[Backport 6.0] Doc: update quickstart with PROJ 6 API + add PROJ 4->6 migration guide (fixes #1403) (#1450)6.0

[Backport 6.0] Doc: update quickstart with PROJ 6 API + add PROJ 4->6 migration guide (fixes #1403)

1 files changed, 19 insertions, 0 deletions

diff --git a/docs/source/development/reference/functions.rst b/docs/source/development/reference/functions.rst
index 00653ad9..319face3 100644
--- a/docs/source/development/reference/functions.rst
+++ b/docs/source/development/reference/functions.rst
@@ -144,6 +144,25 @@ paragraph for more details.
     :type `area`: PJ_AREA
     :returns: :c:type:`PJ*`
 
+.. c:function:: PJ *proj_normalize_for_visualization(PJ_CONTEXT *ctx, const PJ* obj)
+
+    .. versionadded:: 6.1.0
+
+    Returns a PJ* object whose axis order is the one expected for
+    visualization purposes.
+
+    The input object must be a coordinate operation, that has been created with
+    proj_create_crs_to_crs().
+    If the axis order of its source or target CRS is northing,easting, then an
+    axis swap operation will be inserted.
+
+    The returned :c:type:`PJ`-pointer should be deallocated with :c:func:`proj_destroy`.
+
+    :param PJ_CONTEXT* ctx: Threading context.
+    :param `obj`: Object of type CoordinateOperation
+    :returns: :c:type:`PJ*`
+
+
 .. c:function:: PJ* proj_destroy(PJ *P)
 
     Deallocate a :c:type:`PJ` transformation object.