padX
.
padY :: (Backend b R2, Monoid' m) => Double > QDiagram b R2 m > QDiagram b R2 mSource
padY s
"pads" a diagram in the ydirection, expanding its
envelope vertically by a factor of s
(factors between
0 and 1 can be used to shrink the envelope). Note that
the envelope will expand with respect to the local origin,
so if the origin is not centered vertically the padding may appear
"uneven". If this is not desired, the origin can be centered
(using centerY
) before applying padY
.
extrudeLeft :: (Semigroup m, Monoid m) => Double > QDiagram b R2 m > QDiagram b R2 mSource
extrudeLeft s
"extrudes" a diagram in the negative xdirection,
offsetting its envelope by the provided distance. When s < 0
,
the envelope is inset instead.
See the documentation for extrudeEnvelope
for more information.
extrudeRight :: (Semigroup m, Monoid m) => Double > QDiagram b R2 m > QDiagram b R2 mSource
extrudeRight s
"extrudes" a diagram in the positive xdirection,
offsetting its envelope by the provided distance. When s < 0
,
the envelope is inset instead.
See the documentation for extrudeEnvelope
for more information.
extrudeBottom :: (Semigroup m, Monoid m) => Double > QDiagram b R2 m > QDiagram b R2 mSource
extrudeBottom s
"extrudes" a diagram in the negative ydirection,
offsetting its envelope by the provided distance. When s < 0
,
the envelope is inset instead.
See the documentation for extrudeEnvelope
for more information.
extrudeTop :: (Semigroup m, Monoid m) => Double > QDiagram b R2 m > QDiagram b R2 mSource
extrudeTop s
"extrudes" a diagram in the positive ydirection,
offsetting its envelope by the provided distance. When s < 0
,
the envelope is inset instead.
See the documentation for extrudeEnvelope
for more information.
view :: (Backend b R2, Monoid' m) => P2 > R2 > QDiagram b R2 m > QDiagram b R2 mSource
view p v
sets the envelope of a diagram to a rectangle whose
lowerleft corner is at p
and whose upperright corner is at p
.+^ v
. Useful for selecting the rectangular portion of a
diagram which should actually be "viewed" in the final render,
if you don't want to see the entire diagram.
Background
boundingRect :: (Enveloped t, Transformable t, TrailLike t, Monoid t, V t ~ R2, Enveloped a, V a ~ R2) => a > tSource
Construct a bounding rectangle for an enveloped object, that is, the smallest axisaligned rectangle which encloses the object.
bg :: Renderable (Path R2) b => Colour Double > Diagram b R2 > Diagram b R2Source
"Set the background color" of a diagram. That is, place a diagram atop a bounding rectangle of the given color.
Alignment
alignL :: (Alignable a, V a ~ R2) => a > aSource
Align along the left edge, i.e. translate the diagram in a horizontal direction so that the local origin is on the left edge of the envelope.
alignX :: (Alignable a, V a ~ R2) => Double > a > aSource
alignX
moves the local origin horizontally as follows:

alignX (1)
moves the local origin to the left edge of the envelope; 
align 1
moves the local origin to the right edge;  any other argument interpolates linearly between these. For
example,
alignX 0
centers,alignX 2
moves the origin one "radius" to the right of the right edge, and so on.
alignY :: (Alignable a, V a ~ R2) => Double > a > aSource
Like alignX
, but moving the local origin vertically, with an
argument of 1
corresponding to the top edge and (1)
corresponding
to the bottom edge.
Size
Computing size
size2D :: (Enveloped a, V a ~ R2) => a > (Double, Double)Source
Compute the width and height of an enveloped object.
sizeSpec2D :: (Enveloped a, V a ~ R2) => a > SizeSpec2DSource
Compute the size of an enveloped object as a SizeSpec2D
value.
extentX :: (Enveloped a, V a ~ R2) => a > Maybe (Double, Double)Source
Compute the absolute xcoordinate range of an enveloped object in
R2, in the form (lo,hi). Return Nothing
for objects with an
empty envelope.
extentY :: (Enveloped a, V a ~ R2) => a > Maybe (Double, Double)Source
Compute the absolute ycoordinate range of an enveloped object in R2, in the form (lo,hi).
center2D :: (Enveloped a, V a ~ R2) => a > P2Source
Compute the point at the center (in the x and ydirections) of a enveloped object. Return the origin for objects with an empty envelope.
Specifying size
data SizeSpec2D Source
A specification of a (requested) rectangular size.
Width Double  Specify an explicit width. The height should be determined automatically (so as to preserve aspect ratio). 
Height Double  Specify an explicit height. The width should be determined automatically (so as to preserve aspect ratio). 
Dims Double Double  An explicit specification of a width and height. 
Absolute  Absolute size: use whatever size an object already has; do not rescale. 
mkSizeSpec :: Maybe Double > Maybe Double > SizeSpec2DSource
Create a size specification from a possiblyspecified width and height.
Adjusting size
sized :: (Transformable a, Enveloped a, V a ~ R2) => SizeSpec2D > a > aSource
Uniformly scale any enveloped object so that it fits within the given size.
sizedAs :: (Transformable a, Enveloped a, V a ~ R2, Enveloped b, V b ~ R2) => b > a > aSource
Uniformly scale an enveloped object so that it "has the same size as" (fits within the width and height of) some other object.
Visual aids for understanding the internal model
showOrigin :: (Renderable (Path R2) b, Backend b R2, Monoid' m) => QDiagram b R2 m > QDiagram b R2 mSource
Mark the origin of a diagram by placing a red dot 1/50th its size.
showOrigin' :: (Renderable (Path R2) b, Backend b R2, Monoid' m) => OriginOpts > QDiagram b R2 m > QDiagram b R2 mSource
Mark the origin of a diagram, with control over colour and scale of marker dot.
data OriginOpts Source