Neuerstellung

- Quelle: https://github.com/oxyplot/oxyplot

Source/OxyPlot.SkiaSharp/JpegExporter.cs

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+// --------------------------------------------------------------------------------------------------------------------
+// <copyright file="JpegExporter.cs" company="OxyPlot">
+//   Copyright (c) 2020 OxyPlot contributors
+// </copyright>
+// --------------------------------------------------------------------------------------------------------------------
+
+namespace OxyPlot.SkiaSharp
+{
+    using global::SkiaSharp;
+    using System.IO;
+
+    /// <summary>
+    /// Provides functionality to export plots to jpeg using the SkiaSharp renderer.
+    /// </summary>
+    public class JpegExporter : IExporter
+    {
+        /// <summary>
+        /// Gets or sets the DPI.
+        /// </summary>
+        public float Dpi { get; set; } = 96;
+
+        /// <summary>
+        /// Gets or sets the export height (in pixels).
+        /// </summary>
+        public int Height { get; set; }
+
+        /// <summary>
+        /// Gets or sets the export width (in pixels).
+        /// </summary>
+        public int Width { get; set; }
+
+        /// <summary>
+        /// Gets or sets the export quality (0-100).
+        /// </summary>
+        public int Quality { get; set; } = 90;
+
+        /// <summary>
+        /// Exports the specified model to a file.
+        /// </summary>
+        /// <param name="model">The model.</param>
+        /// <param name="path">The path.</param>
+        /// <param name="width">The width (points).</param>
+        /// <param name="height">The height (points).</param>
+        /// <param name="quality">The export quality (0-100).</param>
+        /// <param name="dpi">The DPI (dots per inch).</param>
+        public static void Export(IPlotModel model, string path, int width, int height, int quality, float dpi = 96)
+        {
+            using var stream = File.OpenWrite(path);
+            Export(model, stream, width, height, quality, dpi);
+        }
+
+        /// <summary>
+        /// Exports the specified model to a stream.
+        /// </summary>
+        /// <param name="model">The model.</param>
+        /// <param name="stream">The output stream.</param>
+        /// <param name="width">The width (points).</param>
+        /// <param name="height">The height (points).</param>
+        /// <param name="quality">The export quality (0-100).</param>
+        /// <param name="dpi">The DPI (dots per inch).</param>
+        public static void Export(IPlotModel model, Stream stream, int width, int height, int quality, float dpi = 96)
+        {
+            var exporter = new JpegExporter { Width = width, Height = height, Quality = quality, Dpi = dpi };
+            exporter.Export(model, stream);
+        }
+
+        /// <inheritdoc/>
+        public void Export(IPlotModel model, Stream stream)
+        {
+            using var bitmap = new SKBitmap(this.Width, this.Height);
+
+            using (var canvas = new SKCanvas(bitmap))
+            using (var context = new SkiaRenderContext { RenderTarget = RenderTarget.PixelGraphic, SkCanvas = canvas })
+            {
+                canvas.Clear(SKColors.White);
+                var dpiScale = this.Dpi / 96;
+                context.DpiScale = dpiScale;
+                model.Update(true);
+                var backgroundColor = model.Background;
+
+                // jpg doesn't support transparency
+                if (!backgroundColor.IsVisible())
+                {
+                    backgroundColor = OxyColors.White;
+                }
+
+                canvas.Clear(backgroundColor.ToSKColor());
+                model.Render(context, new OxyRect(0, 0, this.Width / dpiScale, this.Height / dpiScale));
+            }
+
+            using var skStream = new SKManagedWStream(stream);
+            bitmap.Encode(skStream, SKEncodedImageFormat.Jpeg, this.Quality);
+        }
+    }
+}

Source/OxyPlot.SkiaSharp/OxyPlot.SkiaSharp.csproj

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+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <LangVersion>8</LangVersion>
+    <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
+    <Copyright>Copyright (c) 2020 OxyPlot contributors</Copyright>
+    <TargetFrameworks>net462;netstandard2.0</TargetFrameworks>
+    <Authors>OxyPlot contributors</Authors>
+    <Description>OxyPlot is a plotting library for .NET. This package provides rendering based on SkiaSharp.</Description>
+    <PackageTags>plotting plot charting chart skiasharp skia pdf</PackageTags>
+    <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
+    <GenerateDocumentationFile>True</GenerateDocumentationFile>
+    <SignAssembly>true</SignAssembly>
+    <AssemblyOriginatorKeyFile>OxyPlot.SkiaSharp.snk</AssemblyOriginatorKeyFile>
+  </PropertyGroup>
+  <ItemGroup>
+    <PackageReference Include="SkiaSharp" Version="2.88.3" />
+    <PackageReference Include="SkiaSharp.HarfBuzz" Version="2.88.3" />
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="OxyPlot.SkiaSharp.snk" />
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\OxyPlot\OxyPlot.csproj" />
+  </ItemGroup>
+</Project>

Source/OxyPlot.SkiaSharp/PdfExporter.cs

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+// --------------------------------------------------------------------------------------------------------------------
+// <copyright file="PdfExporter.cs" company="OxyPlot">
+//   Copyright (c) 2020 OxyPlot contributors
+// </copyright>
+// --------------------------------------------------------------------------------------------------------------------
+
+namespace OxyPlot.SkiaSharp
+{
+    using global::SkiaSharp;
+    using System.IO;
+
+    /// <summary>
+    /// Provides functionality to export plots to pdf using the SkiaSharp renderer.
+    /// </summary>
+    public class PdfExporter : IExporter
+    {
+        /// <summary>
+        /// Gets or sets the export height (in points, where 1 point equals 1/72 inch).
+        /// </summary>
+        public float Height { get; set; }
+
+        /// <summary>
+        /// Gets or sets the export width (in points, where 1 point equals 1/72 inch).
+        /// </summary>
+        public float Width { get; set; }
+
+        /// <summary>
+        /// Gets or sets a value indicating whether text shaping should be used when rendering text.
+        /// </summary>
+        public bool UseTextShaping { get; set; } = true;
+
+        /// <summary>
+        /// Exports the specified model to a file.
+        /// </summary>
+        /// <param name="model">The model.</param>
+        /// <param name="path">The path.</param>
+        /// <param name="width">The width (points).</param>
+        /// <param name="height">The height (points).</param>
+        public static void Export(IPlotModel model, string path, float width, float height)
+        {
+            using var stream = File.OpenWrite(path);
+            Export(model, stream, width, height);
+        }
+
+        /// <summary>
+        /// Exports the specified model to a stream.
+        /// </summary>
+        /// <param name="model">The model.</param>
+        /// <param name="stream">The output stream.</param>
+        /// <param name="width">The width (points).</param>
+        /// <param name="height">The height (points).</param>
+        public static void Export(IPlotModel model, Stream stream, float width, float height)
+        {
+            var exporter = new PdfExporter { Width = width, Height = height };
+            exporter.Export(model, stream);
+        }
+
+        /// <inheritdoc/>
+        public void Export(IPlotModel model, Stream stream)
+        {
+            using var document = SKDocument.CreatePdf(stream);
+            using var pdfCanvas = document.BeginPage(this.Width, this.Height);
+            using var context = new SkiaRenderContext { RenderTarget = RenderTarget.VectorGraphic, SkCanvas = pdfCanvas, UseTextShaping = this.UseTextShaping };
+            const float dpiScale = 72f / 96;
+            context.DpiScale = dpiScale;
+            model.Update(true);
+            pdfCanvas.Clear(model.Background.ToSKColor());
+            model.Render(context, new OxyRect(0, 0, this.Width / dpiScale, this.Height / dpiScale));
+        }
+    }
+}

Source/OxyPlot.SkiaSharp/PngExporter.cs

@@ -0,0 +1,84 @@
+// --------------------------------------------------------------------------------------------------------------------
+// <copyright file="PngExporter.cs" company="OxyPlot">
+//   Copyright (c) 2020 OxyPlot contributors
+// </copyright>
+// --------------------------------------------------------------------------------------------------------------------
+
+namespace OxyPlot.SkiaSharp
+{
+    using global::SkiaSharp;
+    using System.IO;
+
+    /// <summary>
+    /// Provides functionality to export plots to png using the SkiaSharp renderer.
+    /// </summary>
+    public class PngExporter : IExporter
+    {
+        /// <summary>
+        /// Gets or sets the DPI.
+        /// </summary>
+        public float Dpi { get; set; } = 96;
+
+        /// <summary>
+        /// Gets or sets the export height (in pixels).
+        /// </summary>
+        public int Height { get; set; }
+
+        /// <summary>
+        /// Gets or sets the export width (in pixels).
+        /// </summary>
+        public int Width { get; set; }
+
+        /// <summary>
+        /// Gets or sets a value indicating whether text shaping should be used when rendering text.
+        /// </summary>
+        public bool UseTextShaping { get; set; } = true;
+
+        /// <summary>
+        /// Exports the specified model to a file.
+        /// </summary>
+        /// <param name="model">The model.</param>
+        /// <param name="path">The path.</param>
+        /// <param name="width">The width (points).</param>
+        /// <param name="height">The height (points).</param>
+        /// <param name="dpi">The DPI (dots per inch).</param>
+        public static void Export(IPlotModel model, string path, int width, int height, float dpi = 96)
+        {
+            using var stream = File.OpenWrite(path);
+            Export(model, stream, width, height, dpi);
+        }
+
+        /// <summary>
+        /// Exports the specified model to a stream.
+        /// </summary>
+        /// <param name="model">The model.</param>
+        /// <param name="stream">The output stream.</param>
+        /// <param name="width">The width (points).</param>
+        /// <param name="height">The height (points).</param>
+        /// <param name="dpi">The DPI (dots per inch).</param>
+        public static void Export(IPlotModel model, Stream stream, int width, int height, float dpi = 96)
+        {
+            var exporter = new PngExporter { Width = width, Height = height, Dpi = dpi };
+            exporter.Export(model, stream);
+        }
+
+        /// <inheritdoc/>
+        public void Export(IPlotModel model, Stream stream)
+        {
+            using var bitmap = new SKBitmap(this.Width, this.Height);
+
+            using (var canvas = new SKCanvas(bitmap))
+            using (var context = new SkiaRenderContext { RenderTarget = RenderTarget.PixelGraphic, SkCanvas = canvas, UseTextShaping = this.UseTextShaping })
+            {
+                var dpiScale = this.Dpi / 96;
+                context.DpiScale = dpiScale;
+                model.Update(true);
+                canvas.Clear(model.Background.ToSKColor());
+                model.Render(context, new OxyRect(0, 0, this.Width / dpiScale, this.Height / dpiScale));
+            }
+
+            using var skStream = new SKManagedWStream(stream);
+            bitmap.Encode(skStream, SKEncodedImageFormat.Png, 0);
+        }
+    }
+}

Source/OxyPlot.SkiaSharp/RenderTarget.cs

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+// --------------------------------------------------------------------------------------------------------------------
+// <copyright file="RenderTarget.cs" company="OxyPlot">
+//   Copyright (c) 2020 OxyPlot contributors
+// </copyright>
+// --------------------------------------------------------------------------------------------------------------------
+
+namespace OxyPlot.SkiaSharp
+{
+    /// <summary>
+    /// Defines a render target for <see cref="SkiaRenderContext"/>.
+    /// </summary>
+    public enum RenderTarget
+    {
+        /// <summary>
+        /// Indicates that the <see cref="SkiaRenderContext"/> renders to a screen.
+        /// </summary>
+        /// <remarks>
+        /// The render context may try to snap shapes to device pixels and will use sub-pixel text rendering.
+        /// </remarks>
+        Screen,
+
+        /// <summary>
+        /// Indicates that the <see cref="SkiaRenderContext"/> renders to a pixel graphic.
+        /// </summary>
+        /// <remarks>
+        /// The render context may try to snap shapes to pixels, but will not use sub-pixel text rendering.
+        /// </remarks>
+        PixelGraphic,
+
+        /// <summary>
+        /// Indicates that the <see cref="SkiaRenderContext"/> renders to a vector graphic.
+        /// </summary>
+        /// <remarks>
+        /// The render context will not use any rendering enhancements that are specific to pixel graphics.
+        /// </remarks>
+        VectorGraphic
+    }
+}

Source/OxyPlot.SkiaSharp/SkiaExtensions.cs

@@ -0,0 +1,36 @@
+// --------------------------------------------------------------------------------------------------------------------
+// <copyright file="SkiaExtensions.cs" company="OxyPlot">
+//   Copyright (c) 2020 OxyPlot contributors
+// </copyright>
+// --------------------------------------------------------------------------------------------------------------------
+
+namespace OxyPlot.SkiaSharp
+{
+    using global::SkiaSharp;
+
+    /// <summary>
+    /// Provides extension methods for conversion between SkiaSharp and oxyplot objects.
+    /// </summary>
+    public static class SkiaExtensions
+    {
+        /// <summary>
+        /// Converts a <see cref="OxyColor"/> to a <see cref="SKColor"/>;
+        /// </summary>
+        /// <param name="color">The <see cref="OxyColor"/>.</param>
+        /// <returns>The <see cref="SKColor"/>.</returns>
+        public static OxyColor ToOxyColor(this SKColor color)
+        {
+            return OxyColor.FromArgb(color.Alpha, color.Red, color.Green, color.Blue);
+        }
+
+        /// <summary>
+        /// Converts a <see cref="SKColor"/> to a <see cref="OxyColor"/>;
+        /// </summary>
+        /// <param name="color">The <see cref="SKColor"/>.</param>
+        /// <returns>The <see cref="OxyColor"/>.</returns>
+        public static SKColor ToSKColor(this OxyColor color)
+        {
+            return new SKColor(color.R, color.G, color.B, color.A);
+        }
+    }
+}

Source/OxyPlot.SkiaSharp/SvgExporter.cs

@@ -0,0 +1,44 @@
+// --------------------------------------------------------------------------------------------------------------------
+// <copyright file="SvgExporter.cs" company="OxyPlot">
+//   Copyright (c) 2020 OxyPlot contributors
+// </copyright>
+// --------------------------------------------------------------------------------------------------------------------
+
+namespace OxyPlot.SkiaSharp
+{
+    using global::SkiaSharp;
+    using System.IO;
+
+    /// <summary>
+    /// Provides functionality to export plots to scalable vector graphics using the SkiaSharp SVG canvas.
+    /// </summary>
+    public class SvgExporter : IExporter
+    {
+        /// <summary>
+        /// Gets or sets the height (in user units) of the output area.
+        /// </summary>
+        public float Height { get; set; }
+
+        /// <summary>
+        /// Gets or sets the width (in user units) of the output area.
+        /// </summary>
+        public float Width { get; set; }
+
+        /// <inheritdoc/>
+        public void Export(IPlotModel model, Stream stream)
+        {
+            using var skStream = new SKManagedWStream(stream);
+            using var canvas = SKSvgCanvas.Create(new SKRect(0, 0, this.Width, this.Height), skStream);
+
+            if (!model.Background.IsInvisible())
+            {
+                canvas.Clear(model.Background.ToSKColor());
+            }
+
+            // SVG export does not work with UseTextShaping=true. However SVG does text shaping by itself anyway, so we can just disable it
+            using var context = new SkiaRenderContext { RenderTarget = RenderTarget.VectorGraphic, SkCanvas = canvas, UseTextShaping = false };
+            model.Update(true);
+            model.Render(context, new OxyRect(0, 0, this.Width, this.Height));
+        }
+    }
+}