Use multiple drawLine() calls instead of drawPolyline()

[pulseview.git] / pv / views / trace / analogsignal.cpp

diff --git a/pv/views/trace/analogsignal.cpp b/pv/views/trace/analogsignal.cpp
index cd680085312b07d5249fecca2f51b0c32cdb39de..3430ab3cf48eb6996ca0cd52901c1d9c884aa4cb 100644 (file)
--- a/pv/views/trace/analogsignal.cpp
+++ b/pv/views/trace/analogsignal.cpp
@@ -297,7 +297,7 @@ void AnalogSignal::paint_fore(QPainter &p, ViewItemPaintParams &pp)
                // and we have corresponding data available
                if (show_hover_marker_ && !std::isnan(value_at_hover_pos_)) {
                        infotext = QString("[%1] %2 V/div")
-                               .arg(format_value_si(value_at_hover_pos_, SIPrefix::unspecified, 0, "V", false))
+                               .arg(format_value_si(value_at_hover_pos_, SIPrefix::unspecified, 2, "V", false))
                                .arg(resolution_);
                } else
                        infotext = QString("%1 V/div").arg(resolution_);
@@ -319,6 +319,7 @@ void AnalogSignal::paint_fore(QPainter &p, ViewItemPaintParams &pp)
 
 void AnalogSignal::paint_grid(QPainter &p, int y, int left, int right)
 {
+       bool was_antialiased = p.testRenderHint(QPainter::Antialiasing);
        p.setRenderHint(QPainter::Antialiasing, false);
 
        if (pos_vdivs_ > 0) {
@@ -363,7 +364,7 @@ void AnalogSignal::paint_grid(QPainter &p, int y, int left, int right)
                }
        }
 
-       p.setRenderHint(QPainter::Antialiasing, true);
+       p.setRenderHint(QPainter::Antialiasing, was_antialiased);
 }
 
 void AnalogSignal::paint_trace(QPainter &p,
@@ -443,7 +444,9 @@ void AnalogSignal::paint_trace(QPainter &p,
        }
        delete[] sample_block;
 
-       p.drawPolyline(points, points_count);
+       // QPainter::drawPolyline() is slow, let's paint the lines ourselves
+       for (int64_t i = 1; i < points_count; i++)
+               p.drawLine(points[i - 1], points[i]);
 
        if (show_sampling_points) {
                if (paint_thr_dots) {