racket/collects/plot/common/draw.rkt

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Racket

#lang racket/base
;; Extra drawing, font, color and style functions.
(require racket/draw racket/class racket/match racket/list racket/contract racket/math
"math.rkt"
"contract.rkt"
"contract-doc.rkt"
"sample.rkt")
(provide (all-defined-out))
;; ===================================================================================================
;; Drawing text rotated around an anchor point
(define (draw-text/anchor dc str x y [anchor 'top-left] [combine? #f] [offset 0] [angle 0])
(define-values (width height _1 _2) (send dc get-text-extent str #f combine? offset))
(define dx (case anchor
[(top-left left bottom-left) 0]
[(top center bottom) (* 1/2 width)]
[(top-right right bottom-right) width]
[else (raise-type-error 'draw-text/anchor "anchor/c" anchor)]))
(define dy (case anchor
[(top-left top top-right) 0]
[(left center right) (* 1/2 height)]
[(bottom-left bottom bottom-right) height]))
(define rdx (+ (* (sin angle) dy) (* (cos angle) dx)))
(define rdy (- (* (cos angle) dy) (* (sin angle) dx)))
(send dc draw-text str (- x rdx) (- y rdy) combine? offset angle))
(define (get-text-corners/anchor dc str x y [anchor 'top-left] [combine? #f] [offset 0] [angle 0])
(define-values (width height _1 _2) (send dc get-text-extent str #f combine? offset))
(define dxs (case anchor
[(top-left left bottom-left) (list 0 width)]
[(top center bottom) (list (* -1/2 width) (* 1/2 width))]
[(top-right right bottom-right) (list (- width) 0)]
[else (raise-type-error 'get-text-corners/anchor "anchor/c" anchor)]))
(define dys (case anchor
[(top-left top top-right) (list 0 height)]
[(left center right) (list (* -1/2 height) (* 1/2 width))]
[(bottom-left bottom bottom-right) (list (- height) 0)]))
(for*/list ([dx (in-list dxs)] [dy (in-list dys)])
(define rdx (+ (* (sin angle) dy) (* (cos angle) dx)))
(define rdy (- (* (cos angle) dy) (* (sin angle) dx)))
(vector (+ x rdx) (+ y rdy))))
;; ===================================================================================================
;; Draw paramter normalization
(define (real->font-size size)
(define i (inexact->exact (round size)))
(min (max i 1) 255))
(define (real->color-byte f)
(define i (inexact->exact (floor f)))
(min (max i 0) 255))
(define (color%? c) (is-a? c color%))
(defproc (->color [c color/c]) (list/c real? real? real?)
(match c
[(? color%?) (list (send c red) (send c green) (send c blue))]
[(? string?) (define color (send the-color-database find-color c))
(when (not color) (error 'decode-color "unknown color name ~e" c))
(->color color)]
[(list (? real?) (? real?) (? real?)) c]
[(? symbol?) (->color (symbol->string c))]
[_ (error '->color "unable to convert to color triple: ~e" c)]))
(define (color->color% c)
(match-define (list r g b) c)
(make-object color% (real->color-byte r) (real->color-byte g) (real->color-byte b)))
(define (rgb->hsv rgb)
(match-define (list r g b) (map (λ (x) (/ x 255)) rgb))
(define mx (max r g b))
(define mn (min r g b))
(define c (- mx mn))
(define h (* 60 (cond [(zero? c) 0]
[(= mx r) (/ (- g b) c)]
[(= mx g) (+ (/ (- b r) c) 2)]
[(= mx b) (+ (/ (- r g) c) 4)])))
(list (if (h . < . 0) (+ h 360) h)
(if (zero? mx) 0 (/ c mx))
mx))
(define (hsv->rgb hsv)
(match-define (list h s v) hsv)
(define c (* v s))
(let ([h (/ (real-modulo h 360) 60)])
(define x (* c (- 1 (abs (- (real-modulo h 2) 1)))))
(define-values (r g b)
(cond [(and (0 . <= . h) (h . < . 1)) (values c x 0)]
[(and (1 . <= . h) (h . < . 2)) (values x c 0)]
[(and (2 . <= . h) (h . < . 3)) (values 0 c x)]
[(and (3 . <= . h) (h . < . 4)) (values 0 x c)]
[(and (4 . <= . h) (h . < . 5)) (values x 0 c)]
[(and (5 . <= . h) (h . < . 6)) (values c 0 x)]))
(define m (- v c))
(list (* 255 (+ r m))
(* 255 (+ g m))
(* 255 (+ b m)))))
(define (integer->hue n)
(let ([n (abs n)])
(define i (+ (case (remainder n 6) [(0) 0] [(1) 2] [(2) 4] [(3) 1] [(4) 3] [(5) 5])
(* 6 3 (quotient n 6))))
(remainder (* i 59) 360)))
(define (integer->gray-value n)
(* 1/7 (remainder (abs n) 8)))
(define (integer->pen-color n)
(define h (integer->hue n))
(hsv->rgb (list (- h (* 25 (sin (* (/ h 360) (* 3 pi)))))
1
(+ 1/2 (* 1/6 (sin (* (/ h 360) (* 3 pi))))))))
(define (integer->brush-color n)
(define h (integer->hue n))
(hsv->rgb (list (let ([y (* (/ (- (sqrt (+ (/ h 60) 2)) (sqrt 2))
(- (sqrt 8) (sqrt 2)))
6)])
(- h (* 15 (sin (* (/ y 6) (* 3 pi))))))
(+ 3/16 (* 3/32 (sin (* (/ h 360) (* 2 pi)))))
1)))
(define (integer->gray-pen-color i)
(make-list 3 (* 128 (expt (integer->gray-value i) 3/4))))
(define (integer->gray-brush-color i)
(make-list 3 (+ 127 (* 128 (expt (- 1 (integer->gray-value i)) 3/4)))))
(define pen-colors
(for/vector ([color (in-list (append (list (integer->gray-pen-color 0))
(build-list 120 integer->pen-color)
(build-list 7 (λ (n) (integer->gray-pen-color (- 7 n))))))])
(map real->color-byte color)))
(define brush-colors
(for/vector ([color (in-list (append (list (integer->gray-brush-color 0))
(build-list 120 integer->brush-color)
(build-list 7 (λ (n) (integer->gray-brush-color (- 7 n))))))])
(map real->color-byte color)))
(defproc (->pen-color [c plot-color/c]) (list/c real? real? real?)
(cond [(exact-integer? c) (vector-ref pen-colors (modulo c 128))]
[else (->color c)]))
(defproc (->brush-color [c plot-color/c]) (list/c real? real? real?)
(cond [(exact-integer? c) (vector-ref brush-colors (modulo c 128))]
[else (->color c)]))
#|
(define pen-colors
'#((0 0 0) ; black
(128 0 0) ; red
(0 96 0) ; green
(0 0 160) ; blue
(192 96 0) ; yellow
(0 112 128) ; cyan
(160 32 240) ; magenta
(160 160 160))) ; gray
(defproc (->pen-color [c plot-color/c]) (list/c real? real? real?)
(cond [(exact-integer? c) (vector-ref pen-colors (modulo c 8))]
[else (->color c)]))
(define brush-colors
'#((255 255 255) ; white
(255 192 192) ; red
(192 255 192) ; green
(212 224 240) ; blue
(255 248 192) ; yellow
(192 240 255) ; cyan
(240 224 255) ; magenta
(212 212 212))) ; gray
(defproc (->brush-color [c plot-color/c]) (list/c real? real? real?)
(cond [(exact-integer? c) (vector-ref brush-colors (modulo c 8))]
[else (->color c)]))
|#
(defproc (->pen-style [s plot-pen-style/c]) symbol?
(cond [(exact-integer? s) (case (remainder (abs s) 5)
[(0) 'solid]
[(1) 'dot]
[(2) 'long-dash]
[(3) 'short-dash]
[(4) 'dot-dash])]
[(symbol? s) s]
[else (raise-type-error '->pen-style "symbol or integer" s)]))
(defproc (->brush-style [s plot-brush-style/c]) symbol?
(cond [(exact-integer? s) (case (remainder (abs s) 7)
[(0) 'solid]
[(1) 'bdiagonal-hatch]
[(2) 'fdiagonal-hatch]
[(3) 'crossdiag-hatch]
[(4) 'horizontal-hatch]
[(5) 'vertical-hatch]
[(6) 'cross-hatch])]
[(symbol? s) s]
[else (raise-type-error '->brush-style "symbol or integer" s)]))
;; ===================================================================================================
;; Color functions
(defproc (color-seq [c1 color/c] [c2 color/c] [num exact-nonnegative-integer?]
[#:start? start? boolean? #t]
[#:end? end? boolean? #t]) (listof (list/c real? real? real?))
(match-define (list r1 g1 b1) (->color c1))
(match-define (list r2 g2 b2) (->color c2))
(define rs (linear-seq r1 r2 num #:start? start? #:end? end?))
(define gs (linear-seq g1 g2 num #:start? start? #:end? end?))
(define bs (linear-seq b1 b2 num #:start? start? #:end? end?))
(map list rs gs bs))
(defproc (color-seq* [colors (listof color/c)] [num exact-nonnegative-integer?]
[#:start? start? boolean? #t]
[#:end? end? boolean? #t]) (listof (list/c real? real? real?))
(when (empty? colors) (raise-type-error 'color-seq* "nonempty (listof plot-color/c)" colors))
(match-define (list (list rs gs bs) ...) (map ->color colors))
(let ([rs (linear-seq* rs num #:start? start? #:end? end?)]
[gs (linear-seq* gs num #:start? start? #:end? end?)]
[bs (linear-seq* bs num #:start? start? #:end? end?)])
(map list rs gs bs)))
;; Returns an alpha value b such that, if
(defproc (alpha-expt [a (real-in 0 1)] [n (>/c 0)]) real?
(- 1 (expt (- 1 a) n)))
(defproc (maybe-apply/list [list-or-proc (or/c (listof any/c) (any/c . -> . any/c))]
[xs (listof any/c)]) (listof any/c)
(cond [(procedure? list-or-proc) (list-or-proc xs)]
[else list-or-proc]))
;; ===================================================================================================
;; Subdividing nonlinearly transformed shapes
(define subdivide-fracs '(3/7 4/7 2/7 5/7 1/7 6/7))
(define (subdivide-line transform v1 v2)
(let loop ([v1 v1] [v2 v2] [depth 10])
(let/ec return
(when (zero? depth) (return (list v1 v2)))
(define dc-v1 (transform v1))
(define dc-v2 (transform v2))
(define dc-dv (v- dc-v2 dc-v1))
(when ((vmag dc-dv) . <= . 3)
(return (list v1 v2)))
(define dv (v- v2 v1))
(define-values (max-area vc)
(for/fold ([max-area 0] [vc v1]) ([frac (in-list subdivide-fracs)])
(define test-vc (v+ (v* dv frac) v1))
(define test-area (abs (vcross2 dc-dv (v- (transform test-vc) dc-v1))))
(cond [(test-area . > . max-area) (values test-area test-vc)]
[else (values max-area vc)])))
(when (max-area . <= . 3) (return (list v1 v2)))
;(plot3d-subdivisions (+ (plot3d-subdivisions) 1))
(append (loop v1 vc (- depth 1))
(rest (loop vc v2 (- depth 1)))))))
(define (subdivide-lines transform vs)
(append
(append*
(for/list ([v1 (in-list vs)] [v2 (in-list (rest vs))])
(define line-vs (subdivide-line transform v1 v2))
(take line-vs (sub1 (length line-vs)))))
(list (last vs))))
(define (subdivide-polygon transform vs)
(subdivide-lines transform (cons (last vs) vs)))