Mercurial > hg > svgui
diff layer/ScrollableMagRangeCache.cpp @ 1118:175d4e15884d spectrogram-minor-refactor
Introduce ScrollableMagRangeCache, plus some tidying etc
author | Chris Cannam |
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date | Wed, 20 Jul 2016 08:30:20 +0100 |
parents | |
children | 65cdaf8d6b50 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/layer/ScrollableMagRangeCache.cpp Wed Jul 20 08:30:20 2016 +0100 @@ -0,0 +1,96 @@ +/* -*- 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 <iostream> +using namespace std; + +#define DEBUG_SCROLLABLE_MAG_RANGE_CACHE 1 + +void +ScrollableMagRangeCache::scrollTo(const LayerGeometryProvider *v, + sv_frame_t newStartFrame) +{ + if (m_startFrame == newStartFrame) { + // haven't moved + return; + } + + 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 + + m_startFrame = newStartFrame; + + if (dx == 0) { + // haven't moved visibly (even though start frame may have changed) + return; + } + + int w = int(m_ranges.size()); + + if (dx <= -w || dx >= w) { + // scrolled entirely off + invalidate(); + return; + } + + // 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; + } +} + +void +ScrollableMagRangeCache::sampleColumn(const LayerGeometryProvider *v, + sv_frame_t frame, + const MagnitudeRange &r) +{ + int x = (v->getXForFrame(frame) - + v->getXForFrame(m_startFrame)); + + if (!in_range_for(m_ranges, x)) { + cerr << "WARNING: ScrollableMagRangeCache::sampleColumn: column " << x + << " arising from frame " << frame << " is out of range for cache " + << "of width " << m_ranges.size() << endl; + } else { + sampleColumn(x, r); + } +} +