From 4117403ad5170110849b7d0663337b1571304a8e Mon Sep 17 00:00:00 2001 From: Frederik Gladhorn Date: Mon, 25 Oct 2010 18:32:21 +0200 Subject: Simplify calculation of center point and scale for PinchRecongizer Constructing a QLineF to get at the centerPoint is not precise and can be done simpler. The scale factor can be assigned directly to d->scaleFactor instead of creating a temporary scaleFactor variable. Reviewed-by: Zeno Albisser --- src/gui/kernel/qstandardgestures.cpp | 19 ++++++++----------- 1 file changed, 8 insertions(+), 11 deletions(-) diff --git a/src/gui/kernel/qstandardgestures.cpp b/src/gui/kernel/qstandardgestures.cpp index 893ba2b..1821c3d 100644 --- a/src/gui/kernel/qstandardgestures.cpp +++ b/src/gui/kernel/qstandardgestures.cpp @@ -198,25 +198,22 @@ QGestureRecognizer::Result QPinchGestureRecognizer::recognize(QGesture *state, d->startPosition[0] = p1.screenPos(); d->startPosition[1] = p2.screenPos(); } - QLineF line(p1.screenPos(), p2.screenPos()); - QLineF lastLine(p1.lastScreenPos(), p2.lastScreenPos()); - QLineF tmp(line); - tmp.setLength(line.length() / 2.); - QPointF centerPoint = tmp.p2(); d->lastCenterPoint = d->centerPoint; - d->centerPoint = centerPoint; - d->changeFlags |= QPinchGesture::CenterPointChanged; + d->centerPoint = (p1.screenPos() + p2.screenPos()) / 2.0; - const qreal scaleFactor = line.length() / lastLine.length(); + d->changeFlags |= QPinchGesture::CenterPointChanged; if (d->isNewSequence) { - d->lastScaleFactor = scaleFactor; + d->scaleFactor = 1.0; + d->lastScaleFactor = 1.0; } else { d->lastScaleFactor = d->scaleFactor; + QLineF line(p1.screenPos(), p2.screenPos()); + QLineF lastLine(p1.lastScreenPos(), p2.lastScreenPos()); + d->scaleFactor = line.length() / lastLine.length(); } - d->scaleFactor = scaleFactor; - d->totalScaleFactor = d->totalScaleFactor * scaleFactor; + d->totalScaleFactor = d->totalScaleFactor * d->scaleFactor; d->changeFlags |= QPinchGesture::ScaleFactorChanged; qreal angle = QLineF(p1.screenPos(), p2.screenPos()).angle(); -- cgit v0.12