view widgets/WindowShapePreview.cpp @ 959:2633a1d73e39

Address #1214, layer import produces wrong layer type. We needed a more principled approach to making sure the format gets updated properly and the dialog elements are consistent (basically separating making the dialog elements consistent from subsequently updating the format). This change should provide that, though there may be gotchas still.

/* -*- 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>

#ifndef __GNUC__
#include <alloca.h>
#endif

WindowShapePreview::WindowShapePreview(QWidget *parent) :
    QFrame(parent),
    m_windowType(HanningWindow)
{
    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;
    float 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, float(h) - peak + 1);
    path.lineTo(w, float(h) - peak + 1);

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

#ifdef __GNUC__
    float acc[w];
#else
    float *acc = (float *)alloca(w * sizeof(float));
#endif

    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] + 0.001f) + 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.f * log10f(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, float(h) - peak + 1);
    path.lineTo(fw, float(h) - peak + 1);

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

//    cerr << "maxdb = " << maxdb << ", mindb = " << mindb << ", maxval = " <<maxval << 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.f * log10f(power);
        float val = db + -mindb;
        if (val < 0) val = 0;
        float norm = val / maxval;
        float x = (float(fw) / float(fftsize/2)) * float(i);
        float y = float(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();
}