From 5141b3908e59a26c9fe66de94bb7388bff741b58 Mon Sep 17 00:00:00 2001 From: Kristian Evers Date: Mon, 11 Feb 2019 23:58:16 +0100 Subject: Make tmerc an alias for etmerc. (#1234) * Make tmerc an alias for etmerc This switches the algorithm used in tmerc to the Poder/Engsager tmerc algorithm. The original tmerc algorithm of Evenden/Snyder origin can still be accessed by adding the +approx flag when initializing a tmerc projection. The +approx flag can also be used when initializing UTM projections, in which case the Evenden/Snyder algorithm is used as well. If a tmerc projection is instantiated on a spherical earth the Evenden/Snyder algorithm is used as well since the Poder/Engsager algorithm is only defined on the ellipsoid. +proj=etmerc can still be instantiated for backwards compatibility reasons. Co-authored-by: Kristian Evers Co-authored-by: Even Rouault --- test/unit/test_io.cpp | 31 +++++++++++++++++++++++++++++-- 1 file changed, 29 insertions(+), 2 deletions(-) (limited to 'test/unit/test_io.cpp') diff --git a/test/unit/test_io.cpp b/test/unit/test_io.cpp index 69ef9073..3cb50352 100644 --- a/test/unit/test_io.cpp +++ b/test/unit/test_io.cpp @@ -7654,12 +7654,39 @@ TEST(io, projparse_etmerc) { crs->exportToPROJString( PROJStringFormatter::create(PROJStringFormatter::Convention::PROJ_4) .get()), - "+proj=etmerc +lat_0=0 +lon_0=0 +k=1 +x_0=0 +y_0=0 " + "+proj=tmerc +lat_0=0 +lon_0=0 +k=1 +x_0=0 +y_0=0 " "+datum=WGS84 +units=m +no_defs +type=crs"); auto wkt1 = crs->exportToWKT( WKTFormatter::create(WKTFormatter::Convention::WKT1_GDAL).get()); - EXPECT_TRUE(wkt1.find("EXTENSION[\"PROJ4\",\"+proj=etmerc +lat_0=0 " + EXPECT_TRUE(wkt1.find("EXTENSION[\"PROJ4\"") == std::string::npos) + << wkt1; +} + +// --------------------------------------------------------------------------- + +TEST(io, projparse_tmerc_approx) { + auto obj = + PROJStringParser().createFromPROJString("+proj=tmerc +approx +type=crs"); + auto crs = nn_dynamic_pointer_cast(obj); + ASSERT_TRUE(crs != nullptr); + auto wkt2 = crs->exportToWKT( + &WKTFormatter::create()->simulCurNodeHasId().setMultiLine(false)); + EXPECT_TRUE( + wkt2.find("METHOD[\"Transverse Mercator\",ID[\"EPSG\",9807]]") != + std::string::npos) + << wkt2; + + EXPECT_EQ( + crs->exportToPROJString( + PROJStringFormatter::create(PROJStringFormatter::Convention::PROJ_4) + .get()), + "+proj=tmerc +approx +lat_0=0 +lon_0=0 +k=1 +x_0=0 +y_0=0 " + "+datum=WGS84 +units=m +no_defs +type=crs"); + + auto wkt1 = crs->exportToWKT( + WKTFormatter::create(WKTFormatter::Convention::WKT1_GDAL).get()); + EXPECT_TRUE(wkt1.find("EXTENSION[\"PROJ4\",\"+proj=tmerc +approx +lat_0=0 " "+lon_0=0 +k=1 +x_0=0 +y_0=0 +datum=WGS84 +units=m " "+no_defs\"]") != std::string::npos) << wkt1; -- cgit v1.2.3