+
+static void pr_create_anaglyph_gray(GdkPixbuf *pixbuf, GdkPixbuf *right, gint x, gint y, gint w, gint h)
+{
+ gint srs, drs;
+ guchar *s_pix, *d_pix;
+ guchar *sp, *dp;
+ guchar *spi, *dpi;
+ gint i, j;
+ const double gc[3] = {0.299, 0.587, 0.114};
+
+ srs = gdk_pixbuf_get_rowstride(right);
+ s_pix = gdk_pixbuf_get_pixels(right);
+ spi = s_pix + (x * COLOR_BYTES);
+
+ drs = gdk_pixbuf_get_rowstride(pixbuf);
+ d_pix = gdk_pixbuf_get_pixels(pixbuf);
+ dpi = d_pix + x * COLOR_BYTES;
+
+ for (i = y; i < y + h; i++)
+ {
+ sp = spi + (i * srs);
+ dp = dpi + (i * drs);
+ for (j = 0; j < w; j++)
+ {
+ guchar g1 = dp[0] * gc[0] + dp[1] * gc[1] + dp[2] * gc[2];
+ guchar g2 = sp[0] * gc[0] + sp[1] * gc[1] + sp[2] * gc[2];
+ dp[0] = g2; /* red channel from sp */
+ dp[1] = g1; /* green and blue from dp */
+ dp[2] = g1;
+ sp += COLOR_BYTES;
+ dp += COLOR_BYTES;
+ }
+ }
+}
+
+const double pr_dubois_matrix[3][6] = {
+ { 0.456, 0.500, 0.176, -0.043, -0.088, -0.002},
+ {-0.040, -0.038, -0.016, 0.378, 0.734, -0.018},
+ {-0.015, -0.021, -0.005, -0.072, -0.113, 1.226}
+ };
+
+static void pr_create_anaglyph_dubois(GdkPixbuf *pixbuf, GdkPixbuf *right, gint x, gint y, gint w, gint h)
+{
+ gint srs, drs;
+ guchar *s_pix, *d_pix;
+ guchar *sp, *dp;
+ guchar *spi, *dpi;
+ gint i, j, k;
+
+ srs = gdk_pixbuf_get_rowstride(right);
+ s_pix = gdk_pixbuf_get_pixels(right);
+ spi = s_pix + (x * COLOR_BYTES);
+
+ drs = gdk_pixbuf_get_rowstride(pixbuf);
+ d_pix = gdk_pixbuf_get_pixels(pixbuf);
+ dpi = d_pix + x * COLOR_BYTES;
+
+ for (i = y; i < y + h; i++)
+ {
+ sp = spi + (i * srs);
+ dp = dpi + (i * drs);
+ for (j = 0; j < w; j++)
+ {
+ double res[3];
+ for (k = 0; k < 3; k++)
+ {
+ double *m = pr_dubois_matrix[k];
+ res[k] = sp[0] * m[0] + sp[1] * m[1] + sp[2] * m[2] + dp[0] * m[3] + dp[1] * m[4] + dp[2] * m[5];
+ if (res[k] < 0.0) res[k] = 0;
+ if (res[k] > 255.0) res[k] = 255.0;
+ }
+ dp[0] = res[0];
+ dp[1] = res[1];
+ dp[2] = res[2];
+ sp += COLOR_BYTES;
+ dp += COLOR_BYTES;
+ }
+ }
+}