Simple Filtering for SDFs Masks

SimpleSDF.hlsl

#define inverseLerp(a,b,x) ((x-a)/(b-a))

...

half rawSdf = _Mask.Sample(sampler_Mask, i.uv).r ;
half texelCoverage = fwidth(i.uv) * _Mask_TexelSize.zw; // calculate texelCoverage
texelCoverage = saturate(texelCoverage); //clamp texelCoverage to [0..1]

// you can also use smoothstep(), but inverseLerp uses less instructions 
half filteredSdf = saturate(inverseLerp(-texelSize, texelSize, rawSdf * 2.0 - 1.0));