Shader "Rokid/Dot"
{
    Properties
    {
        _Color ("Color", Color) = (1, 1, 1, 1)
        _InnerDiameter ("InnerDiameter", Range(0, 10.0)) = 1.5
        _OuterDiameter ("OuterDiameter", Range(0.00872665, 10.0)) = 2.0
        _DistanceInMeters ("DistanceInMeters", Range(0.0, 10000.0)) = 2.0
    }

    SubShader
    {
        Tags { "Queue" = "Overlay" "IgnoreProjector" = "True" "RenderType" = "Transparent" }
        Pass
        {
            Blend SrcAlpha OneMinusSrcAlpha, OneMinusDstAlpha One
            AlphaTest Off
            Cull Back
            Lighting Off
            ZWrite Off
            ZTest Always

            Fog
            {
                Mode Off
            }
            CGPROGRAM

            #pragma vertex vert
            #pragma fragment frag

            #include "UnityCG.cginc"

            uniform float4 _Color;
            uniform float _InnerDiameter;
            uniform float _OuterDiameter;
            uniform float _DistanceInMeters;

            struct vertexInput
            {
                float4 vertex: POSITION;
            };

            struct fragmentInput
            {
                float4 position: SV_POSITION;
            };

            fragmentInput vert(vertexInput i)
            {
                float scale = lerp(_OuterDiameter, _InnerDiameter, i.vertex.z);

                float3 vert_out = float3(i.vertex.x * scale, i.vertex.y * scale, _DistanceInMeters);

                fragmentInput o;
                o.position = UnityObjectToClipPos(vert_out);
                return o;
            }

            fixed4 frag(fragmentInput i): SV_Target
            {
                fixed4 ret = _Color;
                return ret;
            }

            ENDCG

        }
    }
}