Shader-Style Graphics - I.e., Pretty Lights!

local function shaderFunc(oldColor, fragCoord, inputs)
    local brightness = 3.
    local ray_brightness = 5.
    local gamma = 6.
    local spot_brightness = 1.5
    local ray_density = 6.
    local curvature = 90.
    local red =   1.8
    local green = 3.
    local blue =  .5
    local noisetype = 1
    local sin_freq = 6.

    local iResolution = inputs[1]
    local iGlobalTime = inputs[2]
    local fragColor

    local function hash(n) return fract(sin(n)*43758.5453) end

    local function noise(x)
        x = vec2(x.x, x.y)
        x = mul2s(x, 1.75)
        local p = vec2(floor(x.x), floor(x.y))
        local f = vec2(fract(x.x), fract(x.y))

        f = mul2(mul2(f, f), (sub2(vec2(3, 3), mul2s(f, 2))))

        local n = p.x + p.y*57.0

        local res = mix(mix( hash(n+  0.0), hash(n+  1.0),f.x),
                        mix( hash(n+ 57.0), hash(n+ 58.0),f.x),f.y)
        return res
    end

    local m2 = { 0.80,  0.60, -0.60,  0.80 };
    local function fbm(p)
        p = vec2(p.x, p.y)
        local z=2.
        local rz = 0.
        p = mul2s(p, 0.25)
        for i = 1, 5 do
            if noisetype == 1 then
                rz = rz + abs((noise(p)-0.5)*2.)/z
            elseif noisetype == 2 then
                rz = rz + (sin(noise(p)*sin_freq)*0.5+0.5) /z
            else
                rz = rz + noise(p)/z
            end
            z = z*2.
            p = mat2mulvec2(m2, mul2s(p, 2)) -- may need to swap these
        end
        return rz
    end

    local function mainImage()
        local t = -iGlobalTime*0.03*4
        uv = sub2s(div2(fragCoord, iResolution), 0.5)
        uv.x = uv.x * iResolution.x/iResolution.y
        uv = add2s(mul2s(mul2s(uv, curvature), .05), 0.0001)

        local r = sqrt(dot2(uv, uv))
        local x = dot2(normalize2(uv), vec2(.5,0.)) + t
        local y = dot2(normalize2(uv), vec2(.0,.5)) + t

        --[[#ifdef YO_DAWG
        x = fbm(vec2(y*ray_density*0.5,r+x*ray_density*.2));
        y = fbm(vec2(r+y*ray_density*0.1,x*ray_density*.5));
        #endif]]

        local val
        val = fbm(vec2(r+y*ray_density,r+x*ray_density-y))
        val = smoothstep(gamma*.02-.1,ray_brightness+(gamma*0.02-.1)+.001,val)
        val = sqrt(val)

        local col = div3(vec3(val, val, val), vec3(red,green,blue))
        --col = clamp(sub3(vec3(1, 1, 1), col),0,1)
        col = vec3(
            clamp(1-col.x, 0, 1),
            clamp(1-col.y, 0, 1),
            clamp(1-col.z, 0, 1))

        --col = mix(col,vec3(1.),spot_brightness-r/0.1/curvature*200./brightness);
        col.x = mix(col.x, 1, spot_brightness-r/0.1/curvature*200./brightness)
        col.y = mix(col.y, 1, spot_brightness-r/0.1/curvature*200./brightness)
        col.z = mix(col.z, 1, spot_brightness-r/0.1/curvature*200./brightness)

        fragColor = vec4(col.x, col.y, col.z, 1.0)
    end

    mainImage()
    return fragColor
end