<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
</head>
<body>
<p>Hi,</p>
<p>It would be interesting if you could bench using proj_trans() or
proj_trans_array() vs <a class="moz-txt-link-freetext" href="OGRCoordinateTransformation::Transform()">OGRCoordinateTransformation::Transform()</a>. My
gut feeling would be that the CPU cost of most coordinate
transformations would be the dominant part, but I might be wrong.</p>
<p>Even</p>
<div class="moz-cite-prefix">Le 06/03/2026 à 18:40, David Klaus via
gdal-dev a écrit :<br>
</div>
<blockquote type="cite"
cite="mid:CAJNrnBWJbQmUbdtuPTdEOa=sK7M5bmYdhwv8zRHPeT4WDftnLg@mail.gmail.com">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<style type="text/css">.style1 {font-family: "Times New Roman";}</style>
<div dir="ltr">Hello GDAL Community,<br>
<br>
I am currently optimizing a routine that transforms a large
number of points using <a class="moz-txt-link-freetext" href="OGRCoordinateTransformation::Transform()">OGRCoordinateTransformation::Transform()</a>.<br>
<br>
As it stands, this function requires separate arrays for the x,
y, z (optional), and t (optional) data. From a memory
perspective, it seems that this approach requires the CPU to
fetch cache lines from multiple different memory pools to
process a single coordinate tuple. I am concerned this might
lead to cache thrashing and degraded performance for massive
arrays.<br>
<br>
Is there an existing method or best practice to provide point
data to GDAL in an interleaved, cache-friendly manner? I believe
that this can be done using proj directly, but I don't see a
solution with GDAL.<br>
<br>
Alternatively is this separation intentional, making my cache
concerns less of an issue in practice?<br>
<br>
Thank you for your time and any insights you can provide,
<div><br>
</div>
<span class="gmail_signature_prefix">-- </span><br>
<div dir="ltr" class="gmail_signature"
data-smartmail="gmail_signature">
<div dir="ltr">David Klaus
<div>Carlson Software</div>
</div>
</div>
</div>
<br>
<br>
<p style="font-family: Verdana; font-size:10pt; color:#777777;"><b>Disclaimer</b></p>
<p style="font-family: Verdana; font-size:8pt; color:#777777;">The
information contained in this communication from the sender is
confidential. It is intended solely for use by the recipient and
others authorized to receive it. If you are not the recipient,
you are hereby notified that any disclosure, copying,
distribution or taking action in relation of the contents of
this information is strictly prohibited and may be unlawful.</p>
<br>
<fieldset class="moz-mime-attachment-header"></fieldset>
<pre wrap="" class="moz-quote-pre">_______________________________________________
gdal-dev mailing list
<a class="moz-txt-link-abbreviated" href="mailto:gdal-dev@lists.osgeo.org">gdal-dev@lists.osgeo.org</a>
<a class="moz-txt-link-freetext" href="https://lists.osgeo.org/mailman/listinfo/gdal-dev">https://lists.osgeo.org/mailman/listinfo/gdal-dev</a>
</pre>
</blockquote>
<pre class="moz-signature" cols="72">--
<a class="moz-txt-link-freetext" href="http://www.spatialys.com">http://www.spatialys.com</a>
My software is free, but my time generally not.</pre>
</body>
</html>