#include "/Engine/Private/Common.ush"
#include "/Engine/Private/RayTracing/RayTracingCommon.ush"
#include "/Engine/Private/RayTracing/RayTracingHitGroupCommon.ush"


RWTexture2D<float4> outTex;
RaytracingAccelerationStructure TLAS;

RAY_TRACING_ENTRY_RAYGEN(RayTraceTestRGS)
{
    // reconstruct camera direction with a small (far) device z
    uint2 PixelCoord = DispatchRaysIndex().xy + View.ViewRectMin.xy;
    float3 WorldPosition;
    float3 CameraDirection;
	ReconstructTranslatedWorldPositionAndCameraDirectionFromDeviceZ(PixelCoord, 0.1f, WorldPosition, CameraDirection);

	// setup ray, simply shoot a long distance
    FRayDesc Ray;
	Ray.Origin = WorldPosition;
    Ray.Direction = CameraDirection;
    Ray.TMin = 0.0f;
    Ray.TMax = 9999;

	//Payload Struct
	FMaterialClosestHitPayload Payload = (FMaterialClosestHitPayload) 0;

	// SETTINGS
	const uint InstanceInclusionMask = RAY_TRACING_MASK_OPAQUE;
	const bool bEnableSkyLightContribution = false;
	const bool bIgnoreTranslucentMaterials = false;
	uint RayFlags = RAY_FLAG_FORCE_OPAQUE | RAY_FLAG_CULL_BACK_FACING_TRIANGLES;
	FRayCone RayCone = (FRayCone)0;

	// TraceRay for FMaterialClosestHitPayload
	FMaterialClosestHitPayload Payload = TraceMaterialRay(
			TLAS,
			RayFlags,
			InstanceInclusionMask,
			Ray,
			RayCone,
			bEnableSkyLightContribution,
			bIgnoreTranslucentMaterials);

	if (Payload.IsHit())
		outTex[PixelCoord] = 1.0f;
	else
		outTex[PixelCoord] = 0.0f;
}

[shader("miss")]
void RayTraceTestMS(inout FMaterialClosestHitPayload data)
{
    data.SetMiss();
}

[shader("closesthit")]
void RayTraceTestCHS(inout FMaterialClosestHitPayload data, BuiltInTriangleIntersectionAttributes attribs)
{
    data.HitT = RayTCurrent();
}