// 第 29 章配图用的简单透明面片（烟雾一类的粒子替身）：Alpha 混合、不写深度。
Shader "Cookbook/Ch29/SoftQuad"
{
    Properties
    {
        [MainTexture] _BaseMap ("Base Map", 2D) = "white" {}
        [MainColor] _BaseColor ("Color", Color) = (1, 1, 1, 0.5)
    }
    SubShader
    {
        Tags { "RenderType"="Transparent" "Queue"="Transparent" "RenderPipeline"="UniversalPipeline" "IgnoreProjector"="True" }
        Pass
        {
            Name "Unlit"
            Tags { "LightMode"="UniversalForward" }
            Blend SrcAlpha OneMinusSrcAlpha
            ZWrite Off
            Cull Off
            HLSLPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Core.hlsl"

            TEXTURE2D(_BaseMap); SAMPLER(sampler_BaseMap);
            CBUFFER_START(UnityPerMaterial)
                float4 _BaseMap_ST;
                half4 _BaseColor;
            CBUFFER_END

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

            Varyings vert(Attributes input)
            {
                Varyings o;
                o.positionCS = TransformObjectToHClip(input.positionOS.xyz);
                o.uv = TRANSFORM_TEX(input.uv, _BaseMap);
                return o;
            }
            half4 frag(Varyings i) : SV_Target
            {
                return SAMPLE_TEXTURE2D(_BaseMap, sampler_BaseMap, i.uv) * _BaseColor;
            }
            ENDHLSL
        }
    }
}