Shader "Bansonic/Sprite Dissolve"
{
    Properties
    {
        [PerRendererData] _MainTex ("Sprite Texture", 2D) = "white" {}
        _NoiseTex ("Noise Texture", 2D) = "white" {}
        _Color ("Tint", Color) = (1,1,1,1)
        _DissolveAmount ("Dissolve Amount", Range(0, 1)) = 0
        _EdgeWidth ("Edge Width", Range(0.001, 0.5)) = 0.08
        _EdgeColor ("Edge Color", Color) = (1,0.6,0.1,1)
        _EdgeEmission ("Edge Emission", Range(0, 5)) = 1.5
        _NoiseTiling ("Noise Tiling", Vector) = (1,1,0,0)
        _NoiseOffset ("Noise Offset", Vector) = (0,0,0,0)
        [MaterialToggle] PixelSnap ("Pixel Snap", Float) = 0
    }

    SubShader
    {
        Tags
        {
            "Queue"="Transparent"
            "IgnoreProjector"="True"
            "RenderType"="Transparent"
            "PreviewType"="Plane"
            "CanUseSpriteAtlas"="True"
        }

        Cull Off
        Lighting Off
        ZWrite Off
        Blend One OneMinusSrcAlpha

        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #pragma target 2.0
            #pragma multi_compile _ PIXELSNAP_ON
            #include "UnityCG.cginc"

            struct appdata_t
            {
                float4 vertex : POSITION;
                float4 color : COLOR;
                float2 texcoord : TEXCOORD0;
            };

            struct v2f
            {
                float4 vertex : SV_POSITION;
                fixed4 color : COLOR;
                float2 uv : TEXCOORD0;
                float2 noiseUV : TEXCOORD1;
            };

            sampler2D _MainTex;
            sampler2D _NoiseTex;
            fixed4 _Color;
            fixed4 _EdgeColor;
            float _DissolveAmount;
            float _EdgeWidth;
            float _EdgeEmission;
            float4 _NoiseTiling;
            float4 _NoiseOffset;

            v2f vert(appdata_t IN)
            {
                v2f OUT;
                OUT.vertex = UnityObjectToClipPos(IN.vertex);
                OUT.uv = IN.texcoord;
                OUT.noiseUV = IN.texcoord * _NoiseTiling.xy + _NoiseOffset.xy;
                OUT.color = IN.color * _Color;

                #ifdef PIXELSNAP_ON
                OUT.vertex = UnityPixelSnap(OUT.vertex);
                #endif

                return OUT;
            }

            fixed4 frag(v2f IN) : SV_Target
            {
                fixed4 baseCol = tex2D(_MainTex, IN.uv) * IN.color;
                float noise = tex2D(_NoiseTex, IN.noiseUV).r;
                float edgeStart = _DissolveAmount - _EdgeWidth;

                clip(noise - _DissolveAmount);

                float edgeMask = 1.0 - saturate((noise - edgeStart) / max(_EdgeWidth, 0.0001));
                fixed3 edgeGlow = _EdgeColor.rgb * edgeMask * _EdgeEmission;

                fixed4 col;
                col.rgb = baseCol.rgb + edgeGlow;
                col.a = baseCol.a;
                return col;
            }
            ENDCG
        }
    }
}