test/OpenGL/tutorial/lesson02.pl

   1 #!/usr/bin/perl -w
   2 # This code was created by Jeff Molofee '99
   3 # (ported to SDL by Sam Lantinga '2000)
   4 # (ported to Perl/SDL by Wayne Keenan '2000)
   5 #
   6 # If you've found this code useful, please let me know.
   7 #
   8 # Visit me at www.demonews.com/hosted/nehe
   9
  10 use strict;
  11 use Getopt::Long;
  12
  13 use SDL;
  14 use SDL::App;
  15 use SDL::OpenGL;
  16 use SDL::Event;
  17
  18 my $arg_screen_width =640;
  19 my $arg_screen_height=512;
  20 my $arg_fullscreen=0;
  21
  22 GetOptions(
  23            "width:i"        => \$arg_screen_width,
  24            "height:i"       => \$arg_screen_height,
  25            "fullscreen!"    => \$arg_fullscreen,
  26
  27           ) or die $!;
  28
  29 main();
  30 exit;
  31
  32
  33 sub main
  34   {
  35    my $done=0;
  36
  37    my $app = new SDL::App ( -title => "Jeff Molofee's GL Code Tutorial ... NeHe '99",
  38                             -icon => "icon.png",
  39                             -width => $arg_screen_width,
  40                             -height =>$arg_screen_height,
  41                             -d => 16,
  42                             -gl => 1,
  43
  44                           );
  45         $app->fullscreen() if ($arg_fullscreen);
  46
  47    SDL::ShowCursor (0);
  48
  49    my $event = new SDL::Event;
  50    $event->set(SDL_SYSWMEVENT,SDL_IGNORE);#
  51
  52    InitGL($arg_screen_width, $arg_screen_height);
  53
  54    while ( ! $done ) {
  55
  56     DrawGLScene();
  57
  58     $app->sync();
  59
  60     $event->pump;
  61     $event->poll;
  62
  63
  64     if ( $event->type == SDL_QUIT ) {
  65      $done = 1;
  66     }
  67
  68     if ( $event->type == SDL_KEYDOWN ) {
  69      if ( $event->key_sym == SDLK_ESCAPE ) {
  70       $done = 1;
  71      }
  72     }
  73    }
  74   }
  75
  76
  77
  78
  79
  80
  81 #########################################################################
  82 #Pretty much in original form, but 'Perlised'
  83
  84
  85 sub InitGL
  86   {
  87    my ($Width, $Height)=@_;
  88
  89    glViewport(0, 0, $Width, $Height);
  90    glClearColor(0.0, 0.0, 0.0, 0.0);                            # This Will Clear The Background Color To Black
  91    glClearDepth(1.0);                                           # Enables Clearing Of The Depth Buffer
  92    glDepthFunc(GL_LESS());                                      # The Type Of Depth Test To Do
  93    glEnable(GL_DEPTH_TEST());                                   # Enables Depth Testing
  94    glShadeModel(GL_SMOOTH());                                   # Enables Smooth Color Shading
  95
  96    glMatrixMode(GL_PROJECTION());
  97    glLoadIdentity();                                            # Reset The Projection Matrix
  98
  99    gluPerspective(45.0, $Width/$Height, 0.1, 100.0);            # Calculate The Aspect Ratio Of The Window
 100
 101    glMatrixMode(GL_MODELVIEW());
 102   }
 103
 104
 105
 106 # The main drawing function.
 107 sub DrawGLScene
 108   {
 109    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);          # Clear The Screen And The Depth Buffer
 110    glLoadIdentity();                                            # Reset The View
 111
 112    glTranslate(-1.5,0.0,-6.0);                                  # Move Left 1.5 Units And Into The Screen 6.0
 113
 114    # draw a triangle
 115    glBegin(GL_POLYGON);                                         # start drawing a polygon
 116    glVertex( 0.0, 1.0, 0.0);                                    # Top
 117    glVertex( 1.0,-1.0, 0.0);                                    # Bottom Right
 118    glVertex(-1.0,-1.0, 0.0);                                    # Bottom Left
 119    glEnd();                                                     # we're done with the polygon
 120
 121    glTranslate(3.0,0.0,0.0);                                    # Move Right 3 Units
 122
 123    # draw a square (quadrilateral)
 124    glBegin(GL_QUADS);                                           # start drawing a polygon (4 sided)
 125    glVertex(-1.0, 1.0, 0.0);                                    # Top Left
 126    glVertex( 1.0, 1.0, 0.0);                                    # Top Right
 127    glVertex( 1.0,-1.0, 0.0);                                    # Bottom Right
 128    glVertex(-1.0,-1.0, 0.0);                                    # Bottom Left
 129    glEnd();                                                     # done with the polygon
 130
 131
 132   }
 133
 134
 135
 136