Module

Graphics.Drawing

Package: purescript-drawing
Repository: paf31/purescript-drawing

This module defines a type Drawing for creating vector graphics.

#Point Source

type Point = { x :: Number, y :: Number }

A Point consists of x and y coordinates.

#rectangle Source

rectangle :: Number -> Number -> Number -> Number -> Shape

Create a rectangle from the left, top, width and height parameters.

#circle Source

circle :: Number -> Number -> Number -> Shape

Create a circle from the left, top and radius parameters.

#arc Source

arc :: Number -> Number -> Number -> Number -> Number -> Shape

Create a circular arc from the left, top, start angle, end angle and radius parameters.

#FillStyle Source

newtype FillStyle

Encapsulates fill color etc.

Instances

#fillColor Source

fillColor :: Color -> FillStyle

Set the fill color.

#OutlineStyle Source

newtype OutlineStyle

Encapsulates outline color etc.

Instances

#outlineColor Source

outlineColor :: Color -> OutlineStyle

Set the outline color.

#lineWidth Source

lineWidth :: Number -> OutlineStyle

Set the line width.

#shadowColor Source

shadowColor :: Color -> Shadow

Set the shadow color.

#shadowBlur Source

shadowBlur :: Number -> Shadow

Set the shadow blur.

#shadowOffset Source

shadowOffset :: Number -> Number -> Shadow

Set the shadow blur.

#Drawing Source

data Drawing

A vector Drawing.

Instances

#outlined Source

outlined :: OutlineStyle -> Shape -> Drawing

Draw the outline of a Shape.

#clipped Source

clipped :: Shape -> Drawing -> Drawing

Clip a Drawing to a Shape.

#scale Source

scale :: Number -> Number -> Drawing -> Drawing

Apply a scale transformation by providing the x and y scale factors.

#translate Source

translate :: Number -> Number -> Drawing -> Drawing

Apply a translation by providing the x and y distances.

#everywhere Source

everywhere :: (Drawing -> Drawing) -> Drawing -> Drawing

Modify a Drawing by applying a transformation to every subdrawing.

Re-exports from Color

#ColorSpace Source

data ColorSpace

Definition of a color space.

RGB: red, green, blue
HSL: hue, saturation, lightness
LCh: Lightness, chroma, hue
Lab: Lightness, a, b

Constructors

RGB
HSL
LCh
Lab

#Color Source

data Color

The representation of a color.

Note:

The Eq instance compares two Colors by comparing their (integer) RGB values. This is different from comparing the HSL values (for example, HSL has many different representations of black (arbitrary hue and saturation values).
Colors outside the sRGB gamut which cannot be displayed on a typical computer screen can not be represented by Color.

Instances

Show Color
Eq Color

#xyz Source

xyz :: Number -> Number -> Number -> Color

Create a Color from XYZ coordinates in the CIE 1931 color space. Note that a Color always represents a color in the sRGB gamut (colors that can be represented on a typical computer screen) while the XYZ color space is bigger. This function will tend to create fully saturated colors at the edge of the sRGB gamut if the coordinates lie outside the sRGB range.

See:

#white Source

white :: Color

Pure white.

#toXYZ Source

toXYZ :: Color -> { x :: Number, y :: Number, z :: Number }

Get XYZ coordinates according to the CIE 1931 color space.

See:

#toRGBA' Source

toRGBA' :: Color -> { a :: Number, b :: Number, g :: Number, r :: Number }

Convert a Color to its red, green, blue and alpha values. All values are numbers in the range from 0.0 to 1.0.

#toRGBA Source

toRGBA :: Color -> { a :: Number, b :: Int, g :: Int, r :: Int }

Convert a Color to its red, green, blue and alpha values. The RGB values are integers in the range from 0 to 255. The alpha channel is a number between 0.0 and 1.0.

#toLab Source

toLab :: Color -> { a :: Number, b :: Number, l :: Number }

Get L, a and b coordinates according to the Lab color space.

See: https://en.wikipedia.org/wiki/Lab_color_space

#toLCh Source

toLCh :: Color -> { c :: Number, h :: Number, l :: Number }

Get L, C and h coordinates according to the CIE LCh color space.

See: https://en.wikipedia.org/wiki/Lab_color_space

#toHexString Source

toHexString :: Color -> String

Return a hexadecimal representation of the color in the form #rrggbb, where rr, gg and bb refer to hexadecimal digits corresponding to the RGB channel values between 00 and ff. The alpha channel is not represented.

#toHSLA Source

toHSLA :: Color -> { a :: Number, h :: Number, l :: Number, s :: Number }

Convert a Color to its hue, saturation, lightness and alpha values. See hsla for the ranges of each channel.

#toGray Source

toGray :: Color -> Color

Convert a color to a gray tone with the same perceived luminance (see luminance).

#textColor Source

textColor :: Color -> Color

Return a readable foreground text color (either black or white) for a given background color.

#saturate Source

saturate :: Number -> Color -> Color

Increase the saturation of a color by adding a certain amount (number between -1.0 and 1.0) to the saturation channel. If the number is negative, the color is desaturated.

#rotateHue Source

rotateHue :: Number -> Color -> Color

Rotate the hue of a Color by a certain angle (in degrees).

#rgba' Source

rgba' :: Number -> Number -> Number -> Number -> Color

Create a Color from RGB and alpha values between 0.0 and 1.0.

#rgba Source

rgba :: Int -> Int -> Int -> Number -> Color

Create a Color from integer RGB values between 0 and 255 and a floating point alpha value between 0.0 and 1.0.

#rgb' Source

rgb' :: Number -> Number -> Number -> Color

Create a Color from RGB values between 0.0 and 1.0.

#rgb Source

rgb :: Int -> Int -> Int -> Color

Create a Color from integer RGB values between 0 and 255.

#mix Source

mix :: ColorSpace -> Color -> Color -> Number -> Color

Mix two colors by linearly interpolating between them in the specified color space. For the HSL colorspace, the shortest path is chosen along the circle of hue values.

#luminance Source

luminance :: Color -> Number

The relative brightness of a color (normalized to 0.0 for darkest black and 1.0 for lightest white), according to the WCAG definition.

See: https://www.w3.org/TR/2008/REC-WCAG20-20081211/#relativeluminancedef

#lighten Source

lighten :: Number -> Color -> Color

Lighten a color by adding a certain amount (number between -1.0 and 1.0) to the lightness channel. If the number is negative, the color is darkened.

#lch Source

lch :: Number -> Number -> Number -> Color

Create a Color from lightness, chroma and hue coordinates in the CIE LCh color space. This is a cylindrical transform of the Lab color space. Note: See documentation for xyz. The same restrictions apply here.

See: https://en.wikipedia.org/wiki/Lab_color_space

#lab Source

lab :: Number -> Number -> Number -> Color

Create a Color from L, a and b coordinates coordinates in the Lab color space. Note: See documentation for xyz. The same restrictions apply here.

See: https://en.wikipedia.org/wiki/Lab_color_space

#isReadable Source

isReadable :: Color -> Color -> Boolean

Determine whether text of one color is readable on a background of a different color (see contrast). This function is symmetric in both arguments.

isReadable c1 c2 = contrast c1 c2 > 4.5

#isLight Source

isLight :: Color -> Boolean

Determine whether a color is perceived as a light color.

isLight c = brightness c > 0.5

#hsla Source

hsla :: Number -> Number -> Number -> Number -> Color

Create a Color from hue, saturation, lightness and alpha values. The hue is given in degrees, as a Number between 0.0 and 360.0. Saturation, lightness and alpha are numbers between 0.0 and 1.0.

#hsl Source

hsl :: Number -> Number -> Number -> Color

Create a Color from hue, saturation and lightness values. The hue is given in degrees, as a Number between 0.0 and 360.0. Both saturation and lightness are numbers between 0.0 and 1.0.

#graytone Source

graytone :: Number -> Color

Create a gray tone from a lightness values (0.0 is black, 1.0 is white).

#fromInt Source

fromInt :: Int -> Color

Converts an integer to a color (RGB representation). 0 is black and 0xffffff is white. Values outside this range will be clamped.

This function is useful if you want to hard-code Hex values. For example:

red = fromInt 0xff0000

#fromHexString Source

fromHexString :: String -> Maybe Color

Parse a hexadecimal RGB code of the form #rgb or #rrggbb. The # character is required. Each hexadecimal digit is of the form [0-9a-fA-F] (case insensitive). Returns Nothing if the string is in a wrong format.

#distance Source

distance :: Color -> Color -> Number

Compute the perceived 'distance' between two colors according to the CIE76 delta-E standard. A distance below ~2.3 is not noticable.

See: https://en.wikipedia.org/wiki/Color_difference

#desaturate Source

desaturate :: Number -> Color -> Color

Decrease the saturation of a color by subtracting a certain amount (number between -1.0 and 1.0) from the saturation channel. If the number is negative, the color is saturated.

#darken Source

darken :: Number -> Color -> Color

Darken a color by subtracting a certain amount (number between -1.0 and 1.0) from the lightness channel. If the number is negative, the color is lightened.

#cssStringRGBA Source

cssStringRGBA :: Color -> String

A CSS representation of the color in the form rgb(..) or rgba(...).

#cssStringHSLA Source

cssStringHSLA :: Color -> String

A CSS representation of the color in the form hsl(..) or hsla(...).

#contrast Source

contrast :: Color -> Color -> Number

The contrast ratio of two colors. A minimum contrast ratio of 4.5 is recommended to ensure that text is readable on a colored background. The contrast ratio is symmetric on both arguments: contrast c1 c2 == contrast c2 c1.

See http://www.w3.org/TR/2008/REC-WCAG20-20081211/#contrast-ratiodef

#complementary Source

complementary :: Color -> Color

Get the complementary color (hue rotated by 180°).

#brightness Source

brightness :: Color -> Number

The percieved brightness of the color (A number between 0.0 and 1.0).

See: https://www.w3.org/TR/AERT#color-contrast

#black Source

black :: Color

Pure black.

Re-exports from Graphics.Drawing.Font

#Font Source

data Font

Fonts.

Instances

Eq Font

#fontString Source

fontString :: Font -> String

Turn a Font into a String which can be used with Graphics.Canvas.setFont.

Modules: Graphics.Drawing; Graphics.Drawing.Font

Graphics.Drawing

#Point Source

#Shape Source

Instances

#path Source

#closed Source

#rectangle Source

#circle Source

#arc Source

#FillStyle Source

Instances

#fillColor Source

#OutlineStyle Source

Instances

#outlineColor Source

#lineWidth Source

#Shadow Source

Instances

#shadowColor Source

#shadowBlur Source

#shadowOffset Source

#Drawing Source

Instances

#filled Source

#outlined Source

#clipped Source

#shadow Source

#scale Source

#translate Source

#rotate Source

#text Source

#everywhere Source

#render Source

Re-exports from Color

#ColorSpace Source

Constructors

#Color Source

Instances

#xyz Source

#white Source

#toXYZ Source

#toRGBA' Source

#toRGBA Source

#toLab Source

#toLCh Source

#toHexString Source

#toHSLA Source

#toGray Source

#textColor Source

#saturate Source

#rotateHue Source

#rgba' Source

#rgba Source

#rgb' Source

#rgb Source

#mix Source

#luminance Source

#lighten Source

#lch Source

#lab Source

#isReadable Source

#isLight Source

#hsla Source

#hsl Source

#graytone Source

#fromInt Source

#fromHexString Source

#distance Source

#desaturate Source

#darken Source

#cssStringRGBA Source

#cssStringHSLA Source

#contrast Source

#complementary Source

#brightness Source

#black Source

Re-exports from Graphics.Drawing.Font

#Font Source

Instances

#fontString Source