From 5f6fac3afdb03aef5a26ce5f60c10ed612fa6fc2 Mon Sep 17 00:00:00 2001 From: Even Rouault Date: Thu, 17 Jun 2021 17:53:11 +0200 Subject: proj_trans/cs2cs: If two operations have the same accuracy, use the one that is contained within a larger one Relates to https://github.com/OSGeo/gdal/issues/3998 Before that change, cs2cs on a NAD83(HARN) to WGS84 transformation would use the "NAD83(HARN) to WGS 84 (1)" transformation (a null Helmert shift) that is valid for whole US, including non-CONUS areas, even when used on points located on CONUS that has a "NAD83(HARN) to WGS 84 (3)" transformation (non-null Helmert shift) with same accuracy (1m). But if doing EPSG:2874 "NAD83(HARN) / California zone 5 (ftUS)" to WGS84, we would use this later "NAD83(HARN) to WGS 84 (3)" transformation because the area of use of EPSG:2874 restricts to CONUS. This isn't consistant. With that change, we now have more consistent behavior, even if it can be argued which of the 2 transformations is the best... $ echo 34 -120 | src/cs2cs -d 8 EPSG:4326 "NAD83(HARN)" | src/cs2cs "NAD83(HARN)" EPSG:2874 5955507.74 1828410.98 0.00 $ echo 34 -120 | src/cs2cs EPSG:4326 EPSG:2874 5955507.74 1828410.98 0.00 --- src/4D_api.cpp | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'src/4D_api.cpp') diff --git a/src/4D_api.cpp b/src/4D_api.cpp index 8b676f9b..95582e48 100644 --- a/src/4D_api.cpp +++ b/src/4D_api.cpp @@ -243,7 +243,15 @@ int pj_get_suggested_operation(PJ_CONTEXT*, // onshore. So in a general way, prefer a onshore area to a // offshore one. if( iBest < 0 || - (alt.accuracy >= 0 && alt.accuracy < bestAccuracy && + (alt.accuracy >= 0 && + (alt.accuracy < bestAccuracy || + // If two operations have the same accuracy, use the one that + // is contained within a larger one + (alt.accuracy == bestAccuracy && + alt.minxSrc > opList[iBest].minxSrc && + alt.minySrc > opList[iBest].minySrc && + alt.maxxSrc < opList[iBest].maxxSrc && + alt.maxySrc < opList[iBest].maxySrc)) && !alt.isOffshore) ) { iBest = i; bestAccuracy = alt.accuracy; -- cgit v1.2.3