src/Projection/WindowProjection.hpp

   1 /*
   2 Copyright_License {
   3
   4   XCSoar Glide Computer - http://www.xcsoar.org/
   5   Copyright (C) 2000-2013 The XCSoar Project
   6   A detailed list of copyright holders can be found in the file "AUTHORS".
   7
   8   This program is free software; you can redistribute it and/or
   9   modify it under the terms of the GNU General Public License
  10   as published by the Free Software Foundation; either version 2
  11   of the License, or (at your option) any later version.
  12
  13   This program is distributed in the hope that it will be useful,
  14   but WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16   GNU General Public License for more details.
  17
  18   You should have received a copy of the GNU General Public License
  19   along with this program; if not, write to the Free Software
  20   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  21 }
  22 */
  23
  24 #ifndef XCSOAR_WINDOW_PROJECTION_HPP
  25 #define XCSOAR_WINDOW_PROJECTION_HPP
  26
  27 #include "Screen/Point.hpp"
  28 #include "Projection.hpp"
  29 #include "Geo/GeoBounds.hpp"
  30 #include "Util/DebugFlag.hpp"
  31
  32 #include <algorithm>
  33
  34 #include <assert.h>
  35
  36 class WindowProjection:
  37   public Projection
  38 {
  39   DebugFlag screen_size_initialised;
  40
  41   unsigned screen_width, screen_height;
  42
  43   /**
  44    * Geographical representation of the screen boundaries.
  45    *
  46    * This is a cached member that has to be updated manually by
  47    * calling UpdateScreenBounds()
  48    */
  49   GeoBounds screenbounds_latlon;
  50
  51 public:
  52   /**
  53    * Converts a geographical location to a screen coordinate if the
  54    * location is within the visible bounds
  55    * @param loc Geographical location
  56    * @param sc Screen coordinate (output)
  57    * @return True if the location is within the bounds
  58    */
  59   bool GeoToScreenIfVisible(const GeoPoint &loc, RasterPoint &sc) const;
  60
  61   /**
  62    * Checks whether a geographical location is within the visible bounds
  63    * @param loc Geographical location
  64    * @return True if the location is within the bounds
  65    */
  66   gcc_pure
  67   bool GeoVisible(const GeoPoint &loc) const;
  68
  69   /**
  70    * Checks whether a screen coordinate is within the visible bounds
  71    * @param P Screen coordinate
  72    * @return True if the screen coordinate is within the bounds
  73    */
  74   gcc_pure
  75   bool ScreenVisible(const RasterPoint &P) const;
  76
  77   void SetScreenSize(PixelSize new_size) {
  78     assert(new_size.cx > 0);
  79     assert(new_size.cy > 0);
  80
  81     screen_width = new_size.cx;
  82     screen_height = new_size.cy;
  83     screen_size_initialised = true;
  84   }
  85
  86   void SetMapRect(const PixelRect &rc) {
  87     SetScreenSize(rc.GetSize());
  88   }
  89
  90   gcc_pure
  91   fixed GetMapScale() const;
  92
  93   /**
  94    * Configure the scale so a centered circle with the specified
  95    * radius is visible.
  96    */
  97   void SetScaleFromRadius(fixed radius);
  98
  99   /**
 100    * Returns the width of the map area in pixels.
 101    */
 102   gcc_pure
 103   unsigned GetScreenWidth() const {
 104     assert(screen_size_initialised);
 105
 106     return screen_width;
 107   }
 108
 109   /**
 110    * Returns the height of the map area in pixels.
 111    */
 112   gcc_pure
 113   unsigned GetScreenHeight() const {
 114     assert(screen_size_initialised);
 115
 116     return screen_height;
 117   }
 118
 119   /**
 120    * Returns the raster coordinates at the center of the map.
 121    */
 122   gcc_pure
 123   RasterPoint GetScreenCenter() const {
 124     RasterPoint pt;
 125     pt.x = GetScreenWidth() / 2;
 126     pt.y = GetScreenHeight() / 2;
 127     return pt;
 128   }
 129
 130   /**
 131    * Returns the width of the map area in meters.
 132    */
 133   fixed GetScreenWidthMeters() const {
 134     return DistancePixelsToMeters(GetScreenWidth());
 135   }
 136
 137   /**
 138    * Returns the length of the larger edge of the map area in pixels.
 139    */
 140   unsigned GetScreenDistance() const
 141   {
 142     return std::max(GetScreenHeight(), GetScreenWidth());
 143   }
 144
 145   /**
 146    * Returns the length of the smaller edge of the map area in pixels.
 147    */
 148   unsigned GetMinScreenDistance() const
 149   {
 150     return std::min(GetScreenHeight(), GetScreenWidth());
 151   }
 152
 153   gcc_pure
 154   fixed GetScreenDistanceMeters() const;
 155
 156   /**
 157    * Returns the GeoPoint at the center of the screen.
 158    */
 159   gcc_pure
 160   GeoPoint GetGeoScreenCenter() const;
 161
 162   // used by terrain renderer, topography and airspace
 163   gcc_pure
 164   const GeoBounds &GetScreenBounds() const {
 165     return screenbounds_latlon;
 166   }
 167
 168   /** Updates the cached screenbounds_latlon member */
 169   void UpdateScreenBounds();
 170
 171 protected:
 172   gcc_pure
 173   int GetMapResolutionFactor() const {
 174     return GetMinScreenDistance() / 8;
 175   }
 176 };
 177
 178 #endif