PixelEffect.shader

Shader "Hidden/PixelEffect"
{
    Properties
    {
        _MainTex ("Texture", 2D) = "white" {}
        _PixelSize("Pixel width", float) = 1.0

    }
    SubShader
    {

        Cull Off ZWrite Off ZTest Always
        Stencil{
            Ref 1
            ReadMask 1
            Comp Equal
            Pass Keep
        }
        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag

            #include "UnityCG.cginc"

            struct appdata
            {
                half4 vertex : POSITION;
                half2 uv : TEXCOORD0;
            };

            struct v2f
            {
                half2 uv : TEXCOORD0;
                half4 vertex : SV_POSITION;
            };

            v2f vert (appdata v)
            {
                v2f o;
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.uv = v.uv;
                return o;
            }

            sampler2D _MainTex;
            half _PixelSize;



            fixed4 frag (v2f i) : SV_Target
            {
                fixed4 col = tex2D(_MainTex, i.uv);
                float2 pixels = _PixelSize * (1 / _ScreenParams.xy);
                float2 pixeluv = float2(pixels * round(i.uv / pixels));
                col = tex2D(_MainTex, pixeluv);
                return col;
            }
            ENDCG
        }
    }
}