#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"

#include <gdk-pixbuf/gdk-pixbuf.h>

#include <gperl.h>
#include <gtk2perl.h>

MODULE = Gtk2::CV PACKAGE = Gtk2::CV::ImageWindow

PROTOTYPES: ENABLE

GdkPixbuf_noinc *
transpose (GdkPixbuf *pb)
	CODE:
{
	int w = gdk_pixbuf_get_width (pb);
        int h = gdk_pixbuf_get_height (pb);
        int bpp = gdk_pixbuf_get_has_alpha (pb) ? 4 : 3;
        int x, y, i;
        guchar *src = gdk_pixbuf_get_pixels (pb), *dst;
        int sstr = gdk_pixbuf_get_rowstride (pb), dstr;

	RETVAL = gdk_pixbuf_new (GDK_COLORSPACE_RGB, bpp == 4, 8, h, w);

        dst = gdk_pixbuf_get_pixels (RETVAL);
        dstr = gdk_pixbuf_get_rowstride (RETVAL);

        for (y = 0; y < h; y++)
          for (x = 0; x < w; x++)
            for (i = 0; i < bpp; i++)
              dst[y * bpp + x * dstr + i] = src[x * bpp + y * sstr + i];
}
	OUTPUT:
        RETVAL

GdkPixbuf_noinc *
flop (GdkPixbuf *pb)
	CODE:
{
	int w = gdk_pixbuf_get_width (pb);
        int h = gdk_pixbuf_get_height (pb);
        int bpp = gdk_pixbuf_get_has_alpha (pb) ? 4 : 3;
        int x, y, i;
        guchar *src = gdk_pixbuf_get_pixels (pb), *dst;
        int sstr = gdk_pixbuf_get_rowstride (pb), dstr;

	RETVAL = gdk_pixbuf_new (GDK_COLORSPACE_RGB, bpp == 4, 8, w, h);

        dst = gdk_pixbuf_get_pixels (RETVAL);
        dstr = gdk_pixbuf_get_rowstride (RETVAL);

        for (y = 0; y < h; y++)
          for (x = 0; x < w; x++)
            for (i = 0; i < bpp; i++)
              dst[(w - x) * bpp + y * dstr + i] = src[x * bpp + y * sstr + i];
}
	OUTPUT:
        RETVAL

MODULE = Gtk2::CV PACKAGE = Gtk2::CV::Schnauzer

GdkPixbuf_noinc *
p7_to_pb (int w, int h, guchar *src)
	CODE:
{
	int x, y;
        guchar *dst, *d;
        int dstr;

	RETVAL = gdk_pixbuf_new (GDK_COLORSPACE_RGB, 0, 8,  w, h);
        dst = gdk_pixbuf_get_pixels (RETVAL);
        dstr = gdk_pixbuf_get_rowstride (RETVAL);

        for (y = 0; y < h; y++)
          for (d = dst + y * dstr, x = 0; x < w; x++)
            {
              *d++ = (((*src >> 5) & 7) * 255 + 4) / 7;
              *d++ = (((*src >> 2) & 7) * 255 + 4) / 7;
              *d++ = (((*src >> 0) & 3) * 255 + 2) / 3;

              src++;
            }
}
	OUTPUT:
        RETVAL

SV *
pb_to_p7 (GdkPixbuf *pb)
	CODE:
{
	int w = gdk_pixbuf_get_width  (pb);
	int h = gdk_pixbuf_get_height (pb);
	int x, y;
        guchar *dst;
        int bpp = gdk_pixbuf_get_has_alpha (pb) ? 4 : 3;
        guchar *src = gdk_pixbuf_get_pixels (pb);
        int sstr = gdk_pixbuf_get_rowstride (pb);

	RETVAL = newSV (w * h);
        SvPOK_only (RETVAL);
        SvCUR_set (RETVAL, w * h);

        dst = SvPVX (RETVAL);

        for (y = 0; y < h; y++)
          {
            /* use a very primitive form of error distribution. */
            int er = 0, eg = 0, eb = 0;

            for (x = 0; x < w; x++)
              {
                int r, g, b;
                guchar *p = src + x * bpp + y * sstr;

                r = ((p[0] + er) * 7 + 128) / 255;
                g = ((p[1] + eg) * 7 + 128) / 255;
                b = ((p[2] + eb) * 3 + 128) / 255;

                r = r > 7 ? 7 : r < 0 ? 0 : r;
                g = g > 7 ? 7 : g < 0 ? 0 : g;
                b = b > 3 ? 3 : b < 0 ? 0 : b;

                er += p[0] - (r * 255 + 4) / 7;
                eg += p[1] - (g * 255 + 4) / 7;
                eb += p[2] - (b * 255 + 2) / 3;

                *dst++ = r << 5 | g << 2 | b;
              }
          }
}
	OUTPUT:
        RETVAL