GameBoy_006_GameBoyShader_03.shader

Shader "Gameboy"
{
  ...

    sampler2D _MainTex;
    float4 _Darkest, _Dark, _Ligt, _Ligtest;

    float4 frag (v2f i) : SV_Target
    {
      float4 originalColor = tex2D(_MainTex, i.uv);
      float luma = dot(originalColor.rgb, float3(0.2126, 0.7152, 0.0722));
      float posterized = floor(luma * 4) / (4 - 1);
    }
  ...
}