From 6c41d2f9329046900066dfc6a230615271d7989a Mon Sep 17 00:00:00 2001
From: James Jackson-South <james_south@hotmail.com>
Date: Fri, 4 Sep 2020 14:13:42 +0100
Subject: [PATCH] Use interest for target bounds. Fixes #1342

---
 .../Resize/ResizeProcessor{TPixel}.cs         | 16 ++++++++-----
 .../Processors/Transforms/ResizeTests.cs      | 24 +++++++++++++++++++
 2 files changed, 34 insertions(+), 6 deletions(-)

diff --git a/src/ImageSharp/Processing/Processors/Transforms/Resize/ResizeProcessor{TPixel}.cs b/src/ImageSharp/Processing/Processors/Transforms/Resize/ResizeProcessor{TPixel}.cs
index 9908d4f799..3c033d89e4 100644
--- a/src/ImageSharp/Processing/Processors/Transforms/Resize/ResizeProcessor{TPixel}.cs
+++ b/src/ImageSharp/Processing/Processors/Transforms/Resize/ResizeProcessor{TPixel}.cs
@@ -147,6 +147,7 @@ private static void ApplyNNResizeFrameTransform(
             var operation = new NNRowOperation(
                 sourceRectangle,
                 destinationRectangle,
+                interest,
                 widthFactor,
                 heightFactor,
                 source,
@@ -197,6 +198,7 @@ private static void ApplyResizeFrameTransform(
         {
             private readonly Rectangle sourceBounds;
             private readonly Rectangle destinationBounds;
+            private readonly Rectangle interest;
             private readonly float widthFactor;
             private readonly float heightFactor;
             private readonly ImageFrame<TPixel> source;
@@ -206,6 +208,7 @@ private static void ApplyResizeFrameTransform(
             public NNRowOperation(
                 Rectangle sourceBounds,
                 Rectangle destinationBounds,
+                Rectangle interest,
                 float widthFactor,
                 float heightFactor,
                 ImageFrame<TPixel> source,
@@ -213,6 +216,7 @@ public NNRowOperation(
             {
                 this.sourceBounds = sourceBounds;
                 this.destinationBounds = destinationBounds;
+                this.interest = interest;
                 this.widthFactor = widthFactor;
                 this.heightFactor = heightFactor;
                 this.source = source;
@@ -224,19 +228,19 @@ public void Invoke(int y)
             {
                 int sourceX = this.sourceBounds.X;
                 int sourceY = this.sourceBounds.Y;
-                int destX = this.destinationBounds.X;
-                int destY = this.destinationBounds.Y;
-                int destLeft = this.destinationBounds.Left;
-                int destRight = this.destinationBounds.Right;
+                int destOriginX = this.destinationBounds.X;
+                int destOriginY = this.destinationBounds.Y;
+                int destLeft = this.interest.Left;
+                int destRight = this.interest.Right;
 
                 // Y coordinates of source points
-                Span<TPixel> sourceRow = this.source.GetPixelRowSpan((int)(((y - destY) * this.heightFactor) + sourceY));
+                Span<TPixel> sourceRow = this.source.GetPixelRowSpan((int)(((y - destOriginY) * this.heightFactor) + sourceY));
                 Span<TPixel> targetRow = this.destination.GetPixelRowSpan(y);
 
                 for (int x = destLeft; x < destRight; x++)
                 {
                     // X coordinates of source points
-                    targetRow[x] = sourceRow[(int)(((x - destX) * this.widthFactor) + sourceX)];
+                    targetRow[x] = sourceRow[(int)(((x - destOriginX) * this.widthFactor) + sourceX)];
                 }
             }
         }
diff --git a/tests/ImageSharp.Tests/Processing/Processors/Transforms/ResizeTests.cs b/tests/ImageSharp.Tests/Processing/Processors/Transforms/ResizeTests.cs
index 51b8ee0264..f40b8d11a0 100644
--- a/tests/ImageSharp.Tests/Processing/Processors/Transforms/ResizeTests.cs
+++ b/tests/ImageSharp.Tests/Processing/Processors/Transforms/ResizeTests.cs
@@ -621,5 +621,29 @@ public void Issue1195()
                         }));
             }
         }
+
+        [Theory]
+        [InlineData(1, 1)]
+        [InlineData(4, 6)]
+        [InlineData(2, 10)]
+        [InlineData(8, 1)]
+        [InlineData(3, 7)]
+        public void Issue1342(int width, int height)
+        {
+            using (var image = new Image<Rgba32>(1, 1))
+            {
+                var size = new Size(width, height);
+                image.Mutate(x => x
+                    .Resize(
+                        new ResizeOptions
+                        {
+                            Size = size,
+                            Sampler = KnownResamplers.NearestNeighbor
+                        }));
+
+                Assert.Equal(width, image.Width);
+                Assert.Equal(height, image.Height);
+            }
+        }
     }
 }