Add Polygon node

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Data/Nodes/Procedural/Shape/PolygonNode.cs

+using System.Reflection;
+using UnityEngine;
+
+namespace UnityEditor.ShaderGraph
+{
+    [Title("Procedural", "Shape", "Polygon")]
+    public class PolygonNode : CodeFunctionNode
+    {
+        public PolygonNode()
+        {
+            name = "Polygon";
+        }
+
+        protected override MethodInfo GetFunctionToConvert()
+        {
+            return GetType().GetMethod("Unity_Polygon", BindingFlags.Static | BindingFlags.NonPublic);
+        }
+
+        static string Unity_Polygon(
+            [Slot(0, Binding.MeshUV0)] Vector2 UV,
+            [Slot(1, Binding.None, 6, 6, 6, 6)] Vector1 Sides,
+            [Slot(2, Binding.None, 1, 1, 1, 1)] Vector1 Radius,
+            [Slot(3, Binding.None)] Vector1 Rotation,
+            [Slot(4, Binding.None)] out DynamicDimensionVector Out)
+        {
+            return
+                @"
+{
+    {precision} tau = 6.28318530718;
+    {precision}2 uv = (UV * 2 - 1) * {precision}2(1, -1);
+    {precision} pCoord = atan2(uv.x, uv.y) + radians(Rotation);
+    {precision} r = tau / Sides;
+    {precision} distance = cos(floor(0.5 + pCoord / r) * r - pCoord) * length(uv);
+    {precision} value = 1.0 - smoothstep(.4, .41, distance);
+    Out = value;
+}
+";
+        }
+    }
+}

MaterialGraphProject/Assets/UnityShaderEditor/Editor/Data/Nodes/Procedural/Shape/PolygonNode.cs.meta

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