The idea is to scale the source image to 270p and apply a linear filter to remove some jaggies, then as 2nd pass apply a scanlines filter that will work just fine on a non-integer 1080p screen (1080=270x4). Code as follows, copy and paste on a text document then save as your_preset.glslp on shaders folder. The idea came when playing on my tiny netbook with 1024x600 screen, i just couldn’t afford to lose any part of the screen, the 2x integer was way too small (did 300 pixels scale there). When i tried it, it looked stunning so i thought why not convert it to 1080p and post it.
shaders = "2"
shader0 = "shaders_glsl/stock.glsl"
filter_linear0 = "true"
wrap_mode0 = "clamp_to_border"
mipmap_input0 = "false"
alias0 = ""
float_framebuffer0 = "false"
srgb_framebuffer0 = "false"
scale_type_x0 = "source"
scale_x0 = "1.000000"
scale_type_y0 = "absolute"
scale_y0 = "270"
shader1 = "shaders_glsl/misc/interlacing.glsl"
filter_linear1 = "false"
wrap_mode1 = "clamp_to_border"
mipmap_input1 = "false"
alias1 = ""
float_framebuffer1 = "false"
srgb_framebuffer1 = "false"
parameters = "percent;enable_480i;top_field_first"
percent = "0.000000"
enable_480i = "1.000000"
top_field_first = "0.000000"
textures = "SamplerLUT1;SamplerLUT2;SamplerLUT3"
SamplerLUT1 = "shaders_glsl/crt/shaders/guest/lut/sony_trinitron1.png"
SamplerLUT1_linear = "true"
SamplerLUT1_wrap_mode = "clamp_to_border"
SamplerLUT1_mipmap = "false"
SamplerLUT2 = "shaders_glsl/crt/shaders/guest/lut/sony_trinitron2.png"
SamplerLUT2_linear = "true"
SamplerLUT2_wrap_mode = "clamp_to_border"
SamplerLUT2_mipmap = "false"
SamplerLUT3 = "shaders_glsl/crt/shaders/guest/lut/other1.png"
SamplerLUT3_linear = "true"
SamplerLUT3_wrap_mode = "clamp_to_border"
SamplerLUT3_mipmap = "false"