Shader "Custom/DepthOnly"
{
    SubShader
    {
        Tags { "RenderType"="Opaque" }
        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #include "UnityCG.cginc"

            struct v2f
            {
                float4 pos : SV_POSITION;
                float depth : TEXCOORD0;
                float4 pos2 : TEXCOORD2;
            };

            v2f vert(appdata_base v)
            {
                v2f o;
                o.pos = UnityObjectToClipPos(v.vertex);
                // o.depth = (o.pos.z + 1.) / 2. / o.pos.w;
                // o.depth = (o.pos.z + 1.) / 2.;
                o.depth = o.pos.z;
                // o.depth = o.pos.z/ o.pos.w ;
                //o.depth = mul(UNITY_MATRIX_M, v.vertex).x;
                // o.pos2 = o.pos;
                return o;
            }

            fixed4 frag(v2f i) : SV_Target
            {
                // ****We had to change Unity's color space to Gamma such that it doesn't add its own gamma correction,
                //     for this to work *******
                return fixed4(i.depth, i.depth, i.depth, 1.0);
                // Output depth as grayscale
                // return fixed4((i.depth), (i.depth), (i.depth), 1.0);
                // return fixed4(
                //     (i.pos2.x) * .5 + .5, 
                //     (i.pos2.x) * .5 + .5, 
                //     (i.pos2.x) * .5 + .5, 1.0);
            }
            ENDCG
        }
    }
    FallBack "Diffuse"
}