Add RotateFlip Fix #261

Also add ClonePixel method to ImageBase


Former-commit-id: e25004eacf2aec54273a98f02a208c0fb60e12ae
Former-commit-id: 6bacacf8cb0bd8315961485b640809e1931e7388
Former-commit-id: f91314805b2aac54b3bab50a9bce782d15d854b1

README.md

@@ -79,7 +79,7 @@ git clone https://github.com/JimBobSquarePants/ImageProcessor
  - [ ] Elliptical Crop
  - [x] Entropy Crop
 - Rotation
- - [ ] Flip (90, 270, FlipType etc. Need help) [#261](https://github.com/JimBobSquarePants/ImageProcessor/issues/261)
+ - [x] Flip (90, 270, FlipType etc. Need help)
  - [ ] Rotate by angle (Need help with Paeth approach) [#258](https://github.com/JimBobSquarePants/ImageProcessor/issues/258)
 - ColorMatrix operations (Uses Matrix4x4)
  - [x] BlackWhite

src/ImageProcessor/IImageBase.cs

@@ -70,14 +70,12 @@ namespace ImageProcessor
         Color this[int x, int y] { get; set; }
 
         /// <summary>
-        /// Sets the pixel array of the image.
+        /// Sets the pixel array of the image to the given value.
         /// </summary>
-        /// <param name="width">
-        /// The new width of the image. Must be greater than zero.</param>
+        /// <param name="width">The new width of the image. Must be greater than zero.</param>
         /// <param name="height">The new height of the image. Must be greater than zero.</param>
         /// <param name="pixels">
-        /// The array with colors. Must be a multiple
-        /// of four, width and height.
+        /// The array with colors. Must be a multiple of four times the width and height.
         /// </param>
         /// <exception cref="ArgumentOutOfRangeException">
         /// Thrown if either <paramref name="width"/> or <paramref name="height"/> are less than or equal to 0.
@@ -86,5 +84,22 @@ namespace ImageProcessor
         /// Thrown if the <paramref name="pixels"/> length is not equal to Width * Height * 4.
         /// </exception>
         void SetPixels(int width, int height, float[] pixels);
+
+        /// <summary>
+        /// Sets the pixel array of the image to the given value, creating a copy of 
+        /// the original pixels.
+        /// </summary>
+        /// <param name="width">The new width of the image. Must be greater than zero.</param>
+        /// <param name="height">The new height of the image. Must be greater than zero.</param>
+        /// <param name="pixels">
+        /// The array with colors. Must be a multiple of four times the width and height.
+        /// </param>
+        /// <exception cref="ArgumentOutOfRangeException">
+        /// Thrown if either <paramref name="width"/> or <paramref name="height"/> are less than or equal to 0.
+        /// </exception>
+        /// <exception cref="ArgumentException">
+        /// Thrown if the <paramref name="pixels"/> length is not equal to Width * Height * 4.
+        /// </exception>
+        void ClonePixels(int width, int height, float[] pixels);
     }
 }

src/ImageProcessor/ImageBase.cs

@@ -183,5 +183,31 @@ namespace ImageProcessor
             this.Height = height;
             this.Pixels = pixels;
         }
+
+        /// <inheritdoc/>
+        public void ClonePixels(int width, int height, float[] pixels)
+        {
+#if DEBUG
+            if (width <= 0)
+            {
+                throw new ArgumentOutOfRangeException(nameof(width), "Width must be greater than or equals than zero.");
+            }
+
+            if (height <= 0)
+            {
+                throw new ArgumentOutOfRangeException(nameof(height), "Height must be greater than or equal than zero.");
+            }
+
+            if (pixels.Length != width * height * 4)
+            {
+                throw new ArgumentException("Pixel array must have the length of Width * Height * 4.");
+            }
+#endif
+            this.Width = width;
+            this.Height = height;
+            float[] clonedPixels = new float[pixels.Length];
+            Array.Copy(pixels, clonedPixels, pixels.Length);
+            this.Pixels = clonedPixels;
+        }
     }
 }

src/ImageProcessor/Samplers/FlipType.cs

@@ -0,0 +1,28 @@
+// <copyright file="FlipType.cs" company="James Jackson-South">
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+// </copyright>
+
+namespace ImageProcessor.Samplers
+{
+    /// <summary>
+    /// Provides enumeration over how a image should be flipped.
+    /// </summary>
+    public enum FlipType
+    {
+        /// <summary>
+        /// Dont flip the image.
+        /// </summary>
+        None,
+
+        /// <summary>
+        /// Flip the image horizontally.
+        /// </summary>
+        Horizontal,
+
+        /// <summary>
+        /// Flip the image vertically.
+        /// </summary>
+        Vertical,
+    }
+}

src/ImageProcessor/Samplers/ImageSampleExtensions.cs

@@ -123,5 +123,17 @@ namespace ImageProcessor.Samplers
         {
             return source.Process(source.Width, source.Height, source.Bounds, source.Bounds, new Resampler(sampler) { Angle = degrees });
         }
+
+        /// <summary>
+        /// Rotates and flips an image by the given instructions.
+        /// </summary>
+        /// <param name="source">The image to resize.</param>
+        /// <param name="rotateType">The <see cref="RotateType"/> to perform the rotation.</param>
+        /// <param name="flipType">The <see cref="FlipType"/> to perform the flip.</param>
+        /// <returns>The <see cref="Image"/></returns>
+        public static Image RotateFlip(this Image source, RotateType rotateType, FlipType flipType)
+        {
+            return source.Process(source.Width, source.Height, source.Bounds, source.Bounds, new RotateFlip(rotateType, flipType));
+        }
     }
 }

src/ImageProcessor/Samplers/Resampler.cs

@@ -120,7 +120,7 @@ namespace ImageProcessor.Samplers
         {
             if (source.Bounds == target.Bounds)
             {
-                target.SetPixels(target.Width, target.Height, source.Pixels);
+                target.ClonePixels(target.Width, target.Height, source.Pixels);
                 return;
             }
 

src/ImageProcessor/Samplers/RotateFlip.cs

@@ -0,0 +1,194 @@
+// <copyright file="RotateFlip.cs" company="James Jackson-South">
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+// </copyright>
+
+namespace ImageProcessor.Samplers
+{
+    using System;
+    using System.Threading.Tasks;
+
+    /// <summary>
+    /// Provides methods that allow the rotation and flipping of an image around its center point.
+    /// </summary>
+    public class RotateFlip : ParallelImageProcessor
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="RotateFlip"/> class.
+        /// </summary>
+        /// <param name="rotateType">The <see cref="RotateType"/> used to perform rotation.</param>
+        /// <param name="flipType">The <see cref="FlipType"/> used to perform flipping.</param>
+        public RotateFlip(RotateType rotateType, FlipType flipType)
+        {
+            this.RotateType = rotateType;
+            this.FlipType = flipType;
+        }
+
+        /// <summary>
+        /// Gets the <see cref="FlipType"/> used to perform flipping.
+        /// </summary>
+        public FlipType FlipType { get; }
+
+        /// <summary>
+        /// Gets the <see cref="RotateType"/> used to perform rotation.
+        /// </summary>
+        public RotateType RotateType { get; }
+
+        /// <inheritdoc/>
+        public override int Parallelism { get; set; } = 1;
+
+        /// <inheritdoc/>
+        protected override void Apply(ImageBase target, ImageBase source, Rectangle targetRectangle, Rectangle sourceRectangle, int startY, int endY)
+        {
+            switch (this.RotateType)
+            {
+                case RotateType.Rotate90:
+                    Rotate90(target, source);
+                    break;
+                case RotateType.Rotate180:
+                    Rotate180(target, source);
+                    break;
+                case RotateType.Rotate270:
+                    Rotate270(target, source);
+                    break;
+                default:
+                    target.ClonePixels(target.Width, target.Height, source.Pixels);
+                    break;
+            }
+
+            switch (this.FlipType)
+            {
+                // No default needed as we have already set the pixels.
+                case FlipType.Vertical:
+                    FlipX(target);
+                    break;
+                case FlipType.Horizontal:
+                    FlipY(target);
+                    break;
+            }
+        }
+
+        /// <summary>
+        /// Rotates the image 270 degrees clockwise at the centre point.
+        /// </summary>
+        /// <param name="target">The target image.</param>
+        /// <param name="source">The source image.</param>
+        private static void Rotate270(ImageBase target, ImageBase source)
+        {
+            int width = source.Width;
+            int height = source.Height;
+            Image temp = new Image(height, width);
+
+            Parallel.For(0, height,
+                y =>
+                {
+                    for (int x = 0; x < width; x++)
+                    {
+                        int newX = height - y - 1;
+                        newX = height - newX - 1;
+                        int newY = width - x - 1;
+                        newY = width - newY - 1;
+                        temp[newX, newY] = source[x, y];
+                    }
+                });
+
+            target.SetPixels(height, width, temp.Pixels);
+        }
+
+        /// <summary>
+        /// Rotates the image 180 degrees clockwise at the centre point.
+        /// </summary>
+        /// <param name="target">The target image.</param>
+        /// <param name="source">The source image.</param>
+        private static void Rotate180(ImageBase target, ImageBase source)
+        {
+            int width = source.Width;
+            int height = source.Height;
+
+            Parallel.For(0, height,
+                y =>
+                {
+                    for (int x = 0; x < width; x++)
+                    {
+                        int newX = width - x - 1;
+                        int newY = height - y - 1;
+                        target[newX, newY] = source[x, y];
+                    }
+                });
+        }
+
+        /// <summary>
+        /// Rotates the image 90 degrees clockwise at the centre point.
+        /// </summary>
+        /// <param name="target">The target image.</param>
+        /// <param name="source">The source image.</param>
+        private static void Rotate90(ImageBase target, ImageBase source)
+        {
+            int width = source.Width;
+            int height = source.Height;
+            Image temp = new Image(height, width);
+
+            Parallel.For(0, height,
+                y =>
+                {
+                    for (int x = 0; x < width; x++)
+                    {
+                        int newX = height - y - 1;
+                        temp[newX, x] = source[x, y];
+                    }
+                });
+
+            target.SetPixels(height, width, temp.Pixels);
+        }
+
+        /// <summary>
+        /// Swaps the image at the X-axis, which goes horizontally through the middle
+        /// at half the height of the image.
+        /// </summary>
+        /// <param name="target">Target image to apply the process to.</param>
+        private static void FlipX(ImageBase target)
+        {
+            int width = target.Width;
+            int height = target.Height;
+            int halfHeight = (int)Math.Ceiling(target.Height / 2d);
+            ImageBase temp = new Image(width, height);
+            temp.ClonePixels(width, height, target.Pixels);
+
+            Parallel.For(0, halfHeight,
+                y =>
+                    {
+                        for (int x = 0; x < width; x++)
+                        {
+                            int newY = height - y - 1;
+                            target[x, y] = temp[x, newY];
+                            target[x, newY] = temp[x, y];
+                        }
+                    });
+        }
+
+        /// <summary>
+        /// Swaps the image at the Y-axis, which goes vertically through the middle
+        /// at half of the width of the image.
+        /// </summary>
+        /// <param name="target">Target image to apply the process to.</param>
+        private static void FlipY(ImageBase target)
+        {
+            int width = target.Width;
+            int height = target.Height;
+            int halfWidth = (int)Math.Ceiling(width / 2d);
+            ImageBase temp = new Image(width, height);
+            temp.ClonePixels(width, height, target.Pixels);
+
+            Parallel.For(0, height,
+                y =>
+                {
+                    for (int x = 0; x < halfWidth; x++)
+                    {
+                        int newX = width - x - 1;
+                        target[x, y] = temp[newX, y];
+                        target[newX, y] = temp[x, y];
+                    }
+                });
+        }
+    }
+}

src/ImageProcessor/Samplers/RotateType.cs

@@ -0,0 +1,33 @@
+// <copyright file="RotateType.cs" company="James Jackson-South">
+// Copyright (c) James Jackson-South and contributors.
+// Licensed under the Apache License, Version 2.0.
+// </copyright>
+
+namespace ImageProcessor.Samplers
+{
+    /// <summary>
+    /// Provides enumeration over how the image should be rotated.
+    /// </summary>
+    public enum RotateType
+    {
+        /// <summary>
+        /// Do not rotate the image.
+        /// </summary>
+        None,
+
+        /// <summary>
+        /// Rotate the image by 90 degrees clockwise.
+        /// </summary>
+        Rotate90,
+
+        /// <summary>
+        /// Rotate the image by 180 degrees clockwise.
+        /// </summary>
+        Rotate180,
+
+        /// <summary>
+        /// Rotate the image by 270 degrees clockwise.
+        /// </summary>
+        Rotate270
+    }
+}

tests/ImageProcessor.Tests/Processors/Samplers/SamplerTests.cs

@@ -29,6 +29,15 @@
                 { "Welch", new WelchResampler() }
             };
 
+        public static readonly TheoryData<RotateType, FlipType> RotateFlips = new TheoryData<RotateType, FlipType>
+        {
+            { RotateType.None, FlipType.Vertical },
+            { RotateType.None, FlipType.Horizontal },
+            { RotateType.Rotate90, FlipType.None },
+            { RotateType.Rotate180, FlipType.None },
+            { RotateType.Rotate270, FlipType.None },
+        };
+
         [Theory]
         [MemberData("Samplers")]
         public void ImageShouldResize(string name, IResampler sampler)
@@ -56,6 +65,33 @@
             }
         }
 
+        [Theory]
+        [MemberData("RotateFlips")]
+        public void ImageShouldRotateFlip(RotateType rotateType, FlipType flipType)
+        {
+            if (!Directory.Exists("TestOutput/RotateFlip"))
+            {
+                Directory.CreateDirectory("TestOutput/RotateFlip");
+            }
+
+            foreach (string file in Files)
+            {
+                using (FileStream stream = File.OpenRead(file))
+                {
+                    Stopwatch watch = Stopwatch.StartNew();
+                    Image image = new Image(stream);
+                    string filename = Path.GetFileNameWithoutExtension(file) + "-" + rotateType + flipType + Path.GetExtension(file);
+                    using (FileStream output = File.OpenWrite($"TestOutput/RotateFlip/{filename}"))
+                    {
+                        image.RotateFlip(rotateType, flipType)
+                             .Save(output);
+                    }
+
+                    Trace.WriteLine($"{rotateType + "-" + flipType}: {watch.ElapsedMilliseconds}ms");
+                }
+            }
+        }
+
         [Theory]
         [MemberData("Samplers")]
         public void ImageShouldRotate(string name, IResampler sampler)