Question

This question is related to: How to convert Bitmap to byte[,,] faster?
I have byte[] which has:
[r0, g0, b0, r1, g1, b1 … ]
(r0 is the r-value of zeroth pixel and so on)
How can I copy this quickly into byte[,,]?
Or maybe I can get byte[,,] ditectly from BitmapData?

Answer 1

Based on Martinho’s answer but perhaps a bit faster(don’t have time for benchmarking now):

struct BitmapDataAccessor
{
    private readonly byte[] data;
    private readonly int[] rowStarts;
    public readonly int Height;
    public readonly int Width;

    public BitmapDataAccessor(byte[] data, int width, int height)
    {
        this.data = data;
        this.Height = height;
        this.Width = width;
        rowStarts = new int[height];
        for(int y=0;y<height;y++)
          rowStarts[y]=y*width;
    }

    public byte this[int x, int y, int color] // Maybe use an enum with Red = 0, Green = 1, and Blue = 2 members?
    {
        get { return data[(rowStarts[y] + x) *3 + color]; }
        set { data[(rowStarts[y] + x) *3 + color] = value; }
    }

    public byte[] Data
    {
        get { return data; }
    }
}