Merge pull request #1764 from rouault/updates_in_resource_files

Doc: resource_files.rst updates

1 files changed, 26 insertions, 4 deletions

diff --git a/docs/source/resource_files.rst b/docs/source/resource_files.rst
index 40eb9731..13b9386d 100644
--- a/docs/source/resource_files.rst
+++ b/docs/source/resource_files.rst
@@ -14,6 +14,32 @@ In addition to the bundled init-files the PROJ project also distributes a number
 of packages containing transformation grids and additional init-files not included
 in the main PROJ package.
 
+Where are PROJ resource files looked for ?
+-------------------------------------------------------------------------------
+
+PROJ will attempt to locate its resource files - database, transformation grids
+or init-files - from several dictionaries.
+The following paths are checked in order:
+
+- For transformation grids that have an explict relative or absolute path,
+  the directory specified in the grid filename.
+- Path resolved by the callback function set with
+  the :c:func:`proj_context_set_file_finder`. If it is set, the next tests
+  will not be run.
+- Path(s) set with the :c:func:`proj_context_set_search_paths`. If set, the
+  next tests will not be run.
+- Path(s) set with by the environment variable :envvar:`PROJ_LIB`.
+  On Linux/MacOSX/Unix, use ``:`` to separate paths. On Windows, ``;``
+- On Windows, the *..\\share\\proj\\* and its contents are found automatically
+  at run-time if the installation respects the build structure. That is, the
+  binaries and proj.dll are installed under *..\\bin\\*, and resource files
+  are in *..\\share\\proj\\*.
+- A path built into PROJ as its resource installation directory (whose value is
+  $(pkgdatadir)), for builds using the Makefile build system. Note, however,
+  that since this is a hard-wired path setting, it only works if the whole
+  PROJ installation is not moved somewhere else.
+- The current directory
+
 .. _proj-db:
 
 proj.db
@@ -363,11 +389,7 @@ Below is a list of the init files that are packaged with PROJ.
     ========    ================================================================
     Name        Description
     ========    ================================================================
-    esri        Auto-generated mapping from Esri projection index. Not
-                maintained any more
-    epsg        EPSG database
     GL27        Great Lakes Grids
-    IGNF        French coordinate systems supplied by the IGNF
     ITRF2000    Full set of transformation parameters between ITRF2000 and other
                 ITRF's
     ITRF2008    Full set of transformation parameters between ITRF2008 and other