Fix incorrect raster reprojection after drawing raster previews

Moved all temporary projector members to a private class,
so even recursive block() calls will not affect each other
(there is no new performance penalty as block() call always
recomputes the temporary control point matrix anyway)

Author: wonder-sk

python/core/raster/qgsrasterprojector.sip

@@ -43,9 +43,6 @@ class QgsRasterProjector : QgsRasterInterface
     /** \brief Get destination CRS */
     QgsCoordinateReferenceSystem destinationCrs() const;
 
-    /** \brief set maximum source resolution */
-    void setMaxSrcRes( double theMaxSrcXRes, double theMaxSrcYRes );
-
     Precision precision() const;
     void setPrecision( Precision precision );
     // Translated precision mode, for use in ComboBox etc.

src/core/raster/qgsrasterprojector.cpp

@@ -24,31 +24,11 @@
 #include "qgscsexception.h"
 
 
-
 QgsRasterProjector::QgsRasterProjector()
     : QgsRasterInterface( nullptr )
     , mSrcDatumTransform( -1 )
     , mDestDatumTransform( -1 )
     , mPrecision( Approximate )
-    , mApproximate( false )
-    , mDestRows( 0 )
-    , mDestCols( 0 )
-    , mDestXRes( 0.0 )
-    , mDestYRes( 0.0 )
-    , mSrcRows( 0 )
-    , mSrcCols( 0 )
-    , mSrcXRes( 0.0 )
-    , mSrcYRes( 0.0 )
-    , mDestRowsPerMatrixRow( 0.0 )
-    , mDestColsPerMatrixCol( 0.0 )
-    , pHelperTop( nullptr )
-    , pHelperBottom( nullptr )
-    , mHelperTopRow( 0 )
-    , mCPCols( 0 )
-    , mCPRows( 0 )
-    , mSqrTolerance( 0.0 )
-    , mMaxSrcXRes( 0 )
-    , mMaxSrcYRes( 0 )
 {
   QgsDebugMsgLevel( "Entered", 4 );
 }
@@ -62,17 +42,12 @@ QgsRasterProjector* QgsRasterProjector::clone() const
   projector->mDestCRS = mDestCRS;
   projector->mSrcDatumTransform = mSrcDatumTransform;
   projector->mDestDatumTransform = mDestDatumTransform;
-  projector->mMaxSrcXRes = mMaxSrcXRes;
-  projector->mMaxSrcYRes = mMaxSrcYRes;
-  projector->mExtent = mExtent;
   projector->mPrecision = mPrecision;
   return projector;
 }
 
 QgsRasterProjector::~QgsRasterProjector()
 {
-  delete[] pHelperTop;
-  delete[] pHelperBottom;
 }
 
 int QgsRasterProjector::bandCount() const
@@ -97,22 +72,36 @@ void QgsRasterProjector::setCrs( const QgsCoordinateReferenceSystem & theSrcCRS,
   mDestDatumTransform = destDatumTransform;
 }
 
-void QgsRasterProjector::calc()
+
+ProjectorData::ProjectorData( const QgsRectangle& extent, int width, int height, QgsRasterInterface* input, const QgsCoordinateTransform& inverseCt, QgsRasterProjector::Precision precision )
+    : mApproximate( false )
+    , mInverseCt( new QgsCoordinateTransform( inverseCt ) )
+    , mDestExtent( extent )
+    , mDestRows( height )
+    , mDestCols( width )
+    , mDestXRes( 0.0 )
+    , mDestYRes( 0.0 )
+    , mSrcRows( 0 )
+    , mSrcCols( 0 )
+    , mSrcXRes( 0.0 )
+    , mSrcYRes( 0.0 )
+    , mDestRowsPerMatrixRow( 0.0 )
+    , mDestColsPerMatrixCol( 0.0 )
+    , pHelperTop( nullptr )
+    , pHelperBottom( nullptr )
+    , mHelperTopRow( 0 )
+    , mCPCols( 0 )
+    , mCPRows( 0 )
+    , mSqrTolerance( 0.0 )
+    , mMaxSrcXRes( 0 )
+    , mMaxSrcYRes( 0 )
 {
   QgsDebugMsgLevel( "Entered", 4 );
-  mCPMatrix.clear();
-  mCPLegalMatrix.clear();
-  delete[] pHelperTop;
-  pHelperTop = nullptr;
-  delete[] pHelperBottom;
-  pHelperBottom = nullptr;
 
   // Get max source resolution and extent if possible
-  mMaxSrcXRes = 0;
-  mMaxSrcYRes = 0;
-  if ( mInput )
+  if ( input )
   {
-    QgsRasterDataProvider *provider = dynamic_cast<QgsRasterDataProvider*>( mInput->sourceInput() );
+    QgsRasterDataProvider *provider = dynamic_cast<QgsRasterDataProvider*>( input->sourceInput() );
     if ( provider )
     {
       if ( provider->capabilities() & QgsRasterDataProvider::Size )
@@ -138,9 +127,7 @@ void QgsRasterProjector::calc()
   double myDestRes = mDestXRes < mDestYRes ? mDestXRes : mDestYRes;
   mSqrTolerance = myDestRes * myDestRes;
 
-  QgsCoordinateTransform inverseCt = QgsCoordinateTransformCache::instance()->transform( mDestCRS.authid(), mSrcCRS.authid(), mDestDatumTransform, mSrcDatumTransform );
-
-  if ( mPrecision == Approximate )
+  if ( precision == QgsRasterProjector::Approximate )
   {
     mApproximate = true;
   }
@@ -219,7 +206,15 @@ void QgsRasterProjector::calc()
   mSrcXRes = mSrcExtent.width() / mSrcCols;
 }
 
-void QgsRasterProjector::calcSrcExtent()
+ProjectorData::~ProjectorData()
+{
+  delete[] pHelperTop;
+  delete[] pHelperBottom;
+  delete mInverseCt;
+}
+
+
+void ProjectorData::calcSrcExtent()
 {
   /* Run around the mCPMatrix and find source extent */
   // Attention, source limits are not necessarily on destination edges, e.g.
@@ -283,7 +278,7 @@ void QgsRasterProjector::calcSrcExtent()
   QgsDebugMsgLevel( "mSrcExtent = " + mSrcExtent.toString(), 4 );
 }
 
-QString QgsRasterProjector::cpToString()
+QString ProjectorData::cpToString()
 {
   QString myString;
   for ( int i = 0; i < mCPRows; i++ )
@@ -308,7 +303,7 @@ QString QgsRasterProjector::cpToString()
   return myString;
 }
 
-void QgsRasterProjector::calcSrcRowsCols()
+void ProjectorData::calcSrcRowsCols()
 {
   // Wee need to calculate minimum cell size in the source
   // TODO: Think it over better, what is the right source resolution?
@@ -347,11 +342,10 @@ void QgsRasterProjector::calcSrcRowsCols()
   else
   {
     // take highest from corners, points in in the middle of corners and center (3 x 3 )
-    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 ) )
+    if ( QgsRasterProjector::extentSize( *mInverseCt, mDestExtent, mDestCols, mDestRows, srcExtent, srcXSize, srcYSize ) )
     {
       double srcXRes = srcExtent.width() / srcXSize;
       double srcYRes = srcExtent.height() / srcYSize;
@@ -383,29 +377,22 @@ void QgsRasterProjector::calcSrcRowsCols()
 }
 
 
-inline void QgsRasterProjector::destPointOnCPMatrix( int theRow, int theCol, double *theX, double *theY )
+inline void ProjectorData::destPointOnCPMatrix( int theRow, int theCol, double *theX, double *theY )
 {
   *theX = mDestExtent.xMinimum() + theCol * mDestExtent.width() / ( mCPCols - 1 );
   *theY = mDestExtent.yMaximum() - theRow * mDestExtent.height() / ( mCPRows - 1 );
 }
 
-inline int QgsRasterProjector::matrixRow( int theDestRow )
+inline int ProjectorData::matrixRow( int theDestRow )
 {
   return static_cast< int >( floor(( theDestRow + 0.5 ) / mDestRowsPerMatrixRow ) );
 }
-inline int QgsRasterProjector::matrixCol( int theDestCol )
+inline int ProjectorData::matrixCol( int theDestCol )
 {
   return static_cast< int >( floor(( theDestCol + 0.5 ) / mDestColsPerMatrixCol ) );
 }
 
-QgsPoint QgsRasterProjector::srcPoint( int theDestRow, int theCol )
-{
-  Q_UNUSED( theDestRow );
-  Q_UNUSED( theCol );
-  return QgsPoint();
-}
-
-void QgsRasterProjector::calcHelper( int theMatrixRow, QgsPoint *thePoints )
+void ProjectorData::calcHelper( int theMatrixRow, QgsPoint *thePoints )
 {
   // TODO?: should we also precalc dest cell center coordinates for x and y?
   for ( int myDestCol = 0; myDestCol < mDestCols; myDestCol++ )
@@ -430,7 +417,8 @@ void QgsRasterProjector::calcHelper( int theMatrixRow, QgsPoint *thePoints )
     thePoints[myDestCol].setY( t );
   }
 }
-void QgsRasterProjector::nextHelper()
+
+void ProjectorData::nextHelper()
 {
   // We just switch pHelperTop and pHelperBottom, memory is not lost
   QgsPoint *tmp;
@@ -441,19 +429,19 @@ void QgsRasterProjector::nextHelper()
   mHelperTopRow++;
 }
 
-bool QgsRasterProjector::srcRowCol( int theDestRow, int theDestCol, int *theSrcRow, int *theSrcCol, const QgsCoordinateTransform& ct )
+bool ProjectorData::srcRowCol( int theDestRow, int theDestCol, int *theSrcRow, int *theSrcCol )
 {
   if ( mApproximate )
   {
     return approximateSrcRowCol( theDestRow, theDestCol, theSrcRow, theSrcCol );
   }
   else
   {
-    return preciseSrcRowCol( theDestRow, theDestCol, theSrcRow, theSrcCol, ct );
+    return preciseSrcRowCol( theDestRow, theDestCol, theSrcRow, theSrcCol );
   }
 }
 
-bool QgsRasterProjector::preciseSrcRowCol( int theDestRow, int theDestCol, int *theSrcRow, int *theSrcCol, const QgsCoordinateTransform& ct )
+bool ProjectorData::preciseSrcRowCol( int theDestRow, int theDestCol, int *theSrcRow, int *theSrcCol )
 {
 #ifdef QGISDEBUG
   QgsDebugMsgLevel( QString( "theDestRow = %1" ).arg( theDestRow ), 5 );
@@ -469,9 +457,9 @@ bool QgsRasterProjector::preciseSrcRowCol( int theDestRow, int theDestCol, int *
   QgsDebugMsgLevel( QString( "x = %1 y = %2" ).arg( x ).arg( y ), 5 );
 #endif
 
-  if ( ct.isValid() )
+  if ( mInverseCt->isValid() )
   {
-    ct.transformInPlace( x, y, z );
+    mInverseCt->transformInPlace( x, y, z );
   }
 
 #ifdef QGISDEBUG
@@ -502,7 +490,7 @@ bool QgsRasterProjector::preciseSrcRowCol( int theDestRow, int theDestCol, int *
   return true;
 }
 
-bool QgsRasterProjector::approximateSrcRowCol( int theDestRow, int theDestCol, int *theSrcRow, int *theSrcCol )
+bool ProjectorData::approximateSrcRowCol( int theDestRow, int theDestCol, int *theSrcRow, int *theSrcCol )
 {
   int myMatrixRow = matrixRow( theDestRow );
   int myMatrixCol = matrixCol( theDestCol );
@@ -559,7 +547,7 @@ bool QgsRasterProjector::approximateSrcRowCol( int theDestRow, int theDestCol, i
   return true;
 }
 
-void QgsRasterProjector::insertRows( const QgsCoordinateTransform& ct )
+void ProjectorData::insertRows( const QgsCoordinateTransform& ct )
 {
   for ( int r = 0; r < mCPRows - 1; r++ )
   {
@@ -583,7 +571,7 @@ void QgsRasterProjector::insertRows( const QgsCoordinateTransform& ct )
   }
 }
 
-void QgsRasterProjector::insertCols( const QgsCoordinateTransform& ct )
+void ProjectorData::insertCols( const QgsCoordinateTransform& ct )
 {
   for ( int r = 0; r < mCPRows; r++ )
   {
@@ -601,7 +589,7 @@ void QgsRasterProjector::insertCols( const QgsCoordinateTransform& ct )
 
 }
 
-void QgsRasterProjector::calcCP( int theRow, int theCol, const QgsCoordinateTransform& ct )
+void ProjectorData::calcCP( int theRow, int theCol, const QgsCoordinateTransform& ct )
 {
   double myDestX, myDestY;
   destPointOnCPMatrix( theRow, theCol, &myDestX, &myDestY );
@@ -626,7 +614,7 @@ void QgsRasterProjector::calcCP( int theRow, int theCol, const QgsCoordinateTran
   }
 }
 
-bool QgsRasterProjector::calcRow( int theRow, const QgsCoordinateTransform& ct )
+bool ProjectorData::calcRow( int theRow, const QgsCoordinateTransform& ct )
 {
   QgsDebugMsgLevel( QString( "theRow = %1" ).arg( theRow ), 3 );
   for ( int i = 0; i < mCPCols; i++ )
@@ -637,7 +625,7 @@ bool QgsRasterProjector::calcRow( int theRow, const QgsCoordinateTransform& ct )
   return true;
 }
 
-bool QgsRasterProjector::calcCol( int theCol, const QgsCoordinateTransform& ct )
+bool ProjectorData::calcCol( int theCol, const QgsCoordinateTransform& ct )
 {
   QgsDebugMsgLevel( QString( "theCol = %1" ).arg( theCol ), 3 );
   for ( int i = 0; i < mCPRows; i++ )
@@ -648,7 +636,7 @@ bool QgsRasterProjector::calcCol( int theCol, const QgsCoordinateTransform& ct )
   return true;
 }
 
-bool QgsRasterProjector::checkCols( const QgsCoordinateTransform& ct )
+bool ProjectorData::checkCols( const QgsCoordinateTransform& ct )
 {
   if ( !ct.isValid() )
   {
@@ -693,7 +681,7 @@ bool QgsRasterProjector::checkCols( const QgsCoordinateTransform& ct )
   return true;
 }
 
-bool QgsRasterProjector::checkRows( const QgsCoordinateTransform& ct )
+bool ProjectorData::checkRows( const QgsCoordinateTransform& ct )
 {
   if ( !ct.isValid() )
   {
@@ -766,22 +754,21 @@ QgsRasterBlock * QgsRasterProjector::block( int bandNo, QgsRectangle  const & ex
     return mInput->block( bandNo, extent, width, height, feedback );
   }
 
-  mDestExtent = extent;
-  mDestRows = height;
-  mDestCols = width;
-  calc();
+  QgsCoordinateTransform inverseCt = QgsCoordinateTransformCache::instance()->transform( mDestCRS.authid(), mSrcCRS.authid(), mDestDatumTransform, mSrcDatumTransform );
+
+  ProjectorData pd( extent, width, height, mInput, inverseCt, mPrecision );
 
-  QgsDebugMsgLevel( QString( "srcExtent:\n%1" ).arg( mSrcExtent.toString() ), 4 );
-  QgsDebugMsgLevel( QString( "srcCols = %1 srcRows = %2" ).arg( mSrcCols ).arg( mSrcRows ), 4 );
+  QgsDebugMsgLevel( QString( "srcExtent:\n%1" ).arg( pd.srcExtent().toString() ), 4 );
+  QgsDebugMsgLevel( QString( "srcCols = %1 srcRows = %2" ).arg( pd.srcCols() ).arg( pd.srcRows() ), 4 );
 
   // If we zoom out too much, projector srcRows / srcCols maybe 0, which can cause problems in providers
-  if ( mSrcRows <= 0 || mSrcCols <= 0 )
+  if ( pd.srcRows() <= 0 || pd.srcCols() <= 0 )
   {
     QgsDebugMsgLevel( "Zero srcRows or srcCols", 4 );
     return new QgsRasterBlock();
   }
 
-  QgsRasterBlock *inputBlock = mInput->block( bandNo, mSrcExtent, mSrcCols, mSrcRows, feedback );
+  QgsRasterBlock *inputBlock = mInput->block( bandNo, pd.srcExtent(), pd.srcCols(), pd.srcRows(), feedback );
   if ( !inputBlock || inputBlock->isEmpty() )
   {
     QgsDebugMsg( "No raster data!" );
@@ -822,23 +809,17 @@ QgsRasterBlock * QgsRasterProjector::block( int bandNo, QgsRectangle  const & ex
   // we cannot fill output block with no data because we use memcpy for data, not setValue().
   bool doNoData = !QgsRasterBlock::typeIsNumeric( inputBlock->dataType() ) && inputBlock->hasNoData() && !inputBlock->hasNoDataValue();
 
-  QgsCoordinateTransform inverseCt;
-  if ( !mApproximate )
-  {
-    inverseCt = QgsCoordinateTransformCache::instance()->transform( mDestCRS.authid(), mSrcCRS.authid(), mDestDatumTransform, mSrcDatumTransform );
-  }
-
   outputBlock->setIsNoData();
 
   int srcRow, srcCol;
   for ( int i = 0; i < height; ++i )
   {
     for ( int j = 0; j < width; ++j )
     {
-      bool inside = srcRowCol( i, j, &srcRow, &srcCol, inverseCt );
+      bool inside = pd.srcRowCol( i, j, &srcRow, &srcCol );
       if ( !inside ) continue; // we have everything set to no data
 
-      qgssize srcIndex = static_cast< qgssize >( srcRow ) * mSrcCols + srcCol;
+      qgssize srcIndex = static_cast< qgssize >( srcRow ) * pd.srcCols() + srcCol;
       QgsDebugMsgLevel( QString( "row = %1 col = %2 srcRow = %3 srcCol = %4" ).arg( i ).arg( j ).arg( srcRow ).arg( srcCol ), 5 );
 
       // isNoData() may be slow so we check doNoData first