Shader "Custom/GlitchAnalog"
{
    Properties
    {
        _MainTex ("Texture", 2D) = "white" {}
        _GlitchIntensity ("Glitch Intensity", Range(0,1)) = 0.5
    }
    SubShader
    {
       Tags { "Queue"="Overlay" "RenderType"="Transparent" }
ZTest Always
ZWrite Off
Cull Off
Blend SrcAlpha OneMinusSrcAlpha
        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #include "UnityCG.cginc"

            sampler2D _MainTex;
            float4 _MainTex_ST;
            float _GlitchIntensity;

            struct appdata {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
            };
            struct v2f {
                float2 uv : TEXCOORD0;
                float4 vertex : SV_POSITION;
            };
            v2f vert (appdata v)
            {
                v2f o;
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.uv = v.uv;
                return o;
            }

            float nrand(float x, float y)
            {
                float2 p = float2(x, y);
                float n = sin(dot(p, float2(12.9898, 78.233))) * 43758.5453;
                n = frac(n);
                n += frac(sin(dot(p * 2.0, float2(39.3468, 11.1351)) + _Time.y * 1.7) * 23421.631);
                n += frac(sin(dot(p * 4.0, float2(73.1567, 52.2351)) - _Time.y * 2.3) * 12345.678);
                return frac(n);
            }

            fixed4 frag (v2f i) : SV_Target
            {
                float2 uv = i.uv;
                float4 rgba = tex2D(_MainTex, uv);

                // 统一强度控制
                float intensity = _GlitchIntensity;

                // 色彩分离和撕裂
                float chromaAmount = (0.01 + abs(sin(_Time.y * 1.3)) * 0.02) * intensity;
                float tearStrength = (nrand(uv.y * 20.0 + _Time.y * 2.0, _Time.y * 1.3) - 0.5) * 0.15 * intensity;

                float2 uvR = uv + float2(chromaAmount, 0) + float2(tearStrength, 0);
                float2 uvG = uv + float2(0, 0) + float2(tearStrength * 0.5, 0);
                float2 uvB = uv - float2(chromaAmount, 0) + float2(tearStrength, 0);
                float r = tex2D(_MainTex, frac(uvR)).r;
                float g = tex2D(_MainTex, frac(uvG)).g;
                float b = tex2D(_MainTex, frac(uvB)).b;
                float3 chromaColor = float3(r, g, b);

                // 扫描线扰动
                float scanJitter = (nrand(uv.y * 60.0, _Time.y * 0.5) - 0.5) * 0.2 * intensity;
                float2 scanUV = uv + float2(scanJitter, 0);
                float3 scanColor = tex2D(_MainTex, frac(scanUV)).rgb;

                // 明暗扫描线效果
                float scanLine = 0.85 + 0.15 * sin(uv.y * 800.0 + _Time.y * 10.0);
                scanColor *= scanLine;

                // 合成最终颜色
                float3 finalColor = lerp(chromaColor, scanColor, 0.7 * intensity);

                return float4(finalColor, rgba.a);
            }
            ENDCG
        }
    }
}