another d demoscene entry

[#ponce]

> Same for me.  It just crashes while loading.  The debug version is more
> informative.  It says:
> 
> Error: CompileError : Cannot compile data/shaders/glow.fs
> LOG :
> (1) : error C5018: length of constructed vectors cannot exceed 4
> 
> These three lines are not in log.txt, but everything else is.  The
> log.txt is attached.

Hey, thanks :) !
Indeed there is an error.
uniform sampler1D tex;

gl_FragColor = gl_Color * vec4(1.0,1.0,1.0, texture1D(tex, a));

should be replaced by: 

gl_FragColor = gl_Color * vec4(1.0,1.0,1.0, texture1D(tex, a).x);