[racket] 2htdp/image: Silent cropping?

From: Robby Findler (robby at eecs.northwestern.edu)
Date: Fri Jan 23 21:30:45 EST 2015

Maybe the right thing to do is leave the arbitrary limit in there, but
make it based on the area, not based independently on the width and
height. Then your example would work, but (ellipse 5050 5050)
wouldn't.

Robby


On Fri, Jan 23, 2015 at 8:22 PM, Robby Findler
<robby at eecs.northwestern.edu> wrote:
> Yes, 2htdp/image truncates the images to 5000x5000 when building a bitmap.
>
> I did that in response to this PR:
>
> http://bugs.racket-lang.org/query/?debug=&database=default&cmd=view+audit-trail&cmd=view&pr=12277
>
> but I'm not sure what's the right answer here. I'm hesitant to add
> errors but maybe that's the best thing.
>
> Robby
>
>
> On Fri, Jan 23, 2015 at 7:52 PM, Jordan Johnson <jmj at fellowhuman.com> wrote:
>> Hi all,
>>
>> A student of mine noticed yesterday that part of an image was getting
>> truncated. Some further experimentation in BSL yielded this example:
>>
>> (ellipse 5050 100 'solid 'blue) ; => image with 50 pixels missing at right
>> end
>> (ellipse 100 5050 'solid 'blue) ; => image with 50 pixels missing at bottom
>>
>> For both images, the image-{width,height} functions produce 100 and 5050;
>> the library simply doesn't draw the entire ellipse, although click-and-drag
>> highlighting does show the image as having 50 extra blank pixels at the end.
>>
>> I can't find documentation of the size limits. Is this intended behavior? If
>> so, an error might be more student-friendly.
>>
>> Cheers,
>> Jordan
>>
>>
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