// S4 fog of war: a ground-hugging grid whose vertex alpha darkens what the viewer's team cannot see.
Shader "Luneraria/FogOverlay"
{
    Properties
    {
        _Color("Fog colour", Color) = (0.03, 0.04, 0.07, 1)
    }
    SubShader
    {
        Tags { "RenderType" = "Transparent" "RenderPipeline" = "UniversalPipeline" "Queue" = "Transparent-50" }
        Pass
        {
            Name "Fog"
            Tags { "LightMode" = "UniversalForward" }
            Blend SrcAlpha OneMinusSrcAlpha
            ZWrite Off
            ZTest LEqual
            Cull Off
            HLSLPROGRAM
            #pragma vertex Vert
            #pragma fragment Frag
            #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Core.hlsl"
            CBUFFER_START(UnityPerMaterial)
                half4 _Color;
            CBUFFER_END
            struct Attributes { float4 positionOS : POSITION; half4 color : COLOR; };
            struct Varyings { float4 positionCS : SV_POSITION; half alpha : TEXCOORD0; };
            Varyings Vert(Attributes input)
            {
                Varyings output;
                output.positionCS = TransformObjectToHClip(input.positionOS.xyz);
                output.alpha = input.color.a;
                return output;
            }
            half4 Frag(Varyings input) : SV_Target { return half4(_Color.rgb, _Color.a * input.alpha); }
            ENDHLSL
        }
    }
}