void ProjectorData::calcHelper( int matrixRow, QgsPointXY *points )
{
// TODO?: should we also precalc dest cell center coordinates for x and y?
for ( int myDestCol = 0; myDestCol < mDestCols; myDestCol++ )
{
double myDestX = mDestExtent.xMinimum() + ( myDestCol + 0.5 ) * mDestXRes;
int myMatrixCol = matrixCol( myDestCol );
double myDestXMin, myDestYMin, myDestXMax, myDestYMax;
destPointOnCPMatrix( matrixRow, myMatrixCol, &myDestXMin, &myDestYMin );
destPointOnCPMatrix( matrixRow, myMatrixCol + 1, &myDestXMax, &myDestYMax );
double xfrac = ( myDestX - myDestXMin ) / ( myDestXMax - myDestXMin );
QgsPointXY &mySrcPoint0 = mCPMatrix[matrixRow][myMatrixCol];
QgsPointXY &mySrcPoint1 = mCPMatrix[matrixRow][myMatrixCol + 1];
double s = mySrcPoint0.x() + ( mySrcPoint1.x() - mySrcPoint0.x() ) * xfrac;
double t = mySrcPoint0.y() + ( mySrcPoint1.y() - mySrcPoint0.y() ) * xfrac;
points[myDestCol].setX( s );
points[myDestCol].setY( t );
}
}
bool ProjectorData::approximateSrcRowCol( int destRow, int destCol, int *srcRow, int *srcCol )
{
int myMatrixRow = matrixRow( destRow );
int myMatrixCol = matrixCol( destCol );
if ( myMatrixRow > mHelperTopRow )
{
// TODO: make it more robust (for random, not sequential reading)
nextHelper();
}
double myDestY = mDestExtent.yMaximum() - ( destRow + 0.5 ) * mDestYRes;
// See the schema in javax.media.jai.WarpGrid doc (but up side down)
// TODO: use some kind of cache of values which can be reused
double myDestXMin, myDestYMin, myDestXMax, myDestYMax;
destPointOnCPMatrix( myMatrixRow + 1, myMatrixCol, &myDestXMin, &myDestYMin );
destPointOnCPMatrix( myMatrixRow, myMatrixCol + 1, &myDestXMax, &myDestYMax );
double yfrac = ( myDestY - myDestYMin ) / ( myDestYMax - myDestYMin );
QgsPointXY &myTop = pHelperTop[destCol];
QgsPointXY &myBot = pHelperBottom[destCol];
// Warning: this is very SLOW compared to the following code!:
//double mySrcX = myBot.x() + (myTop.x() - myBot.x()) * yfrac;
//double mySrcY = myBot.y() + (myTop.y() - myBot.y()) * yfrac;
double tx = myTop.x();
double ty = myTop.y();
double bx = myBot.x();
double by = myBot.y();
double mySrcX = bx + ( tx - bx ) * yfrac;
double mySrcY = by + ( ty - by ) * yfrac;
if ( !mExtent.contains( QgsPointXY( mySrcX, mySrcY ) ) )
{
return false;
}
// TODO: check again cell selection (coor is in the middle)
*srcRow = static_cast< int >( std::floor( ( mSrcExtent.yMaximum() - mySrcY ) / mSrcYRes ) );
*srcCol = static_cast< int >( std::floor( ( mySrcX - mSrcExtent.xMinimum() ) / mSrcXRes ) );
// For now silently correct limits to avoid crashes
// TODO: review
// should not happen
if ( *srcRow >= mSrcRows ) return false;
if ( *srcRow < 0 ) return false;
if ( *srcCol >= mSrcCols ) return false;
if ( *srcCol < 0 ) return false;
return true;
}
void QgsRasterProjector::approximateSrcRowCol( int theDestRow, int theDestCol, int *theSrcRow, int *theSrcCol )
{
int myMatrixRow = matrixRow( theDestRow );
int myMatrixCol = matrixCol( theDestCol );
if ( myMatrixRow > mHelperTopRow )
{
// TODO: make it more robust (for random, not sequential reading)
nextHelper();
}
double myDestY = mDestExtent.yMaximum() - ( theDestRow + 0.5 ) * mDestYRes;
// See the schema in javax.media.jai.WarpGrid doc (but up side down)
// TODO: use some kind of cache of values which can be reused
double myDestXMin, myDestYMin, myDestXMax, myDestYMax;
destPointOnCPMatrix( myMatrixRow + 1, myMatrixCol, &myDestXMin, &myDestYMin );
destPointOnCPMatrix( myMatrixRow, myMatrixCol + 1, &myDestXMax, &myDestYMax );
double yfrac = ( myDestY - myDestYMin ) / ( myDestYMax - myDestYMin );
QgsPoint &myTop = pHelperTop[theDestCol];
QgsPoint &myBot = pHelperBottom[theDestCol];
// Warning: this is very SLOW compared to the following code!:
//double mySrcX = myBot.x() + (myTop.x() - myBot.x()) * yfrac;
//double mySrcY = myBot.y() + (myTop.y() - myBot.y()) * yfrac;
double tx = myTop.x();
double ty = myTop.y();
double bx = myBot.x();
double by = myBot.y();
double mySrcX = bx + ( tx - bx ) * yfrac;
double mySrcY = by + ( ty - by ) * yfrac;
// TODO: check again cell selection (coor is in the middle)
*theSrcRow = ( int ) floor(( mSrcExtent.yMaximum() - mySrcY ) / mSrcYRes );
*theSrcCol = ( int ) floor(( mySrcX - mSrcExtent.xMinimum() ) / mSrcXRes );
// For now silently correct limits to avoid crashes
// TODO: review
if ( *theSrcRow >= mSrcRows )
*theSrcRow = mSrcRows - 1;
if ( *theSrcRow < 0 )
*theSrcRow = 0;
if ( *theSrcCol >= mSrcCols )
*theSrcCol = mSrcCols - 1;
if ( *theSrcCol < 0 )
*theSrcCol = 0;
Q_ASSERT( *theSrcRow < mSrcRows );
Q_ASSERT( *theSrcCol < mSrcCols );
}
