gtk2/gdk-pixbuf/gdk-pixbuf-xform.c

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GdkPixbuf *
gdk_pixbuf_scale (const GdkPixbuf *pixbuf, gint w, gint h)
{
art_u8 *pixels;
gint rowstride;
double affine[6];
ArtAlphaGamma *alphagamma;
ArtPixBuf *art_pixbuf = NULL;
GdkPixbuf *copy = NULL;
alphagamma = NULL;
affine[1] = affine[2] = affine[4] = affine[5] = 0;
affine[0] = w / (double)(pixbuf->art_pixbuf->width);
affine[3] = h / (double)(pixbuf->art_pixbuf->height);
/* rowstride = w * pixbuf->art_pixbuf->n_channels; */
rowstride = w * 3;
pixels = art_alloc (h * rowstride);
art_rgb_pixbuf_affine (pixels, 0, 0, w, h, rowstride,
pixbuf->art_pixbuf,
affine, ART_FILTER_NEAREST, alphagamma);
if (pixbuf->art_pixbuf->has_alpha)
/* should be rgba */
art_pixbuf = art_pixbuf_new_rgb(pixels, w, h, rowstride);
else
art_pixbuf = art_pixbuf_new_rgb(pixels, w, h, rowstride);
copy = gdk_pixbuf_new (art_pixbuf, NULL);
if (!copy)
art_free (pixels);
return copy;
}
GdkPixbuf *
gdk_pixbuf_rotate (GdkPixbuf *pixbuf, gdouble angle)
{
art_u8 *pixels;
gint rowstride, w, h;
gdouble rad;
double rot[6], trans[6], affine[6];
ArtAlphaGamma *alphagamma = NULL;
ArtPixBuf *art_pixbuf = NULL;
w = pixbuf->art_pixbuf->width;
h = pixbuf->art_pixbuf->height;
rad = (M_PI * angle / 180.0);
rot[0] = cos(rad);
rot[1] = sin(rad);
rot[2] = -sin(rad);
rot[3] = cos(rad);
rot[4] = rot[5] = 0;
trans[0] = trans[3] = 1;
trans[1] = trans[2] = 0;
trans[4] = -(double)w / 2.0;
trans[5] = -(double)h / 2.0;
art_affine_multiply(rot, trans, rot);
trans[0] = trans[3] = 1;
trans[1] = trans[2] = 0;
trans[4] = (double)w / 2.0;
trans[5] = (double)h / 2.0;
art_affine_multiply(affine, rot, trans);
g_print("Affine: %e %e %e %e %e %e\n", affine[0], affine[1], affine[2],
affine[3], affine[4], affine[5]);
/* rowstride = w * pixbuf->art_pixbuf->n_channels; */
rowstride = w * 3;
pixels = art_alloc (h * rowstride);
art_rgb_pixbuf_affine (pixels, 0, 0, w, h, rowstride,
pixbuf->art_pixbuf,
affine, ART_FILTER_NEAREST, alphagamma);
if (pixbuf->art_pixbuf->has_alpha)
/* should be rgba */
art_pixbuf = art_pixbuf_new_rgb(pixels, w, h, rowstride);
else
art_pixbuf = art_pixbuf_new_rgb(pixels, w, h, rowstride);
art_pixbuf_free (pixbuf->art_pixbuf);
pixbuf->art_pixbuf = art_pixbuf;
return pixbuf;
}