This append/prepend system can give some nice results even with the simplest shaders.
shaders = "5"
feedback_pass = "0"
shader0 = "shaders_glsl/cubic/shaders/spline16-x.glsl"
filter_linear0 = "false"
wrap_mode0 = "clamp_to_edge"
mipmap_input0 = "false"
alias0 = ""
float_framebuffer0 = "false"
srgb_framebuffer0 = "false"
scale_type_x0 = "viewport"
scale_x0 = "1.000000"
scale_type_y0 = "source"
scale_y0 = "1.000000"
shader1 = "shaders_glsl/cubic/shaders/spline16-y.glsl"
filter_linear1 = "false"
wrap_mode1 = "clamp_to_edge"
mipmap_input1 = "false"
alias1 = ""
float_framebuffer1 = "false"
srgb_framebuffer1 = "false"
shader2 = "shaders_glsl/misc/shaders/chromaticity.glsl"
filter_linear2 = "false"
wrap_mode2 = "clamp_to_border"
mipmap_input2 = "false"
alias2 = ""
float_framebuffer2 = "false"
srgb_framebuffer2 = "false"
shader3 = "shaders_glsl/scanlines/shaders/scanline.glsl"
filter_linear3 = "false"
wrap_mode3 = "clamp_to_border"
mipmap_input3 = "false"
alias3 = ""
float_framebuffer3 = "false"
srgb_framebuffer3 = "false"
scale_type_x3 = "viewport"
scale_x3 = "1.000000"
scale_type_y3 = "viewport"
scale_y3 = "1.000000"
shader4 = "shaders_glsl/crt/shaders/dotmask.glsl"
filter_linear4 = "false"
wrap_mode4 = "clamp_to_border"
mipmap_input4 = "false"
alias4 = ""
float_framebuffer4 = "false"
srgb_framebuffer4 = "false"
shadowMask = "0.000000"
DOTMASK_STRENGTH = "0.400000"