/// <summary>
/// Iterate over an area of the bitmap, calling the specified function for each pixel. Function must be defined as
/// void Func(int x, int y, byte a, byte r, byte g, byte b, int index, IterationResult itres)
/// </summary>
public static void IterateOver(this Bitmap bmp, Rectangle rect, Action <int, int, byte, byte, byte, byte, int, IterationResult> p)
{
// Lock the bitmap's bits.
var bmprect = new Rectangle(0, 0, bmp.Width, bmp.Height);
rect = Rectangle.Intersect(rect, bmprect);
BitmapData bmpData = bmp.LockBits(rect, ImageLockMode.ReadWrite, PixelFormat.Format32bppArgb);
// Get the address of the first line.
IntPtr ptr = bmpData.Scan0;
// Declare an array to hold the bytes of the bitmap.
int bytes = bmpData.Stride * rect.Height;
//if (_rgbValues == null || _rgbValues.Length < bytes) {
// _rgbValues = new byte[bytes];
//}
byte[] rgbValues = new byte[bytes];
// Copy the RGB values into the array.
Marshal.Copy(ptr, rgbValues, 0, bytes);
//int count = 0;
int stride = bmpData.Stride;
bool changedSomething = false;
var itres = new IterationResult();
rect = Rectangle.Intersect(rect, bmprect);
int i = 0;
for (int y = 0; y < rect.Height; y++)
{
for (int x = 0; x < rect.Width; x++)
{
byte b = rgbValues[(y * stride) + (x * 4)];
byte g = rgbValues[(y * stride) + (x * 4) + 1];
byte r = rgbValues[(y * stride) + (x * 4) + 2];
byte a = rgbValues[(y * stride) + (x * 4) + 3];
p(x + rect.Left, y + rect.Top, a, r, g, b, i++, itres.Reset());
if (itres.Color != null)
{
changedSomething = true;
var color = itres.Color.Value;
rgbValues[(y * stride) + (x * 4)] = color.B;
rgbValues[(y * stride) + (x * 4) + 1] = color.G;
rgbValues[(y * stride) + (x * 4) + 2] = color.R;
rgbValues[(y * stride) + (x * 4) + 3] = color.A;
}
if (itres.Abort)
{
break;
}
}
if (itres.Abort)
{
break;
}
}
if (changedSomething)
{
Marshal.Copy(rgbValues, 0, ptr, bytes);
}
bmp.UnlockBits(bmpData);
}
