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We can now determine the srsid of a wkt or proj4 string by trawling t…
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…he srs db. Of ourse the srs must exist in the srs db for that to work. Only implemented against system srs db so far....will do users qgis.db searching next.

When createFromWkt or CreateFromProj are called now, all the QgsSpatialRefSys members should be nicely populated if the reverse matching described above succeeds. Tested with baw's nz data and works a treat....but need to get more varied projected shp datasets to test decently.


git-svn-id: http://svn.osgeo.org/qgis/trunk@3420 c8812cc2-4d05-0410-92ff-de0c093fc19c
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timlinux committed May 21, 2005
1 parent 7db5723 commit bc0e258
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Showing 2 changed files with 196 additions and 51 deletions.
214 changes: 171 additions & 43 deletions src/qgsspatialrefsys.cpp
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Expand Up @@ -220,27 +220,27 @@ bool QgsSpatialRefSys::createFromSrid(long theSrid)
int geo = QString ((char *)sqlite3_column_text(myPreparedStatement,7)).toInt();
mGeoFlag = (geo == 0 ? false : true);
setMapUnits();
isValidFlag==true;
mIsValidFlag==true;

}
else
{
#ifdef QGISDEBUG
std::cout << " QgsSpatialRefSys::createFromSrid failed : " << mySql << std::endl;
#endif
isValidFlag==false;
mIsValidFlag==false;
}
sqlite3_finalize(myPreparedStatement);
sqlite3_close(myDatabase);
return isValidFlag;
return mIsValidFlag;
}

bool QgsSpatialRefSys::createFromWkt(QString theWkt)
{
if (!theWkt)
{
std::cout << "QgsSpatialRefSys::createFromWkt -- theWkt is uninitialised, operation failed" << std::endl;
isValidFlag==false;
mIsValidFlag==false;
return false;
}
#ifdef QGISDEBUG
Expand Down Expand Up @@ -271,7 +271,7 @@ bool QgsSpatialRefSys::createFromWkt(QString theWkt)
std::cout << "This SRS could *** NOT *** be set from the supplied WKT " << std::endl;
std::cout << "INPUT: " << std::endl << theWkt << std::endl;
std::cout << "^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^" << std::endl;
isValidFlag==false;
mIsValidFlag==false;
return false;
}

Expand All @@ -286,7 +286,7 @@ bool QgsSpatialRefSys::createFromWkt(QString theWkt)
// that we can try to fill in the remaining class members...
//create from Proj wil set the isValidFalg
createFromProj4(QString(proj4src));
return isValidFlag;
return mIsValidFlag;
//setMapunits will be called by createfromproj above
}

Expand Down Expand Up @@ -346,19 +346,19 @@ bool QgsSpatialRefSys::createFromEpsg(long theEpsg)
int geo = QString ((char *)sqlite3_column_text(myPreparedStatement,7)).toInt();
mGeoFlag = (geo == 0 ? false : true);
setMapUnits();
isValidFlag==true;
mIsValidFlag==true;

}
else
{
#ifdef QGISDEBUG
std::cout << " QgsSpatialRefSys::createFromEpsg failed : " << mySql << std::endl;
#endif
isValidFlag==false;
mIsValidFlag==false;
}
sqlite3_finalize(myPreparedStatement);
sqlite3_close(myDatabase);
return isValidFlag;
return mIsValidFlag;
}


Expand All @@ -379,9 +379,9 @@ bool QgsSpatialRefSys::createFromSrsId (long theSrsId)
myFileInfo.setFile(myDatabaseFileName);
if ( !myFileInfo.exists( ) )
{
isValidFlag==false;
mIsValidFlag==false;
std::cout << " QgsSpatialRefSys::createFromSrid failed : users qgis.db not found" << std::endl;
return isValidFlag;
return mIsValidFlag;
}
}
else //must be a system projection then
Expand Down Expand Up @@ -438,18 +438,18 @@ bool QgsSpatialRefSys::createFromSrsId (long theSrsId)
int geo = QString ((char *)sqlite3_column_text(myPreparedStatement,7)).toInt();
mGeoFlag = (geo == 0 ? false : true);
setMapUnits();
isValidFlag==true;
mIsValidFlag==true;
}
else
{
#ifdef QGISDEBUG
std::cout << " QgsSpatialRefSys::createFromSrsId failed : " << mySql << std::endl;
#endif
isValidFlag==false;
mIsValidFlag==false;
}
sqlite3_finalize(myPreparedStatement);
sqlite3_close(myDatabase);
return isValidFlag;
return mIsValidFlag;
}


Expand Down Expand Up @@ -482,7 +482,7 @@ bool QgsSpatialRefSys::createFromProj4 (const QString theProj4String)
// +proj=tmerc +lat_0=0 +lon_0=-62 +k=0.999500 +x_0=400000 +y_0=0
// +ellps=clrk80 +towgs84=-255,-15,71,0,0,0,0 +units=m +no_defs
//

mIsValidFlag=false;

QRegExp myProjRegExp( "\\+proj=\\S+" );
int myStart= 0;
Expand All @@ -491,8 +491,8 @@ bool QgsSpatialRefSys::createFromProj4 (const QString theProj4String)
if (myStart==-1)
{
std::cout << "QgsSpatialRefSys::createFromProj4 error proj string supplied has no +proj argument" << std::endl;
isValidFlag=false;
return isValidFlag;

return mIsValidFlag;
}
else
{
Expand All @@ -508,42 +508,70 @@ bool QgsSpatialRefSys::createFromProj4 (const QString theProj4String)
if (myStart==-1)
{
std::cout << "QgsSpatialRefSys::createFromProj4 error proj string supplied has no +ellps argument" << std::endl;
isValidFlag=false;
return isValidFlag;

return mIsValidFlag;
}
else
{
myLength = myEllipseRegExp.matchedLength();
}
mEllipsoidAcronym = theProj4String.mid(myStart+ELLPS_PREFIX_LEN,myLength-ELLPS_PREFIX_LEN);
//mproj4string must be set here for the rest of this method to behave in a meaningful way...
mProj4String = theProj4String;

mProj4String = theProj4String;

/*
* We try to match the proj string to and srsid using the following logic:
*
* - perform a whole text search on srs name (if not null). The srs name will
* have been set if this method has been delegated to from createFromWkt.
* Normally we wouldnt expect this to work, but its worth trying first
* as its quicker than methods below..
*/
getRecord("select * from tbl_srs where where parameters='" + mProj4String + "'");
/*
* - if the above does not match perform a whole text search on proj4 string (if not null)
*/
long mySrsId = 0;
QgsSpatialRefSys::RecordMap myRecord = getRecord("select * from tbl_srs where where description='" + mDescription + "'");
if (!myRecord.empty())
{
mySrsId=myRecord["srs_id"].toLong();
std::cout << "QgsSpatialRefSys::createFromProj4 Projection Description match search for srsid returned srsid: " << mySrsId << std::endl;
if (mySrsId > 0)
{
createFromSrsId(mySrsId);
}
}
else
{
/*
* - if the above does not match perform a whole text search on proj4 string (if not null)
*/
std::cout << "QgsSpatialRefSys::createFromProj4 wholetext match on name failed, trying proj4string match" << std::endl;
myRecord = getRecord("select * from tbl_srs where where parameters='" + mProj4String + "'");
if (!myRecord.empty())
{
mySrsId=myRecord["srs_id"].toLong();
std::cout << "QgsSpatialRefSys::createFromProj4 proj4string match search for srsid returned srsid: " << mySrsId << std::endl;
if (mySrsId > 0)
{
createFromSrsId(mySrsId);
}
}

/*
* - if none of the above match convert the proj4 string to an OGR SRS
* then check if its a geocs or a proj cs (using ogr isGeographic)
* then sequentially walk through the database (first users qgis.db srs tbl then
* system srs.db tbl), converting each entry into an ogr srs and using isSame
* or isSameGeocs (essentially calling the == overloaded operator). We'll try to
* be smart about this and first parse out the proj and ellpse strings and only
* check for a match in entities that have the same ellps and proj entries so
* that it doesnt munch yer cpu so much.
*/
else
{
std::cout << "QgsSpatialRefSys::createFromProj4 globbing search for srsid from this proj string" << std::endl;
mySrsId = findMatchingProj();
std::cout << "QgsSpatialRefSys::createFromProj4 globbing search for srsid returned srsid: " << mySrsId << std::endl;
if (mySrsId > 0)
{
createFromSrsId(mySrsId);
}
}
}

setMapUnits();
isValidFlag=true;
return isValidFlag;
/* If its still empty after all the above steps then all we can do is keep the proj string
* with what was passed in and hope for the best...If its not empty we can fill other member details in
from the record*/
return mIsValidFlag;
}

QgsSpatialRefSys::RecordMap QgsSpatialRefSys::getRecord(QString theSql)
Expand All @@ -558,7 +586,7 @@ QgsSpatialRefSys::RecordMap QgsSpatialRefSys::getRecord(QString theSql)
const char *myTail;
sqlite3_stmt *myPreparedStatement;
int myResult;

#ifdef QGISDEBUG
std::cout << " QgsSpatialRefSys::getRecord...running query:\n"<< theSql << "\n" << std::endl;
std::cout << " QgsSpatialRefSys::getRecord...trying system srs.db" << std::endl;
Expand Down Expand Up @@ -624,7 +652,7 @@ QgsSpatialRefSys::RecordMap QgsSpatialRefSys::getRecord(QString theSql)
assert(myResult == 0);
}


myResult = sqlite3_prepare(myDatabase, (const char *)theSql, theSql.length(), &myPreparedStatement, &myTail);
// XXX Need to free memory from the error msg if one is set
if(myResult == SQLITE_OK)
Expand All @@ -650,6 +678,16 @@ QgsSpatialRefSys::RecordMap QgsSpatialRefSys::getRecord(QString theSql)
}
sqlite3_finalize(myPreparedStatement);
sqlite3_close(myDatabase);

#ifdef QGISDEBUG
std::cout << " QgsSpatialRefSys::getRecord retrieved: " << theSql << std::endl;
RecordMap::Iterator it;
for ( it = myMap.begin(); it != myMap.end(); ++it )
{
std::cout << it.key().latin1() << " => " << it.data().latin1() << std::endl;
}
#endif

return myMap;


Expand Down Expand Up @@ -844,11 +882,101 @@ void QgsSpatialRefSys::setMapUnits()
}


/*
* check if srs is a geocs or a proj cs (using ogr isGeographic)
* then sequentially walk through the database (first users qgis.db srs tbl then
* system srs.db tbl), converting each entry into an ogr srs and using isSame
* or isSameGeocs (essentially calling the == overloaded operator). We'll try to
* be smart about this and first parse out the proj and ellpse strings and only
* check for a match in entities that have the same ellps and proj entries so
* that it doesnt munch yer cpu so much.
*/
long QgsSpatialRefSys::findMatchingProj()
{
#ifdef QGISDEBUG
std::cout << "QgsSpatialRefSys::findMatchingProj..." << std::endl;
#endif
if (!mEllipsoidAcronym || ! mProjectionAcronym || ! mProj4String)
{
std::cout << "QgsSpatialRefSys::findMatchingProj will only work if prj acr ellipsoid acr and proj4string are set!..." << std::endl;
return 0;
}

sqlite3 *myDatabase;
char *myErrorMessage = 0;
const char *myTail;
sqlite3_stmt *myPreparedStatement;
int myResult;

// Set up the query to retreive the projection information needed to populate the list
QString mySql = QString ("select srs_id,parameters from tbl_srs where projection_acronym='" +
mProjectionAcronym + "' and ellipsoid_acronym='" + mEllipsoidAcronym + "'");
#ifdef QGISDEBUG
std::cout << "QgsSpatialRefSys::findMatchingProj list sql\n" << mySql << std::endl;
std::cout << " QgsSpatialRefSys::findMatchingProj...trying system srs.db" << std::endl;
#endif
// Get the package data path and set the full path name to the sqlite3 spatial reference
// database.
#if defined(Q_OS_MACX) || defined(WIN32)
QString PKGDATAPATH = qApp->applicationDirPath() + "/share/qgis";
#endif
QString myDatabaseFileName = PKGDATAPATH;
myDatabaseFileName += "/resources/srs.db";


//check the db is available
myResult = sqlite3_open(myDatabaseFileName.latin1(), &myDatabase);
if(myResult)
{
std::cout << "QgsSpatialRefSys::findMatchingProj Can't open database: " << sqlite3_errmsg(myDatabase) << std::endl;
// XXX This will likely never happen since on open, sqlite creates the
// database if it does not exist.
assert(myResult == 0);
}

myResult = sqlite3_prepare(myDatabase, (const char *)mySql, mySql.length(), &myPreparedStatement, &myTail);
// XXX Need to free memory from the error msg if one is set
if(myResult == SQLITE_OK)
{

while(sqlite3_step(myPreparedStatement) == SQLITE_ROW)
{
QString mySrsId = (char *)sqlite3_column_text(myPreparedStatement,0);
QString myProj4String = (char *)sqlite3_column_text(myPreparedStatement, 1);
if (this->equals(myProj4String))
{
std::cout << "QgsSpatialRefSys::findMatchingProj -------> MATCH FOUND srsid: " << mySrsId << std::endl;
// close the sqlite3 statement
sqlite3_finalize(myPreparedStatement);
sqlite3_close(myDatabase);
return mySrsId.toLong();
}
else
{
std::cout << " Not matched : " << myProj4String << std::endl;
}
}
}
std::cout << "QgsSpatialRefSys::findMatchingProj -------> no match found!" << std::endl;
// close the sqlite3 statement
sqlite3_finalize(myPreparedStatement);
sqlite3_close(myDatabase);
return 0;
//XXX TODO Add on users db search here!
}

bool QgsSpatialRefSys::operator==(const QgsSpatialRefSys &theSrs)
{
qWarning("QgsSpatialRefSys::operator== called ");
qWarning("QgsSpatialRefSys::operator==(const QgsSpatialRefSys &theSrs) called ");
//simply delegate to the overloaded == operator below...
return this->equals((char *)theSrs.mProj4String.latin1());

bool myMatchFlag = true; //innocent until proven guilty
}

bool QgsSpatialRefSys::equals(const char *theProj4CharArray)
{
qWarning("QgsSpatialRefSys::operator==(const char *theProj4CharArray) called ");
bool myMatchFlag = false; //guilty until proven innocent

/* Here are the possible OGR error codes :
typedef int OGRErr;
Expand All @@ -865,7 +993,7 @@ bool QgsSpatialRefSys::operator==(const QgsSpatialRefSys &theSrs)
//get the wkt into ogr
//this is really ugly but we need to get a QString to a char**
const char *myCharArrayPointer1 = (char *)mProj4String.latin1();
const char *myCharArrayPointer2 = (char *)theSrs.mProj4String.latin1();

//note that the proj strings above do not neccessarily need to be exactly the
//same for the projections they define to be equivalent, which is why I dont just
//compare the proj parameter strings and return the result
Expand All @@ -875,7 +1003,7 @@ bool QgsSpatialRefSys::operator==(const QgsSpatialRefSys &theSrs)
OGRSpatialReference myOgrSpatialRef1;
OGRSpatialReference myOgrSpatialRef2;
OGRErr myInputResult1 = myOgrSpatialRef1.importFromProj4( myCharArrayPointer1 );
OGRErr myInputResult2 = myOgrSpatialRef2.importFromProj4( myCharArrayPointer2 );
OGRErr myInputResult2 = myOgrSpatialRef2.importFromProj4( theProj4CharArray );

if (myOgrSpatialRef1.IsGeographic())
{
Expand Down

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