Meziantou.Framework

Shapes and colors

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A shape is drawn in two steps: the path is built (Rectangle, Circle, MoveTo, LineTo, CurveTo...), then painted (Fill, Stroke...) with the colors and the line style of the graphics state.

Fill and outline shapes

public static void DrawShapes(string outputPath)
{
    var document = new PdfDocument();
    document.Pages.Add(new PdfSize(300, 150)).CreateContentBuilder()
        // Filled shapes: set the fill color, build the path, then fill it
        .SetFillRgb(0.27, 0.51, 0.71).Rectangle(15, 80, 55, 55).Fill()
        .SetFillColor(PdfColor.FromRgb24(46, 139, 87)).Circle(112, 107.5, 27.5).Fill()
        .SetFillCmyk(0, 0.2, 0.9, 0).Ellipse(185, 107.5, 35, 22).Fill()
        .SetFillRgb(0.86, 0.08, 0.24).MoveTo(235, 80).LineTo(285, 80).LineTo(260, 135).ClosePath().Fill()

        // Outlines: set the stroke color and the line width, build the path, then stroke it
        .SetStrokeGray(0.3).SetLineWidth(3)
        .Rectangle(15, 15, 55, 50).Stroke()
        .MoveTo(85, 20).CurveTo(100, 75, 125, -15, 140, 60).Stroke() // a cubic Bézier curve

        // Both: fill, then stroke the same path
        .SetFillRgb(1, 0.85, 0.4).Rectangle(160, 15, 50, 50).FillAndStroke()

        // Two squares, one inside the other: with the even-odd rule, the inner one is a hole
        .SetFillRgb(0.58, 0.44, 0.86).Rectangle(230, 15, 55, 50).Rectangle(245, 27.5, 25, 25).Fill(PdfFillRule.EvenOdd);

    document.Save(outputPath);
}

A row of filled shapes (a blue square, a green circle, a yellow ellipse and a red triangle), above a gray square outline, a gray curve, a yellow square with a gray outline and a purple square with a square hole

To buildCall
A rectangleRectangle(x, y, width, height) or Rectangle(PdfRectangle), from its lower-left corner
A circle, an ellipseCircle(centerX, centerY, radius), Ellipse(centerX, centerY, radiusX, radiusY)
LinesMoveTo starts a subpath, LineTo adds a straight line, ClosePath goes back to the start
CurvesCurveTo adds a cubic Bézier curve; CurveToFromCurrentPoint and CurveToEndPoint take one control point from the ends
To paint the pathCall
Fill itFill
Draw its outlineStroke, or CloseAndStroke to close it first
BothFillAndStroke, CloseFillAndStroke
Neither (after a clip)EndPath

Style the lines

public static void DrawLineStyles(string outputPath)
{
    var document = new PdfDocument();
    var builder = document.Pages.Add(new PdfSize(300, 150)).CreateContentBuilder().SetStrokeRgb(0.2, 0.3, 0.5);

    // Caps: the ends of the lines, butt (the default), round and projecting square
    builder.SetLineWidth(10)
        .SetLineCap(PdfLineCap.Butt).MoveTo(25, 125).LineTo(105, 125).Stroke()
        .SetLineCap(PdfLineCap.Round).MoveTo(25, 100).LineTo(105, 100).Stroke()
        .SetLineCap(PdfLineCap.ProjectingSquare).MoveTo(25, 75).LineTo(105, 75).Stroke();

    // Joins: the corners, miter (the default), round and bevel
    builder.SetLineCap(PdfLineCap.Butt)
        .SetLineJoin(PdfLineJoin.Miter).MoveTo(135, 70).LineTo(155, 125).LineTo(175, 70).Stroke()
        .SetLineJoin(PdfLineJoin.Round).MoveTo(190, 70).LineTo(210, 125).LineTo(230, 70).Stroke()
        .SetLineJoin(PdfLineJoin.Bevel).MoveTo(245, 70).LineTo(265, 125).LineTo(285, 70).Stroke();

    // Dashes: 12 points drawn, 6 skipped; then dashes of length 0 with round caps, which are dots
    builder.SetLineWidth(3).SetDashPattern([12, 6]).MoveTo(25, 40).LineTo(285, 40).Stroke()
        .SetLineWidth(5).SetLineCap(PdfLineCap.Round).SetDashPattern([0, 10]).MoveTo(25, 20).LineTo(285, 20).Stroke()
        .SetDashPattern([]); // solid lines again

    document.Save(outputPath);
}

Three thick lines with butt, round and square ends, three peaks with a sharp, a round and a cut corner, a dashed line and a dotted line

  • SetLineWidth sets the width, centered on the path. A width of 0 is the thinnest line the device can draw.
  • SetLineCap sets the ends of open lines and dashes; SetLineJoin the corners. A miter join longer than SetMiterLimit times the width is beveled.
  • SetDashPattern takes the lengths of the dashes and the gaps, and a phase where the pattern starts; an empty array draws solid lines again.

Move, turn and clip

The transformation of the graphics state moves, turns and scales what is drawn after it, and a clip limits the region that can be painted. Both last until the graphics state is restored:

public static void DrawTransformations(string outputPath)
{
    var document = new PdfDocument();
    var builder = document.Pages.Add(new PdfSize(300, 150)).CreateContentBuilder();

    // The same square, turned around the center of the left half: move the origin there, then rotate the axes
    for (var i = 0; i < 6; i++)
    {
        builder.SaveGraphicsState()
            .Translate(75, 75)
            .Rotate(i * 15) // degrees, counterclockwise
            .SetStrokeRgb(0.1, 0.25 + (i * 0.12), 0.6).SetLineWidth(2)
            .Rectangle(-40, -40, 80, 80).Stroke()
            .RestoreGraphicsState(); // back to the coordinates of the page
    }

    // Clipping: stripes painted through a circle
    builder.SaveGraphicsState()
        .Circle(225, 75, 55).Clip().EndPath()
        .SetFillRgb(0.95, 0.6, 0.1);
    for (var x = 165; x < 285; x += 20)
    {
        builder.Rectangle(x, 0, 10, 150);
    }

    builder.Fill()
        .RestoreGraphicsState() // removes the clip
        .SetStrokeGray(0.3).SetLineWidth(1.5).Circle(225, 75, 55).Stroke();

    document.Save(outputPath);
}

Six square outlines turned around the same center, from dark blue to green, and orange vertical stripes inside a circle