view layer/PaintAssistant.cpp @ 1127:9fb8dfd7ce4c spectrogram-minor-refactor

Fix threshold in spectrogram -- it wasn't working in the last release.
There is a new protocol for this. Formerly the threshold parameter had a
range from -50dB to 0 with the default at -50, and -50 treated internally
as "no threshold". However, there was a hardcoded, hidden internal threshold
for spectrogram colour mapping at -80dB with anything below this being rounded
to zero. Now the threshold parameter has range -81 to -1 with the default
at -80, -81 is treated internally as "no threshold", and there is no hidden
internal threshold. So the default behaviour is the same as before, an
effective -80dB threshold, but it is now possible to change this in both
directions. Sessions reloaded from prior versions may look slightly different
because, if the session says there should be no threshold, there will now
actually be no threshold instead of having the hidden internal one.

Still need to do something in the UI to make it apparent that the -81dB
setting removes the threshold entirely. This is at least no worse than the
previous, also obscured, magic -50dB setting.

/* -*- 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 <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;
//            cerr << "\n\nstep goes from " << step;
            step = double(round) / mult;
            n = int(lrint((maxVal - minVal) / step));
            if (mult > 1) {
                mult /= 10;
            }
//            cerr << " to " << step << " (n = " << n << ")" << endl;
        }
    }

    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 = "-Inf";
                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 = "-Inf";
                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 (scale != LinearScale) {
            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 if (ty > rect.y() + h - paint.fontMetrics().descent()) {
//                ty = rect.y() + h - paint.fontMetrics().descent();
            } else {
                ty += toff;
            }

            paint.drawText(tx, ty, text);
            
            lastLabelledY = ty - toff;
            /*
            if (ny != y) {
                ty = ny;
                if (ty < paint.fontMetrics().ascent()) {
                    ty = paint.fontMetrics().ascent();
                } else if (ty > h - paint.fontMetrics().descent()) {
                    ty = h - paint.fontMetrics().descent();
                } else {
                    ty += toff;
                }
                paint.drawText(tx, ty, text);
            }
            */
            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;

//    int m = height/2;
//    int my = minY + m;

    switch (scale) {

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

    case MeterScale:
//        vy = my - AudioLevel::multiplier_to_preview(value, m);
        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));
//        cerr << "drawVisibleText: r = " << r.x() << "," <<r.y() << " " << r.width() << "x" << r.height() << endl;
        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;
    }
}