Update SDKs and use C# 8.0

.travis.yml

@@ -3,10 +3,10 @@ solution: ImageSharp.sln
 
 matrix:
   include:
-    - os: linux # Ubuntu 14.04
-      dist: trusty
+    - os: linux # Ubuntu 16.04
+      dist: xenial
       sudo: required
-      dotnet: 2.1.401
+      dotnet: 2.1.603
       mono: latest
 #    - os: osx # OSX 10.11
 #      osx_image: xcode7.3.1

README.md

@@ -108,7 +108,7 @@ For more examples check out:
 
 If you prefer, you can compile ImageSharp yourself (please do and help!)
 
-- Using [Visual Studio 2017](https://visualstudio.microsoft.com/vs/)
+- Using [Visual Studio 2019](https://visualstudio.microsoft.com/vs/)
   - Make sure you have the latest version installed
   - Make sure you have [the .NET Core 2.1 SDK](https://www.microsoft.com/net/core#windows) installed
 

src/ImageSharp.Drawing/ImageSharp.Drawing.csproj

@@ -11,7 +11,7 @@
     <VersionPrefix Condition="$(packageversion) != ''">$(packageversion)</VersionPrefix>
     <VersionPrefix Condition="$(packageversion) == ''">0.0.1</VersionPrefix>
     <TargetFrameworks>netcoreapp2.1;netstandard1.3;netstandard2.0</TargetFrameworks>
-    <LangVersion>7.3</LangVersion>
+    <LangVersion>8.0</LangVersion>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <AssemblyName>SixLabors.ImageSharp.Drawing</AssemblyName>

src/ImageSharp/Formats/Bmp/BmpInfoHeader.cs

@@ -372,21 +372,13 @@ public static BmpInfoHeader ParseOs2Version2(ReadOnlySpan<byte> data)
 
             // The compression value in OS/2 bitmap has a different meaning than in windows bitmaps.
             // Map the OS/2 value to the windows values.
-            switch (compression)
+            infoHeader.Compression = compression switch
             {
-                case 0:
-                    infoHeader.Compression = BmpCompression.RGB;
-                    break;
-                case 1:
-                    infoHeader.Compression = BmpCompression.RLE8;
-                    break;
-                case 2:
-                    infoHeader.Compression = BmpCompression.RLE4;
-                    break;
-                default:
-                    BmpThrowHelper.ThrowImageFormatException($"Compression type is not supported. ImageSharp only supports uncompressed, RLE4 and RLE8.");
-                    break;
-            }
+                0 => BmpCompression.RGB,
+                1 => BmpCompression.RLE8,
+                2 => BmpCompression.RLE4,
+                _ => throw new ImageFormatException($"Compression type is not supported. ImageSharp only supports uncompressed, RLE4 and RLE8.")
+            };
 
             infoHeader.ImageSize = BinaryPrimitives.ReadInt32LittleEndian(data.Slice(20, 4));
             infoHeader.XPelsPerMeter = BinaryPrimitives.ReadInt32LittleEndian(data.Slice(24, 4));

src/ImageSharp/Formats/Jpeg/JpegEncoderCore.cs

@@ -208,7 +208,7 @@ public void Encode<TPixel>(Image<TPixel> image, Stream stream)
 
             // System.Drawing produces identical output for jpegs with a quality parameter of 0 and 1.
             int qlty = (this.quality ?? metadata.GetFormatMetadata(JpegFormat.Instance).Quality).Clamp(1, 100);
-            this.subsample = this.subsample ?? (qlty >= 91 ? JpegSubsample.Ratio444 : JpegSubsample.Ratio420);
+            this.subsample ??= qlty >= 91 ? JpegSubsample.Ratio444 : JpegSubsample.Ratio420;
 
             // Convert from a quality rating to a scaling factor.
             int scale;

src/ImageSharp/Formats/Png/Adam7.cs

@@ -40,17 +40,17 @@ internal static class Adam7
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public static int ComputeColumns(int width, int passIndex)
         {
-            switch (passIndex)
+            return passIndex switch
             {
-                case 0: return (width + 7) / 8;
-                case 1: return (width + 3) / 8;
-                case 2: return (width + 3) / 4;
-                case 3: return (width + 1) / 4;
-                case 4: return (width + 1) / 2;
-                case 5: return width / 2;
-                case 6: return width;
-                default: throw new ArgumentException($"Not a valid pass index: {passIndex}");
-            }
+                0 => (width + 7) / 8,
+                1 => (width + 3) / 8,
+                2 => (width + 3) / 4,
+                3 => (width + 1) / 4,
+                4 => (width + 1) / 2,
+                5 => width / 2,
+                6 => width,
+                _ => throw new ArgumentException($"Not a valid pass index: {passIndex}")
+            };
         }
     }
 }

src/ImageSharp/Formats/Png/PngEncoderCore.cs

@@ -213,10 +213,10 @@ public void Encode<TPixel>(Image<TPixel> image, Stream stream)
             // Always take the encoder options over the metadata values.
             ImageMetadata metadata = image.Metadata;
             PngMetadata pngMetadata = metadata.GetFormatMetadata(PngFormat.Instance);
-            this.gamma = this.gamma ?? pngMetadata.Gamma;
+            this.gamma ??= pngMetadata.Gamma;
             this.writeGamma = this.gamma > 0;
-            this.pngColorType = this.pngColorType ?? pngMetadata.ColorType;
-            this.pngBitDepth = this.pngBitDepth ?? pngMetadata.BitDepth;
+            this.pngColorType ??= pngMetadata.ColorType;
+            this.pngBitDepth ??= pngMetadata.BitDepth;
             this.use16Bit = this.pngBitDepth == PngBitDepth.Bit16;
 
             // Ensure we are not allowing impossible combinations.

src/ImageSharp/Image.FromFile.cs

@@ -31,7 +31,7 @@ public static IImageFormat DetectFormat(string filePath)
         /// <returns>The mime type or null if none found.</returns>
         public static IImageFormat DetectFormat(Configuration config, string filePath)
         {
-            config = config ?? Configuration.Default;
+            config ??= Configuration.Default;
             using (Stream file = config.FileSystem.OpenRead(filePath))
             {
                 return DetectFormat(config, file);

src/ImageSharp/Image.FromStream.cs

@@ -173,7 +173,7 @@ public static Image<TPixel> Load<TPixel>(Configuration config, Stream stream)
         public static Image<TPixel> Load<TPixel>(Configuration config, Stream stream, out IImageFormat format)
             where TPixel : struct, IPixel<TPixel>
         {
-            config = config ?? Configuration.Default;
+            config ??= Configuration.Default;
             (Image<TPixel> img, IImageFormat format) data = WithSeekableStream(config, stream, s => Decode<TPixel>(s, config));
 
             format = data.format;

src/ImageSharp/ImageSharp.csproj

@@ -25,7 +25,7 @@
     <DebugType Condition="$(codecov) == ''">portable</DebugType>
     <DebugSymbols>True</DebugSymbols>
     <Features>IOperation</Features>
-    <LangVersion>7.3</LangVersion>
+    <LangVersion>8.0</LangVersion>
   </PropertyGroup>
 
   <PropertyGroup Condition=" '$(TargetFramework)' == 'netcoreapp2.1' OR '$(TargetFramework)' == 'net472' ">

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

@@ -24,7 +24,7 @@ public IccOneDimensionalCurve ReadOneDimensionalCurve()
                 breakPoints[i] = this.ReadSingle();
             }
 
-            IccCurveSegment[] segments = new IccCurveSegment[segmentCount];
+            var segments = new IccCurveSegment[segmentCount];
             for (int i = 0; i < segmentCount; i++)
             {
                 segments[i] = this.ReadCurveSegment();
@@ -47,7 +47,7 @@ public IccResponseCurve ReadResponseCurve(int channelCount)
                 measurement[i] = this.ReadUInt32();
             }
 
-            Vector3[] xyzValues = new Vector3[channelCount];
+            var xyzValues = new Vector3[channelCount];
             for (int i = 0; i < channelCount; i++)
             {
                 xyzValues[i] = this.ReadXyzNumber();
@@ -67,9 +67,9 @@ public IccResponseCurve ReadResponseCurve(int channelCount)
         }
 
         /// <summary>
-        /// Reads a <see cref="IccParametricCurve"/>
+        /// Reads a <see cref="IccParametricCurve"/>/
         /// </summary>
-        /// <returns>The read curve</returns>
+        /// <returns>The read curve.</returns>
         public IccParametricCurve ReadParametricCurve()
         {
             ushort type = this.ReadUInt16();
@@ -104,15 +104,15 @@ public IccParametricCurve ReadParametricCurve()
                 f = this.ReadFix16();
             }
 
-            switch (type)
+            return type switch
             {
-                case 0: return new IccParametricCurve(gamma);
-                case 1: return new IccParametricCurve(gamma, a, b);
-                case 2: return new IccParametricCurve(gamma, a, b, c);
-                case 3: return new IccParametricCurve(gamma, a, b, c, d);
-                case 4: return new IccParametricCurve(gamma, a, b, c, d, e, f);
-                default: throw new InvalidIccProfileException($"Invalid parametric curve type of {type}");
-            }
+                0 => new IccParametricCurve(gamma),
+                1 => new IccParametricCurve(gamma, a, b),
+                2 => new IccParametricCurve(gamma, a, b, c),
+                3 => new IccParametricCurve(gamma, a, b, c, d),
+                4 => new IccParametricCurve(gamma, a, b, c, d, e, f),
+                _ => throw new InvalidIccProfileException($"Invalid parametric curve type of {type}")
+            };
         }
 
         /// <summary>