baranalyzer.cpp

Amarok是一款在LINUX或其他类UNIX操作系统中运行的音频播放器软件。 经过两年开发后

//
//
// C++ Implementation: $MODULE$
//
// Description:
//
//
// Author: Mark Kretschmann <[e-mail]>, (C) 2003
//
// Copyright: See COPYING file that comes with this distribution
//
//

#include "baranalyzer.h"
#include <cmath>     //log10(), etc.
#include "debug.h"
#include <qpainter.h>


BarAnalyzer::BarAnalyzer( QWidget *parent )
    : Analyzer::Base2D( parent, 12, 8 )
    //, m_bands( BAND_COUNT )
    //, barVector( BAND_COUNT, 0 )
    //, roofVector( BAND_COUNT, 50 )
    //, roofVelocityVector( BAND_COUNT, ROOF_VELOCITY_REDUCTION_FACTOR )
{
    //roof pixmaps don't depend on size() so we do in the ctor
    m_bg = parent->paletteBackgroundColor();

    QColor fg( 0xff, 0x50, 0x70 );
    #define m_bg backgroundColor()

    double dr = double(m_bg.red()   - fg.red())   / (NUM_ROOFS-1); //-1 because we start loop below at 0
    double dg = double(m_bg.green() - fg.green()) / (NUM_ROOFS-1);
    double db = double(m_bg.blue()  - fg.blue())  / (NUM_ROOFS-1);

    for ( uint i = 0; i < NUM_ROOFS; ++i )
    {
        m_pixRoof[i].resize( COLUMN_WIDTH, 1 );
        m_pixRoof[i].fill( QColor( fg.red()+int(dr*i), fg.green()+int(dg*i), fg.blue()+int(db*i) ) );
    }

    #undef m_bg
}

void BarAnalyzer::resizeEvent( QResizeEvent * e )
{
    debug() << "Baranalyzer Resized(" << width() << "x" << height() << ")" << endl;
    Analyzer::Base2D::resizeEvent( e );
    init();
}

// METHODS =====================================================

void BarAnalyzer::init()
{
    const double MAX_AMPLITUDE = 1.0;
    const double F = double(height() - 2) / (log10( 255 ) * MAX_AMPLITUDE );

    setPaletteBackgroundColor(m_bg);

    BAND_COUNT = width() / 5;
    MAX_DOWN = int(0 -((height() / 50)));
    MAX_UP = int((height() / 25));

    debug() << "BAND_COUNT = " << BAND_COUNT << " MAX_UP = " << MAX_UP << "MAX_DOWN = " << MAX_DOWN << endl;

    barVector.resize( BAND_COUNT, 0 );
    roofVector.resize( BAND_COUNT, height() -5 );
    roofVelocityVector.resize( BAND_COUNT, ROOF_VELOCITY_REDUCTION_FACTOR );
    m_roofMem.resize(BAND_COUNT);
    m_scope.resize(BAND_COUNT);

    //generate a list of values that express amplitudes in range 0-MAX_AMP as ints from 0-height() on log scale
    for ( uint x = 0; x < 256; ++x )
    {
        m_lvlMapper[x] = uint( F * log10( x+1 ) );
    }

    m_pixBarGradient.resize( height()*COLUMN_WIDTH, height() );
    m_pixCompose.resize( size() );

    QPainter p( &m_pixBarGradient );
    for ( int x=0, r=0x40, g=0x30, b=0xff, r2=255-r;
          x < height(); ++x )
    {
        for ( int y = x; y > 0; --y )
        {
            const double fraction = (double)y / height();

//          p.setPen( QColor( r + (int)(r2 * fraction), g, b - (int)(255 * fraction) ) );
            p.setPen( QColor( r + (int)(r2 * fraction), g, b ) );
            p.drawLine( x*COLUMN_WIDTH, height() - y, (x+1)*COLUMN_WIDTH, height() - y );
        }
    }


    setMinimumSize( QSize( BAND_COUNT * COLUMN_WIDTH, 10 ) );
}


void BarAnalyzer::analyze( const Scope &s )
{
    //start with a blank canvas
    eraseCanvas();

    //Analyzer::interpolate( s, m_bands );

    Scope &v = m_scope;
    Analyzer::interpolate( s, v );

    for ( uint i = 0, x = 0, y2; i < v.size(); ++i, x+=COLUMN_WIDTH+1 )
    {
        //assign pre[log10]'d value
        y2 = uint(v[i] * 256); //256 will be optimised to a bitshift //no, it's a float
        y2 = m_lvlMapper[ (y2 > 255) ? 255 : y2 ]; //lvlMapper is array of ints with values 0 to height()

        int change = y2 - barVector[i];

        //using the best of Markey's, piggz and Max's ideas on the way to shift the bars
        //we have the following:
        // 1. don't adjust shift when doing small up movements
        // 2. shift large upwards with a bias towards last value
        // 3. fall downwards at a constant pace

        /*if ( change > MAX_UP ) //anything too much greater than 2 gives "jitter"
           //add some dynamics - makes the value slightly closer to what it was last time
           y2 = ( barVector[i] + MAX_UP );
           //y2 = ( barVector[i] * 2 + y2 ) / 3;
        else*/ if ( change < MAX_DOWN )
           y2 = barVector[i] + MAX_DOWN;


        if ( (int)y2 > roofVector[i] )
        {
            roofVector[i] = (int)y2;
            roofVelocityVector[i] = 1;
        }

        //remember where we are
        barVector[i] = y2;

        if ( m_roofMem[i].size() > NUM_ROOFS )
            m_roofMem[i].erase( m_roofMem[i].begin() );

        //blt last n roofs, a.k.a motion blur
        for ( uint c = 0; c < m_roofMem[i].size(); ++c )
            //bitBlt( m_pComposePixmap, x, m_roofMem[i]->at( c ), m_roofPixmaps[ c ] );
            bitBlt( canvas(), x, m_roofMem[i][c], &m_pixRoof[ NUM_ROOFS - 1 - c ] );

        //blt the bar
        bitBlt( canvas(), x, height() - y2,
                gradient(), y2 * COLUMN_WIDTH, height() - y2, COLUMN_WIDTH, y2, Qt::CopyROP );

        m_roofMem[i].push_back( height() - roofVector[i] - 2 );

        //set roof parameters for the NEXT draw
        if ( roofVelocityVector[i] != 0 )
        {
            if ( roofVelocityVector[i] > 32 ) //no reason to do == 32
                roofVector[i] -= (roofVelocityVector[i] - 32) / 20; //trivial calculation

            if ( roofVector[i] < 0 )
            {
               roofVector[i] = 0; //not strictly necessary
               roofVelocityVector[i] = 0;
            }
            else ++roofVelocityVector[i];
        }
    }
}