SvgGraphicsArch.cs
//
// This code is part of GrapeCity Documents for Imaging samples.
// Copyright (c) GrapeCity, Inc. All rights reserved.
//
using System;
using System.IO;
using System.Drawing;
using System.Collections.Generic;
using System.Linq;
using System.Numerics;
using GrapeCity.Documents.Drawing;
using GrapeCity.Documents.Text;
using GrapeCity.Documents.Imaging;
using GrapeCity.Documents.Svg;
using GcImagingWeb.Samples.Common;

namespace GcImagingWeb.Samples
{
    // This example shows how to render an arch on GcSvgGraphics
    // using graphics paths. The arch is positioned in the center
    // of the resultant image using graphics transformation matrix.
    public class SvgGraphicsArch
    {
        public string DefaultMime { get => Common.Util.MimeTypes.SVG; }

        public Stream GenerateImageStream(string targetMime, Size pixelSize, float dpi, bool opaque, string[] sampleParams = null)
        {
            if (targetMime != Common.Util.MimeTypes.SVG)
                throw new Exception("This sample only supports SVG output format.");

            Color background = Color.PaleGoldenrod,
                line = Color.FromArgb(11, 83, 69),
                arc = Color.FromArgb(22, 160, 133),
                fill = Color.FromArgb(255, 171, 145),
                marks = Color.DarkGray,
                text = Color.Black,
                textBack = Color.Cornsilk;

            var Inch = dpi;
            var ms = new MemoryStream();
            using var g = new GcSvgGraphics(pixelSize.Width, pixelSize.Height);
            if (opaque)
                g.FillRectangle(new RectangleF(0, 0, g.Width, g.Height), background);

            // Arc bounding rectangle:
            var rc = new RectangleF(0, 0, Inch * 4, Inch * 4.8f);

            // Use transform to center all drawing:
            var t = g.Transform;
            g.Transform = Matrix3x2.CreateTranslation(g.Width / 2 - rc.Width / 2, g.Height / 2 - rc.Height / 2);

            // Draw the arc:
            DrawArch(g, rc, rc.Height * 0.3f, rc.Width * 0.08f, line, arc, fill);

            // Add a label:
            var tf = new TextFormat()
            {
                Font = Font.FromFile(Path.Combine("Resources", "Fonts", "times.ttf")),
                FontSize = Inch / 6,
                ForeColor = text,
            };
            g.DrawString("ARCH", tf, rc, TextAlignment.Center, ParagraphAlignment.Center, false);

            // Measurement lines:
            var w = Inch / 8;
            var pen = new Pen(marks);

            var txt = $"{(rc.Width / Inch):F}\"";
            var s = g.MeasureString(txt, tf);
            var d = s.Height * 1.5f;
            g.DrawLine(rc.Left, rc.Top - d, rc.Right, rc.Top - d, pen);
            g.DrawLine(rc.Left, rc.Top - d, rc.Left + w, rc.Top - d - w, pen);
            g.DrawLine(rc.Left, rc.Top - d, rc.Left + w, rc.Top - d + w, pen);
            g.DrawLine(rc.Right, rc.Top - d, rc.Right - w, rc.Top - d - w, pen);
            g.DrawLine(rc.Right, rc.Top - d, rc.Right - w, rc.Top - d + w, pen);

            var rcTxt = new RectangleF(rc.Left + rc.Width / 2 - s.Width / 2, rc.Top - d - s.Height / 2, s.Width, s.Height);
            rcTxt.Inflate(2, 2);
            g.FillRectangle(rcTxt, textBack);
            g.DrawString(txt, tf, rcTxt, TextAlignment.Center, ParagraphAlignment.Center, false);

            txt = $"{(rc.Height / Inch):F}\"";
            s = g.MeasureString(txt, tf);
            d = s.Width;
            g.DrawLine(rc.Left - d, rc.Top, rc.Left - d, rc.Bottom, pen);
            g.DrawLine(rc.Left - d, rc.Top, rc.Left - d - w, rc.Top + w, pen);
            g.DrawLine(rc.Left - d, rc.Top, rc.Left - d + w, rc.Top + w, pen);
            g.DrawLine(rc.Left - d, rc.Bottom, rc.Left - d - w, rc.Bottom - w, pen);
            g.DrawLine(rc.Left - d, rc.Bottom, rc.Left - d + w, rc.Bottom - w, pen);
            rcTxt = new RectangleF(rc.Left - d - s.Width / 2, rc.Top + rc.Height / 2 - s.Height / 2, s.Width, s.Height);
            rcTxt.Inflate(2, 2);
            g.FillRectangle(rcTxt, textBack);
            g.DrawString(txt, tf, rcTxt, TextAlignment.Center, ParagraphAlignment.Center, false);

            // Restore transform:
            g.Transform = t;

            // Done:
            var svg = g.ToSvgDocument();
            svg.Save(ms);
            ms.Seek(0, SeekOrigin.Begin);
            return ms;
        }

        private void DrawArch(GcGraphics g, RectangleF rc, float harc, float wd, Color line, Color arch, Color fill)
        {
            var path = g.CreatePath();
            // Insides filler (start from bottom left, to clockwise):
            path.BeginFigure(rc.Left + wd, rc.Bottom - wd);
            path.AddLine(rc.Left + wd, rc.Top + harc);
            path.AddArc(new ArcSegment()
            {
                ArcSize = ArcSize.Small,
                Point = new PointF(rc.Right - wd, rc.Top + harc),
                RotationAngle = 0,
                Size = new SizeF(rc.Width / 2f - wd, harc - wd),
                SweepDirection = SweepDirection.Clockwise
            });
            path.AddLine(rc.Right - wd, rc.Bottom - wd);
            path.EndFigure(FigureEnd.Closed);
            g.FillPath(path, fill);
            path.Dispose();

            // Arc outlines (start from bottom left, to clockwise):
            path = g.CreatePath();
            path.BeginFigure(rc.Left, rc.Bottom);
            path.AddLine(rc.Left, rc.Top + harc);
            path.AddLine(rc.Left + wd, rc.Top + harc);
            path.AddLine(rc.Left + wd, rc.Bottom - wd);
            path.EndFigure(FigureEnd.Closed);
            path.BeginFigure(rc.Left, rc.Top + harc);
            path.AddArc(new ArcSegment()
            {
                ArcSize = ArcSize.Small,
                Point = new PointF(rc.Right, rc.Top + harc),
                RotationAngle = 0,
                Size = new SizeF(rc.Width / 2f, harc),
                SweepDirection = SweepDirection.Clockwise
            });
            path.AddLine(rc.Right - wd, rc.Top + harc);
            path.AddArc(new ArcSegment()
            {
                ArcSize = ArcSize.Small,
                Point = new PointF(rc.Left + wd, rc.Top + harc),
                RotationAngle = 0,
                Size = new SizeF(rc.Width / 2f - wd, harc - wd),
                SweepDirection = SweepDirection.CounterClockwise
            });
            path.EndFigure(FigureEnd.Closed);
            path.BeginFigure(rc.Right, rc.Top + harc);
            path.AddLine(rc.Right, rc.Bottom);
            path.AddLine(rc.Right - wd, rc.Bottom - wd);
            path.AddLine(rc.Right - wd, rc.Top + harc);
            path.EndFigure(FigureEnd.Closed);
            path.BeginFigure(rc.Right, rc.Bottom);
            path.AddLine(rc.Left, rc.Bottom);
            path.AddLine(rc.Left + wd, rc.Bottom - wd);
            path.AddLine(rc.Right - wd, rc.Bottom - wd);
            path.EndFigure(FigureEnd.Closed);

            g.FillPath(path, arch);
            g.DrawPath(path, new Pen(line, 2));

            path.Dispose();
        }
    }
}