summaryrefslogtreecommitdiffstats
path: root/ex/2/50.rkt
blob: a4f24335766ff7670827015c795edf7a62784d26 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
;;;; License: CC0-1.0

#lang racket

(require "46.rkt")
(require "47.rkt")
(require "49.rkt")


(define (transform-painter painter origin corner1 corner2)
  (lambda (frame)
    (let ((m (frame-coord-map frame)))
      (let ((new-origin (m origin)))
        (painter (make-frame
                  new-origin
                  (sub-vect (m corner1) new-origin)
                  (sub-vect (m corner2) new-origin)))))))


(define (flip-vert painter)
  (transform-painter painter
                     (make-vect 0.0 1.0)
                     (make-vect 1.0 1.0)
                     (make-vect 0.0 0.0)))


(define (flip-horiz painter)
  (transform-painter painter
                     (make-vect 1.0 0.0)
                     (make-vect 0.0 0.0)
                     (make-vect 1.0 1.0)))


(define (counterclockwise-180 painter)
  (transform-painter painter
                     (make-vect 1.0 1.0)
                     (make-vect 0.0 1.0)
                     (make-vect 1.0 0.0)))


(define (counterclockwise-270 painter)
  (transform-painter painter
                     (make-vect 1.0 0.0)
                     (make-vect 1.0 1.0)
                     (make-vect 0.0 0.0)))