Shader "Hidden/OcclusionReplacementShader"
{

    SubShader {
        Tags { 
            "RenderType"="Opaque"
            }

        Pass {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #include "UnityCG.cginc"

            struct appdata {
                float4 vertex : POSITION;
                };
            struct v2f {
                float4 vertex : SV_POSITION;
                };

            v2f vert (appdata v) {
                v2f o;
                o.vertex = UnityObjectToClipPos(v.vertex);
                return o;
                }

            fixed4 frag (v2f i) : SV_Target {
                return half4(0,0,0,1);
                }
            ENDCG
            }
        }
    SubShader {
        Tags {
            "RenderType"="CullHighlightOne"
            }

        ZWrite Off
        Cull Off

        Pass {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #include "UnityCG.cginc"

            

            uniform sampler2D _CameraDepthTexture;
            sampler2D _MainTex;
            float4 _MainTex_ST;

            struct appdata {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
                
                };
            struct v2f {
                float4 vertex : SV_POSITION;
                float2 uv : TEXCOORD0;
                float4 screenPos : TEXCOORD1;
                float2 depth : TEXCOORD2;
                float dist : TEXCOORD3;
                };

            v2f vert (appdata v) {
                v2f o;

                o.vertex = mul(UNITY_MATRIX_MV, v.vertex);
                //o.depth = o.vertex.z;
                o.vertex = mul(UNITY_MATRIX_P, o.vertex);

                //UNITY_TRANSFER_DEPTH(o.depth);

                //o.screenPos = ComputeScreenPos(o.vertex);

                o.dist = distance(_WorldSpaceCameraPos, mul(unity_ObjectToWorld, v.vertex) );

                o.uv = TRANSFORM_TEX(v.uv, _MainTex);
                return o;
                }

            half4 frag (v2f i) : COLOR {
                //float depth = saturate(-0.005f * i.depth);//(i.depth) / _ProjectionParams.z;
                float depth = i.dist/_ProjectionParams.z;//SAMPLE_DEPTH_TEXTURE_PROJ(_CameraDepthTexture, UNITY_PROJ_COORD(i.screenPos)).r;
                //depth = Linear01Depth(depth);
                //depth = Linear01Depth(depth)* _ProjectionParams.z;
                return half4(1-depth,0,depth,1-depth);
                //UNITY_OUTPUT_DEPTH(i.depth);
                }
            ENDCG
            }
        }
    /*
    SubShader {
        Tags {
            "RenderType"="CullHighlightTwo"
            }

        Pass {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #include "UnityCG.cginc"

            sampler2D _CameraDepthTexture;
            sampler2D _MainTex;
            float4 _MainTex_ST;

            struct appdata {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
                };
            struct v2f {
                float4 vertex : SV_POSITION;
                float2 uv : TEXCOORD0;
                };

            v2f vert (appdata v) {
                v2f o;
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.uv = TRANSFORM_TEX(v.uv, _MainTex);
                return o;
                }

            fixed4 frag (v2f i) : SV_Target {
                float depth = tex2D(_CameraDepthTexture,i.uv).r;
                depth = Linear01Depth(depth)* _ProjectionParams.z;
                return half4(0,1,0,depth);
                }
            ENDCG
            }
        }
    SubShader {
        Tags {
            "RenderType"="CullHighlightThree"
            }

        Pass {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #include "UnityCG.cginc"

            sampler2D _CameraDepthTexture;
            sampler2D _MainTex;
            float4 _MainTex_ST;

            struct appdata {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
                };
            struct v2f {
                float4 vertex : SV_POSITION;
                float2 uv : TEXCOORD0;
                };

            v2f vert (appdata v) {
                v2f o;
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.uv = TRANSFORM_TEX(v.uv, _MainTex);
                return o;
                }

            fixed4 frag (v2f i) : SV_Target {
                float depth = tex2D(_CameraDepthTexture,i.uv).r;
                depth = Linear01Depth(depth)* _ProjectionParams.z;
                return half4(0,0,1,depth);
                }
            ENDCG
            }
        }
    */
}