view layer/PaintAssistant.cpp @ 473:4f4f943bfdfc

* Merge from one-fftdataserver-per-fftmodel branch.  This bit of
reworking (which is not described very accurately by the title of
the branch) turns the MatrixFile object into something that either
reads or writes, but not both, and separates the FFT file cache
reader and writer implementations separately.  This allows the
FFT data server to have a single thread owning writers and one reader
per "customer" thread, and for all locking to be vastly simplified
and concentrated in the data server alone (because none of the
classes it makes use of is used in more than one thread at a time).
The result is faster and more trustworthy code.

/* -*- 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;
}