{ "name": "single_sided_buffer", "type": "function", "description": "Returns a geometry formed by buffering out just one side of a linestring geometry. Distances are in the Spatial Reference System of this geometry.", "arguments": [ {"arg":"geometry","description":"a (multi)linestring geometry"}, {"arg":"distance","description":"buffer distance. Positive values will be buffered to the left of lines, negative values to the right"}, {"arg":"segments","optional":true,"default":"8","description":"number of segments to use to represent a quarter circle when a round join style is used. A larger number results in a smoother buffer with more nodes."}, {"arg":"join","optional":true,"default":"1","description":"join style for corners, where 1 = round, 2 = miter and 3 = bevel"}, {"arg":"miter_limit","optional":true,"default":"2.0","description":"limit on the miter ratio used for very sharp corners (when using miter joins only)"}], "examples": [ { "expression":"single_sided_buffer($geometry, 10.5)", "returns":"line buffered to the left by 10.5 units"}, { "expression":"single_sided_buffer($geometry, -10.5)", "returns":"line buffered to the right by 10.5 units"}, { "expression":"single_sided_buffer($geometry, 10.5, segments=16, join=1)", "returns":"line buffered to the left by 10.5 units, using more segments to result in a smoother buffer"}, { "expression":"single_sided_buffer($geometry, 10.5, join=3)", "returns":"line buffered to the left by 10.5 units, using a beveled join"}] }