The shaders subdirectory of the library contains a set of  GLSL  shaders
that are intended to be used in  iStripper  scenes  to  perform  various
effects. They have not been designed for any specific scenes but provide
generaly useful effects.  In  order  to provide flexibility they are all
controlled via a number of GLSL uniform variables that can  be  assigned
values in an iStripper scene description file.

Currently the following shaders are provided

  TheEmuLib.Emu_Rectangle.fsh

    Modify opacities inside and outside a rectangular area.

    Optionaly allows a border around the region in which 
    the opacities change smothly from that used inside
    the are to that used outside.

    May be used to extract rectangular areas from an image.
    May be used to implement vignetting.
   
  TheEmuLib.Emu_Wobble_XY.fsh
  TheEmuLib.Emu_Wobble_RA.fsh

    Cause the image to wobble in either the X and Y directions
    or in the polar R (radial) and A (angle) directions.

    The effect can optionaly be confined to a section of the
    image either by a discontinuity or by smoothly reducing
    the wobble to zero near the edge of the region.

    May be used to cause images to ripple, to pulsate or to
    suffer more extreme dynamic distortions.
   
  TheEmuLib.Emu_Wobble_RGBA_XY.fsh
  TheEmuLib.Emu_Wobble_RGBA_RA.fsh

     Wobbles the colour and opacities of an image. Similar 
     to the Wobble_XY and Wobble_RA shaders but operating
     in colour space. 

     May be used to cause waves of colour to pass across
     an image or to produce more complex colour variations.

     May be used to cause waves of transparancy to pass 
     across an image allowing a second to show through.
   
  TheEmuLib.Emu_Clamp_RGBA.fsh

     Restricts the ranges of the colour and opacitities of
     pixels in an image. 

     Originaly written because when using combinations of
     shaders the R, G, B and A components could go out of
     their normal range of 0.0 to 1.0 which could then
     adversely affect the final image.

     May be used to enforce the normal range for colour
     and opacity components.

     May be used to restrict the range of one or more
     colour components, e.g. to fix the red component
     to have a value of 0.25 or to limit the opacity.