X-Git-Url: http://sigrok.org/gitweb/?a=blobdiff_plain;f=pv%2Fview%2Fview.cpp;h=d32a23da07e3bb30c8553f494636bdda959c6c06;hb=fd03a2797f0352892a8068a0d27da3c420c73973;hp=0844b6a47e6fd13c16d34ba85eddfc7850ec3974;hpb=7ee199a77ecbb7edd6decca4786648cfe07e6eec;p=pulseview.git

diff --git a/pv/view/view.cpp b/pv/view/view.cpp
index 0844b6a4..d32a23da 100644
--- a/pv/view/view.cpp
+++ b/pv/view/view.cpp
@@ -84,7 +84,7 @@ namespace pv {
 namespace view {
 
 const double View::MaxScale = 1e9;
-const double View::MinScale = 1e-15;
+const double View::MinScale = 1e-12;
 
 const int View::MaxScrollValue = INT_MAX / 2;
 const int View::MaxViewAutoUpdateRate = 25; // No more than 25 Hz with sticky scrolling
@@ -104,6 +104,7 @@ View::View(Session &session, QWidget *parent) :
 	always_zoom_to_fit_(false),
 	tick_period_(0.0),
 	tick_prefix_(0),
+	tick_precision_(0),
 	time_unit_(util::Time),
 	show_cursors_(false),
 	cursors_(new CursorPair(*this)),
@@ -236,6 +237,11 @@ unsigned int View::tick_prefix() const
 	return tick_prefix_;
 }
 
+unsigned int View::tick_precision() const
+{
+	return tick_precision_;
+}
+
 double View::tick_period() const
 {
 	return tick_period_;
@@ -487,10 +493,16 @@ void View::set_zoom(double scale, int offset)
 
 void View::calculate_tick_spacing()
 {
-	const double SpacingIncrement = 32.0f;
-	const double MinValueSpacing = 32.0f;
+	const double SpacingIncrement = 10.0f;
+	const double MinValueSpacing = 25.0f;
+
+	// Figure out the highest numeric value visible on a label
+	const QSize areaSize = viewport_->size();
+	const double max_time = max(fabs(offset_),
+		fabs(offset_ + scale_ * areaSize.width()));
 
-	double min_width = SpacingIncrement, typical_width;
+	double min_width = SpacingIncrement;
+	double label_width, tick_period_width;
 
 	QFontMetrics m(QApplication::font());
 
@@ -500,23 +512,37 @@ void View::calculate_tick_spacing()
 		const int order = (int)floorf(log10f(min_period));
 		const double order_decimal = pow(10.0, order);
 
+		// Allow for a margin of error so that a scale unit of 1 can be used.
+		// Otherwise, for a SU of 1 the tick period will almost always be below
+		// the min_period by a small amount - and thus skipped in favor of 2.
+		// Note: margin assumes that SU[0] and SU[1] contain the smallest values
+		double tp_margin = (ScaleUnits[0] + ScaleUnits[1]) / 2.0;
+		double tp_with_margin;
 		unsigned int unit = 0;
 
 		do {
-			tick_period_ = order_decimal * ScaleUnits[unit++];
-		} while (tick_period_ < min_period &&
-			unit < countof(ScaleUnits));
+			tp_with_margin = order_decimal * (ScaleUnits[unit++] + tp_margin);
+		} while (tp_with_margin < min_period && unit < countof(ScaleUnits));
 
+		tick_period_ = order_decimal * ScaleUnits[unit - 1];
 		tick_prefix_ = (order - pv::util::FirstSIPrefixPower) / 3;
 
-		typical_width = m.boundingRect(0, 0, INT_MAX, INT_MAX,
-			Qt::AlignLeft | Qt::AlignTop,
-			format_time(offset_, tick_prefix_, time_unit_)).width() +
+		// Precision is the number of fractional digits required, not
+		// taking the prefix into account (and it must never be negative)
+		tick_precision_ = std::max((int)ceil(log10f(1 / tick_period_)), 0);
+
+		tick_period_width = tick_period_ / scale_;
+
+		const QString label_text =
+			format_time(max_time, tick_prefix_, time_unit_, tick_precision_);
+
+		label_width = m.boundingRect(0, 0, INT_MAX, INT_MAX,
+			Qt::AlignLeft | Qt::AlignTop, label_text).width() +
 				MinValueSpacing;
 
 		min_width += SpacingIncrement;
 
-	} while (typical_width > tick_period_ / scale_);
+	} while (tick_period_width < label_width);
 }
 
 void View::update_scroll()
@@ -899,14 +925,20 @@ void View::signals_changed()
 
 void View::capture_state_updated(int state)
 {
-	// Reset "always zoom to fit" when we change to the stopped state
-	if (always_zoom_to_fit_ && (state == Session::Stopped)) {
-		always_zoom_to_fit_ = false;
-		always_zoom_to_fit_changed(false);
-	}
-
 	if (state == Session::Running)
 		time_unit_ = util::Samples;
+
+	if (state == Session::Stopped) {
+		// After acquisition has stopped we need to re-calculate the ticks once
+		// as it's otherwise done when the user pans or zooms, which is too late
+		calculate_tick_spacing();
+
+		// Reset "always zoom to fit", the acquisition has stopped
+		if (always_zoom_to_fit_) {
+			always_zoom_to_fit_ = false;
+			always_zoom_to_fit_changed(false);
+		}
+	}
 }
 
 void View::data_updated()