src/MapWindow/MapDrawHelper.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 #ifndef ENABLE_OPENGL
  25
  26 #include "MapDrawHelper.hpp"
  27 #include "Screen/Canvas.hpp"
  28 #include "Projection/WindowProjection.hpp"
  29 #include "Renderer/AirspaceRendererSettings.hpp"
  30 #include "MapCanvas.hpp"
  31 #include "Geo/SearchPointVector.hpp"
  32
  33 MapDrawHelper::MapDrawHelper(Canvas &_canvas, Canvas &_buffer, Canvas &_stencil,
  34                              const WindowProjection &_proj,
  35                              const AirspaceRendererSettings &_settings)
  36   :clip(_proj.GetScreenBounds().Scale(fixed(1.1))),
  37    canvas(_canvas),
  38    buffer(_buffer),
  39    stencil(_stencil),
  40    proj(_proj),
  41    buffer_drawn(false),
  42    use_stencil(false),
  43    settings(_settings)
  44 {
  45 }
  46
  47 MapDrawHelper::MapDrawHelper(const MapDrawHelper &other)
  48   :clip(other.clip),
  49    canvas(other.canvas),
  50    buffer(other.buffer),
  51    stencil(other.stencil),
  52    proj(other.proj),
  53    buffer_drawn(other.buffer_drawn),
  54    use_stencil(other.use_stencil),
  55    settings(other.settings)
  56 {
  57 }
  58
  59 void
  60 MapDrawHelper::DrawSearchPointVector(const SearchPointVector &points)
  61 {
  62   size_t size = points.size();
  63   if (size < 3)
  64     return;
  65
  66   /* copy all SearchPointVector elements to geo_points */
  67   geo_points.GrowDiscard(size * 3);
  68   for (unsigned i = 0; i < size; ++i)
  69     geo_points[i] = points[i].GetLocation();
  70
  71   /* clip them */
  72   size = clip.ClipPolygon(geo_points.begin(), geo_points.begin(), size);
  73   if (size < 3)
  74     /* it's completely outside the screen */
  75     return;
  76
  77   /* draw it all */
  78   RasterPoint screen[size];
  79   for (unsigned i = 0; i < size; ++i)
  80     screen[i] = proj.GeoToScreen(geo_points[i]);
  81
  82   if (!MapCanvas::IsVisible(canvas, screen, size))
  83     return;
  84
  85   buffer.DrawPolygon(&screen[0], size);
  86   if (use_stencil)
  87     stencil.DrawPolygon(&screen[0], size);
  88 }
  89
  90 void
  91 MapDrawHelper::DrawCircle(const RasterPoint &center, unsigned radius)
  92 {
  93   buffer.DrawCircle(center.x, center.y, radius);
  94   if (use_stencil)
  95     stencil.DrawCircle(center.x, center.y, radius);
  96 }
  97
  98 void
  99 MapDrawHelper::BufferRenderFinish()
 100 {
 101   if (buffer_drawn) {
 102     if (use_stencil) {
 103 #ifdef ENABLE_SDL
 104       buffer.CopyTransparentBlack(stencil);
 105 #else
 106       buffer.CopyOr(stencil);
 107 #endif
 108     }
 109
 110 #ifdef HAVE_ALPHA_BLEND
 111     if (settings.transparency && AlphaBlendAvailable())
 112       canvas.AlphaBlend(0, 0, canvas.GetWidth(), canvas.GetHeight(),
 113                            buffer,
 114                            0, 0, canvas.GetWidth(), canvas.GetHeight(),
 115                            60);
 116     else
 117 #endif
 118       canvas.CopyAnd(buffer);
 119
 120     buffer_drawn = false;
 121   }
 122 }
 123
 124 void
 125 MapDrawHelper::BufferRenderStart()
 126 {
 127   if (!buffer_drawn) {
 128     ClearBuffer();
 129     buffer_drawn = true;
 130   }
 131 }
 132
 133 void
 134 MapDrawHelper::ClearBuffer()
 135 {
 136   buffer.ClearWhite();
 137
 138   if (use_stencil)
 139     stencil.ClearWhite();
 140 }
 141
 142 #endif // !ENABLE_OPENGL