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/* Pixbufs
*
* A GdkPixbuf represents an image, normally in RGB or RGBA format.
* Pixbufs are normally used to load files from disk and perform
* image scaling.
*
* This demo is not all that educational, but looks cool. It was written
* by Extreme Pixbuf Hacker Federico Mena Quintero. It also shows
* off how to use GtkDrawingArea to do a simple animation.
*
* Look at the Image demo for additional pixbuf usage examples.
*
*/
#include <stdlib.h>
#include <gtk/gtk.h>
#include <math.h>
#define BACKGROUND_NAME "/pixbufs/background.jpg"
static const char *image_names[] = {
"/pixbufs/apple-red.png",
"/pixbufs/gnome-applets.png",
"/pixbufs/gnome-calendar.png",
"/pixbufs/gnome-foot.png",
"/pixbufs/gnome-gmush.png",
"/pixbufs/gnome-gimp.png",
"/pixbufs/gnome-gsame.png",
"/pixbufs/gnu-keys.png"
};
#define N_IMAGES G_N_ELEMENTS (image_names)
/* demo window */
static GtkWidget *window = NULL;
/* Current frame */
static GdkPixbuf *frame;
/* Background image */
static GdkPixbuf *background;
static gint back_width, back_height;
/* Images */
static GdkPixbuf *images[N_IMAGES];
/* Widgets */
static GtkWidget *da;
/* Loads the images for the demo and returns whether the operation succeeded */
static gboolean
load_pixbufs (GError **error)
{
gint i;
if (background)
return TRUE; /* already loaded earlier */
background = gdk_pixbuf_new_from_resource (BACKGROUND_NAME, error);
if (!background)
return FALSE; /* Note that "error" was filled with a GError */
back_width = gdk_pixbuf_get_width (background);
back_height = gdk_pixbuf_get_height (background);
for (i = 0; i < N_IMAGES; i++)
{
images[i] = gdk_pixbuf_new_from_resource (image_names[i], error);
if (!images[i])
return FALSE; /* Note that "error" was filled with a GError */
}
return TRUE;
}
/* Expose callback for the drawing area */
static void
draw_func (GtkDrawingArea *area,
cairo_t *cr,
int width,
int height,
gpointer data)
{
gdk_cairo_set_source_pixbuf (cr, frame, 0, 0);
cairo_paint (cr);
}
#define CYCLE_TIME 3000000 /* 3 seconds */
static gint64 start_time;
/* Handler to regenerate the frame */
static gboolean
on_tick (GtkWidget *widget,
GdkFrameClock *frame_clock,
gpointer data)
{
gint64 current_time;
double f;
int i;
double xmid, ymid;
double radius;
gdk_pixbuf_copy_area (background, 0, 0, back_width, back_height,
frame, 0, 0);
if (start_time == 0)
start_time = gdk_frame_clock_get_frame_time (frame_clock);
current_time = gdk_frame_clock_get_frame_time (frame_clock);
f = ((current_time - start_time) % CYCLE_TIME) / (double)CYCLE_TIME;
xmid = back_width / 2.0;
ymid = back_height / 2.0;
radius = MIN (xmid, ymid) / 2.0;
for (i = 0; i < N_IMAGES; i++)
{
double ang;
int xpos, ypos;
int iw, ih;
double r;
GdkRectangle r1, r2, dest;
double k;
ang = 2.0 * G_PI * (double) i / N_IMAGES - f * 2.0 * G_PI;
iw = gdk_pixbuf_get_width (images[i]);
ih = gdk_pixbuf_get_height (images[i]);
r = radius + (radius / 3.0) * sin (f * 2.0 * G_PI);
xpos = floor (xmid + r * cos (ang) - iw / 2.0 + 0.5);
ypos = floor (ymid + r * sin (ang) - ih / 2.0 + 0.5);
k = (i & 1) ? sin (f * 2.0 * G_PI) : cos (f * 2.0 * G_PI);
k = 2.0 * k * k;
k = MAX (0.25, k);
r1.x = xpos;
r1.y = ypos;
r1.width = iw * k;
r1.height = ih * k;
r2.x = 0;
r2.y = 0;
r2.width = back_width;
r2.height = back_height;
if (gdk_rectangle_intersect (&r1, &r2, &dest))
gdk_pixbuf_composite (images[i],
frame,
dest.x, dest.y,
dest.width, dest.height,
xpos, ypos,
k, k,
GDK_INTERP_NEAREST,
((i & 1)
? MAX (127, fabs (255 * sin (f * 2.0 * G_PI)))
: MAX (127, fabs (255 * cos (f * 2.0 * G_PI)))));
}
gtk_widget_queue_draw (da);
return G_SOURCE_CONTINUE;
}
GtkWidget *
do_pixbufs (GtkWidget *do_widget)
{
if (!window)
{
GError *error;
window = gtk_window_new ();
gtk_window_set_display (GTK_WINDOW (window),
gtk_widget_get_display (do_widget));
gtk_window_set_title (GTK_WINDOW (window), "Pixbufs");
gtk_window_set_resizable (GTK_WINDOW (window), FALSE);
g_object_add_weak_pointer (G_OBJECT (window), (gpointer *)&window);
error = NULL;
if (!load_pixbufs (&error))
{
GtkWidget *dialog;
dialog = gtk_message_dialog_new (GTK_WINDOW (window),
GTK_DIALOG_DESTROY_WITH_PARENT,
GTK_MESSAGE_ERROR,
GTK_BUTTONS_CLOSE,
"Failed to load an image: %s",
error->message);
g_error_free (error);
g_signal_connect (dialog, "response",
G_CALLBACK (gtk_widget_destroy), NULL);
gtk_widget_show (dialog);
}
else
{
frame = gdk_pixbuf_new (GDK_COLORSPACE_RGB, FALSE, 8, back_width, back_height);
da = gtk_drawing_area_new ();
gtk_drawing_area_set_content_width (GTK_DRAWING_AREA (da), back_width);
gtk_drawing_area_set_content_height (GTK_DRAWING_AREA (da), back_height);
gtk_drawing_area_set_draw_func (GTK_DRAWING_AREA (da), draw_func, NULL, NULL);
gtk_window_set_child (GTK_WINDOW (window), da);
gtk_widget_add_tick_callback (da, on_tick, NULL, NULL);
}
}
if (!gtk_widget_get_visible (window))
gtk_widget_show (window);
else
{
gtk_widget_destroy (window);
g_object_unref (frame);
}
return window;
}
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