view layer/PaintAssistant.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 2006-2007 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 "base/AudioLevel.h"

#include <QPaintDevice>
#include <QPainter>

#include <iostream>
#include <cmath>

void
PaintAssistant::paintVerticalLevelScale(QPainter &paint, QRect rect,
					float minVal, float maxVal,
                                        Scale scale, int &mult,
                                        std::vector<int> *vy)
{
    static float 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();

    float 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;
//            std::cerr << "\n\nstep goes from " << step;
            step = float(round) / mult;
            n = lrintf((maxVal - minVal) / step);
            if (mult > 1) {
                mult /= 10;
            }
//            std::cerr << " to " << step << " (n = " << n << ")" << std::endl;
        }
    }

    for (int i = 0; i <= n; ++i) {
        
        float 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);
        }

//        std::cerr << "PaintAssistant::paintVerticalLevelScale: val = "
//                  << val << ", y = " << y << ", h = " << h << std::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(float sample, int m, float maxVal, float minVal) 
{
    if (sample < 0.0) return dBscale(-sample, m, maxVal, minVal);
    float dB = AudioLevel::multiplier_to_dB(sample);
    float mindB = AudioLevel::multiplier_to_dB(minVal);
    float 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, float value, 
                             float minVal, float 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;
}