view base/ResizeableBitset.h @ 1008:d9e0e59a1581

When using an aggregate model to pass data to a transform, zero-pad the shorter input to the duration of the longer rather than truncating the longer. (This is better behaviour for e.g. MATCH, and in any case the code was previously truncating incorrectly and ending up with garbage data at the end.)

/* -*- 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.
*/

#ifndef _RESIZEABLE_BITMAP_H_
#define _RESIZEABLE_BITMAP_H_

#include <vector>
#include <stdint.h>
#include <stddef.h>
#include <stdlib.h>

class ResizeableBitset {

public:
    ResizeableBitset() : m_bits(0), m_size(0) {
    }
    ResizeableBitset(size_t size) : m_bits(new std::vector<uint8_t>), m_size(size) {
        m_bits->assign((size >> 3) + 1, 0);
    }
    ResizeableBitset(const ResizeableBitset &b) {
        m_bits = new std::vector<uint8_t>(*b.m_bits);
    }
    ResizeableBitset &operator=(const ResizeableBitset &b) {
        if (&b != this) return *this;
        delete m_bits;
        m_bits = new std::vector<uint8_t>(*b.m_bits);
        return *this;
    }
    ~ResizeableBitset() {
        delete m_bits;
    }
    
    void resize(size_t size) { // retaining existing data; not thread safe
        size_t bytes = (size >> 3) + 1;
        if (m_bits && bytes == m_bits->size()) return;
        std::vector<uint8_t> *newbits = new std::vector<uint8_t>(bytes);
        newbits->assign(bytes, 0);
        if (m_bits) {
            for (size_t i = 0; i < bytes && i < m_bits->size(); ++i) {
                (*newbits)[i] = (*m_bits)[i];
            }
            delete m_bits;
        }
        m_bits = newbits;
        m_size = size;
    }
    
    bool get(size_t column) const {
        return ((*m_bits)[column >> 3]) & (1u << (column & 0x07));
    }
    
    void set(size_t column) {
        ((*m_bits)[column >> 3]) |=  (uint8_t(1) << (column & 0x07));
    }

    void reset(size_t column) {
        ((*m_bits)[column >> 3]) &= ~(uint8_t(1) << (column & 0x07));
    }

    void copy(size_t source, size_t dest) {
        get(source) ? set(dest) : reset(dest);
    }

    bool isAllOff() const {
        for (size_t i = 0; i < m_bits->size(); ++i) {
            if ((*m_bits)[i]) return false;
        }
        return true;
    }

    bool isAllOn() const {
        for (size_t i = 0; i + 1 < m_bits->size(); ++i) {
            if ((*m_bits)[i] != 0xff) return false;
        }
        for (size_t i = (m_size / 8) * 8; i < m_size; ++i) {
            if (!get(i)) return false;
        }
        return true;
    }

    size_t size() const {
        return m_size;
    }
    
private:
    std::vector<uint8_t> *m_bits;
    size_t m_size;
};


#endif