OpenGl BindBuffer to array

Question

I have this code snippet from OpenTK using Open GL, which is used to draw texture on screen and works completely fine;

GL.BindBuffer(BufferTarget.PixelUnpackBuffer, glOutputBufferID);
GL.BindTexture(TextureTarget.Texture2D, glOutputTexID);
GL.TexSubImage2D(TextureTarget.Texture2D, 0, 0, 0, xRes, yRes,
    PixelFormat.Rgba, PixelType.UnsignedByte, IntPtr.Zero);
GL.BindTexture(TextureTarget.Texture2D, 0);
GL.BindBuffer(BufferTarget.PixelUnpackBuffer, 0); 

But what I want to do, is not to map output data to some texture, but to store it inside array; As I see from kernel code, data comes as uint.

How should I modify this code, so that I could get pixel data as uint[] _array?

Answer 1

I have managed to get it working:

GL.BindBuffer(BufferTarget.PixelUnpackBuffer, bufferID);
Color color = Color.Black;
unsafe
{ 
 byte* basePtr =   (byte*)GL.MapBuffer(BufferTarget.PixelUnpackBuffer,    BufferAccess.ReadOnly);
            byte* pixPtr = basePtr;
            for(int y = 0; y < yRes; y++)
            {
                int flipY = yRes-1-y;  //used to vertically flip the output
                for(int x = 0; x < xRes; x++)
                {
                    result[flipY,x] = Color.FromArgb((int)pixPtr[3], (int)pixPtr[0], (int)pixPtr[1], (int)pixPtr[2]);
                    pixPtr += 4;
                }
            }
            GL.UnmapBuffer(BufferTarget.PixelUnpackBuffer);
        }
        GL.BindBuffer(BufferTarget.PixelUnpackBuffer,0);