stelabouras · October 10, 2023 16:29 · Sep 24, 2023
diff --git a/EdgeMapUtils.cs b/EdgeMapUtils.cs
@@ -0,0 +1,127 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using UnityEditor;
+using UnityEngine;
+
+namespace Editor.Utility
+{
+    public static class EdgeMapUtils
+    {
+        public const int EDGE_SIZE = 2;
+
+        public static void Update(IEnumerable<Sprite> spr)
+        {
+            foreach (var s in spr)
+                Update(s);
+        }
+
+        private static void Update(Sprite s)
+        {
+            //aaahaha, ok, oh boy. Yeah, scan the sprite on the cpu, look for edges and plug those into a texture
+            //make sprite readable
+            var test = s.texture;
+            var path = AssetDatabase.GetAssetPath(s);
+            var spriteTi = (TextureImporter)TextureImporter.GetAtPath(path);
+            spriteTi.isReadable = true;
+            AssetDatabase.ImportAsset(path, ImportAssetOptions.ForceUpdate);
+
+            //DO STUFF
+            var edges = BuildEdgeTexture(s);
+            var savedEdgePath = SaveEdges(s, path, edges);
+
+            //link it to sprite as a secondary map
+            SpriteUtils.TryAddSecondaryTexture(spriteTi, "_EdgeMap", savedEdgePath);
+
+            //put sprite back the way it was.
+            spriteTi.isReadable = false;
+
+
+        }
+
+        private static string SaveEdges(Sprite s, string path, Texture2D edges)
+        {
+            var folder = path.Remove(path.LastIndexOf(s.name) - 1);
+
+            EditorUtils.LazyCreateFolder(folder, "EdgeMaps");
+
+            var edgePath = $"{folder}/EdgeMaps/{s.name}_edges.png";
+
+            var bytes = edges.EncodeToPNG();
+            System.IO.File.WriteAllBytes(edgePath, bytes);
+            AssetDatabase.ImportAsset(edgePath, ImportAssetOptions.ForceSynchronousImport);
+            //AssetDatabase.CreateAsset(edges, edgePath);
+
+            var ti = AssetImporter.GetAtPath(edgePath) as TextureImporter;
+            ti.textureType = TextureImporterType.Sprite;
+            ti.filterMode = FilterMode.Point;
+            ti.textureCompression = TextureImporterCompression.Uncompressed;
+            ti.mipmapEnabled = false;
+            ti.alphaIsTransparency = false;
+            EditorUtility.SetDirty(ti);
+            ti.SaveAndReimport();
+
+            return edgePath;
+        }
+
+
+        private static Texture2D BuildEdgeTexture(Sprite s)
+        {
+            var edges = new Texture2D(s.texture.width, s.texture.height, TextureFormat.RGBA32, false);
+            for (int x = 0; x < s.texture.width; x++)
+            {
+                for (int y = 0; y < s.texture.height; y++)
+                {
+                    edges.SetPixel(x, y, GetEdge(s, x, y));
+                }
+            }
+            edges.Apply();
+
+            return edges;
+        }
+
+        //encodes edge information into 1 channel of the texture
+        private static Color GetEdge(Sprite s, int x, int y)
+        {
+            //MY COUNTERPART IS CustomRenderGraphBlock.hlsl.getSpriteEdges_float
+            var col = new Color(0, 0, 0, 0);
+            var px = s.texture.GetPixel(x, y);
+            if (px.a < 1)
+            {
+                return col;
+            }
+            else
+            {
+                for (int edgeTest = EDGE_SIZE; edgeTest >= 0; edgeTest--)
+                {
+                    float edgeAlpha = 1f - (float)edgeTest / ((float)EDGE_SIZE + 1f);
+                    //test up
+                    if (IsEdge(s, x, y + edgeTest))
+                        col.r = edgeAlpha;
+
+                    //test right
+                    if (IsEdge(s, x + edgeTest, y))
+                        col.g = edgeAlpha;
+
+                    //test left
+                    if (IsEdge(s, x - edgeTest, y))
+                        col.b = edgeAlpha;
+
+                    //test bot
+                    if (IsEdge(s, x, y - edgeTest))
+                        col.a = edgeAlpha;
+                }
+
+            }
+            return col;
+
+        }
+
+        private static bool IsEdge(Sprite s, int x, int y)
+        {
+            if (x < 0 || y < 0 || x >= s.texture.width || y >= s.texture.height)
+                return true;
+            else return s.texture.GetPixel(x, y).a == 0f;
+        }
+    }
+}