SvgShapes.cs
```//
// This code is part of Document Solutions for PDF demos.
//
using System;
using System.IO;
using System.Drawing;
using System.Numerics;
using System.Linq;
using System.Collections.Generic;
using GrapeCity.Documents.Pdf;
using GrapeCity.Documents.Text;
using GrapeCity.Documents.Drawing;
using GrapeCity.Documents.Svg;
using GCTEXT = GrapeCity.Documents.Text;
using GCDRAW = GrapeCity.Documents.Drawing;
using DsPdfWeb.Demos.Common;

namespace DsPdfWeb.Demos
{
// This sample draws some geometric shapes using GcSvgDocument and GcGraphics.DrawSvg().
// The code and the results are similar to the Shapes sample.
public class SvgShapes
{
// Helper method to draw a polygon and a caption beneath it.
// Can also be used to just calculate the points without actual drawing.
// startAngle is for the first point, clockwise from (1,0).
// Points are relative to 'center'.
private SvgPoint[] DrawPolygon(GcGraphics g, PointF center, float r, int n, float startAngle, SvgPaint stroke, string caption = null)
{
const float Q = 1.4f;
var plgn = new SvgPolygonElement();
plgn.Points = new List<SvgPoint>(n);
for (int i = 0; i < n; ++i)
new SvgLength((float)(r * Math.Cos(startAngle + 2 * Math.PI * i / n)) * Q, SvgLengthUnits.Percentage),
new SvgLength((float)(r * Math.Sin(startAngle + 2 * Math.PI * i / n)) * Q, SvgLengthUnits.Percentage)));

if (stroke != null)
{
plgn.Stroke = stroke;
plgn.Fill = new SvgPaint(SvgColor.Transparent);
var svgDoc = new GcSvgDocument();
var svg = svgDoc.RootSvg;
g.DrawSvg(svgDoc, new RectangleF(center.X, center.Y, r * 2, r * 2));
}

if (!string.IsNullOrEmpty(caption))
DrawCaption(g, center, r, caption);

return plgn.Points.ToArray();
}
// Helper method to draw a caption beneath a shape:
private void DrawCaption(GcGraphics g, PointF center, float r, string caption)
{
g.DrawString(caption,
new TextFormat() { Font = StandardFonts.Times, FontSize = 10, },
new RectangleF(center.X - r, center.Y + r, r * 2, 24),
TextAlignment.Center, ParagraphAlignment.Center, false);
}
// Main entry point.
public int CreatePDF(Stream stream)
{
var doc = new GcPdfDocument();
var g = page.Graphics;
g.DrawString("Shapes (SVG)",
new TextFormat() { Font = StandardFonts.TimesBold, FontSize = 14, Underline = true, },
new RectangleF(PointF.Empty, new SizeF(page.Size.Width, 44)),
TextAlignment.Center, ParagraphAlignment.Far);
// Pen used to draw shapes:

// Set up the helper layout grid:
var grid = new
{
Cols = 3,
Rows = 5,
MarginX = 72,
MarginY = 36,
StepX = (page.Size.Width - 144) / 3,
StepY = (page.Size.Height - 72) / 5,
};

// Insertion point of the next figure's center:
var startIp = new PointF(grid.MarginX + grid.StepX / 2, grid.MarginY + grid.StepY / 2 + 10);
var ip = startIp;
// Debug code to show the layout grid:
/*
var ipp = ip;
for (int i = 0; i < grid.Cols; ++i)
{
ipp.Y = ip.Y;
for (int j = 0; j < grid.Rows; ++j)
{
ipp.Y += grid.StepY;
}
ipp.X += grid.StepX;
}
*/

// Reusable SVG primitives:
var len0 = new SvgLength(0, SvgLengthUnits.Percentage);
var len10 = new SvgLength(10, SvgLengthUnits.Percentage);
var len20 = new SvgLength(20, SvgLengthUnits.Percentage);
var len30 = new SvgLength(30, SvgLengthUnits.Percentage);
var len40 = new SvgLength(40, SvgLengthUnits.Percentage);
var len50 = new SvgLength(50, SvgLengthUnits.Percentage);
var len60 = new SvgLength(60, SvgLengthUnits.Percentage);
var len70 = new SvgLength(70, SvgLengthUnits.Percentage);
var len80 = new SvgLength(80, SvgLengthUnits.Percentage);
var len90 = new SvgLength(90, SvgLengthUnits.Percentage);
var len100 = new SvgLength(100, SvgLengthUnits.Percentage);
var paintTrans = new SvgPaint(SvgColor.Transparent);
var pntStroke0 = new SvgPaint(new SvgColor(Color.Green));
var pntStroke0inv = new SvgPaint(new SvgColor(Color.FromArgb(100, Color.Green)));
var pntFill0 = new SvgPaint(new SvgColor(Color.FromArgb(100, Color.Orange)));
var pt0_0 = new SvgPoint(len0, len0);
var pt100_100 = new SvgPoint(len100, len100);

// Circle:
var svgDoc = new GcSvgDocument();
var svg = svgDoc.RootSvg;
{
CenterX = len50,
CenterY = len50,
Fill = paintTrans,
Stroke = pntStroke0,
});
ip.X += grid.StepX;

// Ellipse:
svg.Children.Clear();
{
CenterX = len50,
CenterY = len50,
Fill = paintTrans,
Stroke = pntStroke0,
});
ip.X += grid.StepX;

// Cylinder:
svg.Children.Clear();
float height = grid.Radius * 1.8f;
{
CenterX = len50,
CenterY = len10,
Fill = paintTrans,
Stroke = pntStroke0,
});
{
CenterX = len50,
CenterY = len90,
Fill = pntFill0,
Stroke = pntStroke0,
});
{
X1 = len0,
Y1 = len10,
X2 = len0,
Y2 = len90,
Stroke = pntStroke0,
});
{
X1 = len100,
Y1 = len10,
X2 = len100,
Y2 = len90,
Stroke = pntStroke0,
});
ip.X = startIp.X;
ip.Y += grid.StepY;

// Square:
DrawPolygon(g, ip, grid.Radius, 4, (float)-Math.PI / 4, pntStroke0, "Square");
ip.X += grid.StepX;

// Rectangle:
svg.Children.Clear();
{
X = new SvgLength(-20, SvgLengthUnits.Percentage),
Y = len20,
Width = new SvgLength(140, SvgLengthUnits.Percentage),
Height = len60,
Stroke = pntStroke0,
Fill = paintTrans,
});
ip.X += grid.StepX;

// Cube:
svg.Children.Clear();
{
X = len10,
Y = len10,
Width = len60,
Height = len60,
Stroke = pntStroke0,
Fill = paintTrans,
});
{
X = len30,
Y = len30,
Width = len60,
Height = len60,
Stroke = pntStroke0,
Fill = paintTrans,
});
{
X1 = len10,
Y1 = len10,
X2 = len30,
Y2 = len30,
Stroke = pntStroke0,
});
{
X1 = len10,
Y1 = len70,
X2 = len30,
Y2 = len90,
Stroke = pntStroke0,
});
{
X1 = len70,
Y1 = len10,
X2 = len90,
Y2 = len30,
Stroke = pntStroke0,
});
{
X1 = len70,
Y1 = len70,
X2 = len90,
Y2 = len90,
Stroke = pntStroke0,
});
ip.X = startIp.X;
ip.Y += grid.StepY;

// Pentagon:
DrawPolygon(g, ip, grid.Radius, 5, (float)-Math.PI / 2, pntStroke0, "Pentagon");
ip.X += grid.StepX;

// Hexagon:
// For sample sake, we apply a transform to make the hexagon wider and shorter:
g.Transform = Matrix3x2.CreateScale(1.4f, 0.8f) * Matrix3x2.CreateTranslation(ip.X, ip.Y);
DrawPolygon(g, PointF.Empty, grid.Radius, 6, 0, pntStroke0, null);
g.Transform = Matrix3x2.Identity;
ip.X += grid.StepX;

// Octagon:
DrawPolygon(g, ip, grid.Radius, 8, (float)-Math.PI / 8, pntStroke0, "Octagon");
ip.X = startIp.X;
ip.Y += grid.StepY;

// Triangle:
DrawPolygon(g, ip, grid.Radius, 3, (float)-Math.PI / 2, pntStroke0, "Triangle");
ip.X += grid.StepX;

// Filled pentagram:
var svgPts = DrawPolygon(g, ip, grid.Radius, 5, (float)-Math.PI / 2, pntStroke0, "Pentagram");
svg.Children.Clear();
{
Points = new List<SvgPoint>()
{
svgPts[0], svgPts[2], svgPts[4], svgPts[1], svgPts[3],
},
Stroke = pntStroke0,
Fill = pntFill0,
FillRule = SvgFillRule.EvenOdd,
});
ip.X += grid.StepX;

// Set up a simple kind of oblique projection to draw a pyramid:
var angle = Math.PI / 6;
float s = (float)Math.Sin(angle);
float c = (float)Math.Cos(angle);
Func<float, float, float, PointF> project = (x_, y_, z_) => new PointF(x_ - c * y_ * 0.5f, -(z_ - s * y_ * 0.5f));
Func<Vector3, PointF> p3d = v_ => project(v_.X, v_.Y, v_.Z);
float hedge = grid.Radius; // 1/2 edge
// Debug - draw the 3 axis:
/*
g.DrawLine(project(0, 0, 0), project(100, 0, 0), Color.Red);
g.DrawLine(project(0, 0, 0), project(0, 100, 0), Color.Green);
g.DrawLine(project(0, 0, 0), project(0, 0, 100), Color.Blue);
*/
// 3d points forming a square pyramid:
var pts3d = new Vector3[]
{
new Vector3(-hedge, -hedge, 0),
new Vector3(hedge, -hedge, 0),
new Vector3(hedge, hedge, 0),
new Vector3(-hedge, hedge, 0),
new Vector3(0, 0, hedge * 2),
};
// Project the points to draw the pyramid:
var pts = pts3d.Select(v_ => p3d(v_));
svgPts = pts.Select(p_ => new SvgPoint(new SvgLength(p_.X, SvgLengthUnits.Percentage), new SvgLength(p_.Y, SvgLengthUnits.Percentage))).ToArray();
g.Transform = Matrix3x2.CreateTranslation(0, hedge * 0.7f);
svg.Children.Clear();
// Visible edges:
{
Points = new List<SvgPoint>()
{
svgPts[4],
svgPts[1],
svgPts[2],
svgPts[3],
svgPts[4],
svgPts[2],
},
Stroke = pntStroke0,
Fill = paintTrans,
});
// Bottom:
{
Points = svgPts.Take(4).ToList(),
Fill = pntFill0,
});
// Invisible edges:
{
X1 = svgPts[0].X,
Y1 = svgPts[0].Y,
X2 = svgPts[4].X,
Y2 = svgPts[4].Y,
Stroke = pntStroke0inv,
});
{
X1 = svgPts[0].X,
Y1 = svgPts[0].Y,
X2 = svgPts[1].X,
Y2 = svgPts[1].Y,
Stroke = pntStroke0inv,
});
{
X1 = svgPts[0].X,
Y1 = svgPts[0].Y,
X2 = svgPts[3].X,
Y2 = svgPts[3].Y,
Stroke = pntStroke0inv,
});
g.Transform = Matrix3x2.Identity;
ip.X = startIp.X;
ip.Y += grid.StepY;

// Cone:
float baseh = grid.Radius * 0.3f;
svgPts = DrawPolygon(g, ip, grid.Radius, 3, (float)-Math.PI / 2, null, "Cone");
svg.Children.Clear();
{
Points = new List<SvgPoint>()
{
svgPts[2], svgPts[0], svgPts[1],
},
Stroke = pntStroke0,
Fill = paintTrans,
});
{
CenterX = new SvgLength(svgPts[0].X.Value, SvgLengthUnits.Percentage),
CenterY = svgPts[2].Y,
RadiusX = new SvgLength((svgPts[1].X.Value - svgPts[2].X.Value) / 2, SvgLengthUnits.Percentage),
Fill = pntFill0,
Stroke = pntStroke0,
});
ip.X += grid.StepX;

// Parallelogram (use graphics.Transform on a rectangle):
svg.Children.Clear();
var svgParal = new SvgRectElement()
{
X = new SvgLength(-20, SvgLengthUnits.Percentage),
Y = len20,
Width = new SvgLength(140, SvgLengthUnits.Percentage),
Height = len60,
Stroke = pntStroke0,
Fill = paintTrans,
};
g.Transform = Matrix3x2.CreateSkew((float)Math.PI / 6, 0) * Matrix3x2.CreateTranslation(ip.X, ip.Y);
g.Transform = Matrix3x2.Identity;
ip.X += grid.StepX;

// Trapezoid (use DrawPolygon to just get the points of the square):
svg.Children.Clear();
float dx = 10;
svgPts = DrawPolygon(g, ip, grid.Radius, 4, (float)-Math.PI / 4, null, "Trapezoid");
{
Points = new List<SvgPoint>()
{
new SvgPoint(new SvgLength(svgPts[0].X.Value - dx, SvgLengthUnits.Percentage), svgPts[0].Y),
new SvgPoint(new SvgLength(svgPts[1].X.Value + dx, SvgLengthUnits.Percentage), svgPts[1].Y),
new SvgPoint(new SvgLength(svgPts[2].X.Value - dx, SvgLengthUnits.Percentage), svgPts[2].Y),
new SvgPoint(new SvgLength(svgPts[3].X.Value + dx, SvgLengthUnits.Percentage), svgPts[3].Y),
},
Stroke = pntStroke0,
Fill = paintTrans,
});