addons/GLFW/samples/lesson08.io

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