#include "extdef.h"
#include <QMouseEvent>
+#include <QTextStream>
#include <math.h>
const int SigView::ScaleUnits[3] = {1, 2, 5};
+const QString SigView::SIPrefixes[9] =
+ {"f", "p", "n", QChar(0x03BC), "m", "", "k", "M", "G"};
+const int SigView::FirstSIPrefixPower = -15;
+
SigView::SigView(SigSession &session, QWidget *parent) :
QGLWidget(parent),
_session(session),
void SigView::paintRuler(QPainter &p)
{
- const double MinSpacing = 20;
+ const double MinSpacing = 80;
- double tick_period = 0.0f;
const double min_period = _scale * MinSpacing;
- double order = 10e-15;
- while(tick_period < min_period)
+ const int order = (int)floorf(log10f(min_period));
+ const double order_decimal = pow(10, order);
+
+ int unit = 0;
+ double tick_period = 0.0f;
+
+ do
{
- int unit = 0;
- while(tick_period < min_period &&
- unit < countof(ScaleUnits))
- tick_period = order * ScaleUnits[unit++];
- order *= 10;
- }
+ tick_period = order_decimal * ScaleUnits[unit++];
+ } while(tick_period < min_period && unit < countof(ScaleUnits));
- const double tick_seperation = tick_period / _scale;
+ const int prefix = (order - FirstSIPrefixPower) / 3;
+ assert(prefix >= 0);
+ assert(prefix < countof(SIPrefixes));
- p.setPen(Qt::transparent);
- p.setBrush(QColor(0xC0, 0xC0, 0xC0));
- p.drawRect(LabelMarginWidth, 0,
- width() - LabelMarginWidth, RulerHeight);
+ const int text_height = p.boundingRect(0, 0, INT_MAX, INT_MAX,
+ Qt::AlignLeft | Qt::AlignTop, "8").height();
+ // Draw the tick marks
p.setPen(Qt::black);
- const double offset_ticks = -_offset / tick_period;
- double x = (offset_ticks - floor(offset_ticks)) *
- tick_seperation + LabelMarginWidth;
- while(x < width())
+ double t = ceil(_offset / tick_period) * tick_period;
+ double x = 0.0;
+ while((x = (t - _offset) / _scale + LabelMarginWidth) < width())
{
- p.drawLine(x, 0, x, RulerHeight);
- x += tick_seperation;
+ QString s;
+ QTextStream ts(&s);
+ ts << (t / order_decimal) << SIPrefixes[prefix] << "s";
+ p.drawText(x, 0, 0, text_height, Qt::AlignCenter | Qt::AlignTop |
+ Qt::TextDontClip, s);
+ p.drawLine(x, text_height, x, RulerHeight);
+ t += tick_period;
}
}