From e71450366b914310dae79654aab567f33951324f Mon Sep 17 00:00:00 2001
From: Ellpeck <me@ellpeck.de>
Date: Mon, 15 May 2023 18:36:23 +0200
Subject: [PATCH] additional runtime texture packer improvements

---
 CHANGELOG.md                      |  1 +
 MLEM.Data/RuntimeTexturePacker.cs | 13 +++++++++++--
 Tests/TexturePackerTests.cs       |  2 +-
 3 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8fd9d42..35c3d85 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -50,6 +50,7 @@ Fixes
 ### MLEM.Data
 Improvements
 - Improved RuntimeTexturePacker performance for differently sized textures
+- Allow querying the amount of RuntimeTexturePacker regions
 
 ## 6.1.0
 
diff --git a/MLEM.Data/RuntimeTexturePacker.cs b/MLEM.Data/RuntimeTexturePacker.cs
index 369c0bc..50813e1 100644
--- a/MLEM.Data/RuntimeTexturePacker.cs
+++ b/MLEM.Data/RuntimeTexturePacker.cs
@@ -33,10 +33,15 @@ namespace MLEM.Data {
         /// The time that <see cref="Pack"/> took the last time it was called
         /// </summary>
         public TimeSpan LastTotalTime => this.LastCalculationTime + this.LastPackTime;
+        /// <summary>
+        /// The amount of currently packed texture regions.
+        /// </summary>
+        public int PackedTextures => this.packedTextures.Count;
 
         private readonly List<Request> texturesToPack = new List<Request>();
         private readonly List<Request> packedTextures = new List<Request>();
         private readonly Dictionary<Point, Request> occupiedPositions = new Dictionary<Point, Request>();
+        private readonly Dictionary<Point, Point> initialPositions = new Dictionary<Point, Point>();
         private readonly Dictionary<Texture2D, TextureData> dataCache = new Dictionary<Texture2D, TextureData>();
         private readonly bool autoIncreaseMaxWidth;
         private readonly bool forcePowerOfTwo;
@@ -222,6 +227,7 @@ namespace MLEM.Data {
             this.LastPackTime = TimeSpan.Zero;
             this.texturesToPack.Clear();
             this.packedTextures.Clear();
+            this.initialPositions.Clear();
             this.occupiedPositions.Clear();
             this.dataCache.Clear();
         }
@@ -240,14 +246,17 @@ namespace MLEM.Data {
             if (size.X <= 0 || size.Y <= 0)
                 return Rectangle.Empty;
 
-            var area = new Rectangle(0, 0, size.X, size.Y);
+            var pos = this.initialPositions.TryGetValue(size, out var first) ? first : Point.Zero;
+            var area = new Rectangle(pos.X, pos.Y, size.X, size.Y);
             var lowestY = int.MaxValue;
             while (true) {
                 // check if the current area is already occupied
                 if (!this.occupiedPositions.TryGetValue(area.Location, out var existing)) {
                     existing = this.packedTextures.FirstOrDefault(t => t.PackedArea.Intersects(area));
+                    // if no texture is occupying this space, we have found a free area
                     if (existing == null) {
-                        // if no texture is occupying this space, we have found a free area
+                        // if this is the first position that this request fit in, no other requests of the same size will find a position before it
+                        this.initialPositions[area.Size] = area.Location;
                         this.occupiedPositions.Add(area.Location, request);
                         return area;
                     }
diff --git a/Tests/TexturePackerTests.cs b/Tests/TexturePackerTests.cs
index 9079bd1..4043f88 100644
--- a/Tests/TexturePackerTests.cs
+++ b/Tests/TexturePackerTests.cs
@@ -126,7 +126,7 @@ public class TexturePackerTests {
 
     [Test]
     public void TestPackTimes() {
-        for (var total = 1; total <= 1001; total += 100) {
+        for (var total = 1; total <= 10001; total += 1000) {
             using var sameSizePacker = new RuntimeTexturePacker();
             using var diffSizePacker = new RuntimeTexturePacker();
             for (var i = 0; i < total; i++) {