addons/GLFW/samples/lesson08.io

   1 #!/usr/bin/env io
   2
   3 # Port of http://glfw.sourceforge.net/tutorials/lesson08/lesson08.html
   4
   5 appendProto(GLFW)
   6 appendProto(OpenGL)
   7
   8 draw := method(
   9     # Get current time
  10     t := glfwGetTime()
  11
  12     # Get window size
  13     size := glfwGetWindowSize
  14
  15     # Make sure that height is non-zero to avoid division by zero
  16     if(size height < 1, size setHeight(1))
  17
  18     # Set viewport
  19     glViewport( 0, 0, size width, size height )
  20
  21     # Clear color and depth buffers
  22     glClearColor( 0, 0, 0, 0 )
  23     glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT )
  24
  25     # Calculate field of view as a function of time
  26     fieldOfView := (0.5 * t) sin * 30 + 50;
  27
  28     # Set up projection matrix
  29     glMatrixMode( GL_PROJECTION )     # Select projection matrix
  30     glLoadIdentity                    # Start with an identity matrix
  31     gluPerspective(                   # Set perspective view
  32         fieldOfView,                  # Field of view
  33         size width / size height,     # Window aspect (assumes square pixels)
  34         1,                            # Near Z clipping plane
  35         100                           # Far Z clippling plane
  36     )
  37
  38     # Calculate camera position
  39     camera := vector((0.3 * t) cos * 20, (0.3 * t) sin * 20, t sin + 4)
  40
  41     # Set up modelview matrix
  42     glMatrixMode( GL_MODELVIEW )      # Select modelview matrix
  43     glLoadIdentity                    # Start with an identity matrix
  44     gluLookAt(                        # Set camera position and orientation
  45         camera x, camera y, camera z, # Camera position (x,y,z)
  46         0, 0, 0,                      # View point (x,y,z)
  47         0, 1, 0                       # Up-vector (x,y,z)
  48     )
  49
  50     # Enable Z buffering
  51     glEnable( GL_DEPTH_TEST )
  52     glDepthFunc( GL_LEQUAL )
  53
  54     # Draw a grid
  55     glColor3f( 0.7, 1, 1 )
  56     glBegin( GL_LINES )
  57     (-10) to(10) foreach(i,
  58         glVertex3f( -10, 0, i )  # Line along X axis
  59         glVertex3f(  10, 0, i )  # -"-
  60         glVertex3f( i, 0, -10 )  # Line along Z axis
  61         glVertex3f( i, 0,  10 )  # -"-
  62     )
  63     glEnd
  64
  65     # Create a GLU quadrics object
  66     quadric := gluNewQuadric
  67
  68     # Draw a blue cone in the center
  69     glPushMatrix
  70     glRotatef( -90, 1, 0, 0 )
  71     glColor3f( 0, 0, 1 )
  72     gluCylinder( quadric, 1.5, 0, 4, 30, 30 )
  73     glPopMatrix
  74
  75     # Draw four spheres in the corners o the grid
  76     glColor3f( 1, 0.2, 0 )
  77     glPushMatrix
  78     glTranslatef( -9, 1, -9 )
  79     gluSphere( quadric, 1, 30, 30 )
  80     glPopMatrix
  81     glPushMatrix
  82     glTranslatef(  9, 1, -9 )
  83     gluSphere( quadric, 1, 30, 30 )
  84     glPopMatrix
  85     glPushMatrix
  86     glTranslatef( -9, 1,  9 )
  87     gluSphere( quadric, 1, 30, 30 )
  88     glPopMatrix
  89     glPushMatrix
  90     glTranslatef(  9, 1,  9 )
  91     gluSphere( quadric, 1, 30, 30 )
  92     glPopMatrix
  93
  94     # Destroy the GLU quadrics object
  95     gluDeleteQuadric( quadric )
  96 )
  97
  98 glfwInit
  99
 100 glfwOpenWindow(
 101         640, 480,          # Width and height of window
 102         8, 8, 8,           # Number of red, green, and blue bits for color buffer
 103         8,                 # Number of bits for alpha buffer
 104         24,                # Number of bits for depth buffer (Z-buffer)
 105         0,                 # Number of bits for stencil buffer
 106         GLFW_WINDOW        # We want a desktop window (could be GLFW_FULLSCREEN)
 107 )
 108
 109 glfwSetWindowTitle( "My OpenGL program" )
 110 glfwEnable( GLFW_STICKY_KEYS )
 111
 112 while(glfwGetKey(GLFW_KEY_ESC) == 0 and glfwGetWindowParam(GLFW_OPENED) != 0,
 113         draw
 114         glfwSwapBuffers
 115 )
 116
 117 glfwTerminate