bool QgsRasterProjector::destExtentSize( const QgsRectangle &srcExtent, int srcXSize, int srcYSize,
QgsRectangle &destExtent, int &destXSize, int &destYSize )
{
if ( srcExtent.isEmpty() || srcXSize <= 0 || srcYSize <= 0 )
{
return false;
}
QgsCoordinateTransform ct( mSrcCRS, mDestCRS, mSrcDatumTransform, mDestDatumTransform );
return extentSize( ct, srcExtent, srcXSize, srcYSize, destExtent, destXSize, destYSize );
}
bool QgsRasterProjector::destExtentSize( const QgsRectangle& theSrcExtent, int theSrcXSize, int theSrcYSize,
QgsRectangle& theDestExtent, int& theDestXSize, int& theDestYSize )
{
if ( theSrcExtent.isEmpty() || theSrcXSize <= 0 || theSrcYSize <= 0 )
{
return false;
}
const QgsCoordinateTransform* ct = QgsCoordinateTransformCache::instance()->transform( mSrcCRS.authid(), mDestCRS.authid(), mSrcDatumTransform, mDestDatumTransform );
return extentSize( ct, theSrcExtent, theSrcXSize, theSrcYSize, theDestExtent, theDestXSize, theDestYSize );
}
void QgsRasterProjector::calcSrcRowsCols()
{
// Wee need to calculate minimum cell size in the source
// TODO: Think it over better, what is the right source resolution?
// Taking distances between cell centers projected to source along source
// axis would result in very high resolution
// TODO: different resolution for rows and cols ?
double myMinSize = std::numeric_limits<double>::max();
if ( mApproximate )
{
// For now, we take cell sizes projected to source but not to source axes
double myDestColsPerMatrixCell = ( double )mDestCols / mCPCols;
double myDestRowsPerMatrixCell = ( double )mDestRows / mCPRows;
QgsDebugMsg( QString( "myDestColsPerMatrixCell = %1 myDestRowsPerMatrixCell = %2" ).arg( myDestColsPerMatrixCell ).arg( myDestRowsPerMatrixCell ) );
for ( int i = 0; i < mCPRows - 1; i++ )
{
for ( int j = 0; j < mCPCols - 1; j++ )
{
QgsPoint myPointA = mCPMatrix[i][j];
QgsPoint myPointB = mCPMatrix[i][j+1];
QgsPoint myPointC = mCPMatrix[i+1][j];
if ( mCPLegalMatrix[i][j] && mCPLegalMatrix[i][j+1] && mCPLegalMatrix[i+1][j] )
{
double mySize = sqrt( myPointA.sqrDist( myPointB ) ) / myDestColsPerMatrixCell;
if ( mySize < myMinSize )
myMinSize = mySize;
mySize = sqrt( myPointA.sqrDist( myPointC ) ) / myDestRowsPerMatrixCell;
if ( mySize < myMinSize )
myMinSize = mySize;
}
}
}
}
else
{
// take highest from corners, points in in the middle of corners and center (3 x 3 )
const QgsCoordinateTransform* inverseCt = QgsCoordinateTransformCache::instance()->transform( mDestCRS.authid(), mSrcCRS.authid(), mDestDatumTransform, mSrcDatumTransform );
//double
QgsRectangle srcExtent;
int srcXSize, srcYSize;
if ( extentSize( inverseCt, mDestExtent, mDestCols, mDestRows, srcExtent, srcXSize, srcYSize ) )
{
double srcXRes = srcExtent.width() / srcXSize;
double srcYRes = srcExtent.height() / srcYSize;
myMinSize = std::min( srcXRes, srcYRes );
}
else
{
QgsDebugMsg( "Cannot get src extent/size" );
}
}
// Make it a bit higher resolution
// TODO: find the best coefficient, attention, increasing resolution for WMS
// is changing WMS content
myMinSize *= 0.75;
QgsDebugMsg( QString( "mMaxSrcXRes = %1 mMaxSrcYRes = %2" ).arg( mMaxSrcXRes ).arg( mMaxSrcYRes ) );
// mMaxSrcXRes, mMaxSrcYRes may be 0 - no limit (WMS)
double myMinXSize = mMaxSrcXRes > myMinSize ? mMaxSrcXRes : myMinSize;
double myMinYSize = mMaxSrcYRes > myMinSize ? mMaxSrcYRes : myMinSize;
QgsDebugMsg( QString( "myMinXSize = %1 myMinYSize = %2" ).arg( myMinXSize ).arg( myMinYSize ) );
QgsDebugMsg( QString( "mSrcExtent.width = %1 mSrcExtent.height = %2" ).arg( mSrcExtent.width() ).arg( mSrcExtent.height() ) );
// we have to round to keep alignment set in calcSrcExtent
mSrcRows = ( int ) qRound( mSrcExtent.height() / myMinYSize );
mSrcCols = ( int ) qRound( mSrcExtent.width() / myMinXSize );
QgsDebugMsg( QString( "mSrcRows = %1 mSrcCols = %2" ).arg( mSrcRows ).arg( mSrcCols ) );
}