using System;
using System.Drawing;
using System.Drawing.Imaging;

namespace AForge.Imaging;

public class IntegralImage
{
	protected uint[,] integralImage;

	private int width;

	private int height;

	public int Width => width;

	public int Height => height;

	public uint[,] InternalData => integralImage;

	protected IntegralImage(int width, int height)
	{
		this.width = width;
		this.height = height;
		integralImage = new uint[height + 1, width + 1];
	}

	public static IntegralImage FromBitmap(Bitmap image)
	{
		//IL_0001: Unknown result type (might be due to invalid IL or missing references)
		//IL_000b: Invalid comparison between Unknown and I4
		if ((int)((Image)image).PixelFormat != 198659)
		{
			throw new UnsupportedImageFormatException("Source image can be graysclae (8 bpp indexed) image only.");
		}
		BitmapData val = image.LockBits(new Rectangle(0, 0, ((Image)image).Width, ((Image)image).Height), (ImageLockMode)1, (PixelFormat)198659);
		IntegralImage result = FromBitmap(val);
		image.UnlockBits(val);
		return result;
	}

	public static IntegralImage FromBitmap(BitmapData imageData)
	{
		return FromBitmap(new UnmanagedImage(imageData));
	}

	public unsafe static IntegralImage FromBitmap(UnmanagedImage image)
	{
		//IL_0001: Unknown result type (might be due to invalid IL or missing references)
		//IL_000b: Invalid comparison between Unknown and I4
		if ((int)image.PixelFormat != 198659)
		{
			throw new ArgumentException("Source image can be graysclae (8 bpp indexed) image only.");
		}
		int num = image.Width;
		int num2 = image.Height;
		int num3 = image.Stride - num;
		IntegralImage integralImage = new IntegralImage(num, num2);
		uint[,] array = integralImage.integralImage;
		byte* ptr = (byte*)image.ImageData.ToPointer();
		for (int i = 1; i <= num2; i++)
		{
			uint num4 = 0u;
			int num5 = 1;
			while (num5 <= num)
			{
				num4 += *ptr;
				array[i, num5] = num4 + array[i - 1, num5];
				num5++;
				ptr++;
			}
			ptr += num3;
		}
		return integralImage;
	}

	public uint GetRectangleSum(int x1, int y1, int x2, int y2)
	{
		if (x2 < 0 || y2 < 0 || x1 >= width || y1 >= height)
		{
			return 0u;
		}
		if (x1 < 0)
		{
			x1 = 0;
		}
		if (y1 < 0)
		{
			y1 = 0;
		}
		x2++;
		y2++;
		if (x2 > width)
		{
			x2 = width;
		}
		if (y2 > height)
		{
			y2 = height;
		}
		return integralImage[y2, x2] + integralImage[y1, x1] - integralImage[y2, x1] - integralImage[y1, x2];
	}

	public int GetHaarXWavelet(int x, int y, int radius)
	{
		int y2 = y - radius;
		int y3 = y + radius - 1;
		uint rectangleSum = GetRectangleSum(x, y2, x + radius - 1, y3);
		uint rectangleSum2 = GetRectangleSum(x - radius, y2, x - 1, y3);
		return (int)(rectangleSum - rectangleSum2);
	}

	public int GetHaarYWavelet(int x, int y, int radius)
	{
		int x2 = x - radius;
		int x3 = x + radius - 1;
		float num = GetRectangleSum(x2, y, x3, y + radius - 1);
		float num2 = GetRectangleSum(x2, y - radius, x3, y - 1);
		return (int)(num - num2);
	}

	public uint GetRectangleSumUnsafe(int x1, int y1, int x2, int y2)
	{
		x2++;
		y2++;
		return integralImage[y2, x2] + integralImage[y1, x1] - integralImage[y2, x1] - integralImage[y1, x2];
	}

	public uint GetRectangleSum(int x, int y, int radius)
	{
		return GetRectangleSum(x - radius, y - radius, x + radius, y + radius);
	}

	public uint GetRectangleSumUnsafe(int x, int y, int radius)
	{
		return GetRectangleSumUnsafe(x - radius, y - radius, x + radius, y + radius);
	}

	public float GetRectangleMean(int x1, int y1, int x2, int y2)
	{
		if (x2 < 0 || y2 < 0 || x1 >= width || y1 >= height)
		{
			return 0f;
		}
		if (x1 < 0)
		{
			x1 = 0;
		}
		if (y1 < 0)
		{
			y1 = 0;
		}
		x2++;
		y2++;
		if (x2 > width)
		{
			x2 = width;
		}
		if (y2 > height)
		{
			y2 = height;
		}
		return (float)((double)(integralImage[y2, x2] + integralImage[y1, x1] - integralImage[y2, x1] - integralImage[y1, x2]) / (double)((x2 - x1) * (y2 - y1)));
	}

	public float GetRectangleMeanUnsafe(int x1, int y1, int x2, int y2)
	{
		x2++;
		y2++;
		return (float)((double)(integralImage[y2, x2] + integralImage[y1, x1] - integralImage[y2, x1] - integralImage[y1, x2]) / (double)((x2 - x1) * (y2 - y1)));
	}

	public float GetRectangleMean(int x, int y, int radius)
	{
		return GetRectangleMean(x - radius, y - radius, x + radius, y + radius);
	}

	public float GetRectangleMeanUnsafe(int x, int y, int radius)
	{
		return GetRectangleMeanUnsafe(x - radius, y - radius, x + radius, y + radius);
	}
}