Get consecutive scanlines in a Bitmap using foreach

BitmapScanlineEnumerable.cs

using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Imaging;

class BitmapScanlineEnumerable : IEnumerable<IntPtr>
{
    BitmapData bmd;

    public bool VerticalFlip { get; set; }

    public BitmapScanlineEnumerable(BitmapData bmd, bool verticalFlip)
    {
        this.bmd = bmd;
        VerticalFlip = verticalFlip;
    }

    public IEnumerator<IntPtr> GetEnumerator()
    {
        IntPtr scan = bmd.Scan0;
        if (VerticalFlip) scan += (bmd.Height - 1) * bmd.Stride;

        for (int i = 0; i < bmd.Height; ++i)
        {
            yield return scan;
            if (!VerticalFlip) scan += bmd.Stride;
            else scan -= bmd.Stride;
        }
    }

    System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
    {
        return GetEnumerator();
    }
}

Why? Because trying to calculate scanline addresses inside of loops is annoying, plus what if your source image has scanlines that run from top to bottom instead of bottom to top? Using this code, just focus on getting each row of pixels copied.

Sample usage:

static Bitmap GetBitmapFromRawArgb8888(byte[] data, int width, int height, bool vertFlip)
{
    Bitmap bmp = new Bitmap(width, height, PixelFormat.Format32bppArgb);
    BitmapData lockedBits = bmp.LockBits(new Rectangle(Point.Empty, bmp.Size), ImageLockMode.WriteOnly, PixelFormat.Format32bppArgb);
    unsafe
    {
        int dataIndex = 0;
        foreach (IntPtr scan in new BitmapScanlineEnumerable(lockedBits, vertFlip))
        {
            for (int i = 0; i < width * 4; ++i)
            {
                ((byte*)scan)[i] = data[dataIndex++];
            }
        }
    }
    bmp.UnlockBits(lockedBits);
    return bmp;
}