void Editor::update( float dt )
{
vec2f scrollDir( 0.0f, 0.0f );
// Continuous (key state) keys
Uint8 *keyState = SDL_GetKeyState( NULL );
if ((keyState[SDLK_LEFT]) && (!keyState[SDLK_RIGHT]))
{
scrollDir.x = -1.0;
}
else if ((!keyState[SDLK_LEFT]) && (keyState[SDLK_RIGHT]))
{
scrollDir.x = 1.0;
}
if ((keyState[SDLK_UP]) && (!keyState[SDLK_DOWN]))
{
scrollDir.y = 1.0;
}
else if ((!keyState[SDLK_UP]) && (keyState[SDLK_DOWN]))
{
scrollDir.y = -1.0;
}
// update view
if (m_useEditView)
{
m_viewport += scrollDir * _TV( 0.6f ) * m_viewsize.x * dt;
}
else
{
m_gameview += scrollDir * _TV( 200.0f ) * dt;
}
// update mouse
int mx, my;
SDL_GetMouseState( &mx, &my );
my = 600-my;
if (m_activeShape)
{
if (m_useEditView)
{
m_activeShape->pos.x = m_viewport.x + ((float)mx / 800.0)*m_viewsize.x;
m_activeShape->pos.y = m_viewport.y + ((float)my / 600.0)*m_viewsize.y;
}
else
{
m_activeShape->pos.x = mx + m_gameview.x;
m_activeShape->pos.y = my + m_gameview.y;
}
// remember this pos for otehr use
m_mousePos = m_activeShape->pos;
// offset so active shape is centered
m_activeShape->pos.x -= m_activeShape->m_size.x/2;
m_activeShape->pos.y -= m_activeShape->m_size.y/2;
}
}
/*!
Starts scrolling the widget so that the point \a pos is visible inside
the viewport.
If the specified point cannot be reached, the contents are scrolled to the
nearest valid position (in this case the scroller might or might not overshoot).
The scrolling speed will be calculated so that the given position will
be reached after a platform-defined time span (1 second for Maemo 5).
The final speed at the end position is not guaranteed to be zero.
\sa ensureVisible(), maximumContentPosition()
*/
void QKineticScroller::scrollTo(const QPointF &pos, int scrollTime)
{
Q_D(QKineticScroller);
if (scrollTime <= 0)
scrollTime = 1;
qKSDebug() << "QKS::scrollTo(" << pos << " [pix], " << scrollTime << " [ms])";
qreal time = qreal(scrollTime) / 1000;
if ((pos == contentPosition()) ||
(d->state == QKineticScroller::StatePressed) ||
(d->state == QKineticScroller::StateDragging)) {
return;
}
// estimate the minimal start velocity
// if the start velocity is below that then the scrolling would stop before scrollTime.
//qreal vMin = d->linearDecelerationFactor * time / qPow(d->exponentialDecelerationBase, time);
/*
// estimate of the distance passed within the vMin time during scrollTime
qreal distMin = qreal(scrollTime) * vMin / 2.0;
QPointF v = QPointF((pos.x()-contentPosition().x()) / distMin * vMin,
(pos.y()-contentPosition().y()) / distMin * vMin);
*/
// v(t) = vstart * exponentialDecelerationBase ^ t - linearDecelerationFactor * t
// pos(t) = integrate(v(t) * dt)
// pos(t) = vstart * (eDB ^ t / ln(eDB) + C) - lDF / 2 * t ^ 2
//
// pos(time) = pos - contentsPos()
// vstart = ((lDF / 2) * time ^ 2 + (pos - contentPos())) / (eDB ^ time / ln(eDB) + C)
// (for C = -1/ln(eDB) )
QPointF scrollDir(qSign(pos.x() - contentPosition().x()),
qSign(pos.y() - contentPosition().y()));
QPointF v = (scrollDir * (d->linearDecelerationFactor / qreal(2)) * qreal(time) * qreal(time) + (pos - contentPosition()) / d->pixelPerMeter);
if (d->exponentialDecelerationBase != qreal(1))
v /= (qPow(d->exponentialDecelerationBase, time) - 1) / qLn(d->exponentialDecelerationBase);
else
v /= time;
d->scrollToPosition = pos;
d->scrollToX = true;
d->scrollToY = true;
d->releaseVelocity = v;
d->scrollRelativeTimer.restart();
d->scrollAbsoluteTimer.restart();
d->setState(QKineticScroller::StateScrolling);
}
