old_contents: #!/usr/bin/env python
  """Multiple sinusoidal gratings (with mask)."""
  
  ############################
  #  Import various modules  #
  ############################
  
  from VisionEgg.Core import *
  from VisionEgg.Gratings import SinGrating2D
  from VisionEgg.Textures import Mask2D
  
  #####################################
  #  Initialize OpenGL window/screen  #
  #####################################
  
  screen = get_default_screen()
  
  ######################################
  #  Create sinusoidal grating object  #
  ######################################
  
  mask = Mask2D(function='circle',     # also supports 'gaussian'
                radius_parameter=100,  # radius for circle, sigma for gaussian (units: num_samples)
                num_samples=(256,256)) # this many texture elements in mask (covers whole size specified below)
  
  # NOTE: I have never worked with plaids before, and I'm not sure the
  # arithmetic used when combining these gratings is what people want.
  # Please submit any suggestions.
  
  sin1 = SinGrating2D(center           = ( screen.size[0]/2.0, screen.size[1]/2.0 ),
                      mask             = mask,
                      size             = ( 500.0 , 500.0 ),
                      spatial_freq     = 10.0 / screen.size[0], # units of cycles/pixel
                      temporal_freq_hz = 0.5,
                      orientation      = 45.0,
                      max_alpha        = 0.5) # controls "opacity": 1.0 = completely opaque, 0.0 = completely transparent
  
  sin2 = SinGrating2D(center           = ( screen.size[0]/2.0, screen.size[1]/2.0 ),
                      mask             = mask,
                      size             = ( 500.0 , 500.0 ),
                      spatial_freq     = 10.0 / screen.size[0], # units of cycles/pixel
                      temporal_freq_hz = 0.5,
                      orientation      = 135.0,
                      max_alpha        = 0.5) # controls "opacity": 1.0 = completely opaque, 0.0 = completely transparent
  
  ###############################################################
  #  Create viewport - intermediary between stimuli and screen  #
  ###############################################################
  
  viewport = Viewport( screen=screen, stimuli=[sin1,sin2] )
  
  ########################################
  #  Create presentation object and go!  #
  ########################################
  
  p = Presentation(go_duration=(10.0,'seconds'),viewports=[viewport])
  p.go()
  
new_contents: #!/usr/bin/env python
  """Multiple sinusoidal gratings (with mask)."""
  
  ############################
  #  Import various modules  #
  ############################
  
  from VisionEgg.Core import *
  from VisionEgg.Gratings import SinGrating2D
  from VisionEgg.Textures import Mask2D
  
  #####################################
  #  Initialize OpenGL window/screen  #
  #####################################
  
  screen = get_default_screen()
  
  ######################################
  #  Create sinusoidal grating object  #
  ######################################
  
  mask = Mask2D(function='circle',     # also supports 'gaussian'
                radius_parameter=100,  # radius for circle, sigma for gaussian (units: num_samples)
                num_samples=(256,256)) # this many texture elements in mask (covers whole size specified below)
  
  # NOTE: I have never worked with plaids before, and I'm not sure the
  # arithmetic used when combining these gratings is what people want.
  # Please submit any suggestions.
  
  sin1 = SinGrating2D(position         = ( screen.size[0]/2.0, screen.size[1]/2.0 ),
                      mask             = mask,
                      size             = ( 500.0 , 500.0 ),
                      spatial_freq     = 10.0 / screen.size[0], # units of cycles/pixel
                      temporal_freq_hz = 0.5,
                      orientation      = 45.0,
                      max_alpha        = 0.5) # controls "opacity": 1.0 = completely opaque, 0.0 = completely transparent
  
  sin2 = SinGrating2D(position         = ( screen.size[0]/2.0, screen.size[1]/2.0 ),
                      mask             = mask,
                      size             = ( 500.0 , 500.0 ),
                      spatial_freq     = 10.0 / screen.size[0], # units of cycles/pixel
                      temporal_freq_hz = 0.5,
                      orientation      = 135.0,
                      max_alpha        = 0.5) # controls "opacity": 1.0 = completely opaque, 0.0 = completely transparent
  
  ###############################################################
  #  Create viewport - intermediary between stimuli and screen  #
  ###############################################################
  
  viewport = Viewport( screen=screen, stimuli=[sin1,sin2] )
  
  ########################################
  #  Create presentation object and go!  #
  ########################################
  
  p = Presentation(go_duration=(10.0,'seconds'),viewports=[viewport])
  p.go()
  
subject: stop using deprecated parameters