weight printing experiments, minor changes, comments

src/ImageSharp/Processing/Processors/Transforms/ResamplingWeightedProcessor.Weights.cs

@@ -12,7 +12,7 @@ namespace ImageSharp.Processing.Processors
         /// <summary>
         /// Points to a collection of of weights allocated in <see cref="WeightsBuffer"/>.
         /// </summary>
-        protected unsafe struct WeightsWindow
+        internal unsafe struct WeightsWindow
         {
             /// <summary>
             /// The local left index position
@@ -22,6 +22,8 @@ namespace ImageSharp.Processing.Processors
             /// <summary>
             /// The span of weights pointing to <see cref="WeightsBuffer"/>.
             /// </summary>
+            // TODO: In the case of switching to official System.Memory and System.Buffers.Primitives this should be System.Buffers.Buffer<T> (formerly Memory<T>), because Span<T> is stack-only!
+            // see: https://github.com/dotnet/corefxlab/blob/873d35ebed7264e2f9adb556f3b61bebc12395d6/docs/specs/memory.md
             public BufferSpan<float> Span;
 
             /// <summary>
@@ -129,7 +131,7 @@ namespace ImageSharp.Processing.Processors
         /// <summary>
         /// Holds the <see cref="WeightsWindow"/> values in an optimized contigous memory region.
         /// </summary>
-        protected class WeightsBuffer : IDisposable
+        internal class WeightsBuffer : IDisposable
         {
             private PinnedImageBuffer<float> dataBuffer;
 
@@ -140,8 +142,7 @@ namespace ImageSharp.Processing.Processors
             /// <param name="destinationSize">The size of the destination window</param>
             public WeightsBuffer(int sourceSize, int destinationSize)
             {
-                this.dataBuffer = new PinnedImageBuffer<float>(sourceSize, destinationSize);
-                this.dataBuffer.Clear();
+                this.dataBuffer = PinnedImageBuffer<float>.CreateClean(sourceSize, destinationSize);
                 this.Weights = new WeightsWindow[destinationSize];
             }
 

src/ImageSharp/Processing/Processors/Transforms/ResamplingWeightedProcessor.cs

@@ -68,38 +68,14 @@ namespace ImageSharp.Processing.Processors
         /// </summary>
         protected WeightsBuffer VerticalWeights { get; set; }
 
-        /// <inheritdoc/>
-        protected override void BeforeApply(ImageBase<TColor> source, Rectangle sourceRectangle)
-        {
-            if (!(this.Sampler is NearestNeighborResampler))
-            {
-                this.HorizontalWeights = this.PrecomputeWeights(
-                    this.ResizeRectangle.Width,
-                    sourceRectangle.Width);
-
-                this.VerticalWeights = this.PrecomputeWeights(
-                    this.ResizeRectangle.Height,
-                    sourceRectangle.Height);
-            }
-        }
-
-        /// <inheritdoc />
-        protected override void AfterApply(ImageBase<TColor> source, Rectangle sourceRectangle)
-        {
-            base.AfterApply(source, sourceRectangle);
-            this.HorizontalWeights?.Dispose();
-            this.HorizontalWeights = null;
-            this.VerticalWeights?.Dispose();
-            this.VerticalWeights = null;
-        }
-
         /// <summary>
         /// Computes the weights to apply at each pixel when resizing.
         /// </summary>
         /// <param name="destinationSize">The destination size</param>
         /// <param name="sourceSize">The source size</param>
         /// <returns>The <see cref="WeightsBuffer"/></returns>
-        protected unsafe WeightsBuffer PrecomputeWeights(int destinationSize, int sourceSize)
+        // TODO: Made internal to simplify experimenting with weights data. Make it protected again when finished figuring out how to optimize all the stuff!
+        internal unsafe WeightsBuffer PrecomputeWeights(int destinationSize, int sourceSize)
         {
             float ratio = (float)sourceSize / destinationSize;
             float scale = ratio;
@@ -156,5 +132,30 @@ namespace ImageSharp.Processing.Processors
 
             return result;
         }
+
+        /// <inheritdoc/>
+        protected override void BeforeApply(ImageBase<TColor> source, Rectangle sourceRectangle)
+        {
+            if (!(this.Sampler is NearestNeighborResampler))
+            {
+                this.HorizontalWeights = this.PrecomputeWeights(
+                    this.ResizeRectangle.Width,
+                    sourceRectangle.Width);
+
+                this.VerticalWeights = this.PrecomputeWeights(
+                    this.ResizeRectangle.Height,
+                    sourceRectangle.Height);
+            }
+        }
+
+        /// <inheritdoc />
+        protected override void AfterApply(ImageBase<TColor> source, Rectangle sourceRectangle)
+        {
+            base.AfterApply(source, sourceRectangle);
+            this.HorizontalWeights?.Dispose();
+            this.HorizontalWeights = null;
+            this.VerticalWeights?.Dispose();
+            this.VerticalWeights = null;
+        }
     }
 }

tests/ImageSharp.Tests/Processors/Filters/ResizeProfilingBenchmarks.cs

@@ -1,5 +1,11 @@
 namespace ImageSharp.Tests
 {
+    using System.IO;
+    using System.Text;
+
+    using ImageSharp.Processing;
+    using ImageSharp.Processing.Processors;
+
     using Xunit;
     using Xunit.Abstractions;
 
@@ -26,5 +32,30 @@ namespace ImageSharp.Tests
                         }
                     });
         }
+
+        // [Fact]
+        public void PrintWeightsData()
+        {
+            ResizeProcessor<Color> proc = new ResizeProcessor<Color>(new BicubicResampler(), 200, 200);
+
+            ResamplingWeightedProcessor<Color>.WeightsBuffer weights = proc.PrecomputeWeights(200, 500);
+
+            StringBuilder bld = new StringBuilder();
+
+            foreach (ResamplingWeightedProcessor<Color>.WeightsWindow window in weights.Weights)
+            {
+                for (int i = 0; i < window.Length; i++)
+                {
+                    float value = window.Span[i];
+                    bld.Append(value);
+                    bld.Append("| ");
+                }
+                bld.AppendLine();
+            }
+
+            File.WriteAllText("BicubicWeights.MD", bld.ToString());
+
+            //this.Output.WriteLine(bld.ToString());
+        }
     }
 }