使用Type1字体|的文本渲染| .NET

渲染文字

为了渲染文本，渲染子系统需要实现 Aspose.Font.Rendering.IGlyphOutlinePainter 接口才能绘制字形。这可以使用以下步骤来实现。

通过创建一个需要 System.Drawing.Drawing2D.GraphicsPath 类型对象的类 GlyphOutlinePainter 来实现 IGlyphOutlinePainter 方法。实现如下所示。

 1// For complete examples and data files, please go to https://github.com/aspose-font/Aspose.Font-for-.NET
 2class GlyphOutlinePainter : IGlyphOutlinePainter
 3{ 
 4    private System.Drawing.Drawing2D.GraphicsPath _path;
 5    private System.Drawing.PointF _currentPoint;
 6
 7    public GlyphOutlinePainter(System.Drawing.Drawing2D.GraphicsPath path)
 8    {
 9        _path = path;
10    }
11
12    public void MoveTo(MoveTo moveTo)
13    {
14        _path.CloseFigure();
15        _currentPoint.X = (float)moveTo.X;
16        _currentPoint.Y = (float)moveTo.Y;
17    }
18
19    public void LineTo(LineTo lineTo)
20    {
21        float x = (float)lineTo.X;
22        float y = (float)lineTo.Y;
23        _path.AddLine(_currentPoint.X, _currentPoint.Y, x, y);
24        _currentPoint.X = x;
25        _currentPoint.Y = y;
26    }
27
28    public void CurveTo(CurveTo curveTo)
29    {
30        float x3 = (float)curveTo.X3;
31        float y3 = (float)curveTo.Y3;
32
33        _path.AddBezier(
34                  _currentPoint.X,
35                  _currentPoint.Y,
36                  (float)curveTo.X1,
37                  (float)curveTo.Y1,
38                  (float)curveTo.X2,
39                  (float)curveTo.Y2,
40                  x3,
41                  y3);
42
43        _currentPoint.X = x3;
44        _currentPoint.Y = y3;
45    }
46
47    public void ClosePath()
48    {
49        _path.CloseFigure();
50    }
51}

Examples-CSharp-WorkingWithType1Fonts-RenderingText-2.cs hosted with ❤ by GitHub

创建方法 DrawText() 这将包括以下步骤：

迭代文本字符串中的所有符号。
获取每个处理过的符号的 GID 标识符。
创建 GlyphOutlinePainter 对象，这是渲染子系统绘制当前字形所必需的。
创建 Aspose.Font.Renderers.GlyphOutlineRenderer 对象，并将刚创建的 GlyphOutlinePainter 作为参数传入其构造函数。此 GlyphOutlineRenderer 将用于渲染指定的字形。
使用 GlyphOutlineRenderer.RenderGlyph() 方法渲染当前字形。Aspose.Fonts.Matrix 对象用于指定字形坐标。GID 参数指定要渲染的字形。

Auxillary steps for this strategy

对于此代码段，“ Y”轴的glyph坐标是恒定的。
计算每个加工字形的“ X”轴的字形坐标。
“x”和“y”坐标被传递给 Aspose.Fonts.Matrix 对象，GlyphOutlineRenderer 使用它来绘制字形。
每次迭代都会计算当前处理的字形与前一个字形之间的距离。该距离影响字形的 “x” 坐标。
GlyphOutlinePainter 对象利用 GlyphOutlinePainter 本身绘制字形，而不是直接绘制到位图；它绘制到传入构造函数的 GraphicsPath 对象，然后使用 System.Drawing.Graphics 将 GraphicsPath 绘制到位图上。
方法 FontWidthToImageWith() 用于计算位图坐标系中的字形宽度。

DrawText方法的实现如下所示。

 1// For complete examples and data files, please go to https://github.com/aspose-font/Aspose.Font-for-.NET
 2static void DrawText(string text, IFont font, double fontSize,
 3            Brush backgroundBrush, Brush textBrush, string outFile)
 4{
 5    //Get glyph identifiers for every symbol in text line
 6    GlyphId[] gids = new GlyphId[text.Length];
 7    for (int i = 0; i < text.Length; i++)
 8        gids[i] = font.Encoding.DecodeToGid(text[i]);
 9    // set common drawing settings
10    double dpi = 300;
11
12    double resolutionCorrection = dpi / 72; // 72 is font's internal dpi
13    // prepare output bitmap
14    Bitmap outBitmap = new Bitmap(960, 720);
15    outBitmap.SetResolution((float)dpi, (float)dpi);
16    Graphics outGraphics = Graphics.FromImage(outBitmap);
17    outGraphics.FillRectangle(backgroundBrush, 0, 0, outBitmap.Width, outBitmap.Height);
18    outGraphics.SmoothingMode = SmoothingMode.HighQuality;
19    //declare coordinate variables and previous gid
20    GlyphId previousGid = null;
21    double glyphXCoordinate = 0;
22    double glyphYCoordinate = fontSize * resolutionCorrection;
23    //loop which paints every glyph in gids
24    foreach (GlyphId gid in gids)
25    {
26        // if the font contains the gid
27        if (gid != null)
28        {
29            Glyph glyph = font.GlyphAccessor.GetGlyphById(gid);
30            if (glyph == null)
31                continue;
32
33            // path that accepts drawing instructions
34            GraphicsPath path = new GraphicsPath();
35
36            // Create IGlyphOutlinePainter implementation
37            GlyphOutlinePainter outlinePainter = new GlyphOutlinePainter(path);
38
39            // Create the renderer
40            Aspose.Font.Renderers.IGlyphRenderer renderer = new
41                Aspose.Font.Renderers.GlyphOutlineRenderer(outlinePainter);
42
43            // get common glyph properties
44            double kerning = 0;
45
46            // get kerning value
47            if (previousGid != null)
48            {
49                kerning = (font.Metrics.GetKerningValue(previousGid, gid) /
50                           glyph.SourceResolution) * fontSize * resolutionCorrection;
51                kerning += FontWidthToImageWith(font.Metrics.GetGlyphWidth(previousGid),
52                        glyph.SourceResolution, fontSize);
53            }
54
55            // glyph positioning - increase glyph X coordinate according to kerning distance
56            glyphXCoordinate += kerning;
57
58            // Glyph placement matrix
59            TransformationMatrix glyphMatrix =
60                new TransformationMatrix(
61                    new double[]
62                            {
63                                    fontSize*resolutionCorrection,
64                                    0,
65                                    0,
66                                // negative because of bitmap coordinate system begins from the top
67                                    - fontSize*resolutionCorrection,
68                                    glyphXCoordinate,
69                                    glyphYCoordinate
70                            });
71
72            // render current glyph
73            renderer.RenderGlyph(font, gid, glyphMatrix);
74            // fill the path
75            path.FillMode = FillMode.Winding;
76            outGraphics.FillPath(textBrush, path);
77        }
78        //set current gid as previous to get correct kerning for next glyph
79        previousGid = gid;
80    }
81    //Save results
82    outBitmap.Save(outFile);
83}

Examples-CSharp-WorkingWithType1Fonts-RenderingText-3.cs hosted with ❤ by GitHub

创建实用程序方法以计算字体宽度至图像宽度，如下所示

1// For complete examples and data files, please go to https://github.com/aspose-font/Aspose.Font-for-.NET
2static double FontWidthToImageWith(double width, int fontSourceResulution, double fontSize, double dpi = 300)
3{
4    double resolutionCorrection = dpi / 72; // 72 is font's internal dpi
5    return (width / fontSourceResulution) * fontSize * resolutionCorrection;
6}

Examples-CSharp-WorkingWithType1Fonts-RenderingText-4.cs hosted with ❤ by GitHub

调用渲染文本功能

要使用上述实现，可以从基于控制台的应用程序的主要方法执行以下示例代码。

1// For complete examples and data files, please go to https://github.com/aspose-font/Aspose.Font-for-.NET
2string fileName = dataDir + "courier.pfb"; //Font file name with full path
3
4FontDefinition fd = new FontDefinition(FontType.Type1, new FontFileDefinition("pfb", new FileSystemStreamSource(fileName)));
5Type1Font font = Aspose.Font.Font.Open(fd) as Type1Font;
6            
7
8DrawText("Hello world", font, 14, Brushes.White, Brushes.Black, dataDir + "hello1_type1_out.jpg");
9DrawText("Hello world", font, 14, Brushes.Yellow, Brushes.Red, dataDir + "hello2_type1_out.jpg");

Examples-CSharp-WorkingWithType1Fonts-RenderingText-1.cs hosted with ❤ by GitHub

使用类型1字体的字形和指标使用CFF字体

使用Type1字体|的文本渲染| .NET

渲染文字

调用渲染文本功能

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