view layer/ScrollableMagRangeCache.cpp @ 1386:fc3d89f88690 spectrogramparam

Use log-frequency rather than log-bin for calculating x coord in spectrum. This has the advantage that frequency positions don't move when we change the window size or oversampling ratio, but it does give us an unhelpfully large amount of space for very low frequencies - to be considered

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */

/*
    Sonic Visualiser
    An audio file viewer and annotation editor.
    Centre for Digital Music, Queen Mary, University of London.
    
    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.  See the file
    COPYING included with this distribution for more information.
*/

#include "ScrollableMagRangeCache.h"

#include "base/HitCount.h"

#include <iostream>
using namespace std;

//#define DEBUG_SCROLLABLE_MAG_RANGE_CACHE 1

void
ScrollableMagRangeCache::scrollTo(const LayerGeometryProvider *v,
                                  sv_frame_t newStartFrame)
{        
    static HitCount count("ScrollableMagRangeCache: scrolling");
    
    int dx = (v->getXForFrame(m_startFrame) -
              v->getXForFrame(newStartFrame));

#ifdef DEBUG_SCROLLABLE_MAG_RANGE_CACHE
    cerr << "ScrollableMagRangeCache::scrollTo: start frame " << m_startFrame
         << " -> " << newStartFrame << ", dx = " << dx << endl;
#endif

    if (m_startFrame == newStartFrame) {
        // haven't moved
        count.hit();
        return;
    }
    
    m_startFrame = newStartFrame;

    if (dx == 0) {
        // haven't moved visibly (even though start frame may have changed)
        count.hit();
        return;
    }
        
    int w = int(m_ranges.size());

    if (dx <= -w || dx >= w) {
        // scrolled entirely off
        invalidate();
        count.miss();
        return;
    }

    count.partial();
        
    // dx is in range, cache is scrollable

    if (dx < 0) {
        // The new start frame is to the left of the old start
        // frame. We need to add some empty ranges at the left (start)
        // end and clip the right end. Assemble -dx new values, then
        // w+dx old values starting at index 0.

        auto newRanges = vector<MagnitudeRange>(-dx);
        newRanges.insert(newRanges.end(),
                         m_ranges.begin(), m_ranges.begin() + (w + dx));
        m_ranges = newRanges;
        
    } else {
        // The new start frame is to the right of the old start
        // frame. We want to clip the left (start) end and add some
        // empty ranges at the right end. Assemble w-dx old values
        // starting at index dx, then dx new values.

        auto newRanges = vector<MagnitudeRange>(dx);
        newRanges.insert(newRanges.begin(),
                         m_ranges.begin() + dx, m_ranges.end());
        m_ranges = newRanges;
    }

#ifdef DEBUG_SCROLLABLE_MAG_RANGE_CACHE
    cerr << "maxes (" << m_ranges.size() << ") now: ";
    for (int i = 0; in_range_for(m_ranges, i); ++i) {
        cerr << m_ranges[i].getMax() << " ";
    }
    cerr << endl;
#endif
}

MagnitudeRange
ScrollableMagRangeCache::getRange(int x, int count) const
{
    MagnitudeRange r;
#ifdef DEBUG_SCROLLABLE_MAG_RANGE_CACHE
    cerr << "ScrollableMagRangeCache::getRange(" << x << ", " << count << ")" << endl;
#endif
    for (int i = 0; i < count; ++i) {
        r.sample(m_ranges.at(x + i));
    }
    return r;
}

void
ScrollableMagRangeCache::sampleColumn(int column, const MagnitudeRange &r)
{
    if (!in_range_for(m_ranges, column)) {
        cerr << "ERROR: ScrollableMagRangeCache::sampleColumn: column " << column
             << " is out of range for cache of width " << m_ranges.size()
             << " (with start frame " << m_startFrame << ")" << endl;
        throw logic_error("column out of range");
    } else {
        m_ranges[column].sample(r);
    }
}