Copyright	(c) 2013 diagrams-lib team (see LICENSE)
License	BSD-style (see LICENSE)
Maintainer	diagrams-discuss@googlegroups.com
Safe Haskell	None
Language	Haskell2010

Diagrams.TwoD.Attributes

Contents

Width
Dashing
Textures
Compilation utilities

Description

Diagrams may have attributes which affect the way they are rendered. This module defines Textures (Gradients and Colors) in two dimensions. Like the attriubtes defined in the Diagrams.Attributes module, all attributes defined here use the Last or Recommend semigroup structure. FillColor and LineColor attributes are provided so that backends that don't support gradients need not be concerned with using textures. Backends should only implement color attributes or textures attributes, not both.

Synopsis

Width

data LineWidth

Line widths specified on child nodes always override line widths specified at parent nodes.

Instances

Data LineWidth
Semigroup LineWidth
Default LineWidth
AttributeClass LineWidth
Transformable LineWidth
Typeable * LineWidth
type V LineWidth = R2

getLineWidth :: LineWidth -> Measure R2

lineWidth :: (HasStyle a, V a ~ R2) => Measure R2 -> a -> a

Set the line (stroke) width.

lineWidthA :: (HasStyle a, V a ~ R2) => LineWidth -> a -> a

Apply a LineWidth attribute.

lw :: (HasStyle a, V a ~ R2) => Measure R2 -> a -> a

Default for lineWidth.

lwN :: (HasStyle a, V a ~ R2) => Double -> a -> a

A convenient synonym for 'lineWidth (Normalized w)'.

lwO :: (HasStyle a, V a ~ R2) => Double -> a -> a

A convenient synonym for 'lineWidth (Output w)'.

lwL :: (HasStyle a, V a ~ R2) => Double -> a -> a

A convenient sysnonym for 'lineWidth (Local w)'.

lwG :: (HasStyle a, V a ~ R2) => Double -> a -> a

A convenient synonym for 'lineWidth (Global w)'.

ultraThin :: Measure R2

Standard Measures.

veryThin :: Measure R2

Standard Measures.

thin :: Measure R2

Standard Measures.

medium :: Measure R2

Standard Measures.

thick :: Measure R2

Standard Measures.

veryThick :: Measure R2

Standard Measures.

ultraThick :: Measure R2

Standard Measures.

none :: Measure R2

Standard Measures.

tiny :: Measure R2

Standard Measures.

verySmall :: Measure R2

Standard Measures.

small :: Measure R2

Standard Measures.

normal :: Measure R2

Standard Measures.

large :: Measure R2

Standard Measures.

veryLarge :: Measure R2

Standard Measures.

huge :: Measure R2

Standard Measures.

Dashing

data Dashing

Create lines that are dashing... er, dashed.

Constructors

Dashing [Measure R2] (Measure R2)

Instances

Eq Dashing
Data Dashing
Typeable * Dashing

data DashingA

Instances

Eq DashingA
Data DashingA
Semigroup DashingA
AttributeClass DashingA
Transformable DashingA
Typeable * DashingA
type V DashingA = R2

getDashing :: DashingA -> Dashing

dashing

Arguments

:: (HasStyle a, V a ~ R2)
=> [Measure R2]	A list specifying alternate lengths of on and off portions of the stroke. The empty list indicates no dashing.
-> Measure R2	An offset into the dash pattern at which the stroke should start.
-> a
-> a

Set the line dashing style.

dashingN :: (HasStyle a, V a ~ R2) => [Double] -> Double -> a -> a

A convenient synonym for 'dashing (Normalized w)'.

dashingO :: (HasStyle a, V a ~ R2) => [Double] -> Double -> a -> a

A convenient synonym for 'dashing (Output w)'.

dashingL :: (HasStyle a, V a ~ R2) => [Double] -> Double -> a -> a

A convenient sysnonym for 'dashing (Local w)'.

dashingG :: (HasStyle a, V a ~ R2) => [Double] -> Double -> a -> a

A convenient synonym for 'dashing (Global w)'.

Textures

data Texture

A Texture is either a color SC, linear gradient LG, or radial gradient RG. An object can have only one texture which is determined by the Last semigroup structure.

Constructors

SC SomeColor
LG LGradient
RG RGradient

Instances

Typeable * Texture

solid :: Color a => a -> Texture

Convert a solid colour into a texture.

_SC :: Prism' Texture SomeColor

_LG :: Prism' Texture LGradient

_RG :: Prism' Texture RGradient

defaultLG :: Texture

A default is provided so that linear gradients can easily be created using lenses. For example, lg = defaultLG & lGradStart .~ (0.25 ^& 0.33). Note that no default value is provided for lGradStops, this must be set before the gradient value is used, otherwise the object will appear transparent.

defaultRG :: Texture

A default is provided so that radial gradients can easily be created using lenses. For example, rg = defaultRG & rGradRadius1 .~ 0.25. Note that no default value is provided for rGradStops, this must be set before the gradient value is used, otherwise the object will appear transparent.

data GradientStop

A gradient stop contains a color and fraction (usually between 0 and 1)

Constructors

GradientStop
Fields _stopColor :: SomeColor _stopFraction :: Double

stopColor :: Lens' GradientStop SomeColor

A color for the stop.

stopFraction :: Lens' GradientStop Double

The fraction for stop.

mkStops :: [(Colour Double, Double, Double)] -> [GradientStop]

A convenient function for making gradient stops from a list of triples. (An opaque color, a stop fraction, an opacity).

data SpreadMethod

The SpreadMethod determines what happens before lGradStart and after lGradEnd. GradPad fills the space before the start of the gradient with the color of the first stop and the color after end of the gradient with the color of the last stop. GradRepeat restarts the gradient and GradReflect restarts the gradient with the stops in reverse order.

Constructors

GradPad
GradReflect
GradRepeat

lineLGradient :: (HasStyle a, V a ~ R2) => LGradient -> a -> a

Apply a linear gradient.

lineRGradient :: (HasStyle a, V a ~ R2) => RGradient -> a -> a

Apply a radial gradient.

Linear Gradients

data LGradient

Linear Gradient

Constructors

LGradient
Fields _lGradStops :: [GradientStop] _lGradStart :: P2 _lGradEnd :: P2 _lGradTrans :: T2 _lGradSpreadMethod :: SpreadMethod

lGradStops :: Lens' LGradient [GradientStop]

A list of stops (colors and fractions).

lGradTrans :: Lens' LGradient T2

A transformation to be applied to the gradient. Usually this field will start as the identity transform and capture the transforms that are applied to the gradient.

lGradStart :: Lens' LGradient P2

The starting point for the first gradient stop. The coordinates are in Local units and the default is (-0.5, 0).

lGradEnd :: Lens' LGradient P2

The ending point for the last gradient stop.The coordinates are in Local units and the default is (0.5, 0).

lGradSpreadMethod :: Lens' LGradient SpreadMethod

For setting the spread method.

mkLinearGradient :: [GradientStop] -> P2 -> P2 -> SpreadMethod -> Texture

Make a linear gradient texture from a stop list, start point, end point, and SpreadMethod. The lGradTrans field is set to the identity transfrom, to change it use the lGradTrans lens.

Radial Gradients

data RGradient

Radial Gradient

Constructors

RGradient
Fields _rGradStops :: [GradientStop] _rGradCenter0 :: P2 _rGradRadius0 :: Double _rGradCenter1 :: P2 _rGradRadius1 :: Double _rGradTrans :: T2 _rGradSpreadMethod :: SpreadMethod

rGradStops :: Lens' RGradient [GradientStop]

A list of stops (colors and fractions).

rGradTrans :: Lens' RGradient T2

A transformation to be applied to the gradient. Usually this field will start as the identity transform and capture the transforms that are applied to the gradient.

rGradCenter0 :: Lens' RGradient P2

The center point of the inner circle.

rGradRadius0 :: Lens' RGradient Double

The radius of the inner cirlce in Local coordinates.

rGradCenter1 :: Lens' RGradient P2

The center of the outer circle.

rGradRadius1 :: Lens' RGradient Double

The radius of the outer circle in Local coordinates.

rGradSpreadMethod :: Lens' RGradient SpreadMethod

For setting the spread method.

mkRadialGradient :: [GradientStop] -> P2 -> Double -> P2 -> Double -> SpreadMethod -> Texture

Make a radial gradient texture from a stop list, radius, start point, end point, and SpreadMethod. The rGradTrans field is set to the identity transfrom, to change it use the rGradTrans lens.

Line texture

newtype LineTexture

The texture with which lines are drawn. Note that child textures always override parent textures. More precisely, the semigroup structure on line texture attributes is that of Last.

Constructors

LineTexture (Last Texture)

Instances

Semigroup LineTexture
Default LineTexture
AttributeClass LineTexture
Transformable LineTexture
Typeable * LineTexture
type V LineTexture = R2

getLineTexture :: LineTexture -> Texture

lineTexture :: (HasStyle a, V a ~ R2) => Texture -> a -> a

lineTextureA :: (HasStyle a, V a ~ R2) => LineTexture -> a -> a

mkLineTexture :: Texture -> LineTexture

styleLineTexture :: Setter' (Style v) Texture

Line color

lineColor :: (Color c, HasStyle a, V a ~ R2) => c -> a -> a

Set the line (stroke) color. This function is polymorphic in the color type (so it can be used with either Colour or AlphaColour), but this can sometimes create problems for type inference, so the lc and lcA variants are provided with more concrete types.

lc :: (HasStyle a, V a ~ R2) => Colour Double -> a -> a

A synonym for lineColor, specialized to Colour Double (i.e. opaque colors). See comment in lineColor about backends.

lcA :: (HasStyle a, V a ~ R2) => AlphaColour Double -> a -> a

A synonym for lineColor, specialized to AlphaColour Double (i.e. colors with transparency). See comment in lineColor about backends.

Fill texture

newtype FillTexture

The texture with which objects are filled. The semigroup structure on fill texture attributes is that of 'Recommed . Last'.

Constructors

FillTexture (Recommend (Last Texture))

Instances

Semigroup FillTexture
Default FillTexture
AttributeClass FillTexture
Transformable FillTexture
Typeable * FillTexture
type V FillTexture = R2

getFillTexture :: FillTexture -> Texture

fillTexture :: (HasStyle a, V a ~ R2) => Texture -> a -> a

mkFillTexture :: Texture -> FillTexture

styleFillTexture :: Setter' (Style v) Texture

Fill color

fillColor :: (Color c, HasStyle a, V a ~ R2) => c -> a -> a

Set the fill color. This function is polymorphic in the color type (so it can be used with either Colour or AlphaColour), but this can sometimes create problems for type inference, so the fc and fcA variants are provided with more concrete types.

fc :: (HasStyle a, V a ~ R2) => Colour Double -> a -> a

A synonym for fillColor, specialized to Colour Double (i.e. opaque colors). See comment after fillColor about backends.

fcA :: (HasStyle a, V a ~ R2) => AlphaColour Double -> a -> a

A synonym for fillColor, specialized to AlphaColour Double (i.e. colors with transparency). See comment after fillColor about backends.

recommendFillColor :: (Color c, HasStyle a, V a ~ R2) => c -> a -> a

Set a "recommended" fill color, to be used only if no explicit calls to fillColor (or fc, or fcA) are used. See comment after fillColor about backends.

Compilation utilities

splitTextureFills :: forall b v a. Typeable v => RTree b v a -> RTree b v a

Push fill attributes down until they are at the root of subtrees containing only loops. This makes life much easier for backends, which typically have a semantics where fill attributes are applied to linesnon-closed paths as well as loopsclosed paths, whereas in the semantics of diagrams, fill attributes only apply to loops.