' Gambas module file

'tutorial based on tutorial from NeHe Productions site at http://nehe.gamedev.net/
'visit the page for more info on OpenGL
'
'In this tutorial we add some color to our triangle and quad from tutorial 2

' Gambas module file
Private screen As New Window(True) As "Screen"

Public Sub Main()

  With screen
    .Width = 640
    .Height = 480
    .Text = MMain.Title
    .Show()
  End With

End

Public Sub Screen_Open()

  Gl.ClearDepth(100.0)                'Enables Clearing Of The Depth Buffer
  gl.ClearColor(0.0, 0.0, 0.0, 0.0)   'This Will Clear The Background Color To Black
  gl.DepthFunc(gl.LESS)            'The Type Of Depth Test To Do
  gl.Enable(gl.DEPTH_TEST)         'Enables Depth Testing
  gl.ShadeModel(gl.SMOOTH)         'Enables Smooth Color Shading
  gl.MatrixMode(gl.PROJECTION)
  gl.LoadIdentity()                     'Reset The Projection Matrix
  glu.Perspective(45.0, screen.Width / screen.Height, 0.1, 100.0)   'Calculate The Aspect Ratio Of The Window
  gl.MatrixMode(gl.MODELVIEW)

End

Public Sub Screen_resize()

  Gl.Viewport(0, 0, Screen.Width, Screen.Height)
  Gl.MatrixMode(Gl.PROJECTION)
  Gl.LoadIdentity()                     'Reset The Projection Matrix
  glu.Perspective(45.0, screen.Width / screen.Height, 0.1, 100.0)   'Calculate The Aspect Ratio Of The Window
  Gl.MatrixMode(Gl.MODELVIEW)

End

Public Sub init()



End

Public Sub Screen_Draw()

  gl.Clear(gl.COLOR_BUFFER_BIT Or gl.DEPTH_BUFFER_BIT)    ' Clear The Screen And The Depth Buffer
  gl.LoadIdentity()                                           'Reset The View
  gl.translatef(-1.5, 0.0, -6.0)                             ' MOVE Left 1.5 Units AND Into The Screen 6.0
  gl.Begin(gl.TRIANGLES)                             'Drawing Using Triangles
  gl.Color3f(1.0, 0.0, 0.0)                           'Set The Color TO Red
  gl.Vertex3f(0.0, 1.0, 0.0)                          'Top
  gl.Color3f(0.0, 1.0, 0.0)                           'Set The Color TO Green
  gl.Vertex3f(-1.0, -1.0, 0.0)                        'Bottom Left
  gl.Color3f(0.0, 0.0, 1.0)                           'Set The Color TO Blue
  gl.Vertex3f(1.0, -1.0, 0.0)                         'Bottom Right
  gl.End()                                               'Finished Drawing The Triangle

  gl.Translatef(3.0, 0.0, 0.0)                          'MOVE Right 3 Units

  gl.Color3f(0.5, 0.5, 1.0)                             'Set The Color TO Blue One Time Only
  gl.Begin(gl.QUADS)                                 'Draw A Quad
  gl.Vertex3f(-1.0, 1.0, 0.0)                         'Top Left
  gl.Vertex3f(1.0, 1.0, 0.0)                          'Top Right
  gl.Vertex3f(1.0, -1.0, 0.0)                         'Bottom Right
  gl.Vertex3f(-1.0, -1.0, 0.0)                        'Bottom Left
  gl.End()                                               'Done Drawing The Quad

End