<div dir="ltr">You can look at the <a href="https://github.com/qgis/QGIS/blob/2d1aa68f0d044f2aced7ebeca8d2fa6b754ac970/src/analysis/processing/qgsalgorithmoffsetlines.cpp">implementation</a> of offsetline algorithm and you'll notice that it uses geometry.offsetCurve(). You can do the same in your code.<br clear="all"><div><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div dir="ltr"><div dir="ltr"><div></div><div><table cellpadding="0" cellspacing="0" style="border-spacing:0px;border-collapse:collapse;color:rgb(68,68,68);width:480px;font-size:10pt;font-family:Arial,sans-serif;line-height:normal"><tbody><tr><td valign="top" style="padding:10px 0px 12px;width:160px;vertical-align:top"><a href="https://spatialthoughts.com/" style="background-color:transparent;color:rgb(51,122,183)" target="_blank"><img border="0" alt="Logo" width="141" src="https://spatialthoughts685850346.files.wordpress.com/2019/12/spatial_thoughts_logo.png" style="border:0px;vertical-align:middle;width:141px;height:auto"></a></td><td style="padding:6px 0px;width:320px"><table cellpadding="0" cellspacing="0" style="border-spacing:0px;border-collapse:collapse;background-color:transparent"><tbody><tr><td style="padding:0px;font-size:12pt;font-family:Arial,sans-serif;font-weight:bold;color:rgb(61,60,63)"><span style="color:rgb(0,175,239)">Ujaval Gandhi</span></td></tr><tr><td style="padding:0px 0px 11px;font-size:10pt;font-family:Arial,sans-serif;color:rgb(61,60,63)"><span style="color:rgb(0,175,239)">Spatial Thoughts</span></td></tr><tr><td style="padding:0px;font-size:10pt;font-family:Arial,sans-serif;color:rgb(155,155,155)"><span>mobile: +91-8095684687</span></td></tr><tr><td style="padding:0px;font-size:10pt;font-family:Arial,sans-serif;color:rgb(155,155,155)"><span>email: </span><span style="color:rgb(23,147,210)"><a href="mailto:ujaval@spatialthoughts.com" target="_blank">ujaval@spatialthoughts.com</a></span></td></tr><tr><td style="padding:6px 0px 0px"><span style="display:inline-block;height:22px"><span><a href="https://www.linkedin.com/in/spatialthoughts/" style="background-color:transparent;color:rgb(51,122,183)" target="_blank"><img alt="LinkedIn icon" border="0" width="23" height="23" src="https://codetwocdn.azureedge.net/images/mail-signatures/generator/elegant-logo/ln.png" style="border:0px;vertical-align:middle;height:20px;width:20px"></a>  </span><span><a href="https://twitter.com/spatialthoughts" style="background-color:transparent;color:rgb(51,122,183)" target="_blank"><img alt="Twitter icon" border="0" width="23" height="23" src="https://codetwocdn.azureedge.net/images/mail-signatures/generator/elegant-logo/tt.png" style="border:0px;vertical-align:middle;height:20px;width:20px"></a>  </span></span></td></tr></tbody></table></td></tr><tr><td colspan="2" style="padding:8px 0px 0px;border-top:1px solid rgb(23,147,210);width:480px;font-family:Arial,sans-serif;color:rgb(155,155,155);text-align:justify"></td></tr></tbody></table><br></div></div></div></div></div></div></div></div></div></div></div></div><br></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Wed, Jun 9, 2021 at 1:31 PM Prem Kumar <<a href="mailto:prem.netgis@gmail.com">prem.netgis@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr">Hi Team,<div><br></div><div>Just wondering if there is a python api which gets an offset line or parallel line (to both left and right sides) to a given line geometry in Qgis Python. I know there exists a processing tool called <a href="https://docs.qgis.org/3.16/en/docs/user_manual/processing_algs/qgis/vectorgeometry.html#offset-lines" target="_blank">Offsetlines</a> but need this similar functionality at geometry object level so that I can create offset lines only when needed based on my logic.</div><div><br></div><div>The only way now is that I can perform the Offset lines on the entire layer and then access the offset geometry if needed.</div><div><br></div><div>On other hand, shapely has <a href="https://shapely.readthedocs.io/en/stable/manual.html#object.parallel_offset" target="_blank">parallel_offset</a> but this needs conversion from shapely geometry to qgisgeometry.</div><div><br></div><div>Just looking for thoughts on this to optimize heavy geometry operations. Appreciate your help.</div><div><br></div><div>-Prem</div></div>
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