// jave.lin 2020.03.09
Shader "Custom/GetDepthTexture" {
    Properties
    {
        _MainTex("Texture", 2D) = "white" {}
        //_ExampleName("Example vector", Vector) = (0.0, 0.0, 0.0, 0.0)
    }

    SubShader{
        Cull Off ZWrite Off ZTest Always
        Pass {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #include "UnityCG.cginc"
            struct appdata {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
            };
            struct v2f {
                float2 uv : TEXCOORD0;
                float4 vertex : SV_POSITION;
            };
            float3 _ExampleName;
            sampler2D _CameraDepthTexture;
            
            v2f vert(appdata v) {
                v2f o;
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.uv = v.uv;
                return o;
            }
            fixed4 frag(v2f i) : SV_Target{
                //return Linear01Depth(SAMPLE_DEPTH_TEXTURE(_CameraDepthTexture, i.uv));
                // return LinearEyeDepth(SAMPLE_DEPTH_TEXTURE(_CameraDepthTexture, i.uv));
                return SAMPLE_DEPTH_TEXTURE(_CameraDepthTexture, i.uv);
            }
            ENDCG
        }
    }
}