Add a +proj=tinshift for triangulation-based transformations

Implements RFC-6

data/Makefile.am

@@ -4,7 +4,8 @@ pkgdata_DATA = proj.ini GL27 nad.lst nad27 nad83 world other.extra \
 		CH \
 		ITRF2000 ITRF2008 ITRF2014 proj.db \
 		projjson.schema.json \
-		deformation_model.schema.json
+		deformation_model.schema.json \
+		triangulation.schema.json
 
 SQL_ORDERED_LIST = sql/begin.sql \
 		sql/proj_db_table_defs.sql \
@@ -45,6 +46,7 @@ EXTRA_DIST = proj.ini GL27 nad.lst nad27 nad83 \
 		ITRF2000 ITRF2008 ITRF2014 \
 		projjson.schema.json \
 		deformation_model.schema.json \
+		triangulation.schema.json \
 		CMakeLists.txt \
 		tests/test_nodata.gtx \
 		tests/test_vgrid_bigendian_bigtiff.tif \
@@ -116,6 +118,9 @@ EXTRA_DIST = proj.ini GL27 nad.lst nad27 nad83 \
 		tests/simple_model_wrap_west.json \
 		tests/simple_model_wrap_west.tif \
 		tests/simple_model_projected.json \
+		tests/tinshift_crs_implicit.json \
+		tests/tinshift_simplified_kkj_etrs.json \
+		tests/tinshift_simplified_n60_n2000.json \
 		generate_all_sql_in.cmake sql_filelist.cmake \
 		$(SQL_ORDERED_LIST)
 

data/tests/tinshift_crs_implicit.json

@@ -0,0 +1,46 @@
+{
+  "file_type": "triangulation_file",
+  "format_version": "1.0",
+  "name": "Name",
+  "version": "Version",
+  "publication_date": "2018-07-01T00:00:00Z",
+  "license": "Creative Commons Attribution 4.0 International",
+  "description": "Test triangulation",
+  "authority": {
+    "name": "Authority name",
+    "url": "http://example.com",
+    "address": "Adress",
+    "email": "test@example.com"
+  },
+  "links": [
+    {
+      "href": "https://example.com/about.html",
+      "rel": "about",
+      "type": "text/html",
+      "title": "About"
+    },
+    {
+      "href": "https://example.com/download",
+      "rel": "source",
+      "type": "application/zip",
+      "title": "Authoritative source"
+    },
+    {
+      "href": "https://creativecommons.org/licenses/by/4.0/",
+      "rel": "license",
+      "type": "text/html",
+      "title": "Creative Commons Attribution 4.0 International license"
+    },
+    {
+      "href": "https://example.com/metadata.xml",
+      "rel": "metadata",
+      "type": "application/xml",
+      "title": " ISO 19115 XML encoded metadata regarding the deformation model"
+    }
+  ],
+  "transformed_components": [ "horizontal" ],
+  "vertices_columns": [ "source_x", "source_y", "target_x", "target_y" ],
+  "triangles_columns": [ "idx_vertex1", "idx_vertex2", "idx_vertex3" ],
+  "vertices": [ [2,49,2.1,49.1], [3,50,3.1,50.1], [2, 50, 2.1,50.1] ],
+  "triangles": [ [0, 1, 2] ]
+}

data/tests/tinshift_simplified_kkj_etrs.json

@@ -0,0 +1,50 @@
+{
+  "file_type": "triangulation_file",
+  "format_version": "1.0",
+  "name": "Name",
+  "version": "Version",
+  "publication_date": "2018-07-01T00:00:00Z",
+  "license": "Creative Commons Attribution 4.0 International",
+  "description": "Test triangulation",
+  "authority": {
+    "name": "Authority name",
+    "url": "http://example.com",
+    "address": "Adress",
+    "email": "test@example.com"
+  },
+  "links": [
+    {
+      "href": "https://example.com/about.html",
+      "rel": "about",
+      "type": "text/html",
+      "title": "About"
+    },
+    {
+      "href": "https://example.com/download",
+      "rel": "source",
+      "type": "application/zip",
+      "title": "Authoritative source"
+    },
+    {
+      "href": "https://creativecommons.org/licenses/by/4.0/",
+      "rel": "license",
+      "type": "text/html",
+      "title": "Creative Commons Attribution 4.0 International license"
+    },
+    {
+      "href": "https://example.com/metadata.xml",
+      "rel": "metadata",
+      "type": "application/xml",
+      "title": " ISO 19115 XML encoded metadata regarding the triangulation"
+    }
+  ],
+  "input_crs": "EPSG:2393",
+  "output_crs": "EPSG:3067",
+  "transformed_components": [ "horizontal" ],
+  "vertices_columns": [ "source_x", "source_y", "target_x", "target_y" ],
+  "triangles_columns": [ "idx_vertex1", "idx_vertex2", "idx_vertex3" ],
+  "vertices": [ [3244102.707, 6693710.937, 244037.137, 6690900.686],
+                [3205290.722, 6715311.822, 205240.895, 6712492.577],
+                [3218328.492, 6649538.429, 218273.648, 6646745.973] ],
+  "triangles": [ [0, 1, 2] ]
+}

data/tests/tinshift_simplified_n60_n2000.json

@@ -0,0 +1,50 @@
+{
+  "file_type": "triangulation_file",
+  "format_version": "1.0",
+  "name": "Name",
+  "version": "Version",
+  "publication_date": "2018-07-01T00:00:00Z",
+  "license": "Creative Commons Attribution 4.0 International",
+  "description": "Test triangulation",
+  "authority": {
+    "name": "Authority name",
+    "url": "http://example.com",
+    "address": "Adress",
+    "email": "test@example.com"
+  },
+  "links": [
+    {
+      "href": "https://example.com/about.html",
+      "rel": "about",
+      "type": "text/html",
+      "title": "About"
+    },
+    {
+      "href": "https://example.com/download",
+      "rel": "source",
+      "type": "application/zip",
+      "title": "Authoritative source"
+    },
+    {
+      "href": "https://creativecommons.org/licenses/by/4.0/",
+      "rel": "license",
+      "type": "text/html",
+      "title": "Creative Commons Attribution 4.0 International license"
+    },
+    {
+      "href": "https://example.com/metadata.xml",
+      "rel": "metadata",
+      "type": "application/xml",
+      "title": " ISO 19115 XML encoded metadata regarding the tirangulation"
+    }
+  ],
+  "input_crs": "EPSG:2393+5717",
+  "output_crs": "EPSG:2393+5941",
+  "transformed_components": [ "vertical" ],
+  "vertices_columns": [ "source_x", "source_y", "source_z", "target_z" ],
+  "triangles_columns": [ "idx_vertex1", "idx_vertex2", "idx_vertex3" ],
+  "vertices": [ [3188607.0, 6688748.0, 23.123, 23.4133],
+                [3184981.0, 6725255.0, 8.044, 8.34499],
+                [3220912.0, 6699508.0, 1.724, 2.0101] ],
+  "triangles": [ [0, 1, 2] ]
+}

data/triangulation.schema.json

@@ -0,0 +1,169 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "description": "Schema for triangulation based transformation",
+  "type": "object",
+  "properties": {
+    "file_type": {
+      "type": "string",
+      "enum": [
+        "triangulation_file"
+      ],
+      "description": "File type. Always \"triangulation_file\""
+    },
+    "format_version": {
+      "type": "string",
+      "enum": [
+        "1.0"
+      ]
+    },
+    "name": {
+      "type": "string",
+      "description": "A brief descriptive name of the triangulation"
+    },
+    "version": {
+      "type": "string",
+      "description": "A string identifying the version of the triangulation. The format for specifying version will be defined by the agency responsible for the triangulation"
+    },
+    "publication_date": {
+      "$ref": "#/definitions/datetime",
+      "description": "The date on which this version of the triangulation was published (or possibly the date on which it takes effect?)"
+    },
+    "license": {
+      "type": "string",
+      "description": "License under which the file is published"
+    },
+    "description": {
+      "type": "string",
+      "description": "A text description of the file"
+    },
+    "authority": {
+      "type": "object",
+      "description": "Basic information about the agency responsible for the data set",
+      "properties": {
+        "name": {
+          "type": "string",
+          "description": "The name of the agency"
+        },
+        "url": {
+          "type": "string",
+          "description": "The url of the agency website",
+          "format": "uri"
+        },
+        "address": {
+          "type": "string",
+          "description": "The postal address of the agency"
+        },
+        "email": {
+          "type": "string",
+          "description": "An email contact address for the agency",
+          "format": "email"
+        }
+      },
+      "required": [
+        "name"
+      ],
+      "additionalProperties": false
+    },
+    "links": {
+      "type": "array",
+      "description": "Links to related information",
+      "items": {
+        "type": "object",
+        "properties": {
+          "href": {
+            "type": "string",
+            "description": "The URL holding the information",
+            "format": "uri"
+          },
+          "rel": {
+            "type": "string",
+            "description": "The relationship to the dataset. Proposed relationships are:\n- \"about\": a web page for human consumption describing the model\n- \"source\": the authoritative source data from which the triangulation is built.\n- \"metadata\": ISO 19115 XML metadata regarding the triangulation."
+          },
+          "type": {
+            "type": "string",
+            "description": "MIME type"
+          },
+          "title": {
+            "type": "string",
+            "description": "Description of the link"
+          }
+        },
+        "required": [
+          "href"
+        ],
+        "additionalProperties": false
+      }
+    },
+    "input_crs": {
+      "$ref": "#/definitions/crs",
+      "description": "String identifying the CRS of source coordinates in the vertices. Typically \"EPSG:XXXX\". If the transformation is for vertical component, this should be the code for a compound CRS (can be EPSG:XXXX+YYYY where XXXX is the code of the horizontal CRS and YYYY the code of the vertical CRS). For example, for the KKJ->ETRS89 transformation, this is EPSG:2393 (\"KKJ / Finland Uniform Coordinate System\"). The input coordinates are assumed to be passed in the \"normalized for visualisation\" / \"GIS friendly\" order, that is longitude, latitude for geographic coordinates and easting, northing for projected coordinates."
+    },
+    "output_crs": {
+      "$ref": "#/definitions/crs",
+      "description": "String identifying the CRS of target coordinates in the vertices. Typically \"EPSG:XXXX\". If the transformation is for vertical component, this should be the code for a compound CRS (can be EPSG:XXXX+YYYY where XXXX is the code of the horizontal CRS and YYYY the code of the vertical CRS). For example, for the KKJ->ETRS89 transformation, this is EPSG:3067 (\"ETRS89 / TM35FIN(E,N)\"). The output coordinates will be returned in the \"normalized for visualisation\" / \"GIS friendly\" order, that is easting, that is longitude, latitude for geographic coordinates and easting, northing for projected coordinates."
+    },
+    "transformed_components": {
+      "type": "array",
+      "description": "Specify which component of the coordinates are transformed. Either \"horizontal\", \"vertical\" or both",
+      "minItems": 1,
+      "maxItems": 2,
+      "items": {
+        "type": "string",
+        "enum": [
+          "horizontal",
+          "vertical"
+        ]
+      }
+    },
+    "vertices_columns": {
+      "type": "array",
+      "description": "Specify the name of the columns of the rows in the \"vertices\" array. There must be exactly as many elements in \"vertices_columns\" as in a row of \"vertices\". The following names have a special meaning: \"source_x\", \"source_y\", \"target_x\", \"target_y\", \"source_z\", \"target_z\" and \"offset_z\".  \"source_x\" and \"source_y\" are compulsory. \"source_x\" is for the source longitude (in degree) or easting. \"source_y\" is for the source latitude (in degree) or northing.  \"target_x\" and \"target_y\" are compulsory when \"horizontal\" is specified in \"transformed_components\". (\"source_z\" and \"target_z\") or \"offset_z\" are compulsory when \"vertical\" is specified in \"transformed_components\".",
+      "minItems": 3,
+      "items": {
+        "type": "string"
+      }
+    },
+    "triangles_columns": {
+      "type": "array",
+      "description": "Specify the name of the columns of the rows in the \"triangles\" array. There must be exactly as many elements in \"triangles_columns\" as in a row of \"triangles\". The following names have a special meaning: \"idx_vertex1\", \"idx_vertex2\", \"idx_vertex3\". They are compulsory.",
+      "minItems": 3,
+      "items": {
+        "type": "string"
+      }
+    },
+    "vertices": {
+      "type": "array",
+      "description": "an array whose items are themselves arrays with as many columns as described in \"vertices_columns\"",
+      "items": {
+        "type": "array"
+      }
+    },
+    "triangles": {
+      "type": "array",
+      "description": "an array whose items are themselves arrays with as many columns as described in \"triangles_columns\". The value of the \"idx_vertexN\" columns must be indices (between 0 and len(\"vertices\"-1) of items of the \"vertices\" array",
+      "items": {
+        "type": "array"
+      }
+    }
+  },
+  "required": [
+    "file_type",
+    "format_version",
+    "transformed_components",
+    "vertices_columns",
+    "triangles_columns",
+    "vertices",
+    "triangles"
+  ],
+  "additionalProperties": false,
+  "definitions": {
+    "crs": {
+      "type": "string"
+    },
+     "datetime": {
+      "type": "string",
+      "format": "date-time",
+      "pattern": "^[0-9]{4}-[0-9]{2}-[0-9]{2}T[0-9]{2}:[0-9]{2}:[0-9]{2}Z$"
+    }
+  }
+}

docs/source/operations/transformations/index.rst

@@ -19,5 +19,6 @@ systems are based on different datums.
    molodensky
    molobadekas
    hgridshift
+   tinshift
    vgridshift
    xyzgridshift