Replaced IList with IReadOnlyList wherever possible

Closing #69. Nice.

Runtime/ArrayE.cs

@@ -29,15 +29,15 @@ public static LinkedListNode<T> PreviousOrLast<T>(this LinkedListNode<T> current
         /// <summary>
         /// Two-dimensional indexer getter
         /// </summary>
-        public static T GetXY<T>(this IList<T> list, Vector2Int position, int width)
+        public static T GetXY<T>(this IReadOnlyList<T> list, Vector2Int position, int width)
         {
             return list[position.y*width + position.x];
         }
 
         /// <summary>
         /// Two-dimensional indexer getter
         /// </summary>
-        public static T GetXY<T>(this IList<T> list, int x, int y, int width)
+        public static T GetXY<T>(this IReadOnlyList<T> list, int x, int y, int width)
         {
             return list[y*width + x];
         }
@@ -93,7 +93,7 @@ public static void SetXY<T>(this NativeArray<T> list, int x, int y, int width, T
         /// <summary>
         /// Looped indexer getter, allows out of bounds indices
         /// </summary>
-        public static T GetLooped<T>(this IList<T> list, int index)
+        public static T GetLooped<T>(this IReadOnlyList<T> list, int index)
         {
             while (index < 0)
             {

Runtime/ClipperUtility.cs

@@ -11,7 +11,7 @@ public class ClipperUtility
     {
         public const float ClipperScale = 100000;
 
-        public static List<IntPoint> ToIntPath(IList<Vector2> path)
+        public static List<IntPoint> ToIntPath(IReadOnlyList<Vector2> path)
         {
             var intPath = new List<IntPoint>(path.Count);
             foreach (var vertex in path)

Runtime/Geometry/Geometry.cs

@@ -617,7 +617,7 @@ public static Vector2 GetAngleBisector(Vector2 previous, Vector2 current, Vector
         /// </summary>
         /// <param name="polygon">Vertices of the polygon in clockwise order.</param>
         /// <param name="distance">Offset distance. Positive values offset outside, negative inside.</param>
-        public static List<Vector2> OffsetPolygon(IList<Vector2> polygon, float distance)
+        public static List<Vector2> OffsetPolygon(IReadOnlyList<Vector2> polygon, float distance)
         {
             var newPolygon = new List<Vector2>(polygon.Count);
             for (int i = 0; i < polygon.Count; i++)
@@ -699,7 +699,7 @@ public static float GetAngleBisectorSin(float angle)
         /// Calculates the area of the input polygon.
         /// </summary>
         /// <param name="polygon">Vertices of the polygon.</param>
-        public static float GetArea(IList<Vector2> polygon)
+        public static float GetArea(IReadOnlyList<Vector2> polygon)
         {
             return Mathf.Abs(GetSignedArea(polygon));
         }
@@ -708,7 +708,7 @@ public static float GetArea(IList<Vector2> polygon)
         /// Calculates the signed area of the input polygon.
         /// </summary>
         /// <param name="polygon">Vertices of the polygon.</param>
-        public static float GetSignedArea(IList<Vector2> polygon)
+        public static float GetSignedArea(IReadOnlyList<Vector2> polygon)
         {
             if (polygon.Count < 3) return 0;
             float a = 0;
@@ -723,7 +723,7 @@ public static float GetSignedArea(IList<Vector2> polygon)
         /// Calculates the orientation of the vertices of the input polygon.
         /// </summary>
         /// <param name="polygon">Vertices of the polygon.</param>
-        public static Orientation GetOrientation(IList<Vector2> polygon)
+        public static Orientation GetOrientation(IReadOnlyList<Vector2> polygon)
         {
             if (polygon.Count < 3) return Orientation.NonOrientable;
             float signedArea = GetSignedArea(polygon);
@@ -736,7 +736,7 @@ public static Orientation GetOrientation(IList<Vector2> polygon)
         /// Calculates the perimeter of the input polygon.
         /// </summary>
         /// <param name="polygon">Vertices of the polygon.</param>
-        public static float GetPerimeter(IList<Vector2> polygon)
+        public static float GetPerimeter(IReadOnlyList<Vector2> polygon)
         {
             if (polygon.Count < 2) return 0;
             float perimeter = 0;
@@ -750,7 +750,7 @@ public static float GetPerimeter(IList<Vector2> polygon)
         /// <summary>
         /// Calculates a bounding rect for a set of vertices.
         /// </summary>
-        public static Rect GetRect(IList<Vector2> vertices)
+        public static Rect GetRect(IReadOnlyList<Vector2> vertices)
         {
             Vector2 min = vertices[0];
             Vector2 max = vertices[0];

Runtime/Geometry/StraightSkeleton/StraightSkeletonGenerator.cs

@@ -16,7 +16,7 @@ public class StraightSkeletonGenerator
         private readonly List<Plan> newPlans = new List<Plan>();
         private StraightSkeleton skeleton;
 
-        public StraightSkeleton Generate(IList<Vector2> polygon)
+        public StraightSkeleton Generate(IReadOnlyList<Vector2> polygon)
         {
             activePlans.Clear();
             newPlans.Clear();

Runtime/LibTessDotNet/Tess.cs

@@ -704,7 +704,7 @@ private void OutputContours()
             }
         }
 
-        private Real SignedArea(IList<ContourVertex> vertices)
+        private Real SignedArea(IReadOnlyList<ContourVertex> vertices)
         {
             Real area = 0.0f;
 
@@ -745,12 +745,12 @@ public void AddContour(ContourVertex[] vertices, ContourOrientation forceOrienta
         /// <see cref="ContourOrientation.Clockwise"/> and <see cref="ContourOrientation.CounterClockwise"/> 
         /// force the vertices to have a specified orientation.
         /// </param>
-        public void AddContour(IList<ContourVertex> vertices, ContourOrientation forceOrientation = ContourOrientation.Original)
+        public void AddContour(IReadOnlyList<ContourVertex> vertices, ContourOrientation forceOrientation = ContourOrientation.Original)
         {
             AddContourInternal(vertices, forceOrientation);
         }
 
-        private void AddContourInternal(IList<ContourVertex> vertices, ContourOrientation forceOrientation)
+        private void AddContourInternal(IReadOnlyList<ContourVertex> vertices, ContourOrientation forceOrientation)
         {
             if (_mesh == null)
             {

Runtime/MeshDraft.cs

@@ -295,7 +295,7 @@ private MeshDraft _AddQuad(Vector3 vertex0, Vector3 vertex1, Vector3 vertex2, Ve
         /// <remarks>
         /// https://en.wikipedia.org/wiki/Triangle_fan
         /// </remarks>
-        public MeshDraft AddTriangleFan(IList<Vector3> fan, bool reverseTriangles = false)
+        public MeshDraft AddTriangleFan(IReadOnlyList<Vector3> fan, bool reverseTriangles = false)
         {
             Vector3 normal = Vector3.Cross(fan[1] - fan[0], fan[fan.Count - 1] - fan[0]).normalized;
             return AddTriangleFan(fan, normal, reverseTriangles);
@@ -307,7 +307,7 @@ public MeshDraft AddTriangleFan(IList<Vector3> fan, bool reverseTriangles = fals
         /// <remarks>
         /// https://en.wikipedia.org/wiki/Triangle_fan
         /// </remarks>
-        public MeshDraft AddTriangleFan(IList<Vector3> fan, Vector3 normal, bool reverseTriangles = false)
+        public MeshDraft AddTriangleFan(IReadOnlyList<Vector3> fan, Vector3 normal, bool reverseTriangles = false)
         {
             AddTriangleFanVertices(fan, reverseTriangles);
             for (int i = 0; i < fan.Count; i++)
@@ -323,7 +323,7 @@ public MeshDraft AddTriangleFan(IList<Vector3> fan, Vector3 normal, bool reverse
         /// <remarks>
         /// https://en.wikipedia.org/wiki/Triangle_fan
         /// </remarks>
-        public MeshDraft AddTriangleFan(IList<Vector3> fan, IList<Vector3> normals, bool reverseTriangles = false)
+        public MeshDraft AddTriangleFan(IReadOnlyList<Vector3> fan, IReadOnlyList<Vector3> normals, bool reverseTriangles = false)
         {
             AddTriangleFanVertices(fan, reverseTriangles);
             this.normals.AddRange(normals);
@@ -336,7 +336,7 @@ public MeshDraft AddTriangleFan(IList<Vector3> fan, IList<Vector3> normals, bool
         /// <remarks>
         /// https://en.wikipedia.org/wiki/Triangle_fan
         /// </remarks>
-        public MeshDraft AddTriangleFan(IList<Vector3> fan, IList<Vector2> uv, bool reverseTriangles = false)
+        public MeshDraft AddTriangleFan(IReadOnlyList<Vector3> fan, IReadOnlyList<Vector2> uv, bool reverseTriangles = false)
         {
             this.uv.AddRange(uv);
             return AddTriangleFan(fan, reverseTriangles);
@@ -348,7 +348,7 @@ public MeshDraft AddTriangleFan(IList<Vector3> fan, IList<Vector2> uv, bool reve
         /// <remarks>
         /// https://en.wikipedia.org/wiki/Triangle_fan
         /// </remarks>
-        public MeshDraft AddTriangleFan(IList<Vector3> fan, Vector3 normal, IList<Vector2> uv, bool reverseTriangles = false)
+        public MeshDraft AddTriangleFan(IReadOnlyList<Vector3> fan, Vector3 normal, IReadOnlyList<Vector2> uv, bool reverseTriangles = false)
         {
             this.uv.AddRange(uv);
             return AddTriangleFan(fan, normal, reverseTriangles);
@@ -360,13 +360,14 @@ public MeshDraft AddTriangleFan(IList<Vector3> fan, Vector3 normal, IList<Vector
         /// <remarks>
         /// https://en.wikipedia.org/wiki/Triangle_fan
         /// </remarks>
-        public MeshDraft AddTriangleFan(IList<Vector3> fan, IList<Vector3> normals, IList<Vector2> uv, bool reverseTriangles = false)
+        public MeshDraft AddTriangleFan(IReadOnlyList<Vector3> fan, IReadOnlyList<Vector3> normals, IReadOnlyList<Vector2> uv,
+            bool reverseTriangles = false)
         {
             this.uv.AddRange(uv);
             return AddTriangleFan(fan, normals, reverseTriangles);
         }
 
-        private void AddTriangleFanVertices(IList<Vector3> fan, bool reverseTriangles)
+        private void AddTriangleFanVertices(IReadOnlyList<Vector3> fan, bool reverseTriangles)
         {
             int count = vertices.Count;
             if (reverseTriangles)
@@ -400,7 +401,7 @@ private void AddTriangleFanVertices(IList<Vector3> fan, bool reverseTriangles)
         /// <remarks>
         /// https://en.wikipedia.org/wiki/Triangle_strip
         /// </remarks>
-        public MeshDraft AddTriangleStrip(IList<Vector3> strip)
+        public MeshDraft AddTriangleStrip(IReadOnlyList<Vector3> strip)
         {
             Vector3 normal = Vector3.Cross(strip[1] - strip[0], strip[2] - strip[0]).normalized;
             return AddTriangleStrip(strip, normal);
@@ -412,7 +413,7 @@ public MeshDraft AddTriangleStrip(IList<Vector3> strip)
         /// <remarks>
         /// https://en.wikipedia.org/wiki/Triangle_strip
         /// </remarks>
-        public MeshDraft AddTriangleStrip(IList<Vector3> strip, Vector3 normal)
+        public MeshDraft AddTriangleStrip(IReadOnlyList<Vector3> strip, Vector3 normal)
         {
             for (int i = 0, j = 1, k = 2;
                 i < strip.Count - 2;
@@ -436,7 +437,7 @@ public MeshDraft AddTriangleStrip(IList<Vector3> strip, Vector3 normal)
         /// <remarks>
         /// https://en.wikipedia.org/wiki/Triangle_strip
         /// </remarks>
-        public MeshDraft AddTriangleStrip(IList<Vector3> strip, IList<Vector3> normals)
+        public MeshDraft AddTriangleStrip(IReadOnlyList<Vector3> strip, IReadOnlyList<Vector3> normals)
         {
             for (int i = 0, j = 1, k = 2;
                 i < strip.Count - 2;
@@ -457,7 +458,7 @@ public MeshDraft AddTriangleStrip(IList<Vector3> strip, IList<Vector3> normals)
         /// <remarks>
         /// https://en.wikipedia.org/wiki/Triangle_strip
         /// </remarks>
-        public MeshDraft AddTriangleStrip(IList<Vector3> strip, IList<Vector2> uv)
+        public MeshDraft AddTriangleStrip(IReadOnlyList<Vector3> strip, IReadOnlyList<Vector2> uv)
         {
             this.uv.AddRange(uv);
             return AddTriangleStrip(strip);
@@ -469,7 +470,7 @@ public MeshDraft AddTriangleStrip(IList<Vector3> strip, IList<Vector2> uv)
         /// <remarks>
         /// https://en.wikipedia.org/wiki/Triangle_strip
         /// </remarks>
-        public MeshDraft AddTriangleStrip(IList<Vector3> strip, Vector3 normal, IList<Vector2> uv)
+        public MeshDraft AddTriangleStrip(IReadOnlyList<Vector3> strip, Vector3 normal, IReadOnlyList<Vector2> uv)
         {
             this.uv.AddRange(uv);
             return AddTriangleStrip(strip, normal);
@@ -481,7 +482,7 @@ public MeshDraft AddTriangleStrip(IList<Vector3> strip, Vector3 normal, IList<Ve
         /// <remarks>
         /// https://en.wikipedia.org/wiki/Triangle_strip
         /// </remarks>
-        public MeshDraft AddTriangleStrip(IList<Vector3> strip, IList<Vector3> normals, IList<Vector2> uv)
+        public MeshDraft AddTriangleStrip(IReadOnlyList<Vector3> strip, IReadOnlyList<Vector3> normals, IReadOnlyList<Vector2> uv)
         {
             this.uv.AddRange(uv);
             return AddTriangleStrip(strip, normals);
@@ -494,7 +495,7 @@ public MeshDraft AddTriangleStrip(IList<Vector3> strip, IList<Vector3> normals,
         /// <summary>
         /// Adds a baseless pyramid to the draft
         /// </summary>
-        public MeshDraft AddBaselessPyramid(Vector3 apex, IList<Vector3> ring, bool generateUV, bool reverseTriangles = false)
+        public MeshDraft AddBaselessPyramid(Vector3 apex, IReadOnlyList<Vector3> ring, bool generateUV, bool reverseTriangles = false)
         {
             if (generateUV)
             {
@@ -547,7 +548,7 @@ public MeshDraft AddBaselessPyramid(Vector3 apex, IList<Vector3> ring, bool gene
         /// <summary>
         /// Adds a band made from triangles to the draft
         /// </summary>
-        public MeshDraft AddFlatTriangleBand(IList<Vector3> lowerRing, IList<Vector3> upperRing, bool generateUV)
+        public MeshDraft AddFlatTriangleBand(IReadOnlyList<Vector3> lowerRing, IReadOnlyList<Vector3> upperRing, bool generateUV)
         {
             if (lowerRing.Count != upperRing.Count)
             {
@@ -608,7 +609,7 @@ public MeshDraft AddFlatTriangleBand(IList<Vector3> lowerRing, IList<Vector3> up
         /// <summary>
         /// Adds a band made from quads to the draft
         /// </summary>
-        public MeshDraft AddFlatQuadBand(IList<Vector3> lowerRing, IList<Vector3> upperRing, bool generateUV)
+        public MeshDraft AddFlatQuadBand(IReadOnlyList<Vector3> lowerRing, IReadOnlyList<Vector3> upperRing, bool generateUV)
         {
             if (lowerRing.Count != upperRing.Count)
             {

Runtime/PathClipper.cs

@@ -54,7 +54,7 @@ public PathClipper(InitOptions initOptions = 0)
         /// <param name="polyType"> Type of the path (Subject or Clip). </param>
         /// <param name="closed"> Controls whether the path is closed. Clipping paths must always be closed. </param>
         /// <returns> False if the path is invalid for clipping, true otherwise. </returns>
-        public bool AddPath(IList<Vector2> path, PolyType polyType, bool closed = true)
+        public bool AddPath(IReadOnlyList<Vector2> path, PolyType polyType, bool closed = true)
         {
             return clipper.AddPath(ClipperUtility.ToIntPath(path), polyType, closed);
         }

Runtime/PathOffsetter.cs

@@ -52,7 +52,7 @@ public PathOffsetter(double miterLimit = 2.0, double arcTolerance = 0.25)
         /// <param name="path"> Vertices of the path. </param>
         /// <param name="joinType"> See http://www.angusj.com/delphi/clipper/documentation/Docs/Units/ClipperLib/Types/JoinType.htm </param>
         /// <param name="endType"> See http://www.angusj.com/delphi/clipper/documentation/Docs/Units/ClipperLib/Types/EndType.htm </param>
-        public void AddPath(IList<Vector2> path, JoinType joinType = JoinType.jtMiter, EndType endType = EndType.etClosedPolygon)
+        public void AddPath(IReadOnlyList<Vector2> path, JoinType joinType = JoinType.jtMiter, EndType endType = EndType.etClosedPolygon)
         {
             clipperOffset.AddPath(ClipperUtility.ToIntPath(path), joinType, endType);
         }

Runtime/RandomE.cs

@@ -322,7 +322,7 @@ public static List<ColorHSV> TetradicPalette(float saturation = 1, float value =
         /// <summary>
         /// Returns a random element
         /// </summary>
-        public static T GetRandom<T>(this IList<T> list)
+        public static T GetRandom<T>(this IReadOnlyList<T> list)
         {
             if (list == null)
             {
@@ -338,7 +338,7 @@ public static T GetRandom<T>(this IList<T> list)
         /// <summary>
         /// Returns a random element
         /// </summary>
-        public static T GetRandom<T>(this IList<T> list, ref MRandom random)
+        public static T GetRandom<T>(this IReadOnlyList<T> list, ref MRandom random)
         {
             if (list == null)
             {
@@ -376,7 +376,7 @@ public static T GetRandom<T>(T item1, T item2, params T[] items)
         /// Returns a random element with the chances of rolling based on <paramref name="weights"/>
         /// </summary>
         /// <param name="weights">Positive floats representing weights. Negative values may lead to unpredictable behaviour.</param>
-        public static T GetRandom<T>(this IList<T> list, IList<float> weights)
+        public static T GetRandom<T>(this IReadOnlyList<T> list, IReadOnlyList<float> weights)
         {
             if (list == null)
             {
@@ -423,7 +423,7 @@ public static T GetRandom<T>(this IList<T> list, IList<float> weights)
         /// Returns a random element with the chances of rolling based on <paramref name="weights"/>
         /// </summary>
         /// <param name="weights">Positive floats representing weights. Negative values may lead to unpredictable behaviour.</param>
-        public static T GetRandom<T>(this IList<T> list, IList<float> weights, ref MRandom random)
+        public static T GetRandom<T>(this IReadOnlyList<T> list, IReadOnlyList<float> weights, ref MRandom random)
         {
             if (list == null)
             {

Runtime/Tessellator.cs

@@ -47,7 +47,7 @@ public bool removeEmptyPolygons
         /// <see cref="ContourOrientation.Clockwise"/> and <see cref="ContourOrientation.CounterClockwise"/> 
         /// force the vertices to have a specified orientation.
         /// </param>
-        public void AddContour(IList<Vector2> vertices, ContourOrientation forceOrientation = ContourOrientation.Original)
+        public void AddContour(IReadOnlyList<Vector2> vertices, ContourOrientation forceOrientation = ContourOrientation.Original)
         {
             var contour = new ContourVertex[vertices.Count];
             for (int i = 0; i < vertices.Count; i++)
@@ -68,7 +68,7 @@ public void AddContour(IList<Vector2> vertices, ContourOrientation forceOrientat
         /// <see cref="ContourOrientation.Clockwise"/> and <see cref="ContourOrientation.CounterClockwise"/> 
         /// force the vertices to have a specified orientation.
         /// </param>
-        public void AddContour(IList<Vector3> vertices, ContourOrientation forceOrientation = ContourOrientation.Original)
+        public void AddContour(IReadOnlyList<Vector3> vertices, ContourOrientation forceOrientation = ContourOrientation.Original)
         {
             var contour = new ContourVertex[vertices.Count];
             for (int i = 0; i < vertices.Count; i++)
@@ -89,7 +89,7 @@ public void AddContour(IList<Vector3> vertices, ContourOrientation forceOrientat
         /// <see cref="ContourOrientation.Clockwise"/> and <see cref="ContourOrientation.CounterClockwise"/> 
         /// force the vertices to have a specified orientation.
         /// </param>
-        public void AddContour(IList<ContourVertex> vertices, ContourOrientation forceOrientation = ContourOrientation.Original)
+        public void AddContour(IReadOnlyList<ContourVertex> vertices, ContourOrientation forceOrientation = ContourOrientation.Original)
         {
             tess.AddContour(vertices, forceOrientation);
         }