<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=us-ascii"><meta name=Generator content="Microsoft Word 12 (filtered medium)"><style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Consolas;
panose-1:2 11 6 9 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
span.EmailStyle17
{mso-style-type:personal-compose;
font-family:"Calibri","sans-serif";
color:windowtext;}
.MsoChpDefault
{mso-style-type:export-only;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:70.85pt 3.0cm 70.85pt 3.0cm;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]--></head><body lang=PT link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>Hi,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span lang=EN-GB>I am using the code below to test for geometry intersection and in case of success remove the intersection part from another geometry, but it is not working.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-GB>The </span><b><span lang=EN-GB style='font-size:9.5pt;font-family:Consolas'>polygonCoverageAreasLayer</span></b><span lang=EN-GB style='font-size:9.5pt;font-family:Consolas'> </span><span lang=EN-GB>is a memory polygon layer, and </span><b><span lang=EN-GB style='font-size:9.5pt;font-family:Consolas'>feature</span></b><span lang=EN-GB style='font-size:9.5pt;font-family:Consolas'> </span><span lang=EN-GB>is circle built using rubberBand and the final result is still a circle and not the difference with my base map </span><span lang=EN-GB style='font-size:9.5pt;font-family:Consolas'>costalLineLayer.</span><span lang=EN-GB><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB><o:p> </o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-GB style='font-size:9.5pt;font-family:Consolas'> polygonCoverageAreasLayer->startEditing();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-GB style='font-size:9.5pt;font-family:Consolas'> attrListCL = costalLineLayer->dataProvider()->attributeIndexes();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-GB style='font-size:9.5pt;font-family:Consolas'> costalLineLayer->dataProvider()->select(attrListCL);<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-GB style='font-size:9.5pt;font-family:Consolas'> <span style='color:blue'>while</span>(costalLineLayer->dataProvider()->nextFeature(featureCL))<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-GB style='font-size:9.5pt;font-family:Consolas'> {<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-GB style='font-size:9.5pt;font-family:Consolas'> <span style='color:blue'>if</span> (<b>feature</b>.geometry()->intersects(featureCL.geometry()))<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-GB style='font-size:9.5pt;font-family:Consolas'> {<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-GB style='font-size:9.5pt;font-family:Consolas'> QgsGeometry *geom = <b>feature</b>.geometry()->difference(featureCL.geometry());<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-GB style='font-size:9.5pt;font-family:Consolas'> feature.setGeometry(geom); <span style='color:green'>//applying new geometry</span><o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-GB style='font-size:9.5pt;font-family:Consolas'> polygonCoverageAreasLayer->updateFeature(<b>feature</b>); <o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-GB style='font-size:9.5pt;font-family:Consolas'> }<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-GB style='font-size:9.5pt;font-family:Consolas'> }<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-GB style='font-size:9.5pt;font-family:Consolas'> polygonCoverageAreasLayer->commitChanges();<o:p></o:p></span></p><p class=MsoNormal style='text-autospace:none'><span lang=EN-GB style='font-size:9.5pt;font-family:Consolas'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-GB><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-GB>Any clue, for what I am doing wrong?<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-GB><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-GB>Thanks<o:p></o:p></span></p></div></body></html>