Hello everyone,
I have a question about the GDAL Warp API and the gdalwarp utility.
I have added a new projection to PROJ4 (ticket #179), and would like
to use it with GDAL Warp.
For this purpose, I use the string
"+proj=qsc +a=6378137.0 +b=6356752.314245 +lat_0=90 +lon_0=0 +units=m"
as an argument to the -t_srs option of gdalwarp, and also to
OGRSpatialReference::importFromProj4() for passing the result to the
Warp API.
However, this requires explicit support for the projection not just in
PROJ4, but also in GDAL. I currently use the attached patch to add
that support, but is there a way to avoid patching GDAL for this
purpose?
Best regards,
Martin
>From 6fa1411d314bb966ddaede09339921318db6a948 Mon Sep 17 00:00:00 2001
From: Martin Lambers <[email protected]>
Date: Thu, 15 Dec 2011 11:05:13 +0100
Subject: [PATCH 2/2] Add the Quadrilateralized Spherical Cube (QSC)
projection.
---
ogr/ogr_opt.cpp | 6 ++++++
ogr/ogr_spatialref.h | 3 +++
ogr/ogr_srs_api.h | 6 ++++++
ogr/ogr_srs_proj4.cpp | 14 ++++++++++++++
ogr/ogr_srs_validate.cpp | 6 ++++++
ogr/ogrspatialreference.cpp | 28 ++++++++++++++++++++++++++++
6 files changed, 63 insertions(+)
diff --git a/ogr/ogr_opt.cpp b/ogr/ogr_opt.cpp
index 456493f..848261e 100644
--- a/ogr/ogr_opt.cpp
+++ b/ogr/ogr_opt.cpp
@@ -475,6 +475,12 @@ static const char *papszProjectionDefinitions[] = {
SRS_PP_FALSE_EASTING,
SRS_PP_FALSE_NORTHING,
+ "*",
+ SRS_PT_QSC,
+ "Quadrilateralized Spherical Cube",
+ SRS_PP_LATITUDE_OF_ORIGIN,
+ SRS_PP_CENTRAL_MERIDIAN,
+
NULL
};
diff --git a/ogr/ogr_spatialref.h b/ogr/ogr_spatialref.h
index c14dcec..8c550c5 100644
--- a/ogr/ogr_spatialref.h
+++ b/ogr/ogr_spatialref.h
@@ -536,6 +536,9 @@ class CPL_DLL OGRSpatialReference
OGRErr SetWagner( int nVariation, double dfCenterLat,
double dfFalseEasting, double dfFalseNorthing );
+ /** Quadrilateralized Spherical Cube */
+ OGRErr SetQSC(double dfCenterLat, double dfCenterLong);
+
/** State Plane */
OGRErr SetStatePlane( int nZone, int bNAD83 = TRUE,
const char *pszOverrideUnitName = NULL,
diff --git a/ogr/ogr_srs_api.h b/ogr/ogr_srs_api.h
index 27d8298..82d09f7 100644
--- a/ogr/ogr_srs_api.h
+++ b/ogr/ogr_srs_api.h
@@ -183,6 +183,7 @@ typedef enum {
#define SRS_PT_WAGNER_V "Wagner_V"
#define SRS_PT_WAGNER_VI "Wagner_VI"
#define SRS_PT_WAGNER_VII "Wagner_VII"
+#define SRS_PT_QSC "Quadrilateralized Spherical Cube"
#define SRS_PP_CENTRAL_MERIDIAN "central_meridian"
@@ -665,6 +666,11 @@ OGRErr CPL_DLL OSRSetWagner( OGRSpatialReferenceH hSRS, int nVariation,
double dfFalseEasting,
double dfFalseNorthing );
+/** Quadrilateralized Spherical Cube */
+OGRErr CPL_DLL OSRSetQSC( OGRSpatialReferenceH hSRS,
+ double dfCenterLat, double dfCenterLong );
+
+
void CPL_DLL OSRCleanup( void );
/* -------------------------------------------------------------------- */
diff --git a/ogr/ogr_srs_proj4.cpp b/ogr/ogr_srs_proj4.cpp
index 823e4f4..b86d323 100644
--- a/ogr/ogr_srs_proj4.cpp
+++ b/ogr/ogr_srs_proj4.cpp
@@ -867,6 +867,12 @@ OGRErr OGRSpatialReference::importFromProj4( const char * pszProj4 )
OSR_GDV( papszNV, "y_0", 0.0 ) );
}
+ else if( EQUAL(pszProj,"qsc") )
+ {
+ SetQSC( OSR_GDV( papszNV, "lat_0", 0.0 ),
+ OSR_GDV( papszNV, "lon_0", 0.0 ) );
+ }
+
else if( EQUAL(pszProj,"tpeqd") )
{
SetTPED( OSR_GDV( papszNV, "lat_1", 0.0 ),
@@ -2020,6 +2026,14 @@ OGRErr OGRSpatialReference::exportToProj4( char ** ppszProj4 ) const
GetNormProjParm(SRS_PP_FALSE_NORTHING, 0.0) );
}
+ else if( EQUAL(pszProjection,SRS_PT_QSC) )
+ {
+ sprintf( szProj4+strlen(szProj4),
+ "+proj=qsc +lat_0=%.16g +lon_0=%.16g ",
+ GetNormProjParm(SRS_PP_LATITUDE_OF_ORIGIN,0.0),
+ GetNormProjParm(SRS_PP_CENTRAL_MERIDIAN,0.0) );
+ }
+
/* Note: This never really gets used currently. See bug 423 */
else if( EQUAL(pszProjection,SRS_PT_SWISS_OBLIQUE_CYLINDRICAL) )
{
diff --git a/ogr/ogr_srs_validate.cpp b/ogr/ogr_srs_validate.cpp
index 397c4ed..d6dd960 100644
--- a/ogr/ogr_srs_validate.cpp
+++ b/ogr/ogr_srs_validate.cpp
@@ -126,6 +126,7 @@ static const char *papszProjectionSupported[] =
SRS_PT_WAGNER_V,
SRS_PT_WAGNER_VI,
SRS_PT_WAGNER_VII,
+ SRS_PT_QSC,
SRS_PT_GAUSSSCHREIBERTMERCATOR,
SRS_PT_KROVAK,
SRS_PT_CYLINDRICAL_EQUAL_AREA,
@@ -512,6 +513,11 @@ static const char *papszProjWithParms[] = {
SRS_PP_FALSE_NORTHING,
NULL,
+ SRS_PT_QSC,
+ SRS_PP_LATITUDE_OF_ORIGIN,
+ SRS_PP_CENTRAL_MERIDIAN,
+ NULL,
+
SRS_PT_GAUSSSCHREIBERTMERCATOR,
SRS_PP_LATITUDE_OF_ORIGIN,
SRS_PP_CENTRAL_MERIDIAN,
diff --git a/ogr/ogrspatialreference.cpp b/ogr/ogrspatialreference.cpp
index e2443a9..1cfb280 100644
--- a/ogr/ogrspatialreference.cpp
+++ b/ogr/ogrspatialreference.cpp
@@ -5570,6 +5570,34 @@ OGRErr OSRSetWagner( OGRSpatialReferenceH hSRS,
}
/************************************************************************/
+/* SetQSC() */
+/************************************************************************/
+
+OGRErr OGRSpatialReference::SetQSC( double dfCenterLat, double dfCenterLong )
+
+{
+ SetProjection( SRS_PT_QSC );
+ SetNormProjParm( SRS_PP_LATITUDE_OF_ORIGIN, dfCenterLat );
+ SetNormProjParm( SRS_PP_CENTRAL_MERIDIAN, dfCenterLong );
+
+ return OGRERR_NONE;
+}
+
+/************************************************************************/
+/* OSRSetQSC() */
+/************************************************************************/
+
+OGRErr OSRSetQSC( OGRSpatialReferenceH hSRS,
+ double dfCenterLat, double dfCenterLong )
+
+{
+ VALIDATE_POINTER1( hSRS, "OSRSetQSC", CE_Failure );
+
+ return ((OGRSpatialReference *) hSRS)->SetQSC(
+ dfCenterLat, dfCenterLong );
+}
+
+/************************************************************************/
/* SetAuthority() */
/************************************************************************/
--
1.7.9.5
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