void QgsRasterTerrainAnalysisPlugin::hillshade()
{
QgsRasterTerrainAnalysisDialog d( QgsRasterTerrainAnalysisDialog::HillshadeInput, mIface->mainWindow() );
d.setWindowTitle( tr( "Hillshade" ) );
if ( d.exec() == QDialog::Accepted )
{
QString outputFile = d.outputFile();
QgsHillshadeFilter hillshade( d.inputFile(), outputFile, d.outputFormat(), d.lightAzimuth(), d.lightAngle() );
hillshade.setZFactor( d.zFactor() );
QProgressDialog p( tr( "Calculating hillshade..." ), tr( "Abort" ), 0, 0 );
p.setWindowModality( Qt::WindowModal );
hillshade.processRaster( &p );
if ( d.addResultToProject() )
{
mIface->addRasterLayer( outputFile, QFileInfo( outputFile ).baseName() );
}
}
}
void Hillshade(const Eigen::MatrixBase<Derived> &surface, const double &altitude, const double &azimuth, const Eigen::MatrixBase<Derived> &hillshade_)
{
double zenith_deg = 90.0 - altitude;
double zenith_rad = zenith_deg * kPI / 180.0;
double azimuth_math = 360.0 - azimuth + 90.0;
if (azimuth_math > 360.0) azimuth_math -= 360.0;
double azimuth_rad = azimuth_math * kPI / 180.0;
double z_factor = 1.0;
double cellsize = 5.0;
Eigen::MatrixBase<Derived> &hillshade = const_cast<Eigen::MatrixBase<Derived>& >(hillshade_);
hillshade.derived().resize(surface.rows(), surface.cols());
hillshade.setConstant(0);
for (boost::int32_t r = 1; r < surface.rows() - 1; ++r)
{
for (boost::int32_t c = 1; c < surface.cols() - 1; ++c)
{
double dzdx = ((surface(r - 1, c + 1) + 2 * surface(r, c + 1) + surface(r + 1, c + 1)) -
(surface(r - 1, c - 1) + 2 * surface(r, c - 1) + surface(r + 1, c - 1))) /
(8 * cellsize);
double dzdy = ((surface(r + 1, c - 1) + 2 * surface(r + 1, c) + surface(r + 1, c + 1)) -
(surface(r - 1, c - 1) + 2 * surface(r - 1, c) + surface(r - 1, c + 1))) /
(8 * cellsize);
double slope_rad = std::atan(z_factor * std::sqrt(dzdx * dzdx + dzdy * dzdy));
double aspect_rad = 0.0;
if (std::abs(dzdx) > 0.0)
{
aspect_rad = std::atan2(dzdy, -dzdx);
if (aspect_rad < 0.0)
{
aspect_rad = 2 * kPI + aspect_rad;
}
}
else
{
if (dzdy > 0.0)
{
aspect_rad = kPI / 2.0;
}
else if (dzdy < 0.0)
{
aspect_rad = 2.0 * kPI - kPI / 2.0;
}
// else aspect_rad = aspect_rad; ??
}
hillshade(r, c) = 255.0 * ((std::cos(zenith_rad) * std::cos(slope_rad)) +
(std::sin(zenith_rad) * std::sin(slope_rad) * std::cos(azimuth_rad - aspect_rad)));
}
}
}
void QgsRasterTerrainAnalysisPlugin::initGui()
{
//create Action
if ( mIface )
{
//find raster menu
QString rasterText = QCoreApplication::translate( "QgisApp", "&Raster" );
QMainWindow* mainWindow = qobject_cast<QMainWindow*>( mIface->mainWindow() );
if ( !mainWindow )
{
return;
}
QMenuBar* menuBar = mainWindow->menuBar();
if ( !menuBar )
{
return;
}
QMenu* rasterMenu = 0;
QList<QAction *> menuBarActions = menuBar->actions();
QList<QAction *>::iterator menuActionIt = menuBarActions.begin();
for ( ; menuActionIt != menuBarActions.end(); ++menuActionIt )
{
if (( *menuActionIt )->menu() && ( *menuActionIt )->menu()->title() == rasterText )
{
rasterMenu = ( *menuActionIt )->menu();
rasterMenu->addSeparator();
break;
}
}
if ( !rasterMenu )
{
return;
}
mTerrainAnalysisMenu = new QMenu( tr( "Terrain analysis" ), rasterMenu );
mTerrainAnalysisMenu->setObjectName( "mTerrainAnalysisMenu" );
mTerrainAnalysisMenu->setIcon( QIcon( ":/raster/dem.png" ) );
QAction *slopeAction = mTerrainAnalysisMenu->addAction( tr( "Slope" ), this, SLOT( slope() ) );
slopeAction->setObjectName( "slopeAction" );
QAction *aspectAction = mTerrainAnalysisMenu->addAction( tr( "Aspect" ), this, SLOT( aspect() ) );
aspectAction->setObjectName( "aspectAction" );
QAction *hilshadeAction = mTerrainAnalysisMenu->addAction( tr( "Hillshade" ), this, SLOT( hillshade() ) );
hilshadeAction->setObjectName( "hilshadeAction" );
QAction *reliefAction = mTerrainAnalysisMenu->addAction( tr( "Relief" ), this, SLOT( relief() ) );
reliefAction->setObjectName( "reliefAction" );
QAction *ruggednesIndex = mTerrainAnalysisMenu->addAction( tr( "Ruggedness index" ), this, SLOT( ruggedness() ) );
ruggednesIndex->setObjectName( "ruggednesIndex" );
rasterMenu->addMenu( mTerrainAnalysisMenu );
}
}
