Shader "Aetheria/Dithered Particles"
{
    Properties
    {
        [HDR]_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
    }
    SubShader
    {
        Tags { "RenderType"="Opaque" }
        LOD 200

        CGPROGRAM
        #include "Dither Functions.cginc"
        // Physically based Standard lighting model, and enable shadows on all light types
        #pragma surface surf Standard vertex:vert

        // Use shader model 3.0 target, to get nicer looking lighting
        #pragma target 3.0

        sampler2D _MainTex;

        struct appdata_particles {
            float4 vertex : POSITION;
            float3 normal : NORMAL;
            float4 color : COLOR;
            float4 texcoord : TEXCOORD0;
        };

        struct Input {
            float2 uv_MainTex;
            float2 ditherOffset;
            float4 color;
            float4 screenPos;
        };

        void vert(inout appdata_particles v, out Input o) {
            UNITY_INITIALIZE_OUTPUT(Input,o);
            o.uv_MainTex = v.texcoord.xy;
            o.ditherOffset = v.texcoord.zw;
            o.color = v.color;
        }

        half _Glossiness;
        half _Metallic;
        fixed4 _Color;

        void surf (Input IN, inout SurfaceOutputStandard o)
        {
            // Albedo comes from a texture tinted by color
            fixed4 c = tex2D (_MainTex, IN.uv_MainTex) * _Color;

            // Apply screen space dithering
		    float2 screenUV = IN.screenPos.xy / IN.screenPos.w;
            ditherClip(screenUV + IN.ditherOffset, c.a);
            o.Emission = c.rgb;
            
            // Metallic and smoothness come from slider variables
            o.Metallic = _Metallic;
            o.Smoothness = _Glossiness;
            o.Alpha = 1;
        }
        ENDCG
    }
    FallBack "Diffuse"
}