X-Git-Url: https://sigrok.org/gitweb/?p=pulseview.git;a=blobdiff_plain;f=sigview.cpp;h=5601be575d722df78302897fa19965fe3280464e;hp=dea3cbc1255bc646307cbd39448be239c0982fae;hb=0b02e0578cf750906b20848d98e73b21c23eda42;hpb=aeed8b418c0e751d7fef6aeaea1347af2077f904

diff --git a/sigview.cpp b/sigview.cpp
index dea3cbc1..5601be57 100644
--- a/sigview.cpp
+++ b/sigview.cpp
@@ -35,6 +35,9 @@
 using namespace boost;
 using namespace std;
 
+const double SigView::MaxScale = 1e9;
+const double SigView::MinScale = 1e-15;
+
 const int SigView::SignalHeight = 50;
 const int SigView::LabelMarginWidth = 70;
 const int SigView::RulerHeight = 30;
@@ -59,6 +62,11 @@ SigView::SigView(SigSession &session, QWidget *parent) :
 	setAutoFillBackground(false);
 }
 
+void SigView::zoom(double steps)
+{
+	zoom(steps, (width() - LabelMarginWidth) / 2);
+}
+
 void SigView::initializeGL()
 {
 }
@@ -161,12 +169,7 @@ void SigView::mouseReleaseEvent(QMouseEvent *event)
 void SigView::wheelEvent(QWheelEvent *event)
 {
 	assert(event);
-
-	const double x = event->x() - LabelMarginWidth;
-	const double cursor_offset = _offset + _scale * x;
-	_scale *= powf(3.0/2.0, -event->delta() / 120);
-	_offset = cursor_offset - _scale * x;
-	update();
+	zoom(event->delta() / 120, event->x() - LabelMarginWidth);
 }
 
 void SigView::setup_viewport(int width, int height)
@@ -239,3 +242,12 @@ void SigView::paint_ruler(QPainter &p)
 		division++;
 	}
 }
+
+void SigView::zoom(double steps, int offset)
+{
+	const double cursor_offset = _offset + _scale * offset;
+	_scale *= pow(3.0/2.0, -steps);
+	_scale = max(min(_scale, MaxScale), MinScale);
+	_offset = cursor_offset - _scale * offset;
+	update();
+}