// A basic frame comparision for new object location finder for webcam vision
//
// Cem Aykan
// www.acddv.com
// cemaykan@acddv.com

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Drawing.Imaging;
using System.Text;



namespace GeminiImageTester
{
    //This FindLocation method will compare two BMP's frame0, frame1 to see if frame1 has a new
    //object in it. If it finds a object it will return the location of the new object. Values
    //it can return for the location of the object is on the x axis and are:
    //  -"None"     if the two frames are identical
    //  -"Right"    if object is on the right side
    //  -"Left"     if object is on the left side
    //  -"Middle"   if object is on the middle of the frame
    class GeminiBotObjectFinder
    {
        private int slice1 = 0;
        private int slice2 = 0;
        private int slice3 = 0;

        public string FindLocation(object sender, Bitmap BMPFrame0, Bitmap BMPFrame1)
        {
            BitmapData f0data = BMPFrame0.LockBits(new Rectangle(0, 0, BMPFrame0.Width, BMPFrame0.Height), ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb);
            BitmapData f1data = BMPFrame1.LockBits(new Rectangle(0, 0, BMPFrame1.Width, BMPFrame1.Height), ImageLockMode.ReadWrite, PixelFormat.Format24bppRgb);

            int stridef0 = f0data.Stride;
            System.IntPtr Scan0f0 = f0data.Scan0;

            int stridef1 = f1data.Stride;
            System.IntPtr Scan0f1 = f1data.Scan0;

            unsafe
            {
                byte* p0 = (byte*)(void*)Scan0f0;
                byte* p1 = (byte*)(void*)Scan0f1;

                for (int i = 0; i < f0data.Height; i++)
                {
                    for (int j = 0; j < f0data.Width * 3; j++)
                    {
                        if ((p0[0] - p1[0]) < (byte)(100))
                        {
                            /* Do nothing for now */
                        }
                        else
                        {                           
                            //Calculation of which slice the image is located on
                            if (j < f0data.Width)
                                this.slice1++;
                            else if ((j < f0data.Width * 2) & (j > f0data.Width))
                                this.slice2++;
                            else if ((j < f0data.Width * 3) & (j > f0data.Width * 2))
                                this.slice3++;
                        }

                        p0++;
                        p1++;
                    }
                    p0 += stridef0 - f0data.Width * 3;
                    p1 += stridef1 - f1data.Width * 3;
                }
            }
            BMPFrame0.UnlockBits(f0data);
            BMPFrame1.UnlockBits(f1data);

            return DecideLocation();
        }

        private string DecideLocation()
        {
            string result = "None";

            if ((this.slice1 == this.slice2) & (this.slice2 == this.slice3))
                result = "None";
            else if ((this.slice1 >= this.slice2) & (this.slice1 >= this.slice3))
                result = "Left";
            else if ((this.slice2 >= this.slice1) & (this.slice2 >= this.slice3))
                result = "Middle";
            else if ((this.slice3 >= this.slice1) & (this.slice3 >= this.slice2))
                result = "Right";

            return result;
        }
    }
}