void RulerHelper::Update(ScreenBase const & screen)
{
m2::PointD pivot = screen.PixelRect().Center();
int const minPxWidth = my::rounds(MinPixelWidth * df::VisualParams::Instance().GetVisualScale());
m2::PointD pt1 = screen.PtoG(pivot);
m2::PointD pt0 = screen.PtoG(pivot - m2::PointD(minPxWidth, 0));
double const distanceInMetres = MercatorBounds::DistanceOnEarth(pt0, pt1);
// convert metres to units for calculating m_metresDiff
double metersDiff = CalcMetresDiff(distanceInMetres);
bool const higherThanMax = metersDiff > MaxMetersWidth;
bool const lessThanMin = metersDiff < MinMetersWidth;
m_pixelLength = minPxWidth;
if (higherThanMax)
m_pixelLength = minPxWidth * 3 / 2;
else if (!lessThanMin)
{
double const a = ang::AngleTo(pt1, pt0);
pt0 = MercatorBounds::GetSmPoint(pt1, cos(a) * metersDiff, sin(a) * metersDiff);
m_pixelLength = my::rounds(pivot.Length(screen.GtoP(pt0)));
}
int drawScale = df::GetDrawTileScale(screen);
if (m_currentDrawScale < VISIBLE_RULER_BOTTOM_SCALE &&
drawScale >= VISIBLE_RULER_BOTTOM_SCALE)
{
SetTextDirty();
}
m_currentDrawScale = drawScale;
}
bool ApplyScale(m2::PointD const & pixelScaleCenter, double factor, ScreenBase & screen)
{
m2::PointD const globalScaleCenter = screen.PtoG(screen.P3dtoP(pixelScaleCenter));
ScreenBase tmp = screen;
tmp.Scale(factor);
tmp.MatchGandP3d(globalScaleCenter, pixelScaleCenter);
if (!CheckMinScale(tmp))
return false;
m2::RectD const & worldR = df::GetWorldRect();
if (!CheckBorders(tmp))
{
if (CanShrinkInto(tmp, worldR))
tmp = ShrinkInto(tmp, worldR);
else
return false;
}
if (!CheckMaxScale(tmp))
return false;
// re-checking the borders, as we might violate them a bit (don't know why).
if (!CheckBorders(tmp))
tmp = ScaleInto(tmp, worldR);
screen = tmp;
return true;
}
int GetTileScaleBase(ScreenBase const & s, uint32_t tileSize)
{
ScreenBase tmpS = s;
tmpS.Rotate(-tmpS.GetAngle());
// slightly smaller than original to produce "antialiasing" effect using bilinear filtration.
int const halfSize = static_cast<int>(tileSize / 1.05 / 2.0);
m2::RectD glbRect;
m2::PointD const pxCenter = tmpS.PixelRect().Center();
tmpS.PtoG(m2::RectD(pxCenter - m2::PointD(halfSize, halfSize),
pxCenter + m2::PointD(halfSize, halfSize)),
glbRect);
return GetTileScaleBase(glbRect);
}
/// @name Manipulating with model view
//@{
inline m2::PointD PtoG(m2::PointD const & p) const { return m_currentModelView.PtoG(p); }
