thanks to Joni's tutorial: SVG Pocket Guide
raco pkg install simple-svg
#lang racket
(require simple-svg)
(let ([canvas_size 400])
(with-output-to-file
"recursive.svg" #:exists 'replace
(lambda ()
(printf "~a\n"
(svg-out
canvas_size canvas_size
(lambda ()
(let ([_sstyle (sstyle-new)])
(sstyle-set! _sstyle 'stroke "red")
(sstyle-set! _sstyle 'stroke-width 1)
(letrec ([recur-circle
(lambda (x y radius)
(let ([circle (svg-def-circle radius)])
(svg-use-shape circle _sstyle #:at? (cons x y)))
(when (> radius 8)
(recur-circle (+ x radius) y (floor (/ radius 2)))
(recur-circle (- x radius) y (floor (/ radius 2)))
(recur-circle x (+ y radius) (floor (/ radius 2)))
(recur-circle x (- y radius) (floor (/ radius 2)))))])
(recur-circle 200 200 100)))
(svg-show-default)))))))
(svg-out
width natural?
height natural?
procedure procedure?
[#:viewBox? viewBox? (or/c #f (list/c natural? natural? natural? natural?)) #f]specify width and height manully.
viewBox?: '(x y width height), if needed.
(svg-use-shape
[shape_index string?]
[shape_style sstyle/c]
[#:at? at? (cons/c natural? natural?) '(0 . 0)]
[#:hidden? hidden? boolean? #f]use a shape in group.
hidden? set to true means just use it, but not show it.
(svg-def-group
[group_name string?]
[use-proc procedure?]default, all svg-use-* will be added to "default" group.
use svg-def-group to define a named group to use later.
all svg-use-* in use-proc will be added to the group.
(svg-show-group
[group_name string?]
[group_style sstyle/c]
[#:at? at? (cons/c natural? natural?) '(0 . 0)]show a group by name with style and position.
(svg-show-default)(svg-show-group "default" (sstyle-new))
- use svg-out to generate svg content
- all svg drawings should occur in the svg-out's procedure.
- you should specify the svg whole size manully.
- use svg-...-def define shape first, it includes shape's baisc properties: width, height, radius etc.
- use sstyle struct to give shape style properties: stroke, fill etc.
- svg-use-shape to claim how to show a shape in a group by style(sstyle) and position(#:at?). if not specify which group, all svg-use included in the default group.
- svg-show-default shows default group at '(0 . 0).
define shape first, then define group, reuse shape and style in group(s), show group(s) with style in canvas.
(svg-out
100 100
(lambda ()
(let ([rec (svg-def-rect 100 100)]
[_sstyle (sstyle-new)])
(set-sstyle-fill! _sstyle "#BBC42A")
(svg-use-shape rec _sstyle)
(svg-show-default))))
(let (
[blue_rec (svg-def-rect 150 150)]
[_blue_sstyle (sstyle-new)]
[green_rec (svg-def-rect 100 100)]
[_green_sstyle (sstyle-new)]
[red_rec (svg-def-rect 50 50)]
[_red_sstyle (sstyle-new)]
)
(set-sstyle-fill! _blue_sstyle "blue")
(svg-use-shape blue_rec _blue_sstyle)
(set-sstyle-fill! _green_sstyle "green")
(svg-use-shape green_rec _green_sstyle #:at? '(25 . 25))
(set-sstyle-fill! _red_sstyle "red")
(svg-use-shape red_rec _red_sstyle #:at? '(50 . 50))
(svg-show-default))
(let (
[line1 (svg-def-line '(0 . 0) '(30 . 30))]
[line2 (svg-def-line '(0 . 15) '(30 . 15))]
[line3 (svg-def-line '(15 . 0) '(15 . 30))]
[line4 (svg-def-line '(30 . 0) '(0 . 30))]
[_sstyle (sstyle-new)]
[group_sstyle (sstyle-new)])
(set-sstyle-stroke-width! _sstyle 5)
(set-sstyle-stroke! _sstyle "#765373")
(svg-def-group
"pattern"
(lambda ()
(svg-use-shape line1 _sstyle #:at? '(5 . 5))
(svg-use-shape line2 _sstyle #:at? '(5 . 5))
(svg-use-shape line3 _sstyle #:at? '(5 . 5))
(svg-use-shape line4 _sstyle #:at? '(5 . 5))))
(svg-show-group "pattern" group_sstyle #:at? '(50 . 50))
(svg-show-group "pattern" group_sstyle #:at? '(100 . 100))
(svg-show-group "pattern" group_sstyle #:at? '(80 . 200))
(svg-show-group "pattern" group_sstyle #:at? '(150 . 100))
)
each shape and group can have multiple styles: stroke, fill etc.
sstyle is a struct, it represent a shape or group's style.
svg-use-shape and svg-show-group should use the sstyle.
(define sstyle/c
(struct/dc
sstyle
[fill string?]
[fill-rule (or/c #f 'nonzero 'evenodd 'inerit)]
[fill-opacity (or/c #f (between/c 0 1))]
[stroke (or/c #f string?)]
[stroke-width (or/c #f natural?)]
[stroke-linecap (or/c #f 'butt 'round 'square 'inherit)]
[stroke-linejoin (or/c #f 'miter 'round 'bevel)]
[stroke-miterlimit (or/c #f (>=/c 1))]
[stroke-dasharray (or/c #f string?)]
[stroke-dashoffset (or/c #f natural?)]
[translate (or/c #f (cons/c natural? natural?))]
[rotate (or/c #f integer?)]
[scale (or/c #f natural? (cons/c natural? natural?))]
[skewX (or/c #f natural?)]
[skewY (or/c #f natural?)]
))(sstyle-new) generate a default sstyle.
(ssylte-clone sstyle) clone a exist sstyle.
(svg-def-rect
width natural?
height natural?
#:radius? [radius? #f]define a rectangle.
use radius to set corner radius: '(radiusX . radiusY).
(let ([rec (svg-def-rect 100 100)])
(svg-use rec #:fill? "#BBC42A")
(svg-show-default))
(let ([rec (svg-def-rect 100 100)]
[_sstyle (sstyle-new)])
(set-sstyle-fill! _sstyle "#BBC42A")
(svg-use-shape rec _sstyle)
(svg-show-default))
(let ([rec (svg-def-rect 100 100)]
[_sstyle (sstyle-new)])
(set-sstyle-fill! _sstyle "#BBC42A")
(svg-use-shape rec _sstyle #:at? '(50 . 50))
(svg-show-default))
(let (
[blue_rec (svg-def-rect 150 150)]
[_blue_sstyle (sstyle-new)]
[green_rec (svg-def-rect 100 100)]
[_green_sstyle (sstyle-new)]
[red_rec (svg-def-rect 50 50)]
[_red_sstyle (sstyle-new)])
(set-sstyle-fill! _blue_sstyle "blue")
(svg-use-shape blue_rec _blue_sstyle)
(set-sstyle-fill! _green_sstyle "green")
(svg-use-shape green_rec _green_sstyle #:at? '(25 . 25))
(set-sstyle-fill! _red_sstyle "red")
(svg-use-shape red_rec _red_sstyle #:at? '(50 . 50))
(svg-show-default))
(svg-def-circle
radius natural?)define a circle by radius length.
(let ([circle (svg-def-circle 50)]
[_sstyle (sstyle-new)])
(set-sstyle-fill! _sstyle "#BBC42A")
(svg-use-shape circle _sstyle #:at? '(50 . 50))
(svg-show-default))
(let ([circle (svg-def-circle 50)]
[red_sstyle (sstyle-new)]
[yellow_sstyle (sstyle-new)]
[blue_sstyle (sstyle-new)]
[green_sstyle (sstyle-new)])
(set-sstyle-fill! red_sstyle "red")
(svg-use-shape circle red_sstyle #:at? '(50 . 50))
(set-sstyle-fill! yellow_sstyle "yellow")
(svg-use-shape circle yellow_sstyle #:at? '(150 . 50))
(set-sstyle-fill! blue_sstyle "blue")
(svg-use-shape circle blue_sstyle #:at? '(50 . 150))
(set-sstyle-fill! green_sstyle "green")
(svg-use-shape circle green_sstyle #:at? '(150 . 150))
(svg-show-default))
(svg-def-ellipse
radius (cons/c natural? natural?))define a ellipse by radius length: '(width . height).
(let ([ellipse (svg-def-ellipse '(100 . 50))]
[_sstyle (sstyle-new)])
(set-sstyle-fill! _sstyle "#7AA20D")
(svg-use-shape ellipse _sstyle #:at? '(100 . 50))
(svg-show-default))
(svg-def-line
start_point (cons/c natural? natural?)
end_point (cons/c natural? natural?))define a line by start, end point.
(let ([line (svg-def-line '(0 . 0) '(100 . 100))]
[_sstyle (sstyle-new)])
(set-sstyle-stroke-width! _sstyle 10)
(set-sstyle-stroke! _sstyle "#765373")
(svg-use-shape line _sstyle #:at? '(5 . 5))
(svg-show-default))
(define (polyline points))define a polyline by points list.
(let ([polyline
(svg-def-polyline
'((0 . 0) (40 . 0) (40 . 40) (80 . 40) (80 . 80) (120 . 80) (120 . 120)))]
[_sstyle (sstyle-new)])
(set-sstyle-stroke-width! _sstyle 5)
(set-sstyle-stroke! _sstyle "#BBC42A")
(set-sstyle-fill! _sstyle "blue")
(svg-use-shape polyline _sstyle #:at? '(5 . 5))
(svg-show-default))
(svg-def-polygon
points (listof (cons/c natural? natural?)))define a polygon by points list.
(let ([polygon
(svg-def-polygon
'((0 . 25) (25 . 0) (75 . 0) (100 . 25) (100 . 75) (75 . 100) (25 . 100) (0 . 75)))]
[_sstyle (sstyle-new)])
(set-sstyle-stroke-width! _sstyle 5)
(set-sstyle-stroke! _sstyle "#765373")
(set-sstyle-fill! _sstyle "#ED6E46")
(svg-use-shape polygon _sstyle #:at? '(5 . 5))
(svg-show-default))
define a path programmtially.
(define (svg-def-path
path_proc procedure?))all path actions should be include in this procedure: moveto, curve etc.
(define (svg-path-raw
raw_data string?))define a bunch path by raw data.
(let ([path
(svg-def-path
(lambda ()
(svg-path-raw
"M248.761,92c0,9.801-7.93,17.731-17.71,17.731c-0.319,0-0.617,0-0.935-0.021
c-10.035,37.291-51.174,65.206-100.414,65.206 c-49.261,0-90.443-27.979-100.435-65.334
c-0.765,0.106-1.531,0.149-2.317,0.149c-9.78,0-17.71-7.93-17.71-17.731
c0-9.78,7.93-17.71,17.71-17.71c0.787,0,1.552,0.042,2.317,0.149
C39.238,37.084,80.419,9.083,129.702,9.083c49.24,0,90.379,27.937,100.414,65.228h0.021
c0.298-0.021,0.617-0.021,0.914-0.021C240.831,74.29,248.761,82.22,248.761,92z")))]
[sstyle_path (sstyle-new)])
(set-sstyle-fill! sstyle_path "#7AA20D")
(set-sstyle-stroke-width! sstyle_path 9)
(set-sstyle-stroke! sstyle_path "#7AA20D")
(set-sstyle-stroke-linejoin! sstyle_path 'round)
(svg-use-shape path sstyle_path)
(svg-show-default))
(define (svg-path-moveto point)
(define (svg-path-moveto* point)moveto* use absolute position.
moveto use relative position.
(define (svg-path-close))close a path.
(define (svg-path-lineto point)lineto* is the absolute version. horizontal line: hlineto. vertical line: vlineto.
(let ([path
(svg-def-path
(lambda ()
(svg-path-moveto* '(5 . 5))
(svg-path-hlineto 100)
(svg-path-vlineto 100)
(svg-path-lineto '(-50 . 50))
(svg-path-lineto '(-50 . -50))
(svg-path-close)))]
[sstyle_path (sstyle-new)])
(set-sstyle-stroke-width! sstyle_path 5)
(set-sstyle-stroke! sstyle_path "#7AA20D")
(set-sstyle-stroke-linejoin! sstyle_path 'round)
(svg-use-shape path sstyle_path)
(svg-show-default))
(define (svg-path-qcurve point1 point2)
(define (svg-path-qcurve* point1 point2)use two control points to draw a Quadratic Bezier Curve.
qcurve* use absolute position.
qcurve use relative position, relative to the start position.
(let ([path
(svg-def-path
(lambda ()
(svg-path-moveto* '(10 . 60))
(svg-path-qcurve* '(60 . 10) '(110 . 60))
(svg-path-qcurve* '(160 . 110) '(210 . 60))))
]
[path_style (sstyle-new)]
[red_dot (svg-def-circle 5)]
[dot_style (sstyle-new)])
(set-sstyle-stroke! path_style "#333333")
(set-sstyle-stroke-width! path_style 3)
(svg-use-shape path path_style)
(set-sstyle-fill! dot_style "red")
(svg-use-shape red_dot dot_style #:at? '(10 . 60))
(svg-use-shape red_dot dot_style #:at? '(60 . 10))
(svg-use-shape red_dot dot_style #:at? '(110 . 60))
(svg-use-shape red_dot dot_style #:at? '(160 . 110))
(svg-use-shape red_dot dot_style #:at? '(210 . 60))
(svg-show-default))(svg-path-moveto* '(10 . 60))
(svg-path-qcurve '(50 . -50) '(100 . 0))
(svg-path-qcurve '(50 . 50) '(100 . 0))
(define (svg-path-ccurve point1 point2 point3)
(define (svg-path-ccurve* point1 point2 point3)use three control points to draw a Cubic Bezier Curve.
ccurve* use absolute position.
ccurve use relative position, relative to the start position.
(let ([path
(svg-def-path
(lambda ()
(svg-path-moveto* '(10 . 60))
(svg-path-ccurve* '(30 . 15) '(80 . 15) '(100 . 60))
(svg-path-ccurve* '(120 . 105) '(170 . 105) '(190 . 60))
))]
[path_style (sstyle-new)]
[red_dot (svg-def-circle 5)]
[dot_style (sstyle-new)])
(set-sstyle-stroke! path_style "#333333")
(set-sstyle-stroke-width! path_style 3)
(svg-use-shape path path_style)
(set-sstyle-fill! dot_style "red")
(svg-use-shape red_dot dot_style #:at? '(10 . 60))
(svg-use-shape red_dot dot_style #:at? '(30 . 15))
(svg-use-shape red_dot dot_style #:at? '(80 . 15))
(svg-use-shape red_dot dot_style #:at? '(100 . 60))
(svg-use-shape red_dot dot_style #:at? '(120 . 105))
(svg-use-shape red_dot dot_style #:at? '(170 . 105))
(svg-use-shape red_dot dot_style #:at? '(190 . 60))
(svg-show-default))(svg-path-moveto* '(10 . 60))
(svg-path-ccurve '(20 . -45) '(70 . -45) '(90 . 0))
(svg-path-ccurve '(20 . 45) '(70 . 45) '(90 . 0))
(define (svg-path-arc point radius direction)arc* is the absolute version.
point is the end point.
radius spcify the ellipse's size.
direction is a simplified large-arc-flag and sweep-flag's comibination.
(let (
[arc1
(svg-def-path
(lambda ()
(svg-path-moveto* '(130 . 45))
(svg-path-arc* '(170 . 85) '(80 . 40) 'left_big)))]
[arc2
(svg-def-path
(lambda ()
(svg-path-moveto* '(130 . 45))
(svg-path-arc* '(170 . 85) '(80 . 40) 'left_small)))]
[arc3
(svg-def-path
(lambda ()
(svg-path-moveto* '(130 . 45))
(svg-path-arc* '(170 . 85) '(80 . 40) 'right_big)))]
[arc4
(svg-def-path
(lambda ()
(svg-path-moveto* '(130 . 45))
(svg-path-arc* '(170 . 85) '(80 . 40) 'right_small)))]
[arc_style (sstyle-new)]
[red_dot (svg-def-circle 5)]
[dot_style (sstyle-new)]
)
(set-sstyle-stroke-width! arc_style 3)
(let ([_arc_style (sstyle-clone arc_style)])
(set-sstyle-stroke! _arc_style "#ccccff")
(svg-use-shape arc1 _arc_style))
(let ([_arc_style (sstyle-clone arc_style)])
(set-sstyle-stroke! _arc_style "green")
(svg-use-shape arc2 _arc_style))
(let ([_arc_style (sstyle-clone arc_style)])
(set-sstyle-stroke! _arc_style "blue")
(svg-use-shape arc3 _arc_style))
(let ([_arc_style (sstyle-clone arc_style)])
(set-sstyle-stroke! _arc_style "yellow")
(svg-use-shape arc4 _arc_style))
(set-sstyle-fill! dot_style "red")
(svg-use-shape red_dot dot_style #:at? '(130 . 45))
(svg-use-shape red_dot dot_style #:at? '(170 . 85))
(svg-show-default))
}
define a text programmtially.
(define (svg-text-def
[text string?]
[#:font-size? font-size? (or/c #f natural?) #f]
[#:font-family? font-family? (or/c #f string?) #f]
[#:dx? dx? (or/c #f integer?) #f]
[#:dy? dy? (or/c #f integer?) #f]
[#:rotate? rotate? (or/c #f (listof integer?)) #f]
[#:textLength? textLength? (or/c #f natural?) #f]
[#:kerning? kerning? (or/c #f natural? 'auto 'inherit) #f]
[#:letter-space? letter-space? (or/c #f natural? 'normal 'inherit) #f]
[#:word-space? word-space? (or/c #f natural? 'normal 'inherit) #f]
[#:text-decoration? text-decoration? (or/c #f 'overline 'underline 'line-through) #f]
[#:path? path? (or/c #f string?) #f]
[#:path-startOffset? path-startOffset? (or/c #f (integer-in 0 100)) #f]dx, dy: relative position.
kerning, letter-space, word-space: all about letter and word spaces.
rotate: a list of rotate angles, it represent each letter's rotate, only one means each letter have same angle.
(let ([text (svg-text-def "城春草木深" #:font-size? 50 #:rotate? '(10 20 30 40 50) #:textLength? 300)]
[_sstyle (sstyle-new)])
(set-sstyle-fill! _sstyle "#ED6E46")
(svg-use-shape text _sstyle #:at? '(30 . 60))
(svg-show-default))
}
(let (
[text1 (svg-text-def "国破山河在" #:font-size? 50 #:text-decoration? 'overline)]
[text2 (svg-text-def "国破山河在" #:font-size? 50 #:text-decoration? 'underline)]
[text3 (svg-text-def "国破山河在" #:font-size? 50 #:text-decoration? 'line-through)]
[_sstyle (sstyle-new)]
)
(set-sstyle-fill! _sstyle "#ED6E46")
(svg-use-shape text1 _sstyle #:at? '(30 . 60))
(svg-use-shape text2 _sstyle #:at? '(30 . 160))
(svg-use-shape text3 _sstyle #:at? '(30 . 260))
(svg-show-default))
}
let text follow a path:
(let* ([path
(svg-def-path
(lambda ()
(svg-path-moveto* '(10 . 60))
(svg-path-qcurve* '(110 . 10) '(210 . 60))
(svg-path-qcurve* '(310 . 110) '(410 . 60))))]
[path_sstyle (sstyle-new)]
[text
(svg-text-def "国破山河在 城春草木深 感时花溅泪 恨别鸟惊心"
#:path? path
#:path-startOffset? 5)]
[text_sstyle (sstyle-new)])
(set-sstyle-fill! text_sstyle "#ED6E46")
(svg-use-shape path path_sstyle #:hidden? #t)
(svg-use-shape text text_sstyle)
(svg-show-default))
define a gradient programmtially.
(svg-def-gradient-stop
[#:offset offset (integer-in 0 100)]
[#:color color string?]
[#:opacity? opacity? (between/c 0 1) 1]
)
(list/c (integer-in 0 100) string? (between/c 0 1))offset from 0 to 100, means the distance of the color gradient.
lineargradient and radialgradient both have a stop list.
(svg-def-linear-gradient
[stop_list (listof (list/c (integer-in 0 100) string? (between/c 0 1)))]
[#:x1? x1? (or/c #f natural?) #f]
[#:y1? y1? (or/c #f natural?) #f]
[#:x2? x2? (or/c #f natural?) #f]
[#:y2? y2? (or/c #f natural?) #f]
[#:gradientUnits? gradientUnits? (or/c #f 'userSpaceOnUse 'objectBoundingBox) #f]
[#:spreadMethod? spreadMethod? (or/c #f 'pad 'repeat 'reflect) #f]
)
string?use x1, y1, x2, y2 justify gradient's direction and position.
default is from left to right, x1=0, y1=0, x2=100, y2=0.
(let ([rec (svg-def-rect 100 100)]
[gradient
(svg-def-linear-gradient
(list
(svg-def-gradient-stop #:offset 0 #:color "#BBC42A")
(svg-def-gradient-stop #:offset 100 #:color "#ED6E46")
))]
[_sstyle (sstyle-new)])
(set-sstyle-fill-gradient! _sstyle gradient)
(svg-use-shape rec _sstyle)
(svg-show-default))
(svg-def-radial-gradient
[stop_list (listof (list/c (integer-in 0 100) string? (between/c 0 1)))]
[#:cx? cx? (or/c #f natural?) #f]
[#:cy? cy? (or/c #f natural?) #f]
[#:fx? fx? (or/f #f natural?) #f]
[#:fy? fy? (or/f #f natural?) #f]
[#:r? r? (or/c #f natural?) #f]
[#:gradientUnits? gradientUnits? (or/c #f 'userSpaceOnUse 'objectBoundingBox) #f]
[#:spreadMethod? spreadMethod? (or/c #f 'pad 'repeat 'reflect) #f]
)
string?cx, cy, fx, fy has value 0 - 100, means 0% - 100%, use them to justify gradient's position and direction.
(let ([rec (svg-def-rect 100 100)]
[gradient
(svg-def-radial-gradient
(list
(svg-def-gradient-stop #:offset 0 #:color "#BBC42A")
(svg-def-gradient-stop #:offset 100 #:color "#ED6E46")
))]
[_sstyle (sstyle-new)])
(set-sstyle-fill-gradient! _sstyle gradient)
(svg-use-shape rec _sstyle)
(svg-show-default))