Safe Haskell	None
Language	Haskell2010

Graphics.Rasterific

Contents

Rasterization command
Generating images
Rasterization types
Geometry description
Generic geometry description
Generic geometry manipulation
Helpers
Rasterization control
Debugging helper

Description

Main module of Rasterific, an Haskell rasterization engine.

Creating an image is rather simple, here is a simple example of a drawing and saving it in a PNG file:

import Codec.Picture( PixelRGBA8( .. ), writePng )
import Graphics.Rasterific
import Graphics.Rasterific.Texture

main :: IO ()
main = do
  let white = PixelRGBA8 255 255 255 255
      drawColor = PixelRGBA8 0 0x86 0xc1 255
      recColor = PixelRGBA8 0xFF 0x53 0x73 255
      img = renderDrawing 400 200 white $
         withTexture (uniformTexture drawColor) $ do
            fill $ circle (V2 0 0) 30
            stroke 4 JoinRound (CapRound, CapRound) $
                   circle (V2 400 200) 40
            withTexture (uniformTexture recColor) .
                   fill $ rectangle (V2 100 100) 200 100

  writePng "yourimage.png" img

The coordinate system is the picture classic one, with the origin in the upper left corner; with the y axis growing to the bottom and the x axis growing to the right:

Synopsis

Rasterization command

Filling

fill :: Geometry geom => geom -> Drawing px () Source

Fill some geometry. The geometry should be "looping", ie. the last point of the last primitive should be equal to the first point of the first primitive.

The primitive should be connected.

fill $ circle (V2 100 100) 75

fillWithMethod :: Geometry geom => FillMethod -> geom -> Drawing px () Source

This function let you choose how to fill the primitives in case of self intersection. See FillMethod documentation for more information.

Stroking

stroke Source

Arguments

:: Geometry geom
=> Float	Stroke width
-> Join	Which kind of join will be used
-> (Cap, Cap)	Start and end capping.
-> geom	List of elements to render
-> Drawing px ()

Will stroke geometry with a given stroke width. The elements should be connected

stroke 5 JoinRound (CapRound, CapRound) $ circle (V2 100 100) 75

dashedStroke Source

Arguments

:: Geometry geom
=> DashPattern	Dashing pattern to use for stroking
-> Float	Stroke width
-> Join	Which kind of join will be used
-> (Cap, Cap)	Start and end capping.
-> geom	List of elements to render
-> Drawing px ()

With stroke geometry with a given stroke width, using a dash pattern.

dashedStroke [5, 10, 5] 3 JoinRound (CapRound, CapStraight 0) $
    line (V2 0 100) (V2 200 100)

dashedStrokeWithOffset Source

Arguments

:: Geometry geom
=> Float	Starting offset
-> DashPattern	Dashing pattern to use for stroking
-> Float	Stroke width
-> Join	Which kind of join will be used
-> (Cap, Cap)	Start and end capping.
-> geom	List of elements to render
-> Drawing px ()

With stroke geometry with a given stroke width, using a dash pattern. The offset is there to specify the starting point into the pattern, the value can be negative.

dashedStrokeWithOffset 3 [5, 10, 5] 3 JoinRound (CapRound, CapStraight 0) $
    line (V2 0 100) (V2 200 100)

Text rendering

printTextAt Source

Arguments

:: Font	Drawing font
-> PointSize	font Point size
-> Point	Drawing starting point (base line)
-> String	String to print
-> Drawing px ()

Draw a string at a given position. Text printing imply loading a font, there is no default font (yet). Below an example of font rendering using a font installed on Microsoft Windows.

import Graphics.Text.TrueType( loadFontFile )
import Codec.Picture( PixelRGBA8( .. ), writePng )
import Graphics.Rasterific
import Graphics.Rasterific.Texture

main :: IO ()
main = do
  fontErr <- loadFontFile "test_fonts/DejaVuSans.ttf"
  case fontErr of
    Left err -> putStrLn err
    Right font ->
      writePng "text_example.png" .
          renderDrawing 300 70 (PixelRGBA8 255 255 255 255)
              . withTexture (uniformTexture $ PixelRGBA8 0 0 0 255) $
                      printTextAt font (PointSize 12) (V2 20 40)
                           "A simple text test!"

You can use any texture, like a gradient while rendering text.

printTextRanges Source

Arguments

:: Point	Starting point of the base line
-> [TextRange px]	Ranges description to be printed
-> Drawing px ()

Print complex text, using different texture font and point size for different parts of the text.

let blackTexture =
      Just . uniformTexture $ PixelRGBA8 0 0 0 255
    redTexture =
      Just . uniformTexture $ PixelRGBA8 255 0 0 255
in
printTextRanges (V2 20 40)
  [ TextRange font1 (PointSize 12) "A complex " blackTexture
  , TextRange font2 (PointSize 8) "text test" redTexture]

Texturing

withTexture :: Texture px -> Drawing px () -> Drawing px () Source

Define the texture applyied to all the children draw call.

withTexture (uniformTexture $ PixelRGBA8 0 0x86 0xc1 255) $ do
    fill $ circle (V2 50 50) 20
    fill $ circle (V2 100 100) 20
    withTexture (uniformTexture $ PixelRGBA8 0xFF 0x53 0x73 255)
         $ circle (V2 150 150) 20

withClipping Source

Arguments

:: (forall innerPixel. Drawing innerPixel ())	The clipping path
-> Drawing px ()	The actual geometry to clip
-> Drawing px ()

Draw some geometry using a clipping path.

withClipping (fill $ circle (V2 100 100) 75) $
    mapM_ (stroke 7 JoinRound (CapRound, CapRound))
      [line (V2 0 yf) (V2 200 (yf + 10))
                     | y <- [5 :: Int, 17 .. 200]
                     , let yf = fromIntegral y ]

withGroupOpacity :: Pixel px => PixelBaseComponent px -> Drawing px () -> Drawing px () Source

Will render the whole subaction with a given group opacity, after each element has been rendered. That means that completly opaque overlapping shapes will be rendered transparently, not one after another.

withTexture (uniformTexture $ PixelRGBA8 0xFF 0x53 0x73 255) $
    stroke 3 JoinRound (CapRound, CapRound) $
        line (V2 0 100) (V2 200 100)

withGroupOpacity 128 $ do
   withTexture (uniformTexture $ PixelRGBA8 0 0x86 0xc1 255) .
      fill $ circle (V2 70 100) 60
   withTexture (uniformTexture $ PixelRGBA8 0xff 0xf4 0xc1 255) .
      fill $ circle (V2 120 100) 60

To be compared to the item opacity

withTexture (uniformTexture $ PixelRGBA8 0xFF 0x53 0x73 255) $
    stroke 3 JoinRound (CapRound, CapRound) $
        line (V2 0 100) (V2 200 100)
withTexture (uniformTexture $ PixelRGBA8 0 0x86 0xc1 128) .
   fill $ circle (V2 70 100) 60
withTexture (uniformTexture $ PixelRGBA8 0xff 0xf4 0xc1 128) .
   fill $ circle (V2 120 100) 60

Transformations

withTransformation :: Transformation -> Drawing px () -> Drawing px () Source

Draw all the sub drawing commands using a transformation.

withPathOrientation Source

Arguments

:: Path	Path directing the orientation.
-> Float	Basline Y axis position, used to align text properly.
-> Drawing px ()	The sub drawings.
-> Drawing px ()

This command allows you to draw primitives on a given curve, for example, you can draw text on a curve:

let path = Path (V2 100 180) False
                [PathCubicBezierCurveTo (V2 20 20) (V2 170 20) (V2 300 200)] in
stroke 3 JoinRound (CapStraight 0, CapStraight 0) path
withTexture (uniformTexture $ PixelRGBA8 0 0 0 255) $
  withPathOrientation path 0 $
    printTextAt font (PointSize 24) (V2 0 0) "Text on path"

You can note that the position of the baseline match the size of the characters.

You are not limited to text drawing while using this function, you can draw arbitrary geometry like in the following example:

let path = Path (V2 100 180) False
                [PathCubicBezierCurveTo (V2 20 20) (V2 170 20) (V2 300 200)]
withTexture (uniformTexture $ PixelRGBA8 0 0 0 255) $
  stroke 3 JoinRound (CapStraight 0, CapStraight 0) path

withPathOrientation path 0 $ do
  printTextAt font (PointSize 24) (V2 0 0) "TX"
  fill $ rectangle (V2 (-10) (-10)) 30 20
  fill $ rectangle (V2 45 0) 10 20
  fill $ rectangle (V2 60 (-10)) 20 20
  fill $ rectangle (V2 100 (-15)) 20 50

data TextRange px Source

Structure defining how to render a text range

Constructors

TextRange
Fields _textFont :: Font Font used during the rendering _textSize :: PointSize Size of the text (in pixels) _text :: String Text to draw \| Texture to use for drawing, if Nothing, the currently active texture is used. _textTexture :: Maybe (Texture px)

newtype PointSize :: *

Font size expressed in points. You must convert size expressed in pixels to point using the DPI information. See pixelSizeInPointAtDpi

Constructors

PointSize
Fields getPointSize :: Float

Instances

Eq PointSize
Show PointSize

Generating images

type ModulablePixel px = (Pixel px, PackeablePixel px, Storable (PackedRepresentation px), Modulable (PixelBaseComponent px)) Source

This constraint ensure that a type is a pixel and we're allowed to modulate it's color components generically.

type RenderablePixel px = (ModulablePixel px, Pixel (PixelBaseComponent px), PackeablePixel (PixelBaseComponent px), Num (PackedRepresentation px), Num (PackedRepresentation (PixelBaseComponent px)), Storable (PackedRepresentation (PixelBaseComponent px)), PixelBaseComponent (PixelBaseComponent px) ~ PixelBaseComponent px) Source

This constraint tells us that pixel component must also be pixel and be the "bottom" of component, we cannot go further than a PixelBaseComponent level.

All pixel instances of JuicyPixels should be usable.

renderDrawing Source

Arguments

:: RenderablePixel px
=> Int	Rendering width
-> Int	Rendering height
-> px	Background color
-> Drawing px ()	Rendering action
-> Image px

Function to call in order to start the image creation. Tested pixels type are PixelRGBA8 and Pixel8, pixel types in other colorspace will probably produce weird results. Default DPI is 96

renderDrawingAtDpi Source

Arguments

:: RenderablePixel px
=> Int	Rendering width
-> Int	Rendering height
-> Dpi	Current DPI used for text rendering.
-> px	Background color
-> Drawing px ()	Rendering action
-> Image px

Function to call in order to start the image creation. Tested pixels type are PixelRGBA8 and Pixel8, pixel types in other colorspace will probably produce weird results.

pathToPrimitives :: Path -> [Primitive] Source

Transform a path description into a list of renderable primitives.

Rasterization types

data Texture px Source

Reification of texture type

type Drawing px = F (DrawCommand px) Source

Monad used to record the drawing actions.

class (Ord a, Num a) => Modulable a Source

Typeclass intented at pixel value modulation. May be throwed out soon.

Minimal complete definition

emptyValue, fullValue, clampCoverage, modulate, modiv, alphaOver, alphaCompose

Instances

Modulable Float
Modulable Word8

Geometry description

data V2 a Source

A 2-dimensional vector

>>> pure 1 :: V2 Int
V2 1 1

>>> V2 1 2 + V2 3 4
V2 4 6

>>> V2 1 2 * V2 3 4
V2 3 8

>>> sum (V2 1 2)
3

Constructors

V2 !a !a

Instances

Functor V2
Applicative V2
Metric V2
Additive V2
PointFoldable Point	Just apply the function
Transformable Point	Just apply the function
PlaneBoundable Point
Eq a => Eq (V2 a)
Num a => Num (V2 a)
Show a => Show (V2 a)
Epsilon a => Epsilon (V2 a)

type Point = V2 Float Source

Represent a point

type Vector = V2 Float Source

Represent a vector

data CubicBezier Source

Describe a cubic bezier spline, described using 4 points.

stroke 4 JoinRound (CapRound, CapRound) $
   CubicBezier (V2 0 10) (V2 205 250) (V2 (-10) 250) (V2 160 35)

Constructors

CubicBezier
Fields _cBezierX0 :: !Point Origin point, the spline will pass through it. _cBezierX1 :: !Point First control point of the cubic bezier curve. _cBezierX2 :: !Point Second control point of the cubic bezier curve. _cBezierX3 :: !Point End point of the cubic bezier curve

Instances

Eq CubicBezier
Show CubicBezier
Geometry CubicBezier
Primitivable CubicBezier	toPrim = CubicBezierPrim
PointFoldable CubicBezier
Transformable CubicBezier
PlaneBoundable CubicBezier

data Line Source

Describe a simple 2D line between two points.

fill [ Line (V2 10 10) (V2 190 10)
     , Line (V2 190 10) (V2 95 170)
     , Line (V2 95 170) (V2 10 10)]

Constructors

Line
Fields _lineX0 :: !Point Origin point _lineX1 :: !Point End point

Instances

Eq Line
Show Line
Geometry Line
Primitivable Line	toPrim = LinePrim
PointFoldable Line
Transformable Line
PlaneBoundable Line

data Bezier Source

Describe a quadratic bezier spline, described using 3 points.

fill [Bezier (V2 10 10) (V2 200 50) (V2 200 100)
     ,Bezier (V2 200 100) (V2 150 200) (V2 120 175)
     ,Bezier (V2 120 175) (V2 30 100) (V2 10 10)]

Constructors

Bezier
Fields _bezierX0 :: !Point Origin points, the spline will pass through it. _bezierX1 :: !Point Control point, the spline won't pass on it. _bezierX2 :: !Point End point, the spline will pass through it.

Instances

Eq Bezier
Show Bezier
Geometry Bezier
Primitivable Bezier	toPrim = BezierPrim
PointFoldable Bezier
Transformable Bezier
PlaneBoundable Bezier

data Primitive Source

This datatype gather all the renderable primitives, they are kept separated otherwise to allow specialization on some specific algorithms. You can mix the different primitives in a single call :

fill [ toPrim $ CubicBezier (V2 50 20) (V2 90 60)
                            (V2  5 100) (V2 50 140)
     , toPrim $ Line (V2 50 140) (V2 120 80)
     , toPrim $ Line (V2 120 80) (V2 50 20) ]

Constructors

LinePrim !Line	Primitive used for lines
BezierPrim !Bezier	Primitive used for quadratic beziers curves
CubicBezierPrim !CubicBezier	Primitive used for cubic bezier curve

Instances

Eq Primitive
Show Primitive
Geometry Primitive
Primitivable Primitive	toPrim = id
PointFoldable Primitive
Transformable Primitive
PlaneBoundable Primitive

data Path Source

Describe a path in a way similar to many graphical packages, using a "pen" position in memory and reusing it for the next "move" For example the example from Primitive could be rewritten:

fill $ Path (V2 50 20) True
   [ PathCubicBezierCurveTo (V2 90 60) (V2  5 100) (V2 50 140)
   , PathLineTo (V2 120 80) ]

Constructors

Path
Fields _pathOriginPoint :: Point Origin of the point, equivalent to the first "move" command. _pathClose :: Bool Tell if we must close the path. _pathCommand :: [PathCommand] List of commands in the path

Instances

Eq Path
Show Path
Geometry Path
PointFoldable Path
Transformable Path

data PathCommand Source

Actions to create a path

Constructors

PathLineTo Point	Draw a line from the current point to another point
PathQuadraticBezierCurveTo Point Point	Draw a quadratic bezier curve from the current point through the control point to the end point.
PathCubicBezierCurveTo Point Point Point	Draw a cubic bezier curve using 2 control points.

Instances

Eq PathCommand
Show PathCommand
PointFoldable PathCommand
Transformable PathCommand

Generic geometry description

class Primitivable a where Source

Generalizing constructors of the Primitive type to work generically.

Methods

toPrim :: a -> Primitive Source

Instances

Primitivable Primitive	toPrim = id
Primitivable CubicBezier	toPrim = CubicBezierPrim
Primitivable Bezier	toPrim = BezierPrim
Primitivable Line	toPrim = LinePrim

class Geometry a where Source

All the rasterization works on lists of primitives, in order to ease the use of the library, the Geometry type class provides conversion facility, which help generalising the geometry definition and avoid applying Primitive constructor.

Also streamline the Path conversion.

Minimal complete definition

toPrimitives

Methods

toPrimitives :: a -> [Primitive] Source

Convert an element to a list of primitives to be rendered.

listToPrims :: Foldable f => f a -> [Primitive] Source

Helper method to avoid overlaping instances. You shouldn't use it directly.

Instances

Geometry Path
Geometry Primitive
Geometry CubicBezier
Geometry Bezier
Geometry Line
(Foldable f, Geometry a) => Geometry (f a)	Generalize the geometry to any foldable container, so you can throw any container to the the `fill` or `stroke` function.

Generic geometry manipulation

class Transformable a where Source

This typeclass is there to help transform the geometry, by applying a transformation on every point of a geometric element.

Methods

transform :: (Point -> Point) -> a -> a Source

Apply a transformation function for every point in the element.

Instances

Transformable PathCommand
Transformable Path
Transformable Primitive
Transformable CubicBezier
Transformable Bezier
Transformable Line
Transformable Point	Just apply the function
(Functor f, Transformable a) => Transformable (f a)

class PointFoldable a where Source

Typeclass helper gathering all the points of a given geometry.

Methods

foldPoints :: (b -> Point -> b) -> b -> a -> b Source

Fold an accumulator on all the points of the primitive.

Instances

PointFoldable PathCommand
PointFoldable Path
PointFoldable Primitive
PointFoldable CubicBezier
PointFoldable Bezier
PointFoldable Line
PointFoldable Point	Just apply the function
(Foldable f, PointFoldable a) => PointFoldable (f a)

class PlaneBoundable a where Source

Class used to calculate bounds of various geometrical primitives. The calculated is precise, the bounding should be minimal with respect with drawn curve.

Methods

planeBounds :: a -> PlaneBound Source

Given a graphical elements, calculate it's bounds.

Instances

PlaneBoundable Primitive
PlaneBoundable CubicBezier
PlaneBoundable Bezier
PlaneBoundable Line
PlaneBoundable Point
PlaneBoundable (DrawOrder px)

data PlaneBound Source

Represent the minimal axis aligned rectangle in which some primitives can be drawn. Should fit to bezier curve and not use directly their control points.

Constructors

PlaneBound
Fields _planeMinBound :: !Point Corner upper left of the bounding box of the considered primitives. _planeMaxBound :: !Point Corner lower right of the bounding box of the considered primitives.

Instances

Eq PlaneBound
Show PlaneBound
Monoid PlaneBound

boundWidth :: PlaneBound -> Float Source

Extract the width of the bounds

boundHeight :: PlaneBound -> Float Source

Extract the height of the bound

boundLowerLeftCorner :: PlaneBound -> Point Source

Extract the position of the lower left corner of the bounds.

Helpers

line

line :: Point -> Point -> [Primitive] Source

Return a simple line ready to be stroked.

stroke 17 JoinRound (CapRound, CapRound) $
    line (V2 10 10) (V2 180 170)

Rectangle

rectangle Source

Arguments

:: Point	Corner upper left
-> Float	Width in pixel
-> Float	Height in pixel
-> [Primitive]

Generate a list of primitive representing a rectangle

fill $ rectangle (V2 30 30) 150 100

roundedRectangle Source

Arguments

:: Point	Corner upper left
-> Float	Width in pixel
-> Float	Height in pixel.
-> Float	Radius along the x axis of the rounded corner. In pixel.
-> Float	Radius along the y axis of the rounded corner. In pixel.
-> [Primitive]

Generate a list of primitive representing a rectangle with rounded corner.

fill $ roundedRectangle (V2 10 10) 150 150 20 10

Circles

circle Source

Arguments

:: Point	Circle center in pixels
-> Float	Circle radius in pixels
-> [Primitive]

Generate a list of primitive representing a circle.

fill $ circle (V2 100 100) 75

ellipse :: Point -> Float -> Float -> [Primitive] Source

Generate a list of primitive representing an ellipse.

fill $ ellipse (V2 100 100) 75 30

Polygons

polyline :: [Point] -> [Primitive] Source

Generate a strokable line out of points list. Just an helper around lineFromPath.

stroke 4 JoinRound (CapRound, CapRound) $
   polyline [V2 10 10, V2 100 70, V2 190 190]

polygon :: [Point] -> [Primitive] Source

Generate a fillable polygon out of points list. Similar to the polyline function, but close the path.

fill $ polygon [V2 30 30, V2 100 70, V2 80 170]

Images

drawImageAtSize Source

Arguments

:: (Pixel px, Modulable (PixelBaseComponent px))
=> Image px	Image to be drawn
-> StrokeWidth	Border size, drawn with current texture.
-> Point	Position of the corner upper left of the image.
-> Float	Width of the drawn image
-> Float	Height of the drawn image
-> Drawing px ()

Draw an image with the desired size

drawImageAtSize textureImage 2 (V2 30 30) 128 128

drawImage Source

Arguments

:: ModulablePixel px
=> Image px	Image to be drawn
-> StrokeWidth	Border size, drawn with current texture.
-> Point	Position of the corner upper left of the image.
-> Drawing px ()

Simply draw an image into the canvas. Take into account any previous transformation performed on the geometry.

drawImage textureImage 0 (V2 30 30)

cacheDrawing Source

Arguments

:: RenderablePixel px
=> Int	Max rendering width
-> Int	Max rendering height
-> Dpi
-> Drawing px ()
-> Drawing px ()

This function perform an optimisation, it will render a drawing to an image interanlly and create a new order to render this image instead of the geometry, effectively cuting the geometry generation part.

It can save execution time when drawing complex elements multiple times.

Geometry Helpers

clip Source

Arguments

:: Point	Minimum point (corner upper left)
-> Point	Maximum point (corner bottom right)
-> Primitive	Primitive to be clipped
-> Container Primitive

Clip the geometry to a rectangle.

bezierFromPath :: [Point] -> [Bezier] Source

Create a list of bezier patch from a list of points,

bezierFromPath [a, b, c, d, e] == [Bezier a b c, Bezier c d e]
bezierFromPath [a, b, c, d, e, f] == [Bezier a b c, Bezier c d e]
bezierFromPath [a, b, c, d, e, f, g] ==
    [Bezier a b c, Bezier c d e, Bezier e f g]

lineFromPath :: [Point] -> [Line] Source

Transform a list a point to a list of lines

lineFromPath [a, b, c, d] = [Line a b, Line b c, Line c d]

cubicBezierFromPath :: [Point] -> [CubicBezier] Source

Create a list of cubic bezier patch from a list of points.

cubicBezierFromPath [a, b, c, d, e] = [CubicBezier a b c d]
cubicBezierFromPath [a, b, c, d, e, f, g] =
   [CubicBezier a b c d, CubicBezier d e f g]

firstTangeantOf :: Primitive -> Vector Source

Gives the orientation vector for the start of the primitive.

lastTangeantOf :: Primitive -> Vector Source

Gives the orientation vector at the end of the primitive.

firstPointOf :: Primitive -> Point Source

Extract the first point of the primitive.

lastPointOf :: Primitive -> Point Source

Return the last point of a given primitive.

Rasterization control

data Join Source

Describe how to display the join of broken lines while stroking.

Constructors

JoinRound

Make a curved join.

JoinMiter Float

Make a mitter join. Value must be positive or null. Seems to make sense in [0;1] only

Miter join with 0 :
Miter join with 5 :

Instances

Eq Join
Show Join

data Cap Source

Describe how we will "finish" the stroking that don't loop.

Constructors

CapStraight Float

Create a straight caping on the stroke. Cap value should be positive and represent the distance from the end of curve to the actual cap

cap straight with param 0 :
cap straight with param 1 :

CapRound

Create a rounded caping on the stroke.

Instances

Eq Cap
Show Cap

data SamplerRepeat Source

Describe the behaviour of samplers and texturers when they are out of the bounds of image and/or gradient.

Constructors

SamplerPad	Will clamp (ie. repeat the last pixel) when out of bound
SamplerRepeat	Will loop on it's definition domain
SamplerReflect	Will loop inverting axises

Instances

Enum SamplerRepeat
Eq SamplerRepeat
Show SamplerRepeat

data FillMethod Source

Tell how to fill complex shapes when there is self intersections. If the filling mode is not specified, then it's the FillWinding method which is used.

The examples used are produced with the following function:

fillingSample :: FillMethod -> Drawing px ()
fillingSample fillMethod = fillWithMethod fillMethod geometry where
  geometry = transform (applyTransformation $ scale 0.35 0.4
                                           <> translate (V2 (-80) (-180)))
     [ Path (V2 484 499) True
         [ PathCubicBezierCurveTo (V2 681 452) (V2 639 312) (V2 541 314)
         , PathCubicBezierCurveTo (V2 327 337) (V2 224 562) (V2 484 499)
         ]
     , Path (V2 136 377) True
         [ PathCubicBezierCurveTo (V2 244 253) (V2 424 420) (V2 357 489)
         , PathCubicBezierCurveTo (V2 302 582) (V2 47 481) (V2 136 377)
         ]
     , Path (V2 340 265) True
         [ PathCubicBezierCurveTo (V2 64 371) (V2 128 748) (V2 343 536)
         , PathCubicBezierCurveTo (V2 668 216) (V2 17 273) (V2 367 575)
         , PathCubicBezierCurveTo (V2 589 727) (V2 615 159) (V2 340 265)
         ]
     ]

Constructors

FillWinding

Also known as nonzero rule. To determine if a point falls inside the curve, you draw an imaginary line through that point. Next you will count how many times that line crosses the curve before it reaches that point. For every clockwise rotation, you subtract 1 and for every counter-clockwise rotation you add 1.

FillEvenOdd

This rule determines the insideness of a point on the canvas by drawing a ray from that point to infinity in any direction and counting the number of path segments from the given shape that the ray crosses. If this number is odd, the point is inside; if even, the point is outside.

Instances

Enum FillMethod
Eq FillMethod
Show FillMethod

type DashPattern = [Float] Source

Dash pattern to use

drawOrdersOfDrawing Source

Arguments

:: RenderablePixel px
=> Int	Rendering width
-> Int	Rendering height
-> Dpi	Current assumed DPI
-> px	Background color
-> Drawing px ()	Rendering action
-> [DrawOrder px]

Transform a drawing into a serie of low-level drawing orders.

Debugging helper

dumpDrawing :: (Show px, Show (PixelBaseComponent px), PixelBaseComponent (PixelBaseComponent px) ~ PixelBaseComponent px) => Drawing px () -> String Source

This function will spit out drawing instructions to help debugging.

The outputted code looks like Haskell, but there is no guarantee that it is compilable.