SharpDx：设置字符宽度

Question

我正在使用 SharpDX 编写 C# Direct2D 应用程序，但是我可以理解 C++ 中提供的答案/示例。

我想渲染文本并更改某些字符的宽度以看起来像图片：

字母B扩大到200%，字母D缩小到50%

在下面的代码中，我绘制了字形的几何形状 所以可以改变几何的宽度 但这不是一个好的解决方案，因为绘制出来的几何图形就像您在图片中看到的那样模糊。

总之，有两个问题：

1. 如何更改字符的宽度？

2. 如何在不模糊的情况下绘制字母的几何形状。 （可以用 ClearType 渲染几何图形吗？）

   private void RenderGlyphRun1(FontFace1 fontFace)
   {
       var Offsets = new List<GlyphOffset>();
       var fontEmSize_ = 12;
       GlyphRun glyphRun = new GlyphRun();
       glyphRun.FontFace = fontFace;
       glyphRun.FontSize = fontEmSize_;
       glyphRun.BidiLevel = 1;
       var left = 650f;
       var top = 50f;
   
       var baseLine = (float)(fontFace.Metrics.LineGap + fontFace.Metrics.Ascent) /
           fontFace.Metrics.DesignUnitsPerEm * glyphRun.FontSize;
   
       string textToDraw = "ABCDE";
       foreach (char letter in textToDraw)
       {
           Offsets.Add(new GlyphOffset());
       }
   
       var charArr = textToDraw.Select(x => (int)x).ToArray();
       glyphRun.Indices = fontFace.GetGlyphIndices(charArr);
   
       var metrics = fontFace.GetDesignGlyphMetrics(glyphRun.Indices, false);
       glyphRun.Advances = metrics.Select(x => (float)x.AdvanceWidth /
                fontFace.Metrics.DesignUnitsPerEm * glyphRun.FontSize).ToArray();
   
       glyphRun.Offsets = Offsets.ToArray();
   
       RenderTarget2D.BeginDraw();
       RenderTarget2D.Clear(SharpDX.Color.White);
   
       RenderTarget2D.DrawGlyphRun(new Vector2(left, top),
           glyphRun, new SharpDX.Direct2D1.SolidColorBrush(RenderTarget2D, SharpDX.Color.Black),
           MeasuringMode.Natural);
   
       top += baseLine;
   
       var pathGeometry = new PathGeometry(Factory2D);
       var geometrySink = pathGeometry.Open();
   
       fontFace.GetGlyphRunOutline(glyphRun.FontSize, glyphRun.Indices,
           glyphRun.Advances, glyphRun.Offsets, glyphRun.IsSideways,
           glyphRun.BidiLevel % 2 != 0, geometrySink);
   
       geometrySink.Close();
       geometrySink.Dispose();
       fontFace.Dispose();
   
       var matrix = new Matrix3x2()
       {
           M11 = 1,
           M12 = 0,
           M21 = 0,
           M22 = 1,
           M31 = left,
           M32 = top
       };
   
       var transformedGeometry = new TransformedGeometry(Factory2D, pathGeometry, matrix);
       var brushColor = (Color4)SharpDX.Color.Black;
       var brush = new SolidColorBrush(RenderTarget2D, brushColor);
       RenderTarget2D.FillGeometry(transformedGeometry, brush);
   
       pathGeometry.Dispose();
       transformedGeometry.Dispose();
       brush.Dispose();
   
       RenderTarget2D.EndDraw();
   }       
   

Answer 1

由于有些字母应该是窄的，有些是正常的，有些是宽的，所以你不能使用一个GlyphRun，而必须创建3个不同的GlyphRun。

使任何GlyphRun 的所有字母变宽或变窄：

1. 将Transform 配置为RenderTarget
2. 绘制GlyphRun
3. 返回原Transform

宽变换：RenderTarget2D.Transform = new SharpDX.Mathematics.Interop.RawMatrix3x2(1.5f, 0, 0, 1, 0, 0);

窄变换：RenderTarget2D.Transform = new SharpDX.Mathematics.Interop.RawMatrix3x2(0.5f, 0, 0, 1, 0, 0);

使用此解决方案后，您无需将GlyphRun 转换为geometry 并与模糊字母混淆。

Answer 2

Direct2D 文本呈现功能分两部分提供：

1) DrawText 和 DrawTextLayout 方法，使调用者能够传递字符串和格式参数或用于多种格式的 DWrite 文本布局对象。这应该适合大多数来电者。

2) 第二种方式是渲染文本，公开为DrawGlyphRun 方法，为已经知道要渲染的字形位置的客户提供光栅化。在 Direct2D 中绘图时，以下两条通用规则有助于提高文本性能。

我现在看到您使用的是第二种方法，但是在第一种方法中，您可以将渲染设置为ClearType：

RenderTarget2D.TextAntialiasMode = TextAntialiasMode.Cleartype;

我不确定如何将它包含在您的示例中，但 Sharp DX 示例如下所示：

using System;
using SharpDX;
using SharpDX.Direct2D1;
using SharpDX.DirectWrite;
using SharpDX.Samples;
using TextAntialiasMode = SharpDX.Direct2D1.TextAntialiasMode;

namespace TextRenderingApp
{
  public class Program : Direct2D1DemoApp
  {        
    public TextFormat TextFormat { get; private set; }
    public TextLayout TextLayout { get; private set; }

    protected override void Initialize(DemoConfiguration demoConfiguration)
    {
        base.Initialize(demoConfiguration);

        // Initialize a TextFormat
        TextFormat = new TextFormat(FactoryDWrite, "Calibri", 128) {TextAlignment = TextAlignment.Center, ParagraphAlignment = ParagraphAlignment.Center};

        RenderTarget2D.TextAntialiasMode = TextAntialiasMode.Cleartype;

        // Initialize a TextLayout
        TextLayout = new TextLayout(FactoryDWrite, "SharpDX D2D1 - DWrite", TextFormat, demoConfiguration.Width, demoConfiguration.Height);
    }


    protected override void Draw(DemoTime time)
    {
        base.Draw(time);

        // Draw the TextLayout
        RenderTarget2D.DrawTextLayout(new Vector2(0,0), TextLayout, SceneColorBrush, DrawTextOptions.None );
    }


    [STAThread]
    static void Main(string[] args)
    {
        Program program = new Program();
        program.Run(new DemoConfiguration("SharpDX DirectWrite Text Rendering Demo"));
    }
  }
}

样本取自：https://github.com/sharpdx/SharpDX-Samples/blob/master/Desktop/Direct2D1/TextRenderingApp