Shader "Debug/ReflectionProbePreview"
{
	Properties
	{
		_Cubemap("_Cubemap", Cube) = "white" {}
		_CameraWorldPosition("_CameraWorldPosition", Vector) = (1,1,1,1)
		_MipLevel("_MipLevel", Range(0.0,7.0)) = 0.0
		_Exposure("_Exposure", Range(-10.0,10.0)) = 0.0

	}
	
	SubShader
	{
		Tags{ "RenderPipeline" = "HDRenderPipeline" "RenderType" = "Opaque" "Queue" = "Transparent" }
		ZWrite On
		Cull Back

		Pass
	    {
		    Name "ForwardUnlit"
		    Tags{ "LightMode" = "Forward" }

		    HLSLPROGRAM
            #pragma vertex vert
            #pragma fragment frag

            #include "CoreRP/ShaderLibrary/common.hlsl"
            #include "HDRP/ShaderVariables.hlsl"

		    struct appdata
	        {
		        float4 positionOS : POSITION;
		        float3 normalOS : NORMAL;
	        };

	        struct v2f
	        {
		        float4 positionCS : SV_POSITION;
		        float3 normalWS : NORMAL;
		        float3 positionWS : TEXCOORD0;
	        };

            TEXTURECUBE(_Cubemap);
            SAMPLER(sampler_Cubemap);

	        float3 _CameraWorldPosition;
	        float _MipLevel;
	        float _Exposure;

	        v2f vert(appdata v)
	        {
		        v2f o;
                // Transform local to world before custom vertex code
                o.positionWS = TransformObjectToWorld(v.positionOS.xyz);
                o.positionWS = GetCameraRelativePositionWS(o.positionWS);
                o.positionCS = TransformWorldToHClip(o.positionWS);
                o.normalWS = TransformObjectToWorldNormal(v.normalOS);

		        return o;
	        }

	        float4 frag(v2f i) : SV_Target
	        {
		        //float3 view = normalize(i.worldpos - _CameraWorldPosition);
		        float3 V = normalize(i.positionWS - GetPrimaryCameraPosition());
		        float3 R = reflect(V, i.normalWS);
		        float4 color = SAMPLE_TEXTURECUBE_LOD(_Cubemap, sampler_Cubemap, R, _MipLevel).rgba;
                color = color * exp2(_Exposure);

		        return float4(color);
	        }
		    ENDHLSL
	    }
	}
}