UnityEditor.TerrainInspectorUtil.GetPrototypeCount C# (CSharp) Method

        public static extern int GetPrototypeCount(TerrainData terrainData);
        public static Vector3 GetPrototypeExtent(TerrainData terrainData, int prototypeIndex)

        public static void PlaceTrees(Terrain terrain, float xBase, float yBase)
        {
            int prototypeCount = TerrainInspectorUtil.GetPrototypeCount(terrain.terrainData);

            if (TreePainter.selectedTree == -1 || TreePainter.selectedTree >= prototypeCount)
            {
                return;
            }
            if (!TerrainInspectorUtil.PrototypeIsRenderable(terrain.terrainData, TreePainter.selectedTree))
            {
                return;
            }
            int          num      = 0;
            TreeInstance instance = default(TreeInstance);

            instance.position       = new Vector3(xBase, 0f, yBase);
            instance.color          = TreePainter.GetTreeColor();
            instance.lightmapColor  = Color.white;
            instance.prototypeIndex = TreePainter.selectedTree;
            instance.heightScale    = TreePainter.GetTreeHeight();
            instance.widthScale     = ((!TreePainter.lockWidthToHeight) ? TreePainter.GetTreeWidth() : instance.heightScale);
            instance.rotation       = TreePainter.GetTreeRotation();
            bool flag = Event.current.type == EventType.MouseDrag || TreePainter.brushSize > 1f;

            if (!flag || TerrainInspectorUtil.CheckTreeDistance(terrain.terrainData, instance.position, instance.prototypeIndex, TreePainter.spacing))
            {
                terrain.AddTreeInstance(instance);
                num++;
            }
            Vector3 prototypeExtent = TerrainInspectorUtil.GetPrototypeExtent(terrain.terrainData, TreePainter.selectedTree);

            prototypeExtent.y = 0f;
            float num2 = TreePainter.brushSize / (prototypeExtent.magnitude * TreePainter.spacing * 0.5f);
            int   num3 = (int)(num2 * num2 * 0.5f);

            num3 = Mathf.Clamp(num3, 0, 100);
            int num4 = 1;

            while (num4 < num3 && num < num3)
            {
                Vector2 insideUnitCircle = UnityEngine.Random.insideUnitCircle;
                insideUnitCircle.x *= TreePainter.brushSize / terrain.terrainData.size.x;
                insideUnitCircle.y *= TreePainter.brushSize / terrain.terrainData.size.z;
                Vector3 position = new Vector3(xBase + insideUnitCircle.x, 0f, yBase + insideUnitCircle.y);
                if (position.x >= 0f && position.x <= 1f && position.z >= 0f && position.z <= 1f && TerrainInspectorUtil.CheckTreeDistance(terrain.terrainData, position, TreePainter.selectedTree, TreePainter.spacing * 0.5f))
                {
                    instance                = default(TreeInstance);
                    instance.position       = position;
                    instance.color          = TreePainter.GetTreeColor();
                    instance.lightmapColor  = Color.white;
                    instance.prototypeIndex = TreePainter.selectedTree;
                    instance.heightScale    = TreePainter.GetTreeHeight();
                    instance.widthScale     = ((!TreePainter.lockWidthToHeight) ? TreePainter.GetTreeWidth() : instance.heightScale);
                    instance.rotation       = TreePainter.GetTreeRotation();
                    terrain.AddTreeInstance(instance);
                    num++;
                }
                num4++;
            }
        }