From afc4158dd3c60f1ca4f83fe5720174b3edb19b4d Mon Sep 17 00:00:00 2001
From: Wojtek Figat <wojtek@figat.pl>
Date: Mon, 24 Feb 2025 14:19:51 +0100
Subject: [PATCH] Fix sprite and texture 9-slice rendering brush to properly
 calculate border size

---
 Source/Engine/Render2D/Render2D.cpp          | 18 +++++++++---------
 Source/Engine/UI/GUI/Brushes/SpriteBrush.cs  |  4 +++-
 Source/Engine/UI/GUI/Brushes/TextureBrush.cs |  2 +-
 3 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/Source/Engine/Render2D/Render2D.cpp b/Source/Engine/Render2D/Render2D.cpp
index a51d16ecc..f709ed420 100644
--- a/Source/Engine/Render2D/Render2D.cpp
+++ b/Source/Engine/Render2D/Render2D.cpp
@@ -363,17 +363,17 @@ void Write9SlicingRect(const Rectangle& rect, const Color& color, const Float4&
     const Float2 bottomLeftUV(borderUVs.X, 1.0f - borderUVs.W);
     const Float2 bottomRightUV(1.0f - borderUVs.Y, 1.0f - borderUVs.W);
 
-    WriteRect(upperLeft, color, Float2::Zero, upperLeftUV);
-    WriteRect(upperRight, color, Float2(upperRightUV.X, 0), Float2(1, upperLeftUV.Y));
-    WriteRect(bottomLeft, color, Float2(0, bottomLeftUV.Y), Float2(bottomLeftUV.X, 1));
-    WriteRect(bottomRight, color, bottomRightUV, Float2::One);
+    WriteRect(upperLeft, color, Float2::Zero, upperLeftUV); // Upper left corner
+    WriteRect(upperRight, color, Float2(upperRightUV.X, 0), Float2(1, upperLeftUV.Y)); // Upper right corner
+    WriteRect(bottomLeft, color, Float2(0, bottomLeftUV.Y), Float2(bottomLeftUV.X, 1)); // Bottom left corner
+    WriteRect(bottomRight, color, bottomRightUV, Float2::One); // Bottom right corner
 
-    WriteRect(Rectangle(upperLeft.GetUpperRight(), upperRight.GetBottomLeft() - upperLeft.GetUpperRight()), color, Float2(upperLeftUV.X, 0), upperRightUV);
-    WriteRect(Rectangle(upperLeft.GetBottomLeft(), bottomLeft.GetUpperRight() - upperLeft.GetBottomLeft()), color, Float2(0, upperLeftUV.Y), bottomLeftUV);
-    WriteRect(Rectangle(bottomLeft.GetUpperRight(), bottomRight.GetBottomLeft() - bottomLeft.GetUpperRight()), color, bottomLeftUV, Float2(bottomRightUV.X, 1));
-    WriteRect(Rectangle(upperRight.GetBottomLeft(), bottomRight.GetUpperRight() - upperRight.GetBottomLeft()), color, upperRightUV, Float2(1, bottomRightUV.Y));
+    WriteRect(Rectangle(upperLeft.GetUpperRight(), upperRight.GetBottomLeft() - upperLeft.GetUpperRight()), color, Float2(upperLeftUV.X, 0), upperRightUV); // Top side
+    WriteRect(Rectangle(upperLeft.GetBottomLeft(), bottomLeft.GetUpperRight() - upperLeft.GetBottomLeft()), color, Float2(0, upperLeftUV.Y), bottomLeftUV); // Left side
+    WriteRect(Rectangle(bottomLeft.GetUpperRight(), bottomRight.GetBottomLeft() - bottomLeft.GetUpperRight()), color, bottomLeftUV, Float2(bottomRightUV.X, 1)); // Bottom side
+    WriteRect(Rectangle(upperRight.GetBottomLeft(), bottomRight.GetUpperRight() - upperRight.GetBottomLeft()), color, upperRightUV, Float2(1, bottomRightUV.Y)); // Right Side
 
-    WriteRect(Rectangle(upperLeft.GetBottomRight(), bottomRight.GetUpperLeft() - upperLeft.GetBottomRight()), color, upperRightUV, bottomRightUV);
+    WriteRect(Rectangle(upperLeft.GetBottomRight(), bottomRight.GetUpperLeft() - upperLeft.GetBottomRight()), color, upperLeftUV, bottomRightUV); // Center
 }
 
 void Write9SlicingRect(const Rectangle& rect, const Color& color, const Float4& border, const Float4& borderUVs, const Float2& uvLocation, const Float2& uvSize)
diff --git a/Source/Engine/UI/GUI/Brushes/SpriteBrush.cs b/Source/Engine/UI/GUI/Brushes/SpriteBrush.cs
index 5be953f29..e1f8676bc 100644
--- a/Source/Engine/UI/GUI/Brushes/SpriteBrush.cs
+++ b/Source/Engine/UI/GUI/Brushes/SpriteBrush.cs
@@ -100,9 +100,11 @@ namespace FlaxEngine.GUI
         /// <inheritdoc />
         public unsafe void Draw(Rectangle rect, Color color)
         {
+            if (!Sprite.IsValid)
+                return;
             var border = Border;
             var borderUV = *(Float4*)&border;
-            var borderSize = borderUV * new Float4(BorderSize, BorderSize, BorderSize, BorderSize);
+            var borderSize = new Float4(BorderSize, BorderSize, BorderSize, BorderSize);
             if (Filter == BrushFilter.Point)
                 Render2D.Draw9SlicingSpritePoint(Sprite, rect, borderSize, borderUV, color);
             else
diff --git a/Source/Engine/UI/GUI/Brushes/TextureBrush.cs b/Source/Engine/UI/GUI/Brushes/TextureBrush.cs
index 98e7e5324..8c7618135 100644
--- a/Source/Engine/UI/GUI/Brushes/TextureBrush.cs
+++ b/Source/Engine/UI/GUI/Brushes/TextureBrush.cs
@@ -113,7 +113,7 @@ namespace FlaxEngine.GUI
                 return;
             var border = Border;
             var borderUV = *(Float4*)&border;
-            var borderSize = borderUV * new Float4(BorderSize, BorderSize, BorderSize, BorderSize);
+            var borderSize = new Float4(BorderSize, BorderSize, BorderSize, BorderSize);
             if (Filter == BrushFilter.Point)
                 Render2D.Draw9SlicingTexturePoint(Texture, rect, borderSize, borderUV, color);
             else