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

Minor tweaks to documentation and rotating-triangle test.

Browse Source
This commit is contained in:
Stephen Bloch 2010-12-30 10:29:12 -05:00
parent 7069a267a6
commit f3352794d8
2 changed files with 9 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
collects/picturing-programs/picturing-programs.scrbl
View File

@ -211,7 +211,7 @@ produces a copy of @racket[my-picture] with all the red leached out,
leaving only the blue and green components. leaving only the blue and green components.
Since @racket[make-color] with three arguments defaults alpha to 255, Since @racket[make-color] with three arguments defaults alpha to 255,
this function discards any alpha information (including edge-dithering) this definition of @racket[lose-red] discards any alpha information (including edge-dithering)
that was in the original image. To preserve this information, one could write that was in the original image. To preserve this information, one could write
@racketblock[ @racketblock[
(define (lose-red-but-not-alpha x y old-color) (define (lose-red-but-not-alpha x y old-color)

7
collects/picturing-programs/tests/rotating-triangle.rkt
View File

@ -18,6 +18,13 @@
(define (rotate-1 pic) (define (rotate-1 pic)
(rotate 1 pic)) (rotate 1 pic))
"Triangle rotating around its center:"
(big-bang tricirc
(on-tick rotate-1 .05)
(check-with image?)
(on-draw show-it))
"Triangle rotating around the center of its bounding box:"
(big-bang badtricirc (big-bang badtricirc
(on-tick rotate-1 .05) (on-tick rotate-1 .05)
(check-with image?) (check-with image?)