view data/model/RelativelyFineZoomConstraint.cpp @ 1881:b504df98c3be

Ensure completion on output model is started at zero, so if it's checked before the input model has become ready and the transform has begun, it is not accidentally reported as complete (affected re-aligning models in Sonic Lineup when replacing the session)

/* -*- 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 "RelativelyFineZoomConstraint.h"

#include <vector>
#include <algorithm>
#include <iostream>

using namespace std;

ZoomLevel
RelativelyFineZoomConstraint::getNearestZoomLevel(ZoomLevel requested,
                                                  RoundingDirection dir) const
{
    static vector<int> levels;

    int maxLevel = getMaxZoomLevel().level;

    if (levels.empty()) {
        int level = 1;
        while (level <= maxLevel) {
//            cerr << level << " ";
            levels.push_back(level);
            int step = level / 10;
            int pwr = 0;
            while (step > 0) {
                ++pwr;
                step /= 2;
            }
            step = (1 << pwr);
            level += step;
        }
//        cerr << endl;
    }

    RoundingDirection effective = dir;
    if (requested.zone == ZoomLevel::PixelsPerFrame) {
        if (dir == RoundUp) effective = RoundDown;
        else if (dir == RoundDown) effective = RoundUp;
    }

    // iterator pointing to first level that is >= requested
    auto i = lower_bound(levels.begin(), levels.end(), requested.level);

    ZoomLevel newLevel(requested);

    if (i == levels.end()) {
        newLevel.level = maxLevel;

    } else if (*i == requested.level) {
        newLevel.level = requested.level;

    } else if (effective == RoundUp) {
        newLevel.level = *i;

    } else if (effective == RoundDown) {
        if (i != levels.begin()) {
            --i;
        }
        newLevel.level = *i;

    } else { // RoundNearest
        if (i != levels.begin()) {
            auto j = i;
            --j;
            if (requested.level - *j < *i - requested.level) {
                newLevel.level = *j;
            } else {
                newLevel.level = *i;
            }
        }
    }

    // canonicalise
    if (newLevel.level == 1) {
        newLevel.zone = ZoomLevel::FramesPerPixel;
    }

    using namespace std::rel_ops;
    if (newLevel > getMaxZoomLevel()) {
        newLevel = getMaxZoomLevel();
    } else if (newLevel < getMinZoomLevel()) {
        newLevel = getMinZoomLevel();
    }
    
    return newLevel;
}