Algorithm hit list

• Rotate (expose from qgis API, optional point for centre)
• Extrude (expose from qgis API) (QgsGeometry::extrude is not robust, and breaks for simple cases)
• Segmentize (expose from qgis API, one alg for each mode)
• Line to curve (desegmentize - port from postgis) (IN PROGRESS)
• sample raster at points
• drape raster to z/m
• variable width buffer/tapered buffer
• alpha shapes
• point cluster (e.g. dbscan from turf/mapbox)
• photos to points (extracts geotag from photo, creates point layer)

Missing algs from geos:

• GEOSMinimumWidth_r (returns a LINESTRING geometry which represents the minimum diameter of the geometry. The minimum diameter is defined to be the width of the smallest band that contains the geometry, where a band is a strip of the plane defined by two parallel lines. This can be thought of as the smallest hole that the geometry can be moved through, with a single rotation.
• GEOSMinimumClearanceLine_r
• GEOSNode_r
• GEOSSharedPaths_r

Missing algs from PostGIS:

• Geometry from GeoJSON/WKT/geohash/gml etc
• ST_ForcePolygonCCW — Orients all exterior rings counter-clockwise and all interior rings clockwise.
• ST_ForcePolygonCW — Orients all exterior rings clockwise and all interior rings counter-clockwise.
• ST_Scale — Scale a geometry by given factors.
• ST_FlipCoordinates — Returns a version of the given geometry with X and Y axis flipped. Useful for people who have built latitude/longitude features and need to fix them.
• ST_ShiftLongitude — Toggle geometry coordinates between -180..180 and 0..360 ranges.
• ST_WrapX — Wrap a geometry around an X value.
• ST_SwapOrdinates — Returns a version of the given geometry with given ordinate values swapped.

Missing VECTOR algs from SAGA: TODO

Missing VECTOR algs from gvsig: TODO

Missing VECTOR algs from turf/mapbox: TODO

Tricky stuff in qgis

• linear referencing (single point per feature??? How to handle linework?)
• nearest- type joins. E.g. line to nearest feature
• Handling multi-geometry operations. E.g. hausdorff distance, de-9im relate, etc