[racket] 2htdp/image: Silent cropping?

I prefer leaving it alone but documenting the limitation -- Matthias





On Jan 23, 2015, at 9:30 PM, Robby Findler wrote:

> 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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