Render ruler and signals with sub-pixel accuracy

[pulseview.git] / pv / view / ruler.cpp

diff --git a/pv/view/ruler.cpp b/pv/view/ruler.cpp
index 84a6a2d736afd250cb22bf6bda4d7f3e2135a24c..97c0be6822506ffa1c3056493a629d14428dc6e2 100644 (file)
--- a/pv/view/ruler.cpp
+++ b/pv/view/ruler.cpp
@@ -21,7 +21,7 @@
 #include "ruler.h"
 #include "view.h"
 
-#include "../../extdef.h"
+#include <extdef.h>
 
 #include <assert.h>
 #include <math.h>
@@ -48,6 +48,7 @@ Ruler::Ruler(View &parent) :
 void Ruler::paintEvent(QPaintEvent *event)
 {
        QPainter p(this);
+       p.setRenderHint(QPainter::Antialiasing);
 
        const double MinSpacing = 80;
 
@@ -56,7 +57,7 @@ void Ruler::paintEvent(QPaintEvent *event)
        const int order = (int)floorf(log10f(min_period));
        const double order_decimal = pow(10, order);
 
-       int unit = 0;
+       unsigned int unit = 0;
        double tick_period = 0.0f;
 
        do
@@ -64,11 +65,11 @@ void Ruler::paintEvent(QPaintEvent *event)
                tick_period = order_decimal * ScaleUnits[unit++];
        } while(tick_period < min_period && unit < countof(ScaleUnits));
 
-       const int prefix = (order - FirstSIPrefixPower) / 3;
+       const unsigned int prefix = (order - FirstSIPrefixPower) / 3;
        assert(prefix >= 0);
        assert(prefix < countof(SIPrefixes));
 
-       const double multiplier = pow(0.1, prefix * 3 + FirstSIPrefixPower);
+       const double multiplier = pow(10.0, - prefix * 3 - FirstSIPrefixPower);
 
        const int text_height = p.boundingRect(0, 0, INT_MAX, INT_MAX,
                Qt::AlignLeft | Qt::AlignTop, "8").height();
@@ -101,13 +102,14 @@ void Ruler::paintEvent(QPaintEvent *event)
                        ts << (t * multiplier) << SIPrefixes[prefix] << "s";
                        p.drawText(x, 0, 0, text_height, Qt::AlignCenter |
                                Qt::AlignTop | Qt::TextDontClip, s);
-                       p.drawLine(x, text_height, x, height());
+                       p.drawLine(QPointF(x, text_height),
+                               QPointF(x, height()));
                }
                else
                {
                        // Draw a minor tick
-                       p.drawLine(x, (text_height + height()) / 2,
-                               x, height());
+                       p.drawLine(QPointF(x, (text_height + height()) / 2),
+                               QPointF(x, height()));
                }
 
                division++;