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On 10/29/2021 5:16 AM, Hilaire Fernandes via Cuis-dev wrote:
<blockquote cite="mid:70042827-8752-ce83-4572-ccaec81620ad@drgeo.eu"
type="cite">
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<p><font size="+1">Hi, <br>
</font></p>
<p><font size="+1">When a window is dragged arround, its elements
are doing a belly dance. <br>
</font></p>
<p><font size="+1">Obverve this video: <a moz-do-not-send="true"
class="moz-txt-link-freetext"
href="https://youtu.be/kn5qhPb-8DY">https://youtu.be/kn5qhPb-8DY</a></font></p>
<p><font size="+1">Hilaire</font><br>
</p>
<pre class="moz-signature" cols="72">--
GNU Dr. Geo
<a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://drgeo.eu">http://drgeo.eu</a>
<a moz-do-not-send="true" class="moz-txt-link-freetext" href="http://blog.drgeo.eu">http://blog.drgeo.eu</a></pre>
</blockquote>
<br>
This was not a bug in any of the morphic / graphics code, but a
consequence of adopting the supposedly more "advanced"
round-haf-to-even rule for Floats. See See
<a class="moz-txt-link-freetext" href="https://en.wikipedia.org/wiki/Rounding#Round_half_to_even">https://en.wikipedia.org/wiki/Rounding#Round_half_to_even</a> .<br>
<br>
Fix was to add back the traditional rounding mode taught in school,
as #roundHAFZ (round half way from zero, i.e. 0.5 -> 1), and use
it for pixel coordinates, essentially for BitBlt.<br>
<br>
Fix now at GitHub, with some tests both for Float and Fraction.<br>
<br>
Thanks,<br>
<pre class="moz-signature" cols="72">--
Juan Vuletich
<a class="moz-txt-link-abbreviated" href="http://www.cuis-smalltalk.org">www.cuis-smalltalk.org</a>
<a class="moz-txt-link-freetext" href="https://github.com/Cuis-Smalltalk/Cuis-Smalltalk-Dev">https://github.com/Cuis-Smalltalk/Cuis-Smalltalk-Dev</a>
<a class="moz-txt-link-freetext" href="https://github.com/jvuletich">https://github.com/jvuletich</a>
<a class="moz-txt-link-freetext" href="https://www.linkedin.com/in/juan-vuletich-75611b3">https://www.linkedin.com/in/juan-vuletich-75611b3</a>
@JuanVuletich</pre>
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