Mercurial > hg > svcore
view data/model/PowerOfSqrtTwoZoomConstraint.cpp @ 299:576be0d0d218
* Merge transform directory from sv-match-alignment branch
(the previous comment included notes for this stuff, but I missed it
in the actual merge)
* Fix crash when a transform fails to create an output model and the
thread that created the transform then deletes its input model thinking
it's no longer needed, even though the transform run thread is still
using it -- fix is to wait() on the transform before returning the
null output model
author | Chris Cannam |
---|---|
date | Fri, 28 Sep 2007 16:15:06 +0000 |
parents | 3a13b0d4934e |
children | 166c22eff678 |
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/* -*- 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 file copyright 2006 Chris Cannam. 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 "PowerOfSqrtTwoZoomConstraint.h" #include <iostream> #include <cmath> size_t PowerOfSqrtTwoZoomConstraint::getNearestBlockSize(size_t blockSize, RoundingDirection dir) const { int type, power; size_t rv = getNearestBlockSize(blockSize, type, power, dir); return rv; } size_t PowerOfSqrtTwoZoomConstraint::getNearestBlockSize(size_t blockSize, int &type, int &power, RoundingDirection dir) const { // std::cerr << "given " << blockSize << std::endl; size_t minCachePower = getMinCachePower(); if (blockSize < (1U << minCachePower)) { type = -1; power = 0; float val = 1.0, prevVal = 1.0; while (val + 0.01 < blockSize) { prevVal = val; val *= sqrt(2); } size_t rval; if (dir == RoundUp) rval = size_t(val + 0.01); else if (dir == RoundDown) rval = size_t(prevVal + 0.01); else if (val - blockSize < blockSize - prevVal) rval = size_t(val + 0.01); else rval = size_t(prevVal + 0.01); // std::cerr << "returning " << rval << std::endl; return rval; } unsigned int prevBase = (1 << minCachePower); unsigned int prevPower = minCachePower; unsigned int prevType = 0; size_t result = 0; for (unsigned int i = 0; ; ++i) { power = minCachePower + i/2; type = i % 2; unsigned int base; if (type == 0) { base = (1 << power); } else { base = (((unsigned int)((1 << minCachePower) * sqrt(2) + 0.01)) << (power - minCachePower)); } // std::cerr << "Testing base " << base << std::endl; if (base >= blockSize) { if (dir == RoundNearest) { if (base - blockSize < blockSize - prevBase) { dir = RoundUp; } else { dir = RoundDown; } } if (dir == RoundUp) { result = base; break; } else { type = prevType; power = prevPower; result = prevBase; break; } } prevType = type; prevPower = power; prevBase = base; } if (result > getMaxZoomLevel()) result = getMaxZoomLevel(); return result; }