src/Terrain/RasterTile.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_RASTERTILE_HPP
  25 #define XCSOAR_RASTERTILE_HPP
  26
  27 #include "Terrain/RasterBuffer.hpp"
  28 #include "Util/NonCopyable.hpp"
  29
  30 #include <stdio.h>
  31
  32 class RasterTile : private NonCopyable {
  33   struct MetaData {
  34     unsigned int xstart, ystart, xend, yend;
  35   };
  36
  37 public:
  38   unsigned int xstart, ystart, xend, yend;
  39   unsigned int width, height;
  40
  41   /**
  42    * The distance of this tile to the center of the screen.  This
  43    * attribute is used to determine which tiles should be loaded.
  44    */
  45   unsigned distance;
  46
  47   bool request;
  48
  49   RasterBuffer buffer;
  50
  51 public:
  52   RasterTile()
  53     :xstart(0), ystart(0), xend(0), yend(0),
  54      width(0), height(0) {}
  55
  56   void Set(unsigned _xstart, unsigned _ystart,
  57            unsigned _xend, unsigned _yend) {
  58     xstart = _xstart;
  59     ystart = _ystart;
  60     xend = _xend;
  61     yend = _yend;
  62     width = xend - xstart;
  63     height = yend - ystart;
  64   }
  65
  66   /**
  67    * Permanently disable this tile after a failure.
  68    */
  69   void Clear() {
  70     width = height = 0;
  71     request = false;
  72   }
  73
  74   bool IsDefined() const {
  75     return width > 0 && height > 0;
  76   }
  77
  78   int GetDistance() const {
  79     return distance;
  80   }
  81
  82   bool IsRequested() const {
  83     return request;
  84   }
  85
  86   void SetRequest() {
  87     request = true;
  88   }
  89
  90   void ClearRequest() {
  91     request = false;
  92   }
  93
  94   bool SaveCache(FILE *file) const;
  95   bool LoadCache(FILE *file);
  96
  97   bool CheckTileVisibility(int view_x, int view_y, unsigned view_radius);
  98
  99   void Disable() {
 100     buffer.Reset();
 101   }
 102
 103   void Enable();
 104   bool IsEnabled() const {
 105     return buffer.IsDefined();
 106   }
 107   bool IsDisabled() const {
 108     return !buffer.IsDefined();
 109   }
 110
 111   /**
 112    * Determine the non-interpolated height at the specified pixel
 113    * location.
 114    *
 115    * @param x the pixel column within the tile; may be out of range
 116    * @param y the pixel row within the tile; may be out of range
 117    */
 118   gcc_pure
 119   short GetHeight(unsigned x, unsigned y) const;
 120
 121   /**
 122    * Determine the interpolated height at the specified sub-pixel
 123    * location.
 124    *
 125    * @param x the pixel column within the tile; may be out of range
 126    * @param y the pixel row within the tile; may be out of range
 127    * @param ix the sub-pixel column for interpolation (0..255)
 128    * @param iy the sub-pixel row for interpolation (0..255)
 129    */
 130   gcc_pure
 131   short GetInterpolatedHeight(unsigned x, unsigned y,
 132                               unsigned ix, unsigned iy) const;
 133
 134   inline short* GetImageBuffer() {
 135     return buffer.GetData();
 136   }
 137
 138   bool VisibilityChanged(int view_x, int view_y, unsigned view_radius);
 139
 140   void ScanLine(unsigned ax, unsigned ay, unsigned bx, unsigned by,
 141                 short *dest, unsigned size, bool interpolate) const {
 142     buffer.ScanLine(ax - (xstart << 8), ay - (ystart << 8),
 143                     bx - (xstart << 8), by - (ystart << 8),
 144                     dest, size, interpolate);
 145   }
 146 };
 147
 148 #endif