[plt-scheme] pict->image

Mark,

I believe what you have to do, rather than return b, is return (new  
image-snip% b).

jmj

On Dec 22, 2009, at 8:52 PM, Mark Engelberg wrote:

> I tried this:
>
> (define (pict->image p)
>  (let* ([w (inexact->exact (ceiling (pict-width p)))]
>         [h (inexact->exact (ceiling (pict-height p)))]
>         [b (make-object bitmap% w h)]
>         [dc (new bitmap-dc% [bitmap b])])
>    (draw-pict p dc 0 0)
>    b))
>
> The bitmap doesn't seem to be interchangeable with image.  For
> example, I get errors like:
> place-image: expected <image> as first argument, given: #<bitmap%>
>
> I also tried returning the bitmap-dc% object rather than bitmap%, with
> similar errors.
>
> Can you elaborate a bit on how to make this bitmap work with the image
> teachpack?
>
> Thanks,
>
> Mark
>
> On Tue, Dec 22, 2009 at 8:57 AM, Robby Findler
> <robby at eecs.northwestern.edu> wrote:
>> It is possible to turn a pict into a bitmap, by creating a bitmap% of
>> the right size, putting it into a bitmap-dc% and then using the
>> draw-pict function. This bitmap will work fine as a htdp/image, but
>> won't be optimal as a 2htdp/image, because scaling and image equality
>> won't work as well as it could (but it should still work).
>>
>> hth,.
>> Robby
>>
>> On Mon, Dec 21, 2009 at 6:34 PM, Mark Engelberg
>> <mark.engelberg at gmail.com> wrote:
>>> What's the process for converting a pict (as defined in the  
>>> slideshow
>>> module) to an image (as defined in the image teachpack)?
>>>
>>> Specifically, I want to use slideshow's ability to format long  
>>> text as
>>> a paragraph (par) in order to create paragraphs that can be placed  
>>> in
>>> a universe scene.
>>>
>>> Thanks,
>>>
>>> Mark
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>>
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