src/DrawThread.cpp

   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 #include "DrawThread.hpp"
  25 #include "MapWindow/GlueMapWindow.hpp"
  26
  27 #ifndef ENABLE_OPENGL
  28
  29 /**
  30  * Main loop of the DrawThread
  31  */
  32 void
  33 DrawThread::Run()
  34 {
  35   SetLowPriority();
  36
  37   // bounds_dirty maintains the status of whether the map
  38   // bounds have changed and there are pending idle calls
  39   // to be run in the map.
  40
  41   // wait until the startup is finished
  42   if (CheckStoppedOrSuspended())
  43     return;
  44
  45   // Get data from the DeviceBlackboard
  46   map.ExchangeBlackboard();
  47
  48   bool bounds_dirty = true;
  49
  50   // circle until application is closed
  51   while (true) {
  52     if (!bounds_dirty)
  53       trigger.Wait();
  54
  55     if (!bounds_dirty || trigger.Wait(MIN_WAIT_TIME)) {
  56       /* got the "stop" trigger? */
  57       if (CheckStoppedOrSuspended())
  58         break;
  59
  60       trigger.Reset();
  61
  62       if (IsCommandPending()) {
  63         /* just in case we got another suspend/stop command after
  64            CheckStoppedOrSuspended() returned and before the trigger
  65            got reset: restore the trigger and skip this iteration, to
  66            fix the race condition */
  67         trigger.Signal();
  68         continue;
  69       }
  70
  71       // Get data from the DeviceBlackboard
  72       map.ExchangeBlackboard();
  73
  74       // Draw the moving map
  75       map.Repaint();
  76
  77       if (trigger.Test()) {
  78         // interrupt re-calculation of bounds if there was a
  79         // request made.  Since we will re-enter, we know the remainder
  80         // of this code will be called anyway.
  81         continue;
  82       }
  83
  84       bounds_dirty = map.Idle();
  85     } else if (bounds_dirty) {
  86       /* got the "stop" trigger? */
  87       if (CheckStoppedOrSuspended())
  88         break;
  89
  90       bounds_dirty = map.Idle();
  91     }
  92   }
  93 }
  94
  95 #endif