// Upgrade NOTE: replaced '_Object2World' with 'unity_ObjectToWorld'
// Upgrade NOTE: replaced 'mul(UNITY_MATRIX_MVP,*)' with 'UnityObjectToClipPos(*)'

Shader "Custom/TVStatic"
{

    Properties
    {
        _ColorA("Color A", Color) = (1,1,1,1)
        _ColorB("Color B", Color) = (0,0,0,0)

        _ResX("X Resolution", Float) = 100
        _ResY("Y Resolution", Float) = 200

        _ScaleWithZoom("Scale With Cam Distance", Range(0,1)) = 1.0

    }

        SubShader
    {
        Pass
        {
            CGPROGRAM

            #pragma vertex vert
            #pragma fragment frag
            #pragma target 3.0

            #include "UnityCG.cginc"

            //This produces random values between 0 and 1
            float rand(float2 co)
             {
                     return frac((sin(dot(co.xy , float2(12.345 * _Time.w, 67.890 * _Time.w))) * 12345.67890 + _Time.w));
             }

            fixed4 _ColorA;
            fixed4 _ColorB;

            float _ResX;
            float _ResY;
            float _ScaleWithZoom;

            struct vertexInput
            {
                float4 vertex : POSITION;
                float4 texcoord0 : TEXCOORD0;
                float4 texcoord2 : TEXCOORD2;
            };

            struct fragmentInput
            {
                float4 position : SV_POSITION;//SV_POSITION
                float4 texcoord0 : TEXCOORD0;
                float4 camDist : TEXCOORD2;
            };

            fragmentInput vert(vertexInput i)
            {

                fragmentInput o;
                UNITY_INITIALIZE_OUTPUT(fragmentInput, o); //5-28-2016 added to fix d3d11 errors

                o.position = UnityObjectToClipPos(i.vertex);
                o.texcoord0 = i.texcoord0;

                //get the model's origin, so we can calculate the distance to camera (and scale the noise accordingly)
                 float4 modelOrigin = mul(unity_ObjectToWorld, float4(0.0, 0.0, 0.0, 1.0));

                 o.camDist.x = distance(_WorldSpaceCameraPos.xyz, modelOrigin.xyz);

                 o.camDist.x = lerp(1.0, o.camDist.x, _ScaleWithZoom);

                 return o;

             }

            //5-28-2016 changed VPOS to SV_POSITION to get rid of duplicate semantic error
            fixed4 frag(float4 screenPos : SV_POSITION, fragmentInput i, out float depth : SV_Depth) : SV_Target
            {

                fixed4 sc = fixed4((screenPos.xy), 0.0, 1.0);
                sc *= 0.001;

                sc.xy -= 0.5;
                sc.xy *= i.camDist.xx;
                sc.xy += 0.5;

                //round the screen coordinates to give it a blocky appearance
                 sc.x = round(sc.x * _ResX) / _ResX;
                 sc.y = round(sc.y * _ResY) / _ResY;

                 depth = 1;

                 float noise = rand(sc.xy);

                 float4 stat = lerp(_ColorA, _ColorB, noise.x);


                 return fixed4(stat.xyz, 1.0);
             }

             ENDCG
         }
}
}