src/Renderer/GlassRenderer.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 "GlassRenderer.hpp"
  25 #include "Screen/Canvas.hpp"
  26
  27 #if defined(EYE_CANDY) && defined(ENABLE_OPENGL)
  28
  29 #include "Screen/OpenGL/Scissor.hpp"
  30 #include "Util/Macros.hpp"
  31
  32 constexpr
  33 static unsigned
  34 Shadow(unsigned c)
  35 {
  36   return c * 15 / 16;
  37 }
  38
  39 constexpr
  40 static Color
  41 Shadow(Color c)
  42 {
  43   return Color(Shadow(c.Red()), Shadow(c.Green()), Shadow(c.Blue()));
  44 }
  45
  46 #endif
  47
  48 void
  49 DrawGlassBackground(Canvas &canvas, const PixelRect &rc, Color color)
  50 {
  51   canvas.DrawFilledRectangle(rc, color);
  52
  53 #if defined(EYE_CANDY) && defined(ENABLE_OPENGL)
  54   if (color != COLOR_WHITE)
  55     /* apply only to white background for now */
  56     return;
  57
  58   const GLCanvasScissor scissor(rc);
  59
  60   const Color shadow = Shadow(color);
  61
  62   const RasterPoint center = rc.GetCenter();
  63   const int size = std::min(rc.right - rc.left, rc.bottom - rc.top) / 4;
  64
  65   const RasterPoint vertices[] = {
  66     { center.x + 1024, center.y - 1024 },
  67     { center.x + 1024 + size, center.y - 1024 + size },
  68     { center.x - 1024, center.y + 1024 },
  69     { center.x - 1024 + size, center.y + 1024 + size },
  70   };
  71
  72   glVertexPointer(2, GL_VALUE, 0, vertices);
  73
  74   const Color colors[] = {
  75     shadow, color,
  76     shadow, color,
  77   };
  78
  79   glEnableClientState(GL_COLOR_ARRAY);
  80
  81 #ifdef HAVE_GLES
  82   glColorPointer(4, GL_FIXED, 0, colors);
  83 #else
  84   glColorPointer(4, GL_UNSIGNED_BYTE, 0, colors);
  85 #endif
  86
  87   static_assert(ARRAY_SIZE(vertices) == ARRAY_SIZE(colors),
  88                 "Array size mismatch");
  89
  90   glDrawArrays(GL_TRIANGLE_STRIP, 0, ARRAY_SIZE(vertices));
  91
  92   glDisableClientState(GL_COLOR_ARRAY);
  93 #endif
  94 }