Shader "ElecField"
{
    Properties
    {
        _MainTex("MainTex (RGB)", 2D) = "white" {}
        _Alpha("Alpha", range(0.0, 1.0)) = 1.0
        _NoiseTex("Noise (RGBA)", 2D) = "white" {}
        _Noise("Noise", FLOAT) = 0.2
        _Speed("Speed", FLOAT) = 0.2
        _FallOff("FallOff", FLOAT) = 2
        _Lines("Lines", FLOAT) = 0.2
        _Color("Tint Color", COLOR) = (0.5,0.5,0.5,0.5)
        _Width("Width", FLOAT) = 0.2
    }
    SubShader
    {
        CGPROGRAM
            #pragma surface surf Lambert

            sampler2D _MainTex;
            float _Alpha;

            struct Input
            {
                float2 uv_MainTex;
            };

            void surf (Input IN, inout SurfaceOutput o)
            {
                half4 c = tex2D (_MainTex, IN.uv_MainTex);
                o.Albedo = c.rgb;
                o.Alpha = _Alpha;
            }
        ENDCG

        Pass
        {
            Blend SrcAlpha OneMinusSrcAlpha
            ZWrite Off
            Cull Off

            CGPROGRAM
                #pragma vertex vert
                #pragma fragment frag
                #include "UnityCG.cginc"

                float4 _NoiseTex_ST;
                sampler2D _NoiseTex;
                float _Speed;
                float _Alpha;
                half4 _Color;
                float _FallOff;
                float _Lines;
                float _Noise;
                float _Width;

                struct data
                {
                    float4 vertex : POSITION;
                    float2 texcoord : TEXCOORD;
                    float3 normal : NORMAL;
                };

                struct v2f
                {
                    float4 position : POSITION;
                    float2 uv : TEXCOORD;
                    float viewAngle : TEXCOORD1;
                    float ypos : TEXCOORD2;
                };

                v2f vert(data v)
                {
                    v2f o;
                    o.position = mul(UNITY_MATRIX_MVP, v.vertex + float4(v.normal, 0) * _Width);
                    o.uv = TRANSFORM_TEX(v.texcoord, _NoiseTex);
                    o.viewAngle = 1- abs(dot(v.normal, normalize(ObjSpaceViewDir(v.vertex))));
                    o.ypos = o.position.y;
                    return o;
                }

                half4 frag(v2f i) : COLOR
                {
                    float2 uvOffset1 = _Time.xy*_Noise;
                    float2 uvOffset2 = -_Time.xx*_Noise;
                    half4 noise1 = tex2D(_NoiseTex, i.uv + uvOffset1);
                    half4 noise2 = tex2D(_NoiseTex, i.uv + uvOffset2);
                    float noise = (dot(noise1, noise2) - 1) * _Noise;
                    half4 col = sin((i.ypos*_Lines + _Time.x*_Speed + noise)*100);
                    noise1 = tex2D(_NoiseTex, i.uv*6 + uvOffset1);
                    noise2 = tex2D(_NoiseTex, i.uv*6 + uvOffset2);
                    col.a *= saturate(1.3-(noise1.g+noise2.g)) * pow(i.viewAngle,_FallOff) * 15 * _Alpha;
                    return col * _Color * 2;
                }

            ENDCG
        }
    }
}