aboutsummaryrefslogtreecommitdiffstats
path: root/Software/Visual_Studio/Tango.RemoteDesktop/Comparers/VectorBitmapComparer.cs
blob: 2500e8ac7cebfc4e582c459dbdde810c324f7cf7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Imaging;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Media.Imaging;
using Tango.RemoteDesktop.Frames;

namespace Tango.RemoteDesktop.Comparers
{
    /// <summary>
    /// Represents a vector <see cref="IBitmapComparer{TFrame}"/> comparer which will compare and return a <see cref="VectorFrame"/> difference.
    /// </summary>
    /// <seealso cref="Tango.RemoteDesktop.IBitmapComparer{Tango.RemoteDesktop.Frames.VectorFrame}" />
    public class VectorBitmapComparer : IBitmapComparer<VectorFrame>
    {
        /// <summary>
        /// Creates the difference as <see cref="VectorFrame"/>.
        /// </summary>
        /// <param name="previousBitmap">The previous bitmap.</param>
        /// <param name="currentBitmap">The current bitmap.</param>
        /// <returns></returns>
        /// <exception cref="InvalidOperationException">
        /// Cannot compare image. They are the same instance
        /// or
        /// Cannot compare image of different size.
        /// </exception>
        public unsafe BitmapComparerResult<VectorFrame> CreateDifference(Bitmap previousBitmap, Bitmap currentBitmap)
        {
            VectorFrame vector = new VectorFrame(previousBitmap.Width, previousBitmap.Height);

            bool hasDifference = false;

            if (previousBitmap == null | currentBitmap == null)
                throw new InvalidOperationException("Cannot compare image. They are the same instance");

            if (previousBitmap.Height != currentBitmap.Height || previousBitmap.Width != currentBitmap.Width)
                throw new InvalidOperationException("Cannot compare image of different size.");

            int height = previousBitmap.Height;
            int width = previousBitmap.Width;

            BitmapData data1 = previousBitmap.LockBits(new Rectangle(0, 0, width, height),
                                               ImageLockMode.ReadOnly, PixelFormat.Format32bppArgb);
            BitmapData data2 = currentBitmap.LockBits(new Rectangle(0, 0, width, height),
                                               ImageLockMode.ReadOnly, PixelFormat.Format32bppArgb);
            byte* data1Ptr = (byte*)data1.Scan0;
            byte* data2Ptr = (byte*)data2.Scan0;

            int rowPadding = data1.Stride - (previousBitmap.Width * 4);

            // iterate over height (rows)
            for (int i = 0; i < height; i++)
            {
                // iterate over width (columns)
                for (int j = 0; j < width; j++)
                {
                    int same = 0;

                    byte[] tmp = new byte[4];

                    // compare pixels and copy new values into temporary array
                    for (int x = 0; x < 4; x++)
                    {
                        tmp[x] = data2Ptr[0];
                        if (data1Ptr[0] == data2Ptr[0])
                        {
                            same++;
                        }
                        data1Ptr++; // advance image1 ptr
                        data2Ptr++; // advance image2 ptr
                    }

                    if (same != 4)
                    {
                        int colorIndex = vector.Colors.Count;

                        VectorFrameColor color = new VectorFrameColor()
                        {
                            B = tmp[0],
                            G = tmp[1],
                            R = tmp[2],
                            Index = colorIndex
                        };

                        VectorFrameColor existingColor;

                        if (vector.Colors.TryGetValue(color.ToInt32(), out existingColor))
                        {
                            colorIndex = existingColor.Index;
                        }
                        else
                        {
                            vector.Colors.Add(color.ToInt32(), color);
                        }

                        vector.Pixels.Add(new VectorFramePixel()
                        {
                            X = j,
                            Y = i,
                            ColorIndex = colorIndex,
                            Color = color
                        });

                        hasDifference = true;
                    }
                }

                // at the end of each column, skip extra padding
                if (rowPadding > 0)
                {
                    data1Ptr += rowPadding;
                    data2Ptr += rowPadding;
                }
            }

            previousBitmap.UnlockBits(data1);
            currentBitmap.UnlockBits(data2);

            return new BitmapComparerResult<VectorFrame>()
            {
                Frame = vector,
                ContainsDifference = hasDifference
            };
        }
    }
}