view widgets/WindowShapePreview.cpp @ 349:369a197737c7

* Various fixes to object lifetime management, particularly in the spectrum
  layer and for notification of main model deletion.
  The main purpose of this is to improve the behaviour of the spectrum, but I
  think it may also help with #1840922 Various crashes in Layer Summary window.

/* -*- 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 "WindowShapePreview.h"

#include <QHBoxLayout>
#include <QLabel>
#include <QPainter>
#include <QPainterPath>
#include <QFont>
#include <QString>

#include "data/fft/FFTapi.h"

#include <iostream>

WindowShapePreview::WindowShapePreview(QWidget *parent) :
    QFrame(parent),
    m_windowType(WindowType(999))
{
    QHBoxLayout *layout = new QHBoxLayout;
    layout->setMargin(0);
    setLayout(layout);
    m_windowTimeExampleLabel = new QLabel;
    m_windowFreqExampleLabel = new QLabel;
    layout->addWidget(m_windowTimeExampleLabel);
    layout->addWidget(m_windowFreqExampleLabel);
}

WindowShapePreview::~WindowShapePreview()
{
}

void
WindowShapePreview::updateLabels()
{
    int step = 24;
    int peak = 48;
    int w = step * 4, h = 64;
    WindowType type = m_windowType;
    Window<float> windower = Window<float>(type, step * 2);

    QPixmap timeLabel(w, h + 1);
    timeLabel.fill(Qt::white);
    QPainter timePainter(&timeLabel);

    QPainterPath path;

    path.moveTo(0, h - peak + 1);
    path.lineTo(w, h - peak + 1);

    timePainter.setPen(Qt::gray);
    timePainter.setRenderHint(QPainter::Antialiasing, true);
    timePainter.drawPath(path);
    
    path = QPainterPath();

    float acc[w];
    for (int i = 0; i < w; ++i) acc[i] = 0.f;
    for (int j = 0; j < 3; ++j) {
        for (int i = 0; i < step * 2; ++i) {
            acc[j * step + i] += windower.getValue(i);
        }
    }
    for (int i = 0; i < w; ++i) {
        int y = h - int(peak * acc[i] + 0.001) + 1;
        if (i == 0) path.moveTo(i, y);
        else path.lineTo(i, y);
    }

    timePainter.drawPath(path);
    timePainter.setRenderHint(QPainter::Antialiasing, false);

    path = QPainterPath();

    timePainter.setPen(Qt::black);
    
    for (int i = 0; i < step * 2; ++i) {
        int y = h - int(peak * windower.getValue(i) + 0.001) + 1;
        if (i == 0) path.moveTo(i + step, float(y));
        else path.lineTo(i + step, float(y));
    }

    if (type == RectangularWindow) {
        timePainter.drawPath(path);
        path = QPainterPath();
    }

    timePainter.setRenderHint(QPainter::Antialiasing, true);
    path.addRect(0, 0, w, h + 1);
    timePainter.drawPath(path);

    QFont font;
    font.setPixelSize(10);
    font.setItalic(true);
    timePainter.setFont(font);
    QString label = tr("V / time");
    timePainter.drawText(w - timePainter.fontMetrics().width(label) - 4,
                         timePainter.fontMetrics().ascent() + 1, label);

    m_windowTimeExampleLabel->setPixmap(timeLabel);
    
    int fw = 100;

    QPixmap freqLabel(fw, h + 1);
    freqLabel.fill(Qt::white);
    QPainter freqPainter(&freqLabel);
    path = QPainterPath();

    int fftsize = 512;

    float *input = (float *)fftf_malloc(fftsize * sizeof(float));
    fftf_complex *output =
        (fftf_complex *)fftf_malloc(fftsize * sizeof(fftf_complex));
    fftf_plan plan = fftf_plan_dft_r2c_1d(fftsize, input, output,
                                            FFTW_ESTIMATE);
    for (int i = 0; i < fftsize; ++i) input[i] = 0.f;
    for (int i = 0; i < step * 2; ++i) {
        input[fftsize/2 - step + i] = windower.getValue(i);
    }
    
    fftf_execute(plan);
    fftf_destroy_plan(plan);

    float maxdb = 0.f;
    float mindb = 0.f;
    bool first = true;
    for (int i = 0; i < fftsize/2; ++i) {
        float power = output[i][0] * output[i][0] + output[i][1] * output[i][1];
        float db = mindb;
        if (power > 0) {
            db = 20 * log10(power);
            if (first || db > maxdb) maxdb = db;
            if (first || db < mindb) mindb = db;
            first = false;
        }
    }

    if (mindb > -80.f) mindb = -80.f;

    // -- no, don't use the actual mindb -- it's easier to compare
    // plots with a fixed min value
    mindb = -170.f;

    float maxval = maxdb + -mindb;

//    float ly = h - ((-80.f + -mindb) / maxval) * peak + 1;

    path.moveTo(0, h - peak + 1);
    path.lineTo(fw, h - peak + 1);

    freqPainter.setPen(Qt::gray);
    freqPainter.setRenderHint(QPainter::Antialiasing, true);
    freqPainter.drawPath(path);
    
    path = QPainterPath();
    freqPainter.setPen(Qt::black);

//    std::cerr << "maxdb = " << maxdb << ", mindb = " << mindb << ", maxval = " <<maxval << std::endl;

    for (int i = 0; i < fftsize/2; ++i) {
        float power = output[i][0] * output[i][0] + output[i][1] * output[i][1];
        float db = 20 * log10(power);
        float val = db + -mindb;
        if (val < 0) val = 0;
        float norm = val / maxval;
        float x = (fw / float(fftsize/2)) * i;
        float y = h - norm * peak + 1;
        if (i == 0) path.moveTo(x, y);
        else path.lineTo(x, y);
    }

    freqPainter.setRenderHint(QPainter::Antialiasing, true);
    path.addRect(0, 0, fw, h + 1);
    freqPainter.drawPath(path);

    fftf_free(input);
    fftf_free(output);

    freqPainter.setFont(font);
    label = tr("dB / freq");
    freqPainter.drawText(fw - freqPainter.fontMetrics().width(label) - 4,
                         freqPainter.fontMetrics().ascent() + 1, label);

    m_windowFreqExampleLabel->setPixmap(freqLabel);
}

void
WindowShapePreview::setWindowType(WindowType type)
{
    if (m_windowType == type) return;
    m_windowType = type;
    updateLabels();
}