view layer/PaintAssistant.cpp @ 1386:fc3d89f88690 spectrogramparam

Use log-frequency rather than log-bin for calculating x coord in spectrum. This has the advantage that frequency positions don't move when we change the window size or oversampling ratio, but it does give us an unhelpfully large amount of space for very low frequencies - to be considered

/* -*- 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 2006-2007 Chris Cannam and QMUL.
   
    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 "PaintAssistant.h"

#include "LayerGeometryProvider.h"

#include "base/AudioLevel.h"
#include "base/Strings.h"
#include "base/Debug.h"

#include <QPaintDevice>
#include <QPainter>

#include <iostream>
#include <cmath>

void
PaintAssistant::paintVerticalLevelScale(QPainter &paint, QRect rect,
                                        double minVal, double maxVal,
                                        Scale scale, int &mult,
                                        std::vector<int> *vy)
{
    static double meterdbs[] = { -40, -30, -20, -15, -10,
                                -5, -3, -2, -1, -0.5, 0 };

    int h = rect.height(), w = rect.width();
    int textHeight = paint.fontMetrics().height();
    int toff = -textHeight/2 + paint.fontMetrics().ascent() + 1;

    int lastLabelledY = -1;

    int n = 10;
    if (vy) vy->clear();

    double step = 0;
    mult = 1;
    if (scale == LinearScale) {
        step = (maxVal - minVal) / n;
        int round = 0, limit = 10000000;
        do {
            round = int(minVal + step * mult);
            mult *= 10;
        } while (!round && mult < limit);
        if (round) {
            mult /= 10;
            step = double(round) / mult;
            n = int(lrint((maxVal - minVal) / step));
            if (mult > 1) {
                mult /= 10;
            }
        }
    }

    for (int i = 0; i <= n; ++i) {
        
        double val = 0.0, nval = 0.0;
        QString text = "";

        switch (scale) {
                
        case LinearScale:
            val = (minVal + (i * step));
            text = QString("%1").arg(mult * val);
            break;
            
        case MeterScale: // ... min, max
            val = AudioLevel::dB_to_multiplier(meterdbs[i]);
            text = QString("%1").arg(meterdbs[i]);
            if (i == n) text = "0dB";
            if (i == 0) {
                text = Strings::minus_infinity;
                val = 0.0;
            }
            break;

        case dBScale: // ... min, max
            val = AudioLevel::dB_to_multiplier(-(10*n) + i * 10);
            text = QString("%1").arg(-(10*n) + i * 10);
            if (i == n) text = "0dB";
            if (i == 0) {
                text = Strings::minus_infinity;
                val = 0.0;
            }
            break;
        }

        if (val < minVal || val > maxVal) continue;

        int y = getYForValue(scale, val, minVal, maxVal, rect.y(), h);
            
        int ny = y;
        if (nval != 0.0) {
            ny = getYForValue(scale, nval, minVal, maxVal, rect.y(), h);
        }

//        SVDEBUG << "PaintAssistant::paintVerticalLevelScale: val = "
//                  << val << ", y = " << y << ", h = " << h << endl;

        bool spaceForLabel = (i == 0 ||
                              abs(y - lastLabelledY) >= textHeight - 1);
        
        if (spaceForLabel) {
            
            int tx = 3;
            if (paint.fontMetrics().width(text) < w - 10) {
                tx = w - 10 - paint.fontMetrics().width(text);
            }
            
            int ty = y;

            if (ty < paint.fontMetrics().ascent()) {
                ty = paint.fontMetrics().ascent();
            } else {
                ty += toff;
            }

            paint.drawText(tx, ty, text);
            
            lastLabelledY = ty - toff;

            paint.drawLine(w - 7, y, w, y);
            if (vy) vy->push_back(y);

            if (ny != y) {
                paint.drawLine(w - 7, ny, w, ny);
                if (vy) vy->push_back(ny);
            }
            
        } else {
            
            paint.drawLine(w - 4, y, w, y);
            if (vy) vy->push_back(y);

            if (ny != y) {
                paint.drawLine(w - 4, ny, w, ny);
                if (vy) vy->push_back(ny);
            }
        }
    }
}

static int
dBscale(double sample, int m, double maxVal, double minVal) 
{
    if (sample < 0.0) return dBscale(-sample, m, maxVal, minVal);
    double dB = AudioLevel::multiplier_to_dB(sample);
    double mindB = AudioLevel::multiplier_to_dB(minVal);
    double maxdB = AudioLevel::multiplier_to_dB(maxVal);
    if (dB < mindB) return 0;
    if (dB > 0.0) return m;
    return int(((dB - mindB) * m) / (maxdB - mindB) + 0.1);
}

int
PaintAssistant::getYForValue(Scale scale, double value, 
                             double minVal, double maxVal,
                             int minY, int height)
{
    int vy = 0;

    switch (scale) {

    case LinearScale:
        vy = minY + height - int(((value - minVal) / (maxVal - minVal)) * height);
        break;

    case MeterScale:
        vy = minY + height - AudioLevel::multiplier_to_preview
            ((value - minVal) / (maxVal - minVal), height);
        break;

    case dBScale:
        vy = minY + height - dBscale(value, height, maxVal, minVal);
        break;
    }

    return vy;
}

void
PaintAssistant::drawVisibleText(const LayerGeometryProvider *v,
                                QPainter &paint, int x, int y,
                                QString text, TextStyle style)
{
    if (style == OutlinedText || style == OutlinedItalicText) {

        paint.save();

        if (style == OutlinedItalicText) {
            QFont f(paint.font());
            f.setItalic(true);
            paint.setFont(f);
        }

        QColor penColour, surroundColour, boxColour;

        penColour = v->getForeground();
        surroundColour = v->getBackground();
        boxColour = surroundColour;
        boxColour.setAlpha(127);

        paint.setPen(Qt::NoPen);
        paint.setBrush(boxColour);
        
        QRect r = paint.fontMetrics().boundingRect(text);
        r.translate(QPoint(x, y));
        paint.drawRect(r);
        paint.setBrush(Qt::NoBrush);

        paint.setPen(surroundColour);

        for (int dx = -1; dx <= 1; ++dx) {
            for (int dy = -1; dy <= 1; ++dy) {
                if (!(dx || dy)) continue;
                paint.drawText(x + dx, y + dy, text);
            }
        }

        paint.setPen(penColour);

        paint.drawText(x, y, text);

        paint.restore();

    } else {

        std::cerr << "ERROR: PaintAssistant::drawVisibleText: Boxed style not yet implemented!" << std::endl;
    }
}

double
PaintAssistant::scaleSize(double size)
{
    static double ratio = 0.0;
    if (ratio == 0.0) {
        double baseEm;
#ifdef Q_OS_MAC
        baseEm = 17.0;
#else
        baseEm = 15.0;
#endif
        double em = QFontMetrics(QFont()).height();
        ratio = em / baseEm;

        SVDEBUG << "PaintAssistant::scaleSize: ratio is " << ratio
                << " (em = " << em << ")" << endl;

        if (ratio < 1.0) {
            SVDEBUG << "PaintAssistant::scaleSize: rounding ratio up to 1.0"
                    << endl;
            ratio = 1.0;
        }
    }

    return size * ratio;
}

double
PaintAssistant::scalePenWidth(double width)
{
    if (width <= 0) {
        // zero-width pen, produce a scaled one-pixel pen
        width = 1;
    }

    return scaleSize(width);
}

QPen
PaintAssistant::scalePen(QPen pen)
{
    return QPen(pen.color(), scalePenWidth(pen.width()));
}