You could also just swap some of the pixels:

| w h f |
f := (PNGReadWriter formFromFileNamed: 
'/Users/bob/squeak/Squeak4.3/blur_ulam_1.png') asFormOfDepth: 32.
w := f width - 1.
h := f height - 1.
0 to: h by: 2 do: [ :y || c |
     c := f colorAt: 0 at y.
     f colorAt: 0 at y put: (f colorAt: w at y).
     f colorAt: w at y put: c.
].
0 to: w by: 2 do: [ :x || c |
     c := f colorAt: x at 0.
     f colorAt: x at 0 put: (f colorAt: x at h).
     f colorAt: x at h put: c.
].
ActiveWorld color: (InfiniteForm with: f)

Cheers,
Bob

On 11/22/12 10:14 AM, Frank Shearar wrote:
> On 22 November 2012 14:27, Bert Freudenberg <bert at freudenbergs.de> wrote:
>> On 2012-11-22, at 14:27, Frank Shearar <frank.shearar at gmail.com> wrote:
>>
>>> On 21 November 2012 18:22, Bob Arning <arning315 at comcast.net> wrote:
>>>> It's always fun to try it with Squeak. convert the form to 32 bits and try
>>>> this:
>>>>
>>>> 0 to: self height - 1 do: [ :y |
>>>>     self colorAt: self width-1 at y put: ((self colorAt: 0 at y) mixed: 0.5 with:
>>>> (self colorAt: self width-2 at y)).
>>>>     self colorAt: 0 at y put: ((self colorAt: 2 at y) mixed: 0.5 with: (self
>>>> colorAt: self width-1 at y))
>>>> ].
>>>>
>>>> Seems to fuzz it up pretty well.
>>> That's exactly what I'd like to do. The form's an 8 bit ColorForm
>>> though, and doesn't like depths > 8. So I thought I'd be extra clever
>>> and make a 32 bit form and copy the bits:
>>>
>>> | form |
>>> form := PNGReadWriter formFromFileNamed:
>>> '/home/frank/Downloads/blur_ulam_1.png'.
>>> form := (Form extent: form extent depth: 32) bits: form bits.
>> You can't just use an 8 bit form's bits in a 32 bit form. Use asFormOfDepth:.
> Ah! That works. OK, so I need just fix the horizontal glitch in a
> similar manner and I'll be happy.
>
> Thanks, Bert!
>
> frank
>
>> - Bert -
>>
>>> 0 to: form height - 1 do: [ :y |
>>>        form
>>>                colorAt: form width-1 at y
>>>                put: ((form colorAt: 0 at y)
>>>                        mixed: 0.5
>>>                        with: (form colorAt: form width-2 at y)).
>>>        form
>>>                colorAt: 0 at y
>>>                put: ((form colorAt: 2 at y)
>>>                        mixed: 0.5
>>>                        with: (form colorAt: form width-1 at y)) asFloat
>>> ].
>>>
>>> ActiveWorld color: (InfiniteForm with: form)
>>>
>>> However, I still can't run the script, because I get an "Error: Bad
>>> BitBlt arg (Fraction?). I can't even just wrap-and-resume the Error
>>> because, of course, Error is not resumable.
>>>
>>> Ideas? What am I missing?
>>>
>>> frank
>>>
>>>> Cheers,
>>>> Bob
>>>>
>>>> On 11/21/12 10:53 AM, Frank Shearar wrote:
>>>>
>>>> On 21 November 2012 14:39, Frank Shearar <frank.shearar at gmail.com> wrote:
>>>>
>>>> Hi folks,
>>>>
>>>> Apologies for the silence: things have been a bit busy.
>>>>
>>>> Test wise we're looking pretty good. We still have a few red lights but I
>>>> don't see much point in delaying further: some of the test failures are
>>>> because of VM sensitivities.
>>>>
>>>> Off the top of my head we/I still need to write a changelog, and otherwise a
>>>> bunch of infrastructural stuff's all that's needed: a new update stream,
>>>> switching it over, etc. I wrote a ReleaseBuilder script but of course should
>>>> actually publish it.
>>>>
>>>> I've also nearly finished the new background, and just need to figure out
>>>> how to clean the edges of the pic to make it tile properly. Given I'm
>>>> writing this mail on my phone I will have to mail the proposed image
>>>> separately, at a later stage.
>>>>
>>>> For better or worse, here it is. Test it with
>>>>
>>>>     ActiveWorld color: (InfiniteForm with: (PNGReadWriter
>>>> readFromFileNamed: 'my/path/to/blur_ulam_1.png'))
>>>>
>>>> Note the strange vertical white-ish line between the tiles. The image
>>>> is filled all the way to the edge, but the left and right edges differ
>>>> sufficiently to create the artifact. I'm not sure how to get rid of
>>>> it, never having attempted to make a tile-able image before.
>>>>
>>>> Anyone spot anything missing off the swiki release page?
>>>>
>>>> That would be http://wiki.squeak.org/squeak/6188.
>>>>
>>>> frank
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>
>>
>>
>

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