Add Vector coverage algorithms

Fixes qgis#9082

docs/user_manual/processing_algs/qgis/index.rst

@@ -33,6 +33,7 @@ algorithms.
      rasterterrainanalysis
      rastertools
      vectoranalysis
+     vectorcoverage
      vectorcreation
      vectorgeneral
      vectorgeometry

docs/user_manual/processing_algs/qgis/vectorcoverage.rst

@@ -0,0 +1,228 @@
+Vector coverage
+===============
+
+.. only:: html
+
+   .. contents::
+      :local:
+      :depth: 1
+
+
+.. _qgiscoverageunion:
+
+Dissolve coverage
+-----------------
+
+Operates on a coverage (represented as a set of polygon features with exactly matching edge geometry)
+to dissolve (union) the geometries.
+It provides a heavily optimized approach for unioning these features compared with the standard Dissolve tools.
+
+.. seealso:: :ref:`qgisdissolve`
+
+Parameters
+..........
+
+.. list-table::
+   :header-rows: 1
+   :widths: 20 20 20 40
+
+   * - Label
+     - Name
+     - Type
+     - Description
+   * - **Input layer**
+     - ``INPUT``
+     - [vector: polygon]
+     - Input polygon vector layer
+   * - **Dissolved**
+     - ``OUTPUT``
+     - [vector: polygon]
+
+       Default: ``[Create temporary layer]``
+     - Specify the output vector layer. One of:
+
+       .. include:: ../algs_include.rst
+          :start-after: **layer_output_types**
+          :end-before: **end_layer_output_types**
+
+Outputs
+.......
+
+.. list-table::
+   :header-rows: 1
+   :widths: 20 20 20 40
+
+   * - Label
+     - Name
+     - Type
+     - Description
+   * - **Dissolved**
+     - ``OUTPUT``
+     - [vector: polygon]
+     - The output polygon vector layer with dissolved geometries.
+
+Python code
+...........
+
+**Algorithm ID**: ``native:coverageunion``
+
+.. include:: ../algs_include.rst
+  :start-after: **algorithm_code_section**
+  :end-before: **end_algorithm_code_section**
+
+
+.. _qgiscoveragesimplify:
+
+Simplify coverage
+-----------------
+
+Operates on a coverage (represented as a set of polygon features with exactly matching edge geometry)
+to apply a Visvalingam–Whyatt simplification to the edges, reducing complexity in proportion with the provided tolerance,
+while retaining a valid coverage (i.e. no edges will cross or touch after the simplification).
+Geometries will never be removed, but they may be simplified down to just a triangle.
+Also, some geometries (such as polygons which have too few non-repeated points) will be returned unchanged.
+
+If the input dataset is not a valid coverage due to overlaps, it will still be simplified,
+but invalid topology such as crossing edges will still be invalid.
+
+**Requires version of GEOS >= 3.12**
+
+.. seealso:: :ref:`qgissimplifygeometries`, `qgissmoothgeometry`
+
+Parameters
+..........
+
+.. list-table::
+   :header-rows: 1
+   :widths: 20 20 20 40
+
+   * - Label
+     - Name
+     - Type
+     - Description
+   * - **Input layer**
+     - ``INPUT``
+     - [vector: polygon]
+     - Input polygon vector layer
+   * - **Tolerance**
+     - ``TOLERANCE``
+     - [number]
+
+       Default: 0.0
+     - The maximum distance (in unit of choice) between two consecutive vertices to get merged.
+   * - **Preserve boundary**
+     - ``PRESERVE_BOUNDARY``
+     - [number]
+
+       Default: False
+     - When enabled, the outside edges of the coverage will be preserved without simplification
+   * - **Simplified**
+     - ``OUTPUT``
+     - [vector: polygon]
+
+       Default: ``[Create temporary layer]``
+     - Specify the output vector layer. One of:
+
+       .. include:: ../algs_include.rst
+          :start-after: **layer_output_types**
+          :end-before: **end_layer_output_types**
+
+Outputs
+.......
+
+.. list-table::
+   :header-rows: 1
+   :widths: 20 20 20 40
+
+   * - Label
+     - Name
+     - Type
+     - Description
+   * - **Simplified**
+     - ``OUTPUT``
+     - [vector: polygon]
+     - The output polygon vector layer, with a lower number of vertices.
+
+Python code
+...........
+
+**Algorithm ID**: ``native:coveragesimplify``
+
+.. include:: ../algs_include.rst
+  :start-after: **algorithm_code_section**
+  :end-before: **end_algorithm_code_section**
+
+
+.. _qgiscoveragevalidate:
+
+Validate coverage
+-----------------
+
+Analyzes a coverage (represented as a set of polygon features with exactly matching edge geometry)
+to find places where the assumption of exactly matching edges is not met.
+Invalidity includes polygons that overlap or that have gaps smaller than the specified gap width.
+
+**Requires version of GEOS >= 3.12**
+
+.. seealso:: :ref:`qgischeckvalidity`
+
+Parameters
+..........
+
+.. list-table::
+   :header-rows: 1
+   :widths: 20 20 20 40
+
+   * - Label
+     - Name
+     - Type
+     - Description
+   * - **Input layer**
+     - ``INPUT``
+     - [vector: polygon]
+     - Input polygon vector layer
+   * - **Gap width**
+     - ``GAP_WIDTH``
+     - [number]
+
+       Default: 0.0
+     - The maximum width of gap to detect
+   * - **Invalid edges**
+     - ``INVALID_EDGES``
+     - [vector: line]
+
+       Default: ``[Create temporary layer]``
+     - Specify the output vector layer. One of:
+
+       .. include:: ../algs_include.rst
+          :start-after: **layer_output_types_skip**
+          :end-before: **end_layer_output_types_skip**
+
+Outputs
+.......
+
+.. list-table::
+   :header-rows: 1
+   :widths: 20 20 20 40
+
+   * - Label
+     - Name
+     - Type
+     - Description
+   * - **Invalid edges**
+     - ``OUTPUT``
+     - [vector: line]
+     - The output line vector layer showing error edges for each invalid polygon.
+   * - **Validity result**
+     - ``IS_VALID``
+     - [boolean]
+     - Returns whether the coverage is valid or not.
+
+Python code
+...........
+
+**Algorithm ID**: ``native:coveragevalidate``
+
+.. include:: ../algs_include.rst
+  :start-after: **algorithm_code_section**
+  :end-before: **end_algorithm_code_section**

docs/user_manual/processing_algs/qgis/vectorgeometry.rst

@@ -844,7 +844,7 @@ additional information (number of errors found and types of error):
 **Default menu**: :menuselection:`Vector --> Geometry Tools`
 
 .. seealso:: :ref:`qgisfixgeometries` and the core plugin
-   :ref:`geometry_checker`
+   :ref:`geometry_checker`, :ref:`qgiscoveragevalidate`
 
 Parameters
 ..........
@@ -2134,7 +2134,7 @@ input feature that happens to be processed.
 
 **Default menu**: :menuselection:`Vector --> Geoprocessing Tools`
 
-.. seealso:: :ref:`qgisaggregate`, :ref:`qgiscollect`
+.. seealso:: :ref:`qgiscoverageunion`, :ref:`qgisaggregate`, :ref:`qgiscollect`
 
 Parameters
 ..........
@@ -6159,7 +6159,7 @@ of line and polygon features
 
 **Default menu**: :menuselection:`Vector --> Geometry Tools`
 
-.. seealso:: :ref:`qgissmoothgeometry`, :ref:`qgisdensifygeometries`,
+.. seealso:: :ref:`qgiscoveragesimplify`, :ref:`qgissmoothgeometry`, :ref:`qgisdensifygeometries`,
  :ref:`qgisdensifygeometriesgivenaninterval`
 
 Parameters
@@ -6400,9 +6400,8 @@ this will not be smoothed. For example, setting the maximum angle to
 :ref:`features in-place modification <processing_inplace_edit>`
 of line and polygon features
 
-.. seealso:: :ref:`qgissimplifygeometries`,
-   :ref:`qgisdensifygeometries`,
-   :ref:`qgisdensifygeometriesgivenaninterval`
+.. seealso:: :ref:`qgissimplifygeometries`, :ref:`qgiscoveragesimplify`,
+   :ref:`qgisdensifygeometries`, :ref:`qgisdensifygeometriesgivenaninterval`
 
 Parameters
 ..........