Adjacent areas

[davalv@…]

I propose a new functionality.

Suppose that we have 2 overlapping areas (partially or totally), for example landuse=residential the first and landuse=forest the second.
Suppose that I have created a very large residential area and then I want to insert within a forest area.
I am lazy, I don't want to change the residential area. So i draw the forest area on it.
But it is not correct. I should draw them so that they are not overlapping.

So I select the residential area, then the forest area and press a "magic button": the border of the residential area that was affected by the overlap now shares the same nodes of the forest one.

Steps of the new functionality:

• identify which parts of the residential perimeter intersect forest area and deletes them
  
• connect each orphan residential node to the nearest one of forest perimeter
  
• recreate the missing residential perimeter following the forest perimeter and using the same nodes
  

[mdk]

The "ContourMerge" plug-in provides this functionality.

For the above case do the following:

• Mark the two points where forest and residential are crossing each other with active ConturMege tool (if they don't have nodes at these crossings, add them before)
• Both nodes are now marked with a yellow cross
• Grab the way segment you want merge to an other contour. In this case the residential outline overlapped by the forest.
• Drop the way segment on the outer way segment to merge with. In this case the forest outline inside the residential.

ContourMerge helps selecting the source and destination by highlighting the affected way segments in red.

It is not exactly the "magic" function described above, but I don't think we will find good rules to automatically choose which way segment should be merged with which other segment just by selecting the two ways. Also the "matching" of nodes is not longer a problem: The merged way replaces all nodes between the selected nodes with the nodes of the segment dropped on. Only the merged way will be modified.

ContourMerge solves the described kind of problems in a very easy way. Mark two nodes and Drag & Drop a way segment.

[mdk]

Does it make sense to keep this issue open?

There is an existing implementation and nobody (including the author) is interested in this ticket.

[akks]

This would be a nice feature, in the same group as Join areas (core), Split area (Utilsplugin2) and ContourMerge-like plugins.

Nobody touched it only because it will be a real pain for multipolygonal areas (with closed ways, tags on lines etc.)