﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using Emgu.CV;
using Emgu.CV.Structure;
using System.Runtime.InteropServices;

namespace Emgu.CV.WPF
{
    /// <summary>
    /// Interaction logic for Window1.xaml
    /// </summary>
    public partial class Window1 : Window
    {
        public Window1()
        {
            InitializeComponent();
        }

        private void image1_Initialized(object sender, EventArgs e)
        {
            Image<Bgr, Byte> image = new Image<Bgr, byte>(400, 100, new Bgr(255, 255, 255));
            MCvFont f = new MCvFont(Emgu.CV.CvEnum.FONT.CV_FONT_HERSHEY_PLAIN, 3.0, 3.0);
            image.Draw("Hello, world", ref f, new System.Drawing.Point(10, 50), new Bgr(255.0, 0.0, 0.0));

            image1.Source = ToBitmapSource(image);
        }

        /// <summary>
        /// Delete a GDI object
        /// </summary>
        /// <param name="o">The poniter to the GDI object to be deleted</param>
        /// <returns></returns>
        [DllImport("gdi32")]
        private static extern int DeleteObject(IntPtr o);

        /// <summary>
        /// Convert an IImage to a WPF BitmapSource. The result can be used in the Set Property of Image.Source
        /// </summary>
        /// <param name="image">The Emgu CV Image</param>
        /// <returns>The equivalent BitmapSource</returns>
        public static BitmapSource ToBitmapSource(IImage image)
        {
            using (System.Drawing.Bitmap source = image.Bitmap)
            {
                IntPtr ptr = source.GetHbitmap(); //obtain the Hbitmap
                
                BitmapSource bs = System.Windows.Interop.Imaging.CreateBitmapSourceFromHBitmap(
                    ptr, 
                    IntPtr.Zero, 
                    Int32Rect.Empty,
                    System.Windows.Media.Imaging.BitmapSizeOptions.FromEmptyOptions());

                DeleteObject(ptr); //release the HBitmap
                return bs;
            }
        }
    }
}
