CreateBufferArea

globalmapper.CreateBufferArea(GM_LayerHandle_t32 aFeatureLayer, GM_FeatureClassType_t8 aFeatureClassType, uint32 aFeatureIndex, float aBufferDistance, GM_LayerHandle_t32 aBufferLayer) → GM_Error_t32[source]

Create a buffer area some distance around the specified feature. The parameters specify the existing feature (this can be a point, line, or area feature) that you want to create a buffer around as well as the buffer distance to use. If you want to create a buffer inside an area boundary, use a negative buffer distance. The newly created buffer area(s) will be added to the layer aBufferLayer.

You can use CreateCustomVectorLayer if you want to add these to a new layer. The new buffer areas will be added to the end of the area list for aBufferLayer, so you can use the mNumAreas value in the GM_LayerInfo_t structure for that layer before and after the call to determine how many buffer areas were added and the indices used.

Parameters:

  • aFeatureLayer (GM_LayerHandle_t32) – Layer the feature is in

  • aFeatureClassType (GM_FeatureClassType_t8) – Type of feature class (area, point, line)

  • aFeatureIndex (uint32) – Index of feature in layer

  • aBufferDistance (float) – Distance in meters of buffer to create (use negative values to create a buffer inside an area feature)

  • aBufferLayer (GM_LayerHandle_t32) – Layer to add new buffer area(s) to

Returns:

Error Code

Return type:

GM_Error_t32