qgsrasterblock.h

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/***************************************************************************
    qgsrasterblock.h - Class representing a block of raster data
     --------------------------------------
    Date                 : Oct 9, 2012
    Copyright            : (C) 2012 by Radim Blazek
    email                : radim dot blazek at gmail dot com
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/

#ifndef QGSRASTERBLOCK_H
#define QGSRASTERBLOCK_H

#include "qgis_core.h"
#include "qgis_sip.h"
#include <limits>
#include <QImage>
#include "qgis.h"
#include "qgserror.h"
#include "qgslogger.h"
#include "qgsrasterrange.h"

class QgsRectangle;

class CORE_EXPORT QgsRasterBlock
{
  public:
    QgsRasterBlock();

    QgsRasterBlock( Qgis::DataType dataType, int width, int height );

    virtual ~QgsRasterBlock();

    bool reset( Qgis::DataType dataType, int width, int height );

    // TODO: consider if use isValid() at all, isEmpty() should be sufficient
    // and works also if block is valid but empty - difference between valid and empty?

    bool isValid() const { return mValid; }

    void setValid( bool valid ) { mValid = valid; }

    bool isEmpty() const;

    // Return data type size in bytes
    static int typeSize( int dataType )
    {
      // Modified and extended copy from GDAL
      switch ( dataType )
      {
        case Qgis::Byte:
          return 1;

        case Qgis::UInt16:
        case Qgis::Int16:
          return 2;

        case Qgis::UInt32:
        case Qgis::Int32:
        case Qgis::Float32:
        case Qgis::CInt16:
          return 4;

        case Qgis::Float64:
        case Qgis::CInt32:
        case Qgis::CFloat32:
          return 8;

        case Qgis::CFloat64:
          return 16;

        case Qgis::ARGB32:
        case Qgis::ARGB32_Premultiplied:
          return 4;

        default:
          return 0;
      }
    }

    // Data type in bytes
    int dataTypeSize() const
    {
      return typeSize( mDataType );
    }

    static bool typeIsNumeric( Qgis::DataType type );

    static bool typeIsColor( Qgis::DataType type );

    Qgis::DataType dataType() const { return mDataType; }

    static Qgis::DataType typeWithNoDataValue( Qgis::DataType dataType, double *noDataValue );

    bool hasNoDataValue() const { return mHasNoDataValue; }

    bool hasNoData() const
    {
      return mHasNoDataValue || mNoDataBitmap;
    }

    void setNoDataValue( double noDataValue );

    void resetNoDataValue();

    double noDataValue() const { return mNoDataValue; }

    static QByteArray valueBytes( Qgis::DataType dataType, double value );

    double value( int row, int column ) const
    {
      return value( static_cast< qgssize >( row ) * mWidth + column );
    }

    double value( qgssize index ) const;

    QRgb color( int row, int column ) const
    {
      if ( !mImage ) return NO_DATA_COLOR;

      return mImage->pixel( column, row );
    }

    QRgb color( qgssize index ) const
    {
      int row = static_cast< int >( std::floor( static_cast< double >( index ) / mWidth ) );
      int column = index % mWidth;
      return color( row, column );
    }

    bool isNoData( int row, int column )
    {
      return isNoData( static_cast< qgssize >( row ) * mWidth + column );
    }

    bool isNoData( qgssize index )
    {
      if ( !mHasNoDataValue && !mNoDataBitmap )
        return false;
      if ( index >= static_cast< qgssize >( mWidth )*mHeight )
      {
        QgsDebugMsg( QStringLiteral( "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;
    }

    bool setValue( int row, int column, double value )
    {
      return setValue( static_cast< qgssize >( row ) * mWidth + column, value );
    }

    bool setValue( qgssize index, double value )
    {
      if ( !mData )
      {
        QgsDebugMsg( QStringLiteral( "Data block not allocated" ) );
        return false;
      }
      if ( index >= static_cast< qgssize >( mWidth ) *mHeight )
      {
        QgsDebugMsg( QStringLiteral( "Index %1 out of range (%2 x %3)" ).arg( index ).arg( mWidth ).arg( mHeight ) );
        return false;
      }
      writeValue( mData, mDataType, index, value );
      return true;
    }

    bool setColor( int row, int column, QRgb color )
    {
      return setColor( static_cast< qgssize >( row ) * mWidth + column, color );
    }

    bool setColor( qgssize index, QRgb color )
    {
      if ( !mImage )
      {
        QgsDebugMsg( QStringLiteral( "Image not allocated" ) );
        return false;
      }

      if ( index >= static_cast< qgssize >( mImage->width() ) * mImage->height() )
      {
        QgsDebugMsg( QStringLiteral( "index %1 out of range" ).arg( index ) );
        return false;
      }

      // setPixel() is slow, see Qt doc -> use direct access
      QRgb *bits = reinterpret_cast< QRgb * >( mImage->bits() );
      bits[index] = color;
      return true;
    }

    bool setIsNoData( int row, int column )
    {
      return setIsNoData( static_cast< qgssize >( row ) * mWidth + column );
    }

    bool setIsNoData( qgssize index )
    {
      if ( mHasNoDataValue )
      {
        return setValue( index, mNoDataValue );
      }
      else
      {
        if ( !mNoDataBitmap )
        {
          if ( !createNoDataBitmap() )
          {
            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 nodata = 0x80 >> bit;
        //QgsDebugMsg ( QString("set byte = %1 bit = %2 no data by %3").arg(byte).arg(bit).arg(nodata, 0,2 ) );
        mNoDataBitmap[byte] = mNoDataBitmap[byte] | nodata;
        return true;
      }
    }

    bool setIsNoData();

    bool setIsNoDataExcept( QRect exceptRect );

    void setIsData( int row, int column )
    {
      setIsData( static_cast< qgssize >( row )*mWidth + column );
    }

    void setIsData( qgssize index )
    {
      if ( mHasNoDataValue )
      {
        //no data value set, so mNoDataBitmap is not being used
        return;
      }

      if ( !mNoDataBitmap )
      {
        return;
      }

      // 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 nodata = 0x80 >> bit;
      mNoDataBitmap[byte] = mNoDataBitmap[byte] & ~nodata;
    }

    QByteArray data() const;

    void setData( const QByteArray &data, int offset = 0 );

    char *bits( int row, int column ) SIP_SKIP;

    char *bits( qgssize index ) SIP_SKIP;

    char *bits() SIP_SKIP;

    static QString printValue( double value );

    static QString printValue( float value ) SIP_SKIP;

    bool convert( Qgis::DataType destDataType );

    QImage image() const;

    bool setImage( const QImage *image );

    inline static double readValue( void *data, Qgis::DataType type, qgssize index ) SIP_SKIP;

    inline static void writeValue( void *data, Qgis::DataType type, qgssize index, double value ) SIP_SKIP;

    void applyNoDataValues( const QgsRasterRangeList &rangeList );

    void applyScaleOffset( double scale, double offset );

    QgsError error() const { return mError; }

    void setError( const QgsError &error ) { mError = error;}

    QString toString() const;

    static QRect subRect( const QgsRectangle &extent, int width, int height, const QgsRectangle &subExtent );

    int width() const { return mWidth; }

    int height() const { return mHeight; }

  private:
    static QImage::Format imageFormat( Qgis::DataType dataType );
    static Qgis::DataType dataType( QImage::Format format );

    static bool isNoDataValue( double value, double noDataValue )
    {
      // TODO: optimize no data value test by memcmp()
      // More precise would be std::isnan(value) && std::isnan(noDataValue(bandNo)), but probably
      // not important and slower
      return std::isnan( value ) ||
             qgsDoubleNear( value, noDataValue );
    }

    bool isNoDataValue( double value ) const;

    bool createNoDataBitmap();

    static void *convert( void *srcData, Qgis::DataType srcDataType, Qgis::DataType destDataType, qgssize size );

    // Valid
    bool mValid = true;

    // Data type
    Qgis::DataType mDataType = Qgis::UnknownDataType;

    // Data type size in bytes, to make bits() fast
    int mTypeSize = 0;

    // Width
    int mWidth = 0;

    // Height
    int mHeight = 0;

    // Has no data value
    bool mHasNoDataValue = false;

    // No data value
    double mNoDataValue;

    static const QRgb NO_DATA_COLOR;

    // Data block for numerical data types, not used with image data types
    // QByteArray does not seem to be intended for large data blocks, does it?
    void *mData = nullptr;

    // Image for image data types, not used with numerical data types
    QImage *mImage = nullptr;

    // Bitmap of no data. One bit for each pixel. Bit is 1 if a pixels is no data.
    // Each row is represented by whole number of bytes (last bits may be unused)
    // to make processing rows easy.
    char *mNoDataBitmap = nullptr;

    // number of bytes in mNoDataBitmap row
    int mNoDataBitmapWidth = 0;

    // total size in bytes of mNoDataBitmap
    qgssize mNoDataBitmapSize = 0;

    // Error
    QgsError mError;
};

inline double QgsRasterBlock::readValue( void *data, Qgis::DataType type, qgssize index ) SIP_SKIP
{
  if ( !data )
  {
    return std::numeric_limits<double>::quiet_NaN();
  }

  switch ( type )
  {
    case Qgis::Byte:
      return static_cast< double >( ( static_cast< quint8 * >( data ) )[index] );
      break;
    case Qgis::UInt16:
      return static_cast< double >( ( static_cast< quint16 * >( data ) )[index] );
      break;
    case Qgis::Int16:
      return static_cast< double >( ( static_cast< qint16 * >( data ) )[index] );
      break;
    case Qgis::UInt32:
      return static_cast< double >( ( static_cast< quint32 * >( data ) )[index] );
      break;
    case Qgis::Int32:
      return static_cast< double >( ( static_cast< qint32 * >( data ) )[index] );
      break;
    case Qgis::Float32:
      return static_cast< double >( ( static_cast< float * >( data ) )[index] );
      break;
    case Qgis::Float64:
      return static_cast< double >( ( static_cast< double * >( data ) )[index] );
      break;
    default:
      QgsDebugMsg( QString( "Data type %1 is not supported" ).arg( type ) );
      break;
  }

  return std::numeric_limits<double>::quiet_NaN();
}

inline void QgsRasterBlock::writeValue( void *data, Qgis::DataType type, qgssize index, double value ) SIP_SKIP
{
  if ( !data ) return;

  switch ( type )
  {
    case Qgis::Byte:
      ( static_cast< quint8 * >( data ) )[index] = static_cast< quint8 >( value );
      break;
    case Qgis::UInt16:
      ( static_cast< quint16 * >( data ) )[index] = static_cast< quint16 >( value );
      break;
    case Qgis::Int16:
      ( static_cast< qint16 * >( data ) )[index] = static_cast< qint16 >( value );
      break;
    case Qgis::UInt32:
      ( static_cast< quint32 * >( data ) )[index] = static_cast< quint32 >( value );
      break;
    case Qgis::Int32:
      ( static_cast< qint32 * >( data ) )[index] = static_cast< qint32 >( value );
      break;
    case Qgis::Float32:
      ( static_cast< float * >( data ) )[index] = static_cast< float >( value );
      break;
    case Qgis::Float64:
      ( static_cast< double * >( data ) )[index] = value;
      break;
    default:
      QgsDebugMsg( QString( "Data type %1 is not supported" ).arg( type ) );
      break;
  }
}

inline double QgsRasterBlock::value( qgssize index ) const SIP_SKIP
{
  if ( !mData )
  {
    QgsDebugMsg( QStringLiteral( "Data block not allocated" ) );
    return std::numeric_limits<double>::quiet_NaN();
  }
  return readValue( mData, mDataType, index );
}

inline bool QgsRasterBlock::isNoDataValue( double value ) const SIP_SKIP
{
  return std::isnan( value ) || qgsDoubleNear( value, mNoDataValue );
}

#endif