From 9477b5f1d1d36a2698f2dd9be136072c8ee7e0be Mon Sep 17 00:00:00 2001
From: Ellpeck <megamaximal@gmail.com>
Date: Thu, 23 Jul 2020 23:30:44 +0200
Subject: [PATCH] added a pivot point to TextureRegion

---
 MLEM/Textures/TextureRegion.cs | 22 +++++++++++++++++++---
 Sandbox/GameImpl.cs            | 14 +++++++++++---
 2 files changed, 30 insertions(+), 6 deletions(-)

diff --git a/MLEM/Textures/TextureRegion.cs b/MLEM/Textures/TextureRegion.cs
index 1177b45..abe25f8 100644
--- a/MLEM/Textures/TextureRegion.cs
+++ b/MLEM/Textures/TextureRegion.cs
@@ -41,6 +41,22 @@ namespace MLEM.Textures {
         /// The height of this texture region
         /// </summary>
         public int Height => this.Area.Height;
+        /// <summary>
+        /// The pivot point of this texture region, where 0, 0 is the top left and 1, 1 is the bottom right of the texture.
+        /// When drawing, this will be seen as the origin from where to start drawing.
+        /// </summary>
+        public Vector2 Pivot = Vector2.Zero;
+        /// <summary>
+        /// The <see cref="Pivot"/> of this texture region, but in absolute pixels rather than percentage.
+        /// </summary>
+        public Vector2 PivotPixels {
+            get => this.Pivot * this.Size.ToVector2();
+            set => this.Pivot = value / this.Size.ToVector2();
+        }
+        /// <summary>
+        /// The name of this texture region. By default, this name is <see cref="string.Empty"/>.
+        /// </summary>
+        public string Name = string.Empty;
 
         /// <summary>
         /// Creates a new texture region from a texture and a rectangle which defines the region's area
@@ -88,7 +104,7 @@ namespace MLEM.Textures {
 
         /// <inheritdoc cref="SpriteBatch.Draw(Texture2D, Vector2, Rectangle?, Color, float, Vector2, Vector2, SpriteEffects, float)"/>
         public static void Draw(this SpriteBatch batch, TextureRegion texture, Vector2 position, Color color, float rotation, Vector2 origin, Vector2 scale, SpriteEffects effects, float layerDepth) {
-            batch.Draw(texture.Texture, position, texture.Area, color, rotation, origin, scale, effects, layerDepth);
+            batch.Draw(texture.Texture, position, texture.Area, color, rotation, origin + texture.PivotPixels, scale, effects, layerDepth);
         }
 
         /// <inheritdoc cref="SpriteBatch.Draw(Texture2D, Vector2, Rectangle?, Color, float, Vector2, Vector2, SpriteEffects, float)"/>
@@ -98,12 +114,12 @@ namespace MLEM.Textures {
 
         /// <inheritdoc cref="SpriteBatch.Draw(Texture2D, Vector2, Rectangle?, Color, float, Vector2, Vector2, SpriteEffects, float)"/>
         public static void Draw(this SpriteBatch batch, TextureRegion texture, Rectangle destinationRectangle, Color color, float rotation, Vector2 origin, SpriteEffects effects, float layerDepth) {
-            batch.Draw(texture.Texture, destinationRectangle, texture.Area, color, rotation, origin, effects, layerDepth);
+            batch.Draw(texture.Texture, destinationRectangle, texture.Area, color, rotation, origin + texture.PivotPixels, effects, layerDepth);
         }
 
         /// <inheritdoc cref="SpriteBatch.Draw(Texture2D, Vector2, Rectangle?, Color, float, Vector2, Vector2, SpriteEffects, float)"/>
         public static void Draw(this SpriteBatch batch, TextureRegion texture, RectangleF destinationRectangle, Color color, float rotation, Vector2 origin, SpriteEffects effects, float layerDepth) {
-            batch.Draw(texture.Texture, destinationRectangle, texture.Area, color, rotation, origin, effects, layerDepth);
+            batch.Draw(texture.Texture, destinationRectangle, texture.Area, color, rotation, origin + texture.PivotPixels, effects, layerDepth);
         }
 
         /// <inheritdoc cref="SpriteBatch.Draw(Texture2D, Vector2, Rectangle?, Color, float, Vector2, Vector2, SpriteEffects, float)"/>
diff --git a/Sandbox/GameImpl.cs b/Sandbox/GameImpl.cs
index cc6c8ea..c811dc1 100644
--- a/Sandbox/GameImpl.cs
+++ b/Sandbox/GameImpl.cs
@@ -23,6 +23,8 @@ using MLEM.Ui.Elements;
 using MLEM.Ui.Style;
 using MonoGame.Extended;
 using MonoGame.Extended.BitmapFonts;
+using MonoGame.Extended.Sprites;
+using MonoGame.Extended.TextureAtlases;
 using MonoGame.Extended.Tiled;
 using RectangleF = MonoGame.Extended.RectangleF;
 
@@ -136,12 +138,18 @@ namespace Sandbox {
             this.tokenized.Split(font, 400, sc);
 
             var square = this.SpriteBatch.GenerateSquareTexture(Color.Yellow);
-            var round = this.SpriteBatch.GenerateCircleTexture(Color.Green, 1024);
+            var round = this.SpriteBatch.GenerateCircleTexture(Color.Green, 128);
+
+            var region = new TextureRegion(round) {Pivot = new Vector2(0.5F)};
+            var region2 = new TextureRegion(round);
 
             this.OnDraw += (g, time) => {
                 this.SpriteBatch.Begin(samplerState: SamplerState.PointClamp);
-                this.SpriteBatch.Draw(square, new Rectangle(10, 10, 400, 400), Color.White);
-                this.SpriteBatch.Draw(round, new Rectangle(10, 10, 400, 400), Color.White);
+                //this.SpriteBatch.Draw(square, new Rectangle(10, 10, 400, 400), Color.White);
+                //this.SpriteBatch.Draw(round, new Rectangle(10, 10, 400, 400), Color.White);
+                this.SpriteBatch.Draw(region, new Vector2(50, 50), Color.White, 0, Vector2.Zero, 0.5F, SpriteEffects.None, 0);
+                this.SpriteBatch.Draw(region2, new Vector2(50, 50), Color.Yellow * 0.5F, 0, Vector2.Zero, 0.5F, SpriteEffects.None, 0);
+                this.SpriteBatch.Draw(this.SpriteBatch.GetBlankTexture(), new Vector2(50, 50), Color.Pink);
 
                 //this.SpriteBatch.FillRectangle(new RectangleF(400, 20, 400, 1000), Color.Green);
                 //font.DrawString(this.SpriteBatch, this.tokenized.DisplayString, new Vector2(400, 20), Color.White * 0.25F, 0, Vector2.Zero, sc, SpriteEffects.None, 0);