bool QgsRasterBlock::isNoData( qgssize index )
{
if ( !mHasNoDataValue && !mNoDataBitmap ) return false;
if ( index >= static_cast< qgssize >( mWidth )*mHeight )
{
QgsDebugMsg( QString( "Index %1 out of range (%2 x %3)" ).arg( index ).arg( mWidth ).arg( mHeight ) );
return true; // we consider no data if outside
}
if ( mHasNoDataValue )
{
double value = readValue( mData, mDataType, index );
return isNoDataValue( value );
}
// use no data bitmap
if ( !mNoDataBitmap )
{
// no data are not defined
return false;
}
// TODO: optimize
int row = static_cast< int >( index ) / mWidth;
int column = index % mWidth;
qgssize byte = static_cast< qgssize >( row ) * mNoDataBitmapWidth + column / 8;
int bit = column % 8;
int mask = 0x80 >> bit;
//int x = mNoDataBitmap[byte] & mask;
//QgsDebugMsg ( QString("byte = %1 bit = %2 mask = %3 nodata = %4 is nodata = %5").arg(byte).arg(bit).arg(mask, 0, 2 ).arg( x, 0, 2 ).arg( (bool)(x) ) );
return mNoDataBitmap[byte] & mask;
}
QMap<QString, QString> QgsRasterDataProvider::identify( const QgsPoint & thePoint, const QgsRectangle &theExtent, int theWidth, int theHeight )
{
QMap<QString, QString> results;
QgsRasterDataProvider::IdentifyFormat identifyFormat;
if ( capabilities() & QgsRasterDataProvider::IdentifyValue )
{
identifyFormat = QgsRasterDataProvider::IdentifyFormatValue;
}
else if ( capabilities() & QgsRasterDataProvider::IdentifyHtml )
{
identifyFormat = QgsRasterDataProvider::IdentifyFormatHtml;
}
else if ( capabilities() & QgsRasterDataProvider::IdentifyText )
{
identifyFormat = QgsRasterDataProvider::IdentifyFormatText;
}
else
{
return results;
}
QMap<int, QVariant> myResults = identify( thePoint, identifyFormat, theExtent, theWidth, theHeight );
if ( identifyFormat == QgsRasterDataProvider::IdentifyFormatValue )
{
foreach ( int bandNo, myResults.keys() )
{
double value = myResults.value( bandNo ).toDouble();
QString valueString;
if ( isNoDataValue( bandNo, value ) )
{
valueString = tr( "no data" );
}
else
{
valueString = QgsRasterBlock::printValue( value );
}
results.insert( generateBandName( bandNo ), valueString );
}
}