Added DrawExtendedAutoTile to the AutoTiling class

CHANGELOG.md

@@ -14,6 +14,7 @@ Additions
 - Added StaticSpriteBatch class
 - Added missing easing functions Quart and Quint to Easings
 - Added RotationVector extension methods for Matrix and Quaternion
+- Added DrawExtendedAutoTile to the AutoTiling class
 
 Improvements
 - Cache TokenizedString inner offsets for non-Left text alignments to improve performance

Demos/AutoTilingDemo.cs

@@ -9,6 +9,7 @@ namespace Demos {
     /// </summary>
     public class AutoTilingDemo : Demo {
 
+        private const int TileSize = 8;
         private Texture2D texture;
         private string[] layout;
 
@@ -17,23 +18,16 @@ namespace Demos {
 
         public override void LoadContent() {
             base.LoadContent();
-            // The layout of the texture is important for auto tiling to work correctly.
+            // The layout of the texture is important for auto tiling to work correctly, and is explained in the XML docs for the methods used
-            // It needs to be laid out as follows: Five tiles aligned horizontally within the texture file, with the following information
-            // 1. The texture used for filling big areas
-            // 2. The texture used for straight, horizontal borders, with the borders facing away from the center
-            // 3. The texture used for outer corners, with the corners facing away from the center
-            // 4. The texture used for straight, vertical borders, with the borders facing away from the center
-            // 5. The texture used for inner corners, with the corners facing away from the center
-            // Note that the AutoTiling.png texture contains an example of this layout
             this.texture = LoadContent<Texture2D>("Textures/AutoTiling");
 
             // in this example, a simple string array is used for layout purposes. As the AutoTiling method allows any kind of
             // comparison, the actual implementation can vary (for instance, based on a more in-depth tile map)
             this.layout = new[] {
+                "XXX X ",
+                "XXXXXX",
                 "XXX  X",
-                "XXXXX",
+                "XXXXX ",
-                "XX   ",
-                "XXXX ",
                 " X    "
             };
         }
@@ -41,13 +35,9 @@ namespace Demos {
         public override void DoDraw(GameTime gameTime) {
             this.GraphicsDevice.Clear(Color.Black);
 
-            // the texture region supplied to the AutoTiling method should only encompass the first filler tile's location and size
-            const int tileSize = 8;
-            var region = new Rectangle(0, 0, tileSize, tileSize);
-
             // drawing the auto tiles
             this.SpriteBatch.Begin(SpriteSortMode.Deferred, null, SamplerState.PointClamp, transformMatrix: Matrix.CreateScale(10));
-            for (var x = 0; x < 5; x++) {
+            for (var x = 0; x < 6; x++) {
                 for (var y = 0; y < 5; y++) {
                     // don't draw non-grass tiles ( )
                     if (this.layout[y][x] != 'X')
@@ -61,13 +51,17 @@ namespace Demos {
                     // and where there are none ( ).
                     bool ConnectsTo(int xOff, int yOff) {
                         // don't auto-tile out of bounds
-                        if (x1 + xOff < 0 || y1 + yOff < 0 || x1 + xOff >= 5 || y1 + yOff >= 5)
+                        if (x1 + xOff < 0 || y1 + yOff < 0 || x1 + xOff >= 6 || y1 + yOff >= 5)
                             return false;
                         // check if the neighboring tile is also grass (X)
                         return this.layout[y1 + yOff][x1 + xOff] == 'X';
                     }
 
-                    AutoTiling.DrawAutoTile(this.SpriteBatch, new Vector2(x, y) * tileSize, this.texture, region, ConnectsTo, Color.White);
+                    // the texture region supplied to the AutoTiling method should only encompass the first filler tile's location and size
+                    AutoTiling.DrawAutoTile(this.SpriteBatch, new Vector2(x + 1, y + 1) * TileSize, this.texture, new Rectangle(0, 0, TileSize, TileSize), ConnectsTo, Color.White);
+
+                    // when drawing extended auto-tiles, the same rules apply, but the source texture layout is different
+                    AutoTiling.DrawExtendedAutoTile(this.SpriteBatch, new Vector2(x + 8, y + 1) * TileSize, this.texture, new Rectangle(0, TileSize * 2, TileSize, TileSize), ConnectsTo, Color.White);
                 }
             }
             this.SpriteBatch.End();

MLEM/Misc/AutoTiling.cs

@@ -3,9 +3,8 @@ using Microsoft.Xna.Framework.Graphics;
 
 namespace MLEM.Misc {
     /// <summary>
-    /// This class contains a <see cref="DrawAutoTile"/> method that allows users to easily draw a tile with automatic connections.
+    /// This class contains a <see cref="DrawAutoTile"/> method that allows users to easily draw a tile with automatic connections, as well as a more complex <see cref="DrawExtendedAutoTile"/> method.
-    /// For auto-tiling in this manner to work, auto-tiled textures have to be laid out in a format described in <see cref="DrawAutoTile"/>.
+    /// Note that <see cref="StaticSpriteBatch"/> can also be used for drawing by using the <see cref="AddAutoTile"/> and <see cref="AddExtendedAutoTile"/> methods instead.
-    /// Note that <see cref="StaticSpriteBatch"/> can also be used for drawing by using the <see cref="AddAutoTile"/> method instead.
     /// </summary>
     public static class AutoTiling {
 
@@ -21,7 +20,7 @@ namespace MLEM.Misc {
         /// <item><description>The texture used for straight, vertical borders, with the borders facing away from the center</description></item>
         /// <item><description>The texture used for inner corners, with the corners facing away from the center</description></item>
         /// </list>
-        /// For more information and an example, see https://github.com/Ellpeck/MLEM/blob/main/Demos/AutoTilingDemo.cs#L20-L28.
+        /// For more information and an example, see https://github.com/Ellpeck/MLEM/blob/main/Demos/AutoTilingDemo.cs and its source texture https://github.com/Ellpeck/MLEM/blob/main/Demos/Content/Textures/AutoTiling.png.
         /// </summary>
         /// <param name="batch">The sprite batch to use for drawing.</param>
         /// <param name="pos">The position to draw at.</param>
@@ -53,6 +52,61 @@ namespace MLEM.Misc {
             batch.Add(texture, p4, r4, color, 0, orig, sc, SpriteEffects.None, layerDepth);
         }
 
+        /// <summary>
+        /// This method allows for a tiled texture to be drawn in an auto-tiling mode.
+        /// This allows, for example, a grass patch on a tilemap to have nice looking edges that transfer over into a path without any hard edges between tiles.
+        ///
+        /// This method is a more complex version of <see cref="DrawAutoTile"/> that overlays separate border textures on a base texture, which also allows for non-rectangular texture areas to be used easily. 
+        /// For auto-tiling in this way to work, the tiles have to be laid out as follows: 17 tiles aligned horizontally within the texture file, with the following information:
+        /// <list type="number">
+        /// <item><description>The texture used for filling big areas</description></item>
+        /// <item><description>The texture used for straight, horizontal borders, with the borders facing away from the center, split up into four parts: top left, then top right, then bottom left, then bottom right</description></item>
+        /// <item><description>The texture used for outer corners, with the corners facing away from the center, split up into four parts: top left, then top right, then bottom left, then bottom right</description></item>
+        /// <item><description>The texture used for straight, vertical borders, with the borders facing away from the center, split up into four parts: top left, then top right, then bottom left, then bottom right</description></item>
+        /// <item><description>The texture used for inner corners, with the corners facing away from the center, split up into four parts: top left, then top right, then bottom left, then bottom right</description></item>
+        /// </list>
+        /// For more information and an example, see https://github.com/Ellpeck/MLEM/blob/main/Demos/AutoTilingDemo.cs and its source texture https://github.com/Ellpeck/MLEM/blob/main/Demos/Content/Textures/AutoTiling.png.
+        /// </summary>
+        /// <param name="batch">The sprite batch to use for drawing.</param>
+        /// <param name="pos">The position to draw at.</param>
+        /// <param name="texture">The texture to use for drawing.</param>
+        /// <param name="textureRegion">The location of the first texture region, as described in the summary.</param>
+        /// <param name="connectsTo">A function that determines whether two positions should connect.</param>
+        /// <param name="color">The color to draw with.</param>
+        /// <param name="origin">The origin to draw from.</param>
+        /// <param name="scale">The scale to draw with.</param>
+        /// <param name="layerDepth">The layer depth to draw with.</param>
+        public static void DrawExtendedAutoTile(SpriteBatch batch, Vector2 pos, Texture2D texture, Rectangle textureRegion, ConnectsTo connectsTo, Color color, Vector2? origin = null, Vector2? scale = null, float layerDepth = 0) {
+            var orig = origin ?? Vector2.Zero;
+            var sc = scale ?? Vector2.One;
+            var (p1, r1, p2, r2, p3, r3, p4, r4) = CalculateExtendedAutoTile(pos, textureRegion, connectsTo, sc);
+            batch.Draw(texture, pos, textureRegion, color, 0, orig, sc, SpriteEffects.None, layerDepth);
+            if (r1 != Rectangle.Empty)
+                batch.Draw(texture, p1, r1, color, 0, orig, sc, SpriteEffects.None, layerDepth);
+            if (r2 != Rectangle.Empty)
+                batch.Draw(texture, p2, r2, color, 0, orig, sc, SpriteEffects.None, layerDepth);
+            if (r3 != Rectangle.Empty)
+                batch.Draw(texture, p3, r3, color, 0, orig, sc, SpriteEffects.None, layerDepth);
+            if (r4 != Rectangle.Empty)
+                batch.Draw(texture, p4, r4, color, 0, orig, sc, SpriteEffects.None, layerDepth);
+        }
+
+        /// <inheritdoc cref="DrawExtendedAutoTile"/>
+        public static void AddExtendedAutoTile(StaticSpriteBatch batch, Vector2 pos, Texture2D texture, Rectangle textureRegion, ConnectsTo connectsTo, Color color, float rotation = 0, Vector2? origin = null, Vector2? scale = null, float layerDepth = 0) {
+            var orig = origin ?? Vector2.Zero;
+            var sc = scale ?? Vector2.One;
+            var (p1, r1, p2, r2, p3, r3, p4, r4) = CalculateExtendedAutoTile(pos, textureRegion, connectsTo, sc);
+            batch.Add(texture, pos, textureRegion, color, 0, orig, sc, SpriteEffects.None, layerDepth);
+            if (r1 != Rectangle.Empty)
+                batch.Add(texture, p1, r1, color, 0, orig, sc, SpriteEffects.None, layerDepth);
+            if (r2 != Rectangle.Empty)
+                batch.Add(texture, p2, r2, color, 0, orig, sc, SpriteEffects.None, layerDepth);
+            if (r3 != Rectangle.Empty)
+                batch.Add(texture, p3, r3, color, 0, orig, sc, SpriteEffects.None, layerDepth);
+            if (r4 != Rectangle.Empty)
+                batch.Add(texture, p4, r4, color, 0, orig, sc, SpriteEffects.None, layerDepth);
+        }
+
         private static (Vector2, Rectangle, Vector2, Rectangle, Vector2, Rectangle, Vector2, Rectangle) CalculateAutoTile(Vector2 pos, Rectangle textureRegion, ConnectsTo connectsTo, Vector2 scale) {
             var up = connectsTo(0, -1);
             var down = connectsTo(0, 1);
@@ -73,6 +127,26 @@ namespace MLEM.Misc {
                 new Vector2(pos.X + w2 * scale.X, pos.Y + h2 * scale.Y), new Rectangle(textureRegion.X + w2 + xDr * w, textureRegion.Y + h2, w2, h2));
         }
 
+        private static (Vector2, Rectangle, Vector2, Rectangle, Vector2, Rectangle, Vector2, Rectangle) CalculateExtendedAutoTile(Vector2 pos, Rectangle textureRegion, ConnectsTo connectsTo, Vector2 scale) {
+            var up = connectsTo(0, -1);
+            var down = connectsTo(0, 1);
+            var left = connectsTo(-1, 0);
+            var right = connectsTo(1, 0);
+            var xUl = up && left ? connectsTo(-1, -1) ? -1 : 13 : left ? 1 : up ? 9 : 5;
+            var xUr = up && right ? connectsTo(1, -1) ? -1 : 14 : right ? 2 : up ? 10 : 6;
+            var xDl = down && left ? connectsTo(-1, 1) ? -1 : 15 : left ? 3 : down ? 11 : 7;
+            var xDr = down && right ? connectsTo(1, 1) ? -1 : 16 : right ? 4 : down ? 12 : 8;
+
+            var (w, h) = textureRegion.Size;
+            var (w2, h2) = new Point(w / 2, h / 2);
+
+            return (
+                new Vector2(pos.X, pos.Y), xUl < 0 ? Rectangle.Empty : new Rectangle(textureRegion.X + xUl * w, textureRegion.Y, w2, h2),
+                new Vector2(pos.X + w2 * scale.X, pos.Y), xUr < 0 ? Rectangle.Empty : new Rectangle(textureRegion.X + w2 + xUr * w, textureRegion.Y, w2, h2),
+                new Vector2(pos.X, pos.Y + h2 * scale.Y), xDl < 0 ? Rectangle.Empty : new Rectangle(textureRegion.X + xDl * w, textureRegion.Y + h2, w2, h2),
+                new Vector2(pos.X + w2 * scale.X, pos.Y + h2 * scale.Y), xDr < 0 ? Rectangle.Empty : new Rectangle(textureRegion.X + w2 + xDr * w, textureRegion.Y + h2, w2, h2));
+        }
+
         /// <summary>
         /// A delegate function that determines if a given offset position connects to an auto-tile location.
         /// </summary>