Ejemplo de un Scriptable Brush

LineBrush proporciona la capacidad de dibujar fácilmente líneas de Tiles en Tilemap especificando el punto de inicio y el punto final. El método Paint para LineBrush se reemplaza para permitir al usuario especificar el inicio de una línea con el primer clic del mouse en el modo Paint y dibujar la línea con el segundo clic del mouse en el modo Paint. El método OnPaintSceneGUI se reemplaza para producir la vista previa de la línea que se dibujará entre el primer y segundo clics del mouse. La siguiente es una secuencia de comandos utilizada para crear el Pincel.

using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Tilemaps;

namespace UnityEditor
{
    [CustomGridBrush(true, false, false, "Line Brush")]
    public class LineBrush : GridBrush {
        public bool lineStartActive = false;
        public Vector3Int lineStart = Vector3Int.zero;
        public override void Paint(GridLayout grid, GameObject brushTarget, Vector3Int position)
        {
            if (lineStartActive)
            {
                Vector2Int startPos = new Vector2Int(lineStart.x, lineStart.y);
                Vector2Int endPos = new Vector2Int(position.x, position.y);
                if (startPos == endPos)
                    base.Paint(grid, brushTarget, position);    
                else
                {
                    foreach (var point in GetPointsOnLine(startPos, endPos))
                    {
                        Vector3Int paintPos = new Vector3Int(point.x, point.y, position.z);
                        base.Paint(grid, brushTarget, paintPos);
                    }
                }
                lineStartActive = false;
            }
            else
            {
                lineStart = position;
                lineStartActive = true;
            }
        }
        [MenuItem("Assets/Create/Line Brush")]
        public static void CreateBrush()
        {
            string path = EditorUtility.SaveFilePanelInProject("Save Line Brush", "New Line Brush", "Asset", "Save Line Brush", "Assets");
            if (path == "")
                return;
AssetDatabase.CreateAsset(ScriptableObject.CreateInstance<LineBrush>(), path);
        }
        // http://ericw.ca/notes/bresenhams-line-algorithm-in-csharp.html
        public static IEnumerable<Vector2Int> GetPointsOnLine(Vector2Int p1, Vector2Int p2)
        {
            int x0 = p1.x;
            int y0 = p1.y;
            int x1 = p2.x;
            int y1 = p2.y;
            bool steep = Math.Abs(y1 - y0) > Math.Abs(x1 - x0);
            if (steep)
            {
                int t;
                t = x0; // swap x0 and y0
                x0 = y0;
                y0 = t;
                t = x1; // swap x1 and y1
                x1 = y1;
                y1 = t;
            }
            if (x0 > x1)
            {
                int t;
                t = x0; // swap x0 and x1
                x0 = x1;
                x1 = t;
                t = y0; // swap y0 and y1
                y0 = y1;
                y1 = t;
            }
            int dx = x1 - x0;
            int dy = Math.Abs(y1 - y0);
            int error = dx / 2;
            int ystep = (y0 < y1) ? 1 : -1;
            int y = y0;
            for (int x = x0; x <= x1; x++)
            {
                yield return new Vector2Int((steep ? y : x), (steep ? x : y));
                error = error - dy;
                if (error < 0)
                {
                    y += ystep;
                    error += dx;
                }
            }
            yield break;
        }
    }
    [CustomEditor(typeof(LineBrush))]
    public class LineBrushEditor : GridBrushEditor
    {
        private LineBrush lineBrush { get { return target as LineBrush; } }
        public override void OnPaintSceneGUI(GridLayout grid, GameObject brushTarget, BoundsInt position, GridBrushBase.Tool tool, bool executing)
        {
            base.OnPaintSceneGUI(grid, brushTarget, position, tool, executing);
            if (lineBrush.lineStartActive)
            {
                Tilemap tilemap = brushTarget.GetComponent<Tilemap>();
                if (tilemap != null)
                    tilemap.ClearAllEditorPreviewTiles();
                // Draw preview tiles for tilemap
                Vector2Int startPos = new Vector2Int(lineBrush.lineStart.x, lineBrush.lineStart.y);
                Vector2Int endPos = new Vector2Int(position.x, position.y);
                if (startPos == endPos)
                    PaintPreview(grid, brushTarget, position.min);
                else
                {
                    foreach (var point in LineBrush.GetPointsOnLine(startPos, endPos))
                    {
                        Vector3Int paintPos = new Vector3Int(point.x, point.y, position.z);
                        PaintPreview(grid, brushTarget, paintPos);
                    }
                }
                if (Event.current.type == EventType.Repaint)
                {
                    var min = lineBrush.lineStart;
                    var max = lineBrush.lineStart + position.size;
                    // Draws a box on the picked starting position
                    GL.PushMatrix();
                    GL.MultMatrix(GUI.matrix);
                    GL.Begin(GL.LINES);
                    Handles.color = Color.blue;
                    Handles.DrawLine(new Vector3(min.x, min.y, min.z), new Vector3(max.x, min.y, min.z));
                    Handles.DrawLine(new Vector3(max.x, min.y, min.z), new Vector3(max.x, max.y, min.z));
                    Handles.DrawLine(new Vector3(max.x, max.y, min.z), new Vector3(min.x, max.y, min.z));
                    Handles.DrawLine(new Vector3(min.x, max.y, min.z), new Vector3(min.x, min.y, min.z));
                    GL.End();
                    GL.PopMatrix();
                }
            }
        }
    }
}

• 2017–09–06 Page published with limited editorial review