src/map/emptymap.cpp

   1 #include <QtGlobal>
   2 #include <QPainter>
   3 #include "common/coordinates.h"
   4 #include "common/rectc.h"
   5 #include "common/wgs84.h"
   6 #include "emptymap.h"
   7
   8
   9 #define ZOOM_MIN 0
  10 #define ZOOM_MAX 19
  11 #define TILE_SIZE 256
  12
  13 static QPointF ll2m(const Coordinates &c)
  14 {
  15         return QPointF(c.lon(), rad2deg(log(tan(M_PI_4 + deg2rad(c.lat())/2.0))));
  16 }
  17
  18 static Coordinates m2ll(const QPointF &p)
  19 {
  20         return Coordinates(p.x(), rad2deg(2.0 * atan(exp(deg2rad(p.y()))) - M_PI_2));
  21 }
  22
  23 static qreal zoom2scale(int zoom)
  24 {
  25         return (360.0/(qreal)((1<<zoom) * TILE_SIZE));
  26 }
  27
  28 static int scale2zoom(qreal scale)
  29 {
  30         return (int)log2(360.0/(scale * (qreal)TILE_SIZE));
  31 }
  32
  33 static int limitZoom(int zoom)
  34 {
  35         if (zoom < ZOOM_MIN)
  36                 return ZOOM_MIN;
  37         if (zoom > ZOOM_MAX)
  38                 return ZOOM_MAX;
  39
  40         return zoom;
  41 }
  42
  43
  44 EmptyMap::EmptyMap(QObject *parent) : Map(parent)
  45 {
  46         _zoom = ZOOM_MAX;
  47 }
  48
  49 QRectF EmptyMap::bounds() const
  50 {
  51         return QRectF(ll2xy(Coordinates(-180, 85)), ll2xy(Coordinates(180, -85)));
  52 }
  53
  54 int EmptyMap::zoomFit(const QSize &size, const RectC &rect)
  55 {
  56         if (!rect.isValid())
  57                 _zoom = ZOOM_MAX;
  58         else {
  59                 QRectF tbr(ll2m(rect.topLeft()), ll2m(rect.bottomRight()));
  60                 QPointF sc(tbr.width() / size.width(), tbr.height() / size.height());
  61
  62                 _zoom = limitZoom(scale2zoom(qMax(sc.x(), -sc.y())));
  63         }
  64
  65         return _zoom;
  66 }
  67
  68 qreal EmptyMap::resolution(const QRectF &rect)
  69 {
  70         qreal scale = zoom2scale(_zoom);
  71
  72         return (WGS84_RADIUS * 2.0 * M_PI * scale / 360.0
  73           * cos(2.0 * atan(exp(deg2rad(-rect.center().y() * scale))) - M_PI/2));
  74 }
  75
  76 int EmptyMap::zoomIn()
  77 {
  78         _zoom = qMin(_zoom + 1, ZOOM_MAX);
  79         return _zoom;
  80 }
  81
  82 int EmptyMap::zoomOut()
  83 {
  84         _zoom = qMax(_zoom - 1, ZOOM_MIN);
  85         return _zoom;
  86 }
  87
  88 void EmptyMap::draw(QPainter *painter, const QRectF &rect, bool block)
  89 {
  90         Q_UNUSED(painter);
  91         Q_UNUSED(rect);
  92         Q_UNUSED(block);
  93 }
  94
  95 QPointF EmptyMap::ll2xy(const Coordinates &c) const
  96 {
  97         qreal scale = zoom2scale(_zoom);
  98         QPointF m = ll2m(c);
  99         return QPointF(m.x() / scale, m.y() / -scale);
 100 }
 101
 102 Coordinates EmptyMap::xy2ll(const QPointF &p) const
 103 {
 104         qreal scale = zoom2scale(_zoom);
 105         return m2ll(QPointF(p.x() * scale, -p.y() * scale));
 106 }