remove unused variables and methods (#963)

* remove unused variables and methods

* remove some redundant variables

* remove some redundant variables

* redundant variables

* Update DrawTextOnImageTests.cs

* Minor optimizations

* cleanup

Author: SimonCropp

src/ImageSharp/Advanced/AdvancedImageExtensions.cs

@@ -1,4 +1,4 @@
-// Copyright (c) Six Labors and contributors.
+// Copyright (c) Six Labors and contributors.
 // Licensed under the Apache License, Version 2.0.
 
 using System;
@@ -153,42 +153,6 @@ internal static Memory<TPixel> GetPixelRowMemory<TPixel>(this Image<TPixel> sour
         internal static MemoryAllocator GetMemoryAllocator(this IConfigurable source)
             => GetConfiguration(source).MemoryAllocator;
 
-        /// <summary>
-        /// Gets the span to the backing buffer.
-        /// </summary>
-        /// <typeparam name="TPixel">The type of the pixel.</typeparam>
-        /// <param name="source">The source.</param>
-        /// <returns>The span returned from Pixel source</returns>
-        private static Span<TPixel> GetSpan<TPixel>(IPixelSource<TPixel> source)
-            where TPixel : struct, IPixel<TPixel>
-            => source.PixelBuffer.GetSpan();
-
-        /// <summary>
-        /// Gets the span to the backing buffer at the given row.
-        /// </summary>
-        /// <typeparam name="TPixel">The type of the pixel.</typeparam>
-        /// <param name="source">The source.</param>
-        /// <param name="row">The row.</param>
-        /// <returns>
-        /// The span returned from Pixel source
-        /// </returns>
-        private static Span<TPixel> GetSpan<TPixel>(IPixelSource<TPixel> source, int row)
-            where TPixel : struct, IPixel<TPixel>
-            => GetSpan(source.PixelBuffer, row);
-
-        /// <summary>
-        /// Gets the span to the backing buffer at the given row.
-        /// </summary>
-        /// <typeparam name="TPixel">The type of the pixel.</typeparam>
-        /// <param name="source">The source.</param>
-        /// <param name="row">The row.</param>
-        /// <returns>
-        /// The span returned from Pixel source.
-        /// </returns>
-        private static Span<TPixel> GetSpan<TPixel>(Buffer2D<TPixel> source, int row)
-            where TPixel : struct, IPixel<TPixel>
-            => source.GetSpan().Slice(row * source.Width, source.Width);
-
         /// <summary>
         /// Gets the configuration.
         /// </summary>

src/ImageSharp/Common/Helpers/Guard.cs

@@ -1,4 +1,4 @@
-// Copyright (c) Six Labors and contributors.
+// Copyright (c) Six Labors and contributors.
 // Licensed under the Apache License, Version 2.0.
 
 using System;
@@ -51,28 +51,6 @@ public static void NotNullOrWhiteSpace(string value, string parameterName)
             }
         }
 
-        /// <summary>
-        /// Ensures that the enumeration is not null or empty.
-        /// </summary>
-        /// <typeparam name="T">The type of objects in the <paramref name="value"/></typeparam>
-        /// <param name="value">The target enumeration, which should be checked against being null or empty.</param>
-        /// <param name="parameterName">Name of the parameter.</param>
-        /// <exception cref="ArgumentNullException"><paramref name="value"/> is null.</exception>
-        /// <exception cref="ArgumentException"><paramref name="value"/> is empty.</exception>
-        [MethodImpl(InliningOptions.ShortMethod)]
-        public static void NotNullOrEmpty<T>(ICollection<T> value, string parameterName)
-        {
-            if (value is null)
-            {
-                ThrowArgumentNullException(parameterName);
-            }
-
-            if (value.Count == 0)
-            {
-                ThrowArgumentException("Must not be empty.", parameterName);
-            }
-        }
-
         /// <summary>
         /// Ensures that the specified value is less than a maximum value.
         /// </summary>

src/ImageSharp/Formats/Png/Filters/SubFilter.cs

@@ -1,4 +1,4 @@
-// Copyright (c) Six Labors and contributors.
+// Copyright (c) Six Labors and contributors.
 // Licensed under the Apache License, Version 2.0.
 
 using System;
@@ -25,12 +25,8 @@ public static void Decode(Span<byte> scanline, int bytesPerPixel)
             ref byte scanBaseRef = ref MemoryMarshal.GetReference(scanline);
 
             // Sub(x) + Raw(x-bpp)
-            int x = 1;
-            for (; x <= bytesPerPixel /* Note the <= because x starts at 1 */; ++x)
-            {
-                ref byte scan = ref Unsafe.Add(ref scanBaseRef, x);
-            }
-
+            int x = bytesPerPixel + 1;
+            Unsafe.Add(ref scanBaseRef, x);
             for (; x < scanline.Length; ++x)
             {
                 ref byte scan = ref Unsafe.Add(ref scanBaseRef, x);

src/ImageSharp/MetaData/Profiles/Exif/ExifReader.cs

@@ -1,4 +1,4 @@
-// Copyright (c) Six Labors and contributors.
+// Copyright (c) Six Labors and contributors.
 // Licensed under the Apache License, Version 2.0.
 
 using System;
@@ -419,16 +419,6 @@ private ushort ReadUInt16()
                 : default;
         }
 
-        private string ReadString(int length)
-        {
-            if (this.TryReadSpan(length, out ReadOnlySpan<byte> span) && span.Length != 0)
-            {
-                return this.ConvertToString(span);
-            }
-
-            return null;
-        }
-
         private void GetThumbnail(uint offset)
         {
             var values = new List<ExifValue>();

src/ImageSharp/MetaData/Profiles/ICC/DataReader/IccDataReader.TagDataEntry.cs

@@ -1,4 +1,4 @@
-// Copyright (c) Six Labors and contributors.
+// Copyright (c) Six Labors and contributors.
 // Licensed under the Apache License, Version 2.0.
 
 using System;
@@ -526,9 +526,8 @@ public IccMultiProcessElementsTagDataEntry ReadMultiProcessElementsTagDataEntry(
         {
             int start = this.currentIndex - 8;
 
-            // TODO: Why are we storing variable
-            ushort inChannelCount = this.ReadUInt16();
-            ushort outChannelCount = this.ReadUInt16();
+            this.ReadUInt16();
+            this.ReadUInt16();
             uint elementCount = this.ReadUInt32();
 
             var positionTable = new IccPositionNumber[elementCount];
@@ -902,4 +901,4 @@ public IccUcrBgTagDataEntry ReadUcrBgTagDataEntry(uint size)
             return new IccUcrBgTagDataEntry(ucrCurve, bgCurve, description);
         }
     }
-}
+}

src/ImageSharp/MetaData/Profiles/ICC/DataReader/IccDataReader.cs

@@ -1,4 +1,4 @@
-// Copyright (c) Six Labors and contributors.
+// Copyright (c) Six Labors and contributors.
 // Licensed under the Apache License, Version 2.0.
 
 using System;
@@ -83,16 +83,5 @@ private bool GetBit(byte value, int position)
         {
             return ((value >> (7 - position)) & 1) == 1;
         }
-
-        /// <summary>
-        /// Gets the bit value at a specified position
-        /// </summary>
-        /// <param name="value">The value from where the bit will be extracted</param>
-        /// <param name="position">Position of the bit. Zero based index from left to right.</param>
-        /// <returns>The bit value at specified position</returns>
-        private bool GetBit(ushort value, int position)
-        {
-            return ((value >> (15 - position)) & 1) == 1;
-        }
     }
 }

src/ImageSharp/MetaData/Profiles/ICC/DataWriter/IccDataWriter.Curves.cs

@@ -41,7 +41,6 @@ public int WriteOneDimensionalCurve(IccOneDimensionalCurve value)
         public int WriteResponseCurve(IccResponseCurve value)
         {
             int count = this.WriteUInt32((uint)value.CurveType);
-            int channels = value.XyzValues.Length;
 
             foreach (IccResponseNumber[] responseArray in value.ResponseArrays)
             {

src/ImageSharp/MetaData/Profiles/ICC/DataWriter/IccDataWriter.NonPrimitives.cs

@@ -1,4 +1,4 @@
-// Copyright (c) Six Labors and contributors.
+// Copyright (c) Six Labors and contributors.
 // Licensed under the Apache License, Version 2.0.
 
 using System;
@@ -37,9 +37,6 @@ public int WriteVersionNumber(in IccVersion value)
             int minor = value.Minor.Clamp(0, 15);
             int bugfix = value.Patch.Clamp(0, 15);
 
-            // TODO: This is not used?
-            byte mb = (byte)((minor << 4) | bugfix);
-
             int version = (major << 24) | (minor << 20) | (bugfix << 16);
             return this.WriteInt32(version);
         }

src/ImageSharp/PixelFormats/PixelImplementations/Gray16.cs

@@ -1,4 +1,4 @@
-// Copyright (c) Six Labors and contributors.
+// Copyright (c) Six Labors and contributors.
 // Licensed under the Apache License, Version 2.0.
 
 using System.Numerics;
@@ -15,7 +15,6 @@ namespace SixLabors.ImageSharp.PixelFormats
     public partial struct Gray16 : IPixel<Gray16>, IPackedVector<ushort>
     {
         private const float Max = ushort.MaxValue;
-        private const float Average = 1 / 3F;
 
         /// <summary>
         /// Initializes a new instance of the <see cref="Gray16"/> struct.

src/ImageSharp/PixelFormats/PixelImplementations/Gray8.cs

@@ -1,4 +1,4 @@
-// Copyright (c) Six Labors and contributors.
+// Copyright (c) Six Labors and contributors.
 // Licensed under the Apache License, Version 2.0.
 
 using System.Numerics;
@@ -16,12 +16,6 @@ public partial struct Gray8 : IPixel<Gray8>, IPackedVector<byte>
     {
         private static readonly Vector4 MaxBytes = new Vector4(255F);
         private static readonly Vector4 Half = new Vector4(0.5F);
-        private const float Average = 1 / 3F;
-
-        private static readonly Vector4 Min = new Vector4(0, 0, 0, 1f);
-        private static readonly Vector4 Max = Vector4.One;
-
-        private static readonly Vector4 Accumulator = new Vector4(255f * Average, 255f * Average, 255f * Average, 0.5f);
 
         /// <summary>
         /// Initializes a new instance of the <see cref="Gray8"/> struct.