//// This code is part of Document Solutions for Imaging demos.// Copyright (c) MESCIUS inc. All rights reserved.//using System;using System.IO;using System.Drawing;using System.Collections.Generic;using System.Linq;using GrapeCity.Documents.Text;using GrapeCity.Documents.Imaging;using GrapeCity.Documents.Svg;using GCTEXT = GrapeCity.Documents.Text;using DsImagingWeb.Demos.Common;
namespace DsImagingWeb.Demos{    // This sample is similar to SvgClipArt, but after loading each SVG image    // it converts all strokes and fills in it to grayscale.    //    // The SVG clip art used in this sample is from freesvg.org.    public class SvgToGrayscale    {        void ToGrayscale(SvgElementCollection elements)        {            foreach (var el in elements)            {                if (el is SvgGraphicsElement elg)                {                    elg.Stroke = PaintToGrayscale(elg.Stroke);                    elg.Fill = PaintToGrayscale(elg.Fill);                }                ToGrayscale(el.Children);            }        }
        // Simplified conversion of an SvgPaint to grayscale        // (Y formula from https://goodcalculators.com/rgb-to-grayscale-conversion-calculator/):        SvgPaint PaintToGrayscale(SvgPaint src)        {            if (src == null)                return null;            else if (src.PaintType == SvgPaintType.Color)            {                var rgb = src.Color.Rgb;                var Y = (int)Math.Round(0.299 * rgb.R + 0.587 * rgb.G + 0.114 * rgb.B);                return new SvgPaint(Color.FromArgb(Y, Y, Y));            }            else            {                return new SvgPaint(Color.Gray);            }        }
        // Main entry point.        public GcBitmap GenerateImage(Size pixelSize, float dpi, bool opaque, string[] sampleParams = null)        {            const int rows = 4;            const int cols = 4;            float margin = dpi / 2;            float sMargin = margin / 4;
            // Load images from the resources folder:            var fnames = new List<string>(Directory.GetFiles(Path.Combine("Resources", "SvgClipArt"), "*", SearchOption.AllDirectories));            fnames.Shuffle();            var images = new List<(string, GcSvgDocument)>();            foreach (var fname in fnames.Take(rows * cols))            {                var svg = GcSvgDocument.FromFile(fname);                ToGrayscale(svg.RootSvg.Children);                images.Add((Path.GetFileName(fname), svg));            }
            // Font and format for captions:            var font = GCTEXT.Font.FromFile(Path.Combine("Resources", "Fonts", "FreeSans.ttf"));            var tf = new TextFormat() { Font = font, FontSize = sMargin * 0.65f };
            // Set up a 4x4 layout grid:            float gapx = margin / 4, gapy = gapx;            float sWidth = (pixelSize.Width - margin * 2 + gapx) / cols;            float sHeight = (pixelSize.Height - margin * 2 + gapy) / rows;            if (sWidth > sHeight)            {                gapx += sWidth - sHeight;                sWidth = sHeight;            }            else            {                gapy += sHeight - sWidth;                sHeight = sWidth;            }            var ip = new PointF(margin, margin);
            // Resulting bitmap:            var bmp = new GcBitmap(pixelSize.Width, pixelSize.Height, opaque, dpi, dpi);            // Render all images within the grid, adding new pages as needed:            using var g = bmp.CreateGraphics(Color.White);            for (int i = 0; i < images.Count(); ++i)            {                // Draw border around image:                var rect = new RectangleF(ip, new SizeF(sWidth - gapx, sHeight - gapy));                g.FillRectangle(rect, Color.LightGray);                g.DrawRectangle(rect, Color.Black, 0.5f);                rect.Inflate(-sMargin, -sMargin);
                // Draw the SVG:                var svg = images[i].Item2;                var s = svg.GetIntrinsicSize(SvgLengthUnits.Points);                if (s.Width > 0 && s.Height > 0)                {                    // If image proportions are different from our target rectangle,                    // we resize the rectangle centering the image in it:                    var qSrc = s.Width / s.Height;                    var qTgt = rect.Width / rect.Height;                    if (qSrc < qTgt)                        rect.Inflate(rect.Width * (qSrc / qTgt - 1) / 2, 0);                    else if (qSrc > qTgt)                        rect.Inflate(0, rect.Height * (qTgt / qSrc - 1) / 2);                }                // Render the SVG:                g.DrawSvg(svg, rect);
                // Print image file name as caption in the bottom slide margin:                g.DrawString(Path.GetFileName(images[i].Item1), tf,                    new RectangleF(rect.X, rect.Bottom, rect.Width, sMargin),                    TextAlignment.Center, ParagraphAlignment.Near, false);                ip.X += sWidth;                if (ip.X + sWidth > pixelSize.Width && i < images.Count() - 1)                {                    ip.X = margin;                    ip.Y += sHeight;                }            }            // Dispose images after saving the result:            images.ForEach(t_ => t_.Item2.Dispose());            // Done:            return bmp;        }    }}