git.sesse.net Git - nageru/blob - nageru/compression_reduction_meter.cpp

   1 #include "compression_reduction_meter.h"
   2
   3 #include <QFont>
   4 #include <QPaintDevice>
   5 #include <QPainter>
   6 #include <QPixmap>
   7 #include <QRect>
   8 #include <QWidget>
   9 #include <math.h>
  10 #include <stddef.h>
  11 #include <stdio.h>
  12 #include <mutex>
  13 #include <vector>
  14 #include "piecewise_interpolator.h"
  15 #include "vu_common.h"
  16
  17 class QPaintEvent;
  18 class QResizeEvent;
  19
  20 using namespace std;
  21
  22 namespace {
  23
  24 vector<PiecewiseInterpolator::ControlPoint> control_points = {
  25         { 60.0f, 6.0f },
  26         { 30.0f, 5.0f },
  27         { 18.0f, 4.0f },
  28         { 12.0f, 3.0f },
  29         { 6.0f, 2.0f },
  30         { 3.0f, 1.0f },
  31         { 0.0f, 0.0f }
  32 };
  33 PiecewiseInterpolator interpolator(control_points);
  34
  35 }  // namespace
  36
  37 CompressionReductionMeter::CompressionReductionMeter(QWidget *parent)
  38         : QWidget(parent)
  39 {
  40 }
  41
  42 void CompressionReductionMeter::resizeEvent(QResizeEvent *event)
  43 {
  44         recalculate_pixmaps();
  45 }
  46
  47 void CompressionReductionMeter::paintEvent(QPaintEvent *event)
  48 {
  49         QPainter painter(this);
  50
  51         float level_db;
  52         {
  53                 lock_guard<mutex> lock(level_mutex);
  54                 level_db = this->level_db;
  55         }
  56
  57         int on_pos = lrint(db_to_pos(level_db));
  58
  59         QRect on_rect(0, 0, width(), on_pos);
  60         QRect off_rect(0, on_pos, width(), height());
  61
  62         painter.drawPixmap(on_rect, on_pixmap, on_rect);
  63         painter.drawPixmap(off_rect, off_pixmap, off_rect);
  64 }
  65
  66 void CompressionReductionMeter::recalculate_pixmaps()
  67 {
  68         constexpr int y_offset = text_box_height / 2;
  69         constexpr int text_margin = 5;
  70         float margin = 0.5 * (width() - meter_width);
  71
  72         on_pixmap = QPixmap(width(), height());
  73         QPainter on_painter(&on_pixmap);
  74         on_painter.fillRect(0, 0, width(), height(), parentWidget()->palette().window());
  75         draw_vu_meter(on_painter, width(), meter_height(), margin, 2.0, true, min_level, max_level, /*flip=*/true, y_offset);
  76         draw_scale(&on_painter, 0.5 * width() + 0.5 * meter_width + text_margin);
  77
  78         off_pixmap = QPixmap(width(), height());
  79         QPainter off_painter(&off_pixmap);
  80         off_painter.fillRect(0, 0, width(), height(), parentWidget()->palette().window());
  81         draw_vu_meter(off_painter, width(), meter_height(), margin, 2.0, false, min_level, max_level, /*flip=*/true, y_offset);
  82         draw_scale(&off_painter, 0.5 * width() + 0.5 * meter_width + text_margin);
  83 }
  84
  85 void CompressionReductionMeter::draw_scale(QPainter *painter, int x_pos)
  86 {
  87         QFont font;
  88         font.setPointSize(8);
  89         painter->setPen(Qt::black);
  90         painter->setFont(font);
  91         for (size_t i = 0; i < control_points.size(); ++i) {
  92                 char buf[256];
  93                 snprintf(buf, 256, "%.0f", control_points[i].db_value);
  94                 double y = db_to_pos(control_points[i].db_value);
  95                 painter->drawText(QRect(x_pos, y - text_box_height / 2, text_box_width, text_box_height),
  96                         Qt::AlignCenter | Qt::AlignVCenter, buf);
  97         }
  98 }
  99
 100 double CompressionReductionMeter::db_to_pos(double level_db) const
 101 {
 102         float value = interpolator.db_to_fraction(level_db);
 103         return height() - lufs_to_pos(value, meter_height(), min_level, max_level) - text_box_height / 2;
 104 }
 105
 106 int CompressionReductionMeter::meter_height() const
 107 {
 108         return height() - text_box_height;
 109 }