gpesquero/organicmaps
1
Fork 0
forked from organicmaps/organicmaps
Code Pull requests Activity

Tuned kinetic scroll

Browse source
This commit is contained in:
r.kuznetsov 2015-09-01 10:35:40 +03:00
parent 230de3ef48
commit 6d361300ba
1 changed files with 12 additions and 7 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

19
drape_frontend/kinetic_scroller.cpp
View file

@ -5,6 +5,12 @@
namespace df
{
double const kKineticDuration = 0.375;
double const kKineticFeedback = 0.2;
double const kKineticFadeoff = 5.0;
double const kKineticThreshold = 10.0;
double const kKineticInertia = 0.8;
class KineticScrollAnimation : public BaseModelViewAnimation
{
public:
@ -23,7 +29,7 @@ public:
{
// current position = target position - amplutide * e ^ (elapsed / duration)
// we calculate current position not based on start position, but based on target position
return m2::AnyRectD(m_targetCenter - m_direction * exp(-GetT()), m_angle, m_localRect);
return m2::AnyRectD(m_targetCenter - m_direction * exp(-kKineticFadeoff * GetT()), m_angle, m_localRect);
}
m2::AnyRectD GetTargetRect() const override
@ -75,7 +81,7 @@ void KineticScroller::GrabViewRect(ScreenBase const & modelView, double timeStam
// velocity on pixels
double v = pxDeltaLength / elapsed;
// at this point length(m_direction) already in pixel space, and delta normalized
m_direction = delta * 0.8 * v + m_direction * 0.2;
m_direction = delta * kKineticInertia * v + m_direction * (1.0 - kKineticInertia);
m_lastTimestamp = timeStamp;
m_lastRect = modelView.GlobalRect();
@ -89,17 +95,16 @@ void KineticScroller::CancelGrab()
unique_ptr<BaseModelViewAnimation> KineticScroller::CreateKineticAnimation(ScreenBase const & modelView)
{
static double VELOCITY_THRESHOLD = 10.0 * VisualParams::Instance().GetVisualScale();
if (m_direction.Length() < VELOCITY_THRESHOLD)
static double kVelocityThreshold = kKineticThreshold * VisualParams::Instance().GetVisualScale();
if (m_direction.Length() < kVelocityThreshold)
return unique_ptr<BaseModelViewAnimation>();
double const KINETIC_DURATION = 0.375;
// Before we start animation we have to convert length(m_direction) from pixel space to mercator space
m2::PointD center = m_lastRect.GlobalCenter();
double glbLength = 0.5 * (modelView.PtoG(modelView.GtoP(center) + m_direction) - center).Length();
double glbLength = kKineticFeedback * (modelView.PtoG(modelView.GtoP(center) + m_direction) - center).Length();
return unique_ptr<BaseModelViewAnimation>(new KineticScrollAnimation(m_lastRect,
m_direction.Normalize() * glbLength,
KINETIC_DURATION));
kKineticDuration));
}
} // namespace df