Source/Stereo.cpp

   1 /*
   2 Copyright (C) 2003, 2010 - Wolfire Games
   3
   4 This file is part of Lugaru.
   5
   6 Lugaru is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2 of the License, or
   9 (at your option) any later version.
  10
  11 Lugaru is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with Lugaru.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "Game.h"
  21 #include "Stereo.h"
  22
  23
  24 extern int kContextWidth;
  25 extern int kContextHeight;
  26
  27 bool CanInitStereo(StereoMode mode)
  28 {
  29     GLint stencilbits = 0;
  30
  31     switch (mode) {
  32     case stereoNone:
  33         return true;
  34         break;
  35     case stereoAnaglyph:
  36         return true;
  37         break;
  38     case stereoHorizontalInterlaced:
  39     case stereoVerticalInterlaced:
  40         glGetIntegerv(GL_STENCIL_BITS, &stencilbits);
  41         if ( stencilbits < 1 ) {
  42             fprintf(stderr, "Failed to get a stencil buffer, interlaced stereo not available.\n");
  43             return false;
  44         } else {
  45             fprintf(stderr, "Stencil buffer has %i bits, good.\n", stencilbits);
  46         }
  47         return true;
  48         break;
  49     default:
  50         return false;
  51     }
  52
  53 }
  54
  55 void InitStereo(StereoMode mode)
  56 {
  57     switch (mode) {
  58     default:
  59     case stereoNone:
  60     case stereoAnaglyph:
  61         glDisable(GL_STENCIL_TEST);
  62         return;
  63     case stereoHorizontalInterlaced:
  64     case stereoVerticalInterlaced:
  65         fprintf(stderr, "Screen width is %i, height is %i\n", kContextWidth, kContextHeight);
  66
  67         // Setup stencil buffer
  68         glDisable( GL_DEPTH_TEST);
  69         glDisable(GL_CULL_FACE);
  70         glDisable(GL_LIGHTING);
  71         glDisable(GL_TEXTURE_2D);
  72
  73         glEnable( GL_STENCIL_TEST);
  74         glClearStencil(0);
  75         glClear(  GL_STENCIL_BUFFER_BIT );
  76         glStencilFunc(GL_ALWAYS, 0x1, 0x1);
  77         glStencilOp(GL_REPLACE, GL_REPLACE, GL_REPLACE);
  78
  79         // Setup viewport
  80         glViewport(0, 0, kContextWidth, kContextHeight);
  81         glMatrixMode(GL_PROJECTION);
  82         glPushMatrix();
  83         glLoadIdentity();
  84         glOrtho((GLdouble)0, (GLdouble)kContextWidth, (GLdouble)kContextHeight, 0, -1, 1);
  85         glMatrixMode(GL_MODELVIEW);
  86         glPushMatrix();
  87         glLoadIdentity();
  88         glColorMask( GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE );
  89         glDisable(GL_LINE_SMOOTH);
  90
  91         // Add 0.5 to the coordinates, because OpenGL considers a pixel should be
  92         // turned on when a line passes through the center of it.
  93         if ( mode == stereoHorizontalInterlaced ) {
  94             for (int y = 0; y < kContextHeight; y += 2) {
  95                 glBegin(GL_LINES);
  96                 glVertex3f(0.5, y + 0.5, 0);
  97                 glVertex3f(kContextWidth + 0.5, y + 0.5, 0);
  98                 glEnd();
  99             }
 100         } else {
 101             for (int x = 0; x < kContextWidth; x += 2) {
 102                 glBegin(GL_LINES);
 103                 glVertex3f(x + 0.5, 0.5, 0);
 104                 glVertex3f(x + 0.5, kContextHeight + 0.5, 0);
 105                 glEnd();
 106             }
 107         }
 108
 109         glColorMask( GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE );
 110
 111         glPopMatrix();
 112         glMatrixMode(GL_PROJECTION);
 113         glPopMatrix();
 114
 115         glStencilFunc(GL_NOTEQUAL, 0x01, 0x01);
 116         glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
 117         glEnable( GL_DEPTH_TEST);
 118         glEnable(GL_CULL_FACE);
 119         glEnable(GL_LIGHTING);
 120         glEnable(GL_TEXTURE_2D);
 121     }
 122
 123 }
 124
 125 const char* StereoModeName(StereoMode mode)
 126 {
 127     switch (mode) {
 128     case stereoNone:
 129         return "None";
 130         break;
 131     case stereoAnaglyph:
 132         return "Anaglyph";
 133         break;
 134     case stereoHorizontalInterlaced:
 135         return "Horizontal interlacing";
 136         break;
 137     case stereoVerticalInterlaced:
 138         return "Vertical interlacing";
 139         break;
 140     case stereoHorizontalSplit:
 141         return "Horizontal split";
 142         break;
 143     case stereoVerticalSplit:
 144         return "Vertical split";
 145         break;
 146     case stereoOpenGL:
 147         return "OpenGL";
 148         break;
 149     default:
 150         return "(error)";
 151         break;
 152     }
 153 }