Shader "Custom/SoapBubbleShader"
{
    Properties
    {
        _MainTex ("Texture", 2D) = "white" {}
        _NoiseTex ("Noise Texture", 2D) = "white" {} // 用于模拟薄膜干涉的噪声图
        _RimColor ("Rim Color", Color) = (1,1,1,1) // 边缘光颜色
        _RimPower ("Rim Power", Range(0.5, 8.0)) = 3.0 // 边缘光强度
        _Refraction ("Refraction", Range(0, 1)) = 0.1 // 折射强度
        _InterferenceStrength ("Interference Strength", Range(0, 1)) = 0.5 // 薄膜干涉强度
        _InterferenceSpeed ("Interference Speed", Range(0, 1)) = 0.1 // 薄膜干涉动画速度
    }
    SubShader
    {
        Tags { "Queue"="Transparent" "RenderType"="Transparent" }
        LOD 200

        GrabPass { "_GrabTexture" } // 抓取屏幕内容用于折射

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

            struct appdata
            {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
            };

            struct v2f
            {
                float4 pos : SV_POSITION;
                float2 uv : TEXCOORD0;
                float4 worldPos : TEXCOORD1;
                float3 viewDir : TEXCOORD2;
                float4 grabPos : TEXCOORD3;
            };

            sampler2D _MainTex;
            sampler2D _NoiseTex;
            sampler2D _GrabTexture;
            float4 _RimColor;
            float _RimPower;
            float _Refraction;
            float _InterferenceStrength;
            float _InterferenceSpeed;

            v2f vert (appdata v)
            {
                v2f o;
                o.pos = UnityObjectToClipPos(v.vertex);
                o.uv = v.uv;
                o.worldPos = mul(unity_ObjectToWorld, v.vertex);
                o.viewDir = normalize(UnityWorldSpaceViewDir(o.worldPos));
                o.grabPos = ComputeGrabScreenPos(o.pos);
                return o;
            }

            fixed4 frag (v2f i) : SV_Target
            {
                // 采样噪声图，模拟薄膜干涉
                float noise = tex2D(_NoiseTex, i.uv + float2(_Time.y * _InterferenceSpeed, 0)).r;
                float interference = sin(noise * 10.0) * _InterferenceStrength;

                // 折射效果
                float2 offset = i.viewDir.xy * _Refraction * noise;
                i.grabPos.xy += offset;
                fixed4 refrColor = tex2Dproj(_GrabTexture, i.grabPos);

                // Rim效果（边缘光）
                float rim = 1.0 - saturate(dot(i.viewDir, normalize(i.worldPos)));
                rim = pow(rim, _RimPower);
                fixed4 rimColor = _RimColor * rim;

                // 薄膜干涉颜色
                fixed4 interferenceColor = fixed4(interference, interference * 0.5, 1 - interference, 1);

                // 最终颜色
                fixed4 texColor = tex2D(_MainTex, i.uv);
                fixed4 finalColor = lerp(refrColor, rimColor, texColor.a);
                finalColor = lerp(finalColor, interferenceColor, _InterferenceStrength);

                return finalColor;
            }
            ENDCG
        }
    }
}