AltTrees importer

// add following fields to 'public class AddTreesStruct'
        public float height = -1.0f;
        public float width = -1.0f;
        public Color color = new Color(1, 1, 1, 0);

// copy to the end of 'public override void OnInspectorGUI()' in AltTrees_Editor.cs
            if (GUILayout.Button("Clear"))
            {
                List<AltTreesPatch> allPatches = new List<AltTreesPatch>(obj.altTreesManagerData.patches);
                foreach (var patch in allPatches)
                {
                    removePatch(patch);
                }
            }
            if (GUILayout.Button("Convert terrains"))
            {
                ConvertTerrains();
            }

// implementation, copy anywhere in AltTrees_Editor.cs
        void ConvertTerrains()
        {
            List<GameObject> prefabs = new List<GameObject>();
            for (int i = 0; i < Terrain.activeTerrains.Length; i++)
            {
                var terrainData = Terrain.activeTerrains[i].terrainData;
                foreach(var t in terrainData.treePrototypes)
                {
                    prefabs.Add(t.prefab);
                }
            }

            SpeedTreeImporter[] speedTreeImporters = new SpeedTreeImporter[prefabs.Count];
            for (int i = 0; i < prefabs.Count; i++)
            {
                string path = AssetDatabase.GetAssetPath(prefabs[i]);
                var importer = AssetImporter.GetAtPath(path);
                if (importer is SpeedTreeImporter)
                {
                    speedTreeImporters[i] = importer as SpeedTreeImporter;
                }
            }

            AltTree[] trees = new AltTree[prefabs.Count];
            for (int i = 0; i < prefabs.Count; i++)
            {
                AltTree treeTemp2 = null;
                treeTemp2 = dataLinks.getAltTree(prefabs[i]);
                if (treeTemp2 == null)
                {
                    ImportTreeWindow.ConvertTree(prefabs[i], this, null, false, false);
                    return;
                }

                trees[i] = dataLinks.getAltTree(prefabs[i]);
            }

            List<AltTreesPatch> allPatches = new List<AltTreesPatch>(obj.altTreesManagerData.patches);
            foreach(var patch in allPatches)
            {
                removePatch(patch);
            }

            Dictionary<AltTreesPatch, List<AddTreesStruct>> tempListPatches = new Dictionary<AltTreesPatch, List<AddTreesStruct>>();
            for (int i = 0; i < Terrain.activeTerrains.Length; i++)
            {
                var terrainData = Terrain.activeTerrains[i].terrainData;
                for (int t = 0; t < terrainData.treeInstances.Length; t++)
                {
                    var tree = terrainData.treeInstances[t];
                    Vector3 posTemp = Vector3.Scale(tree.position, terrainData.size) + Terrain.activeTerrains[i].GetPosition();

                    var atpTree = trees[tree.prototypeIndex];
                    var atp = new AddTreesStruct(posTemp, atpTree);
                    atp.width = tree.widthScale;
                    atp.height = tree.heightScale;
                    if (speedTreeImporters[tree.prototypeIndex] != null)
                    {
                        atp.color = speedTreeImporters[tree.prototypeIndex].hueVariation;
                    }

                    var patch = getPatch(posTemp);
                    List<AddTreesStruct> addTo = null;

                    if (tempListPatches.ContainsKey(patch))
                    {
                        addTo = tempListPatches[patch];
                    }
                    else
                    {
                        addTo = new List<AddTreesStruct>();
                        tempListPatches.Add(patch, addTo);
                    }

                    patch.checkTreePrototype(atpTree.id, atpTree);
                    addTo.Add(atp);
                }

                terrainData.treeInstances = new TreeInstance[0];
                terrainData.RefreshPrototypes();
                Terrain.activeTerrains[i].Flush();
            }

            foreach (AltTreesPatch key in tempListPatches.Keys)
            {
                key.addTrees(tempListPatches[key].ToArray(), true, false, 2.0f, 1.0f, true, false, 1.0f, 1.0f, new Color32(0, 0, 0, 0), new Color32(0, 0, 0, 0), false, false);
            }
        }