Available since LÖVE 0.9.0  
 It has been renamed from love.graphics.getPixelEffect. 
 Gets the current Shader. Returns nil if none is set. 
shader = love.graphics.getShader( )
None.
 
    © 2006–2016 LÖVE Development Team
Licensed under the GNU Free Documentation License, Version 1.3.
    https://love2d.org/wiki/love.graphics.getShader