Create a Rounded image in gtk - c

Question

How can I make an image round?
I tried setting border-radius to gtk image. But it does not work. Here is my code.
GdkPixbuf *pixbuf;
pixbuf=gdk_pixbuf_new_from_file_at_size ("sample.jpg", 48, 48, NULL);
GtkWidget *image = GTK_WIDGET(gtk_builder_get_object(builder,"image"));;
gtk_image_set_from_pixbuf(GTK_IMAGE(image),pixbuf);
g_object_unref (pixbuf);
I want to round the image widget. Is there any option in glade to round the image? I don't find any.
Thanks.

Answer 1

As pointed out by #iharob in comments, you need a cairo surface .
Change the radius (in this example 40) to the desired size:
#include <cairo.h>
#include <gtk/gtk.h>
#include <math.h>
#include <stdlib.h>
#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif
static void do_drawing(cairo_t *, GtkWidget *);
struct {
cairo_surface_t *image;
} glob;
static gboolean on_draw_event(GtkWidget *widget, cairo_t *cr,
gpointer user_data)
{
do_drawing(cr, widget);
return FALSE;
}
static void do_drawing(cairo_t *cr, GtkWidget *widget)
{
GtkWidget *win = gtk_widget_get_toplevel(widget);
gint width, height;
gtk_window_get_size(GTK_WINDOW(win), &width, &height);
cairo_set_source_surface(cr, glob.image, 1, 1);
cairo_arc(cr, /*x*/ 128, /* y */ 128, /* radius */ 40, 0, 2*M_PI);
cairo_clip(cr);
cairo_paint(cr);
}
int main(int argc, char *argv[])
{
GtkWidget *window;
GtkWidget *darea;
gint width, height;
glob.image = cairo_image_surface_create_from_png("image.png");
width = cairo_image_surface_get_width(glob.image);
height = cairo_image_surface_get_height(glob.image);
gtk_init(&argc, &argv);
window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
darea = gtk_drawing_area_new();
gtk_container_add(GTK_CONTAINER (window), darea);
g_signal_connect(G_OBJECT(darea), "draw",
G_CALLBACK(on_draw_event), NULL);
g_signal_connect(G_OBJECT(window), "destroy",
G_CALLBACK(gtk_main_quit), NULL);
gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER);
gtk_window_set_default_size(GTK_WINDOW(window), width+2, height+2);
gtk_window_set_title(GTK_WINDOW(window), "Round image");
gtk_widget_show_all(window);
gtk_main();
cairo_surface_destroy(glob.image);
return 0;
}

Answer 2

// compila con valac --pkg cairo nombre_archivo.gs
uses Cairo
init
// crea una superficie (una imagen de 256x256) y un contexto
surface: Cairo.ImageSurface = new Cairo.ImageSurface (Cairo.Format.ARGB32, 256, 256)
context: Cairo.Context = new Cairo.Context (surface)
// arco
context.arc (128.0, 128.0, 76.8, 0, 2*Math.PI)
context.clip () // recorta el arco
context.new_path () // después de clip, la ruta se borró
// imagen de origen (ruta y formato)
image_path:string = GLib.Path.build_filename (GLib.Path.get_dirname (args[0]) , "paisaje.png")
image: Cairo.ImageSurface = new Cairo.ImageSurface.from_png (image_path)
// escala
w:int = image.get_width ()
h:int= image.get_height ()
context.scale (256.0/w, 256.0/h)
context.set_source_surface (image, 0, 0)
context.paint ()
// guarda la nueva imagen
surface.write_to_png ("paisaje_arco.png")
More examples of Genie + Gtk + Cairo in http://genie.webierta.skn1.com