Moved GetBisector and OffsetPolygon from RoofGenerator to Geometry

Examples/Buildings/RoofGenerator.cs

@@ -1,7 +1,6 @@
 using System;
 using System.Collections.Generic;
 using UnityEngine;
-using UnityEngine.Assertions;
 
 namespace ProceduralToolkit.Examples
 {
@@ -15,7 +14,7 @@ public static MeshDraft Generate(
             float roofHeight,
             RoofConfig roofConfig)
         {
-            List<Vector2> roofPolygon = OffsetPolygon(foundationPolygon, roofConfig.overhang);
+            List<Vector2> roofPolygon = Geometry.OffsetPolygon(foundationPolygon, roofConfig.overhang);
 
             MeshDraft roofDraft;
             switch (roofConfig.type)
@@ -90,6 +89,7 @@ public static MeshDraft GenerateHipped(List<Vector2> roofPolygon, RoofConfig roo
             Vector3 ridgeOffset = (b - a).normalized*2;
             Vector3 ridge0 = (a + d)/2 + ridgeHeight + ridgeOffset;
             Vector3 ridge1 = (b + c)/2 + ridgeHeight - ridgeOffset;
+
             var roofDraft = new MeshDraft();
             roofDraft.AddQuad(a, ridge0, ridge1, b);
             roofDraft.AddTriangle(b, ridge1, c);
@@ -102,52 +102,14 @@ private static MeshDraft GenerateBorder(List<Vector2> roofPolygon, RoofConfig ro
         {
             List<Vector3> lowerRing = roofPolygon.ConvertAll(v => v.ToVector3XZ());
             List<Vector3> upperRing = roofPolygon.ConvertAll(v => v.ToVector3XZ() + Vector3.up*roofConfig.thickness);
-            var border = new MeshDraft().AddFlatQuadBand(lowerRing, upperRing, false);
-            return border;
+            return new MeshDraft().AddFlatQuadBand(lowerRing, upperRing, false);
         }
 
         private static MeshDraft GenerateOverhang(List<Vector2> foundationPolygon, List<Vector2> roofPolygon)
         {
             List<Vector3> lowerRing = foundationPolygon.ConvertAll(v => v.ToVector3XZ());
             List<Vector3> upperRing = roofPolygon.ConvertAll(v => v.ToVector3XZ());
-            var overhang = new MeshDraft().AddFlatQuadBand(lowerRing, upperRing, false);
-            return overhang;
-        }
-
-        private static List<Vector2> OffsetPolygon(List<Vector2> polygon, float distance)
-        {
-            var newPolygon = new List<Vector2>();
-            for (int i = 0; i < polygon.Count; i++)
-            {
-                var previous = polygon.GetLooped(i - 1);
-                var current = polygon[i];
-                var next = polygon.GetLooped(i + 1);
-                float angle;
-                Vector2 bisector = GetBisector(previous, current, next, out angle);
-                float hypotenuse = distance/GetBisectorSin(angle);
-
-                newPolygon.Add(current + bisector*hypotenuse);
-            }
-            return newPolygon;
-        }
-
-        private static Vector2 GetBisector(Vector2 previous, Vector2 current, Vector2 next, out float angle)
-        {
-            Vector2 toPrevious = (previous - current).normalized;
-            Vector2 toNext = (next - current).normalized;
-
-            angle = VectorE.SignedAngle(toPrevious, toNext);
-            Assert.IsFalse(float.IsNaN(angle));
-            return toPrevious.RotateCW(angle/2);
-        }
-
-        private static float GetBisectorSin(float angle)
-        {
-            if (angle > 180)
-            {
-                angle = 360 - angle;
-            }
-            return Mathf.Sin(angle/2*Mathf.Deg2Rad);
+            return new MeshDraft().AddFlatQuadBand(lowerRing, upperRing, false);
         }
     }
 

Scripts/Geometry/Geometry.cs

@@ -1,5 +1,6 @@
 using UnityEngine;
 using System.Collections.Generic;
+using UnityEngine.Assertions;
 
 namespace ProceduralToolkit
 {
@@ -10,6 +11,8 @@ public static class Geometry
     {
         public const float Epsilon = 0.00001f;
 
+        #region Point samplers
+
         /// <summary>
         /// Returns a point on a circle in the XY plane
         /// </summary>
@@ -175,5 +178,52 @@ public static Vector3 PointOnTeardrop(float radius, float height, float horizont
                 y: height*sinVertical,
                 z: radius*Mathf.Cos(horizontalRadians)*teardrop);
         }
+
+        #endregion Point samplers
+
+        /// <summary>
+        /// Returns the bisector of an angle
+        /// </summary>
+        /// <param name="previous">Previous vertex</param>
+        /// <param name="current">Current vertex</param>
+        /// <param name="next">Next vertex</param>
+        /// <param name="degrees">Value of an angle in degrees</param>
+        public static Vector2 GetAngleBisector(Vector2 previous, Vector2 current, Vector2 next, out float degrees)
+        {
+            Vector2 toPrevious = (previous - current).normalized;
+            Vector2 toNext = (next - current).normalized;
+
+            degrees = VectorE.SignedAngle(toPrevious, toNext);
+            Assert.IsFalse(float.IsNaN(degrees));
+            return toPrevious.RotateCW(degrees/2);
+        }
+
+        /// <summary>
+        /// Offsets the supplied polygon. Does not handle intersections.
+        /// </summary>
+        /// <param name="polygon">Vertices of the polygon</param>
+        /// <param name="distance">Offset distance. Positive values offset inside, negative outside.</param>
+        public static List<Vector2> OffsetPolygon(List<Vector2> polygon, float distance)
+        {
+            var newPolygon = new List<Vector2>();
+            for (int i = 0; i < polygon.Count; i++)
+            {
+                Vector2 previous = polygon.GetLooped(i - 1);
+                Vector2 current = polygon[i];
+                Vector2 next = polygon.GetLooped(i + 1);
+
+                float angle;
+                Vector2 bisector = GetAngleBisector(previous, current, next, out angle);
+
+                if (angle > 180)
+                {
+                    angle = 360 - angle;
+                }
+                float hypotenuse = distance/Mathf.Sin(angle/2*Mathf.Deg2Rad);
+
+                newPolygon.Add(current + bisector*hypotenuse);
+            }
+            return newPolygon;
+        }
     }
 }