Shader "Custom/URP_Dissolve"
{
	Properties {
		_Color ("Color", Color) = (1,1,1,1)
		_MainTex ("Albedo (RGB)", 2D) = "white" {}
		_Glossiness ("Smoothness", Range(0,1)) = 0.5
		_Metallic ("Metallic", Range(0,1)) = 0.0
		_DissolveTexture("Dissolve Texture", 2D) = "white" {}
		_Amount("Amount", Range(0,1)) = 0
		_DissolveColor ("Dissolve Color", Color) = (1,1,1,1)
		_DissolveColorAlpha ("Dissolve Color Alpha", Range(0,1)) = 0.0
	}
	SubShader {
		Tags { "RenderType"="Opaque" }
		LOD 200
		Cull Off

		Pass {
			Name "FORWARD"
			Tags { "LightMode" = "UniversalForward" }

			HLSLPROGRAM
			#pragma vertex vert
			#pragma fragment frag
			#pragma multi_compile_fog
			#include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Core.hlsl"

			struct Attributes {
				float4 positionOS : POSITION;
				float2 uv         : TEXCOORD0;
			};

			   struct Varyings {
				   float4 positionHCS : SV_POSITION;
				   float2 uv          : TEXCOORD0;
				   float fogFactor    : TEXCOORD1;
			   };

			CBUFFER_START(UnityPerMaterial)
				float4 _Color;
				float _Glossiness;
				float _Metallic;
				float4 _DissolveColor;
				float _DissolveColorAlpha;
				float _Amount;
			CBUFFER_END

			TEXTURE2D(_MainTex); SAMPLER(sampler_MainTex);
			TEXTURE2D(_DissolveTexture); SAMPLER(sampler_DissolveTexture);

			Varyings vert(Attributes IN)
			{
				Varyings OUT;
				OUT.positionHCS = TransformObjectToHClip(IN.positionOS.xyz);
				OUT.uv = IN.uv;
			OUT.fogFactor = ComputeFogFactor(OUT.positionHCS.z / OUT.positionHCS.w);
				return OUT;
			}

			float4 frag(Varyings IN) : SV_Target
			{
				float dissolve_value = SAMPLE_TEXTURE2D(_DissolveTexture, sampler_DissolveTexture, IN.uv).r;
				clip(dissolve_value - _Amount);

				float4 albedo = SAMPLE_TEXTURE2D(_MainTex, sampler_MainTex, IN.uv) * _Color;

				// Simple metallic/smoothness (not PBR, but for effect)
				float3 emission = _DissolveColor.rgb * step(dissolve_value - _Amount, _DissolveColorAlpha);

				float3 color = albedo.rgb + emission;
				float alpha = albedo.a;
			color = MixFog(color, IN.fogFactor);
				return float4(color, alpha);
			}
			ENDHLSL
		}
	}
	FallBack "Universal Forward"
}