suzanne.soy/racket
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

started on overlay/offset

Browse Source
This commit is contained in:
Robby Findler 2011-02-19 20:55:34 -06:00
parent 33d01a681e
commit 5822f1e95f
1 changed files with 14 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
collects/2htdp/private/image-more.rkt
View File

@ -403,6 +403,20 @@
(if (< dy 0) (- dy) 0)
#f))))
(define (overlay/offset image1 dx dy image2)
(overlay/offset/internal image1 dx dy image2 'middle 'middle))
(define (overlay/offset/internal image orig-dx orig-dy scene x-place y-place)
(let ([dx (- orig-dx (find-x-spot x-place image))]
[dy (- orig-dy (find-y-spot y-place image))])
(overlay/δ image
(if (< dx 0) 0 dx)
(if (< dy 0) 0 dy)
scene
(if (< dx 0) (- dx) 0)
(if (< dy 0) (- dy) 0)
#f)))
(define/chk (scene+line image x1 y1 x2 y2 color)
(let* ([dx (abs (min 0 x1 x2))]
[dy (abs (min 0 y1 y2))])