23 lines
941 B
HTML
23 lines
941 B
HTML
---
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layout: example.html
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title: Tracing around a polygon
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shortdesc: Example of setting up a draw interaction to easily snap to an existing feature.
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docs: >
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This example showcases how the draw interaction API can be set up to make snapping along
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an existing geometry easier while preserving topology, which is sometimes called "tracing".
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When the user clicks on two different points on the Idaho state border,
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the part of the border comprised between these two points is added to
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the currently drawn feature.
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This leverages the `appendCoordinates` method of the `ol/interaction/Draw` interaction.
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tags: "draw, trace, snap, vector, topology"
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---
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<div id="map" class="map"></div>
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<form class="form-inline">
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<label for="type">Geometry type </label>
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<select id="type">
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<option value="Polygon">Polygon</option>
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<option value="LineString">LineString</option>
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<option value="None">None</option>
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</select>
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</form>
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