ScriptableRenderPipeline/com.unity.shadergraph/Editor/Data/Nodes/Input/Geometry/TangentVectorNode.cs

using UnityEngine;
using UnityEditor.Graphing;

namespace UnityEditor.ShaderGraph
{
    [Title("Input", "Geometry", "Tangent Vector")]
    public class TangentVectorNode : GeometryNode, IMayRequireTangent
    {
        public const int kOutputSlotId = 0;
        public const string kOutputSlotName = "Out";

        public TangentVectorNode()
        {
            name = "Tangent Vector";
            UpdateNodeAfterDeserialization();
        }

        public override string documentationURL
        {
            get { return "https://github.com/Unity-Technologies/ShaderGraph/wiki/Tangent-Vector-Node"; }
        }

        public sealed override void UpdateNodeAfterDeserialization()
        {
            AddSlot(new Vector3MaterialSlot(kOutputSlotId, kOutputSlotName, kOutputSlotName, SlotType.Output, new Vector4(0, 0, 1, 1)));
            RemoveSlotsNameNotMatching(new[] { kOutputSlotId });
        }

        public override string GetVariableNameForSlot(int slotId)
        {
            return string.Format("IN.{0}", space.ToVariableName(InterpolatorType.Tangent));
        }

        public NeededCoordinateSpace RequiresTangent()
        {
            return space.ToNeededCoordinateSpace();
        }
    }
}