addons/OpenGL/docs/tutorial/lesson3/main.io

   1 // NeHe Tutorial #3
   2 // See original source and C based tutorial at:
   3 // http://nehe.gamedev.net/data/lessons/lesson.asp?lesson=03
   4 //
   5 // Ported to Io by Steve Dekorte 2003
   6 // 2004-08-01 Updated by Doc O'Leary
   7
   8 Demo := Object clone
   9 Demo appendProto(OpenGL)
  10
  11 Demo reshape := method(w, h,
  12     glViewport(0, 0, w, h)
  13     glMatrixMode(GL_PROJECTION)
  14     glLoadIdentity
  15     gluPerspective(45.0, w / h, 0.1, 100.0)
  16     glMatrixMode(GL_MODELVIEW)
  17     glLoadIdentity
  18 )
  19
  20 Demo InitGL := method(
  21     glShadeModel(GL_SMOOTH)
  22     glClearColor(0, 0, 0, 0)
  23     glClearDepth(1)
  24     glEnable(GL_DEPTH_TEST)
  25     glDepthFunc(GL_LEQUAL)
  26
  27     glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST)
  28 )
  29
  30 // Ooooo, pretty colors!
  31 Demo display := method(
  32     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
  33     glLoadIdentity
  34
  35     // Move Left 1.5 units and into the screen 6.0 units.
  36     glTranslated(-1.5, 0.0, -6.0)
  37
  38     // Draw a triangle
  39     glBegin(GL_TRIANGLES)   // Start drawing a triangle
  40     glColor3d(1, 0, 0)      // Set the color to red
  41     glVertex3d(0, 1, 0)     // Top
  42     glColor3d(0, 1, 0)      // Set the color to green
  43     glVertex3d(1, -1, 0)    // Bottom Right
  44     glColor3d(0, 0, 1)      // Set the color to blue
  45     glVertex3d(-1, -1, 0)   // Bottom Left
  46     glEnd                   // We are done with the triangle
  47
  48     glTranslated(3.0, 0.0, 0.0)
  49
  50     // Draw a square (quadrilateral)
  51     glColor3d(0.5, 0.5, 1)      // Set The Color To Blue One Time Only
  52     glBegin(GL_QUADS)           // Start drawing a 4 sided polygon
  53     glVertex3d(-1.0, 1.0, 0.0)  // Top Left
  54     glVertex3d(1.0, 1.0, 0.0)   // Top Right
  55     glVertex3d(1.0, -1.0, 0.0)  // Bottom Right
  56     glVertex3d(-1.0, -1.0, 0.0) // Bottom Left
  57     glEnd
  58
  59     glutSwapBuffers
  60 )
  61
  62 Demo main := method(
  63     glutInit
  64     glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH)
  65     glutInitWindowSize(640, 480)
  66     glutCreateWindow("Jeff Molofee's GL Code Tutorial ... NeHe '99")
  67     glutEventTarget(self)
  68
  69     self InitGL
  70
  71     glutDisplayFunc
  72     glutReshapeFunc
  73
  74     glutMainLoop
  75 )
  76
  77 Demo main
  78