Representación de texto usando fuente Type1 | .NET

Representación de texto

Para representar texto, el subsistema de Renderizado requiere la implementación de la interfaz Aspose.Font.Rendering.IGlyphOutlinePainter para dibujar glifos. Esto se puede lograr mediante los siguientes pasos.

  1. Implemente los métodos IGlyphOutlinePainter creando una clase GlyphOutlinePainter que requiere un objeto de tipo System.Drawing.Drawing2D.GraphicsPath para los objetivos de dibujo gráfico. La implementación es como se ilustra a continuación.
 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}
  1. Cree el método DrawText() que dibuja el texto especificado en el objeto System.Drawing.Bitmap y guarda el mapa de bits resultante en el disco. Esto incluirá los siguientes pasos:

Pasos auxiliares para esta estrategia

La implementación del método DrawText se muestra a continuación.

 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}
  1. Cree un método de utilidad para calcular el ancho de la fuente con respecto al ancho de la imagen como se muestra en el ejemplo de código siguiente
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}

Llamar a la funcionalidad de renderizado de texto

Para utilizar las implementaciones anteriores, se puede ejecutar el siguiente código de muestra desde el método Main de una aplicación basada en consola.

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");

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