Shader "Custom/URP/GTASAHintMarker"
{
    Properties
    {
        [ToggleUI] _Enabled ("Enabled", Float) = 1
        
        [HDR] _HintColor ("Marker Color", Color) = (1, 0.8, 0, 0.5)
        
        _FadeStart ("Fade Start Height (World Y)", Float) = 0.0
        _FadeEnd ("Fade End Height (World Y)", Float) = 2.0
        
        _HoleRadius ("Hole Radius", Range(0.0, 1.0)) = 0.5
        _HoleSmoothness ("Hole Smoothness", Range(0.001, 0.5)) = 0.05
        
        _PulseSpeed ("Pulse Speed", Float) = 6.0
        _PulseIntensity ("Pulse Intensity", Range(0, 1)) = 0.3  
    }

    SubShader
    {
        Tags 
        { 
            "RenderType" = "Transparent" 
            "Queue" = "Transparent+10" 
            "RenderPipeline" = "UniversalPipeline"
            "IgnoreProjector" = "True" 
        }
        
        LOD 100

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

            Blend SrcAlpha OneMinusSrcAlpha 
            ZWrite Off 
            Cull Off                     

            HLSLPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #pragma target 3.0

            #pragma multi_compile_instancing

            #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Core.hlsl"

            // CBUFFER необходим для совместимости с SRP Batcher
            CBUFFER_START(UnityPerMaterial)
                float4 _HintColor;
                float _Enabled;
                float _FadeStart;
                float _FadeEnd;
                float _HoleRadius;
                float _HoleSmoothness;
                float _PulseSpeed;
                float _PulseIntensity;
            CBUFFER_END

            struct Attributes
            {
                float4 positionOS : POSITION;
                float3 normalOS   : NORMAL;
                UNITY_VERTEX_INPUT_INSTANCE_ID
            };

            struct Varyings
            {
                float4 positionCS : SV_POSITION;
                float3 positionWS : TEXCOORD0; 
                float3 positionOS : TEXCOORD1;
                float3 normalOS   : NORMAL;
                UNITY_VERTEX_INPUT_INSTANCE_ID
            };

            Varyings vert(Attributes input)
            {
                Varyings output = (Varyings)0;

                UNITY_SETUP_INSTANCE_ID(input);
                UNITY_TRANSFER_INSTANCE_ID(input, output);

                VertexPositionInputs vertexInput = GetVertexPositionInputs(input.positionOS.xyz);

                output.positionCS = vertexInput.positionCS;
                output.positionWS = vertexInput.positionWS;
                output.positionOS = input.positionOS.xyz;
                output.normalOS   = input.normalOS;

                return output;
            }

            half4 frag(Varyings input) : SV_Target
            {
                UNITY_SETUP_INSTANCE_ID(input);

                if (_Enabled < 0.5)
                {
                    discard;
                }

                // Отсечение верхней крышки цилиндра/маркера
                if (input.normalOS.y > 0.5 && input.positionOS.y > 0.0)
                {
                    discard; 
                }

                // Вертикальный градиент затухания по высоте
                float heightRange = max(_FadeEnd - _FadeStart, 0.001);
                float gradient = saturate((input.positionWS.y - _FadeStart) / heightRange);
                float alphaFade = 1.0 - gradient;

                // Маска отверстия в нижней части
                float distFromCenter = length(input.positionOS.xz);
                if (input.normalOS.y < -0.5)
                {
                    float targetRadius = _HoleRadius * 0.5;
                    float holeMask = smoothstep(targetRadius, targetRadius + _HoleSmoothness, distFromCenter);
                    alphaFade *= holeMask;
                }

                half4 finalColor = _HintColor;
                finalColor.a *= alphaFade;

                // Пульсация прозрачности во времени
                float pulseWave = sin(_Time.y * _PulseSpeed) * 0.5 + 0.5;
                float pulse = (1.0 - _PulseIntensity) + pulseWave * _PulseIntensity;
                finalColor.a *= pulse;

                return finalColor;
            }
            ENDHLSL
        }
    }
    FallBack "Hidden/Universal Render Pipeline/FallbackError"
}