Finish ResizeModes proper

Former-commit-id: 4582848b6fb5eee5c57c3a087ebd754015afe7b0
Former-commit-id: 79bf4fed23de01d328004558b9d1389ededc6192
Former-commit-id: 0ffc0e8c7fb9b123b251123f1aeb66612a09d089

src/ImageProcessorCore/Samplers/IImageSampler.cs

@@ -11,7 +11,8 @@ namespace ImageProcessorCore.Samplers
     public interface IImageSampler : IImageProcessor
     {
         /// <summary>
-        /// Gets or sets a value indicating whether to compand the value on processing.
+        /// Gets or sets a value indicating whether to compress
+        /// or expand individual pixel colors the value on processing.
         /// </summary>
         bool Compand { get; set; }
     }

src/ImageProcessorCore/Samplers/Resize.cs

@@ -56,8 +56,10 @@ namespace ImageProcessorCore.Samplers
             int width = target.Width;
             int height = target.Height;
             int sourceHeight = sourceRectangle.Height;
-            int targetY = targetRectangle.Y;
-            int targetBottom = targetRectangle.Bottom;
+            int targetX = target.Bounds.X;
+            int targetY = target.Bounds.Y;
+            int targetRight = target.Bounds.Right;
+            int targetBottom = target.Bounds.Bottom;
             int startX = targetRectangle.X;
             int endX = targetRectangle.Right;
             bool compand = this.Compand;
@@ -65,25 +67,28 @@ namespace ImageProcessorCore.Samplers
             if (this.Sampler is NearestNeighborResampler)
             {
                 // Scaling factors
-                float widthFactor = source.Width / (float)target.Width;
-                float heightFactor = source.Height / (float)target.Height;
+                float widthFactor = sourceRectangle.Width / (float)targetRectangle.Width;
+                float heightFactor = sourceRectangle.Height / (float)targetRectangle.Height;
 
                 Parallel.For(
                     startY,
                     endY,
                     y =>
                     {
-                        if (y >= targetY && y < targetBottom)
+                        if (targetY <= y && y < targetBottom)
                         {
                             // Y coordinates of source points
-                            int originY = (int)((y - targetY) * heightFactor);
+                            int originY = (int)((y - startY) * heightFactor);
 
                             for (int x = startX; x < endX; x++)
                             {
-                                // X coordinates of source points
-                                int originX = (int)((x - startX) * widthFactor);
+                                if (targetX <= x && x < targetRight)
+                                {
+                                    // X coordinates of source points
+                                    int originX = (int)((x - startX) * widthFactor);
 
-                                target[x, y] = source[originX, originY];
+                                    target[x, y] = source[originX, originY];
+                                }
                             }
 
                             this.OnRowProcessed();

src/ImageProcessorCore/Samplers/ResizeHelper.cs

@@ -26,6 +26,8 @@ namespace ImageProcessorCore.Samplers
         {
             switch (options.Mode)
             {
+                case ResizeMode.Crop:
+                    return CalculateCropRectangle(source, options);
                 case ResizeMode.Pad:
                     return CalculatePadRectangle(source, options);
                 case ResizeMode.BoxPad:
@@ -35,9 +37,9 @@ namespace ImageProcessorCore.Samplers
                 case ResizeMode.Min:
                     return CalculateMinRectangle(source, options);
 
-                // Default case ResizeMode.Crop
+                // Last case ResizeMode.Stretch:
                 default:
-                    return CalculateCropRectangle(source, options);
+                    return CalculateStretchRectangle(source, options);
             }
         }
 
@@ -348,12 +350,16 @@ namespace ImageProcessorCore.Samplers
             if (sourceRatio < ratio)
             {
                 destinationHeight = Convert.ToInt32(source.Height * percentWidth);
+                height = destinationHeight;
             }
             else
             {
                 destinationWidth = Convert.ToInt32(source.Width * percentHeight);
+                width = destinationWidth;
             }
 
+            // Replace the size to match the rectangle.
+            options.Size = new Size(width, height);
             return new Rectangle(0, 0, destinationWidth, destinationHeight);
         }
 
@@ -372,12 +378,12 @@ namespace ImageProcessorCore.Samplers
             int destinationWidth;
             int destinationHeight;
 
-            // Fractional variants for preserving aspect ratio.
-            double percentHeight = Math.Abs(height / (double)source.Height);
-            double percentWidth = Math.Abs(width / (double)source.Width);
-
-            height = height > 0 ? height : Convert.ToInt32(source.Height * percentWidth);
-            width = width > 0 ? width : Convert.ToInt32(source.Width * percentHeight);
+            // Don't upscale
+            if (width > source.Width || height > source.Height)
+            {
+                options.Size = new Size(source.Width, source.Height);
+                return new Rectangle(0, 0, source.Width, source.Height);
+            }
 
             double sourceRatio = (double)source.Height / source.Width;
 
@@ -401,7 +407,22 @@ namespace ImageProcessorCore.Samplers
                 destinationHeight = height;
             }
 
+            // Replace the size to match the rectangle.
+            options.Size = new Size(width, height);
             return new Rectangle(0, 0, destinationWidth, destinationHeight);
         }
+
+        /// <summary>
+        /// Calculates the target rectangle for stretch mode.
+        /// </summary>
+        /// <param name="source">The source image.</param>
+        /// <param name="options">The resize options.</param>
+        /// <returns>
+        /// The <see cref="Rectangle"/>.
+        /// </returns>
+        private static Rectangle CalculateStretchRectangle(ImageBase source, ResizeOptions options)
+        {
+            return new Rectangle(0, 0, options.Size.Width, options.Size.Height);
+        }
     }
 }

src/ImageProcessorCore/Samplers/ResizeMode.cs

@@ -22,9 +22,11 @@ namespace ImageProcessorCore.Samplers
         Pad,
 
         /// <summary>
-        /// Stretches the resized image to fit the bounds of its container.
+        /// Pads the image to fit the bound of the container without resizing the 
+        /// original source.
+        /// When downscaling, performs the same functionality as <see cref="ResizeMode.Pad"/>
         /// </summary>
-        Stretch,
+        BoxPad,
 
         /// <summary>
         /// Constrains the resized image to fit the bounds of its container maintaining
@@ -34,14 +36,14 @@ namespace ImageProcessorCore.Samplers
 
         /// <summary>
         /// Resizes the image until the shortest side reaches the set given dimension.
+        /// Upscaling is disabled in this mode and the original image will be returned 
+        /// if attempted.
         /// </summary>
         Min,
 
         /// <summary>
-        /// Pads the image to fit the bound of the container without resizing the 
-        /// original source.
-        /// When downscaling, performs the same functionality as <see cref="ResizeMode.Pad"/>
+        /// Stretches the resized image to fit the bounds of its container.
         /// </summary>
-        BoxPad
+        Stretch
     }
 }

src/ImageProcessorCore/Samplers/ResizeOptions.cs

@@ -33,8 +33,15 @@ namespace ImageProcessorCore.Samplers
         /// </summary>
         public Size Size { get; set; }
 
+        /// <summary>
+        /// Gets or sets the sampler to perform the resize operation.
+        /// </summary>
         public IResampler Sampler { get; set; } = new BicubicResampler();
 
+        /// <summary>
+        /// Gets or sets a value indicating whether to compress
+        /// or expand individual pixel colors the value on processing.
+        /// </summary>
         public bool Compand { get; set; }
     }
 }

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

@@ -215,7 +215,8 @@
                         ResizeOptions options = new ResizeOptions()
                         {
                             Size = new Size(image.Width , image.Height + 200),
-                            Mode = ResizeMode.Pad
+                            Mode = ResizeMode.Pad,
+                            Sampler = new NearestNeighborResampler()
                         };
 
                         image.Resize(options, this.ProgressUpdate)