//// 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 GrapeCity.Documents.Drawing;using GrapeCity.Documents.Text;using GrapeCity.Documents.Imaging;using GCTEXT = GrapeCity.Documents.Text;
namespace DsImagingWeb.Demos{    // This sample demonstrates how to resize (downscale) an existing image    // to create a thumbnail, using different interpolation modes.    public class DownscaleImage    {        public GcBitmap GenerateImage(Size pixelSize, float dpi, bool opaque, string[] sampleParams = null)        {            var origImagePath = Path.Combine("Resources", "Images", "minerva.jpg");            // Create and fill the target bitmap:            var targetBmp = new GcBitmap(pixelSize.Width, pixelSize.Height, true, dpi, dpi);            using (var g = targetBmp.CreateGraphics(Color.FromArgb(unchecked((int)0xff004d99))))            {                // creating a graphics with a fill color does what we need            }            const int fontSize = 16, fpad = 4, xpad = 10, ypad = 3;            TextFormat tf = new TextFormat            {                ForeColor = Color.FromArgb(unchecked((int)0xffffcc00)),                Font = GCTEXT.Font.FromFile(Path.Combine("Resources", "Fonts", "FreeSerif.ttf")),                FontSize = fontSize,            };            using (var origBmp = new GcBitmap())            {                using (var stm = new FileStream(origImagePath, FileMode.Open, FileAccess.Read, FileShare.Read, 4096, FileOptions.RandomAccess))                    origBmp.Load(stm);
                // Bitwise copy the original image with the original size:                targetBmp.BitBlt(origBmp, 0, 0);                using (var g = targetBmp.CreateGraphics(null))                    g.DrawString($"Original image ({origBmp.Width} by {origBmp.Height} pixels)", tf, new PointF(fpad, origBmp.Height + fpad));                int dx = (int)origBmp.Width + xpad;
                // Scale down the image using the various interpolation modes,                // and render those on the right of the original:                float f = (origBmp.Height - ypad * 3) / origBmp.Height / 4;                int twidth = (int)Math.Round(origBmp.Width * f);                int theight = (int)Math.Round(origBmp.Height * f);
                using (var bmp = origBmp.Resize(twidth, theight, InterpolationMode.NearestNeighbor))                    targetBmp.BitBlt(bmp, dx, 0);                drawCaption("InterpolationMode.NearestNeighbor", dx, 0);
                using (var bmp = origBmp.Resize(twidth, theight, InterpolationMode.Linear))                    targetBmp.BitBlt(bmp, dx, theight + ypad);                drawCaption("InterpolationMode.Linear", dx, theight + ypad);
                using (var bmp = origBmp.Resize(twidth, theight, InterpolationMode.Cubic))                    targetBmp.BitBlt(bmp, dx, (theight + ypad) * 2);                drawCaption("InterpolationMode.Cubic", dx, (theight + ypad) * 2);
                using (var bmp = origBmp.Resize(twidth, theight, InterpolationMode.Downscale))                    targetBmp.BitBlt(bmp, dx, (theight + ypad) * 3);                drawCaption("InterpolationMode.Downscale", dx, (theight + ypad) * 3);                //                void drawCaption(string caption, float x, float y)                {                    using (var g = targetBmp.CreateGraphics(null))                        g.DrawString(caption, tf, new PointF(x + twidth + fpad, y + fpad));                }            }            return targetBmp;        }    }}