Accessing PixBuf pixels

["Luka Napotnik" <luka napotnik gmail com>]

Hello. I have some difficulties with manipulation of pixels in the
GdkPixbuf data buffer. I use the following loop to iterate thought
each pixel:

-----------------------------------
n_channels = gdk_pixbuf_get_n_channels(pixbuf);
guchar *pixel;
guchar *data = gdk_pixbuf_get_pixels(pixbuf);

for (i = 0; i < width*height; i++) {
    pixel = buffer + i * n_channels;

    pixel[0] = 100; /* Red channel */
    pixel[1] = 100; /* Green channel */
    pixel[2] = 100; /* Blue channel */
    pixel[3] = 100; /* Alpha channel */
}
-----------------------------------

Is this the right way to handle a RGBA buffer?

Greets,
Luka