GtkSharp/sample/GtkDemo/DemoPixbuf.cs

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// DemoPixbuf.cs: Pixbuf demonstration
//
// Gtk# port of pixbuf demo in gtk-demo app.
//
// Author: Yves Kurz <yves@magnific.ch>
//
// <c> 2003 Yves Kurz
/* Pixbufs
*
* A Pixbuf 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 DrawingArea to do a simple animation.
*
* Look at the Image demo for additional pixbuf usage examples.
*
*/
using Gdk;
using Gtk;
using System;
namespace GtkDemo
{
[Demo ("Pixbuf", "DemoPixbuf.cs")]
public class DemoPixbuf : Gtk.Window
{
const int FrameDelay = 50;
const int CycleLen = 60;
const string BackgroundName = "background.jpg";
string [] ImageNames = {
"apple-red.png",
"gnome-applets.png",
"gnome-calendar.png",
"gnome-foot.png",
"gnome-gmush.png",
"gnome-gimp.png",
"gnome-gsame.png",
"gnu-keys.png"
};
// current frame
Pixbuf frame;
int frameNum;
// background image
Pixbuf background;
int backWidth, backHeight;
// images
Pixbuf[] images;
// drawing area
DrawingArea drawingArea;
// Loads the images for the demo
void LoadPixbuf ()
{
background = Gdk.Pixbuf.LoadFromResource (BackgroundName);
backWidth = background.Width;
backHeight = background.Height;
images = new Pixbuf[ImageNames.Length];
int i = 0;
foreach (string im in ImageNames)
images[i++] = Gdk.Pixbuf.LoadFromResource (im);
}
// Expose callback for the drawing area
void Expose (object o, ExposeEventArgs args)
{
Widget widget = (Widget) o;
frame.RenderToDrawableAlpha(
widget.GdkWindow,
0, 0,
0, 0,
backWidth, backHeight,
Gdk.PixbufAlphaMode.Full, 8,
RgbDither.Normal,
100, 100);
}
// timeout handler to regenerate the frame
bool timeout ()
{
background.CopyArea (0, 0, backWidth, backHeight, frame, 0, 0);
double f = (double) (frameNum % CycleLen) / CycleLen;
int xmid = backWidth / 2;
int ymid = backHeight / 2;
double radius = Math.Min (xmid, ymid) / 2;
for (int i = 0; i < images.Length; i++) {
double ang = 2 * Math.PI * i / images.Length - f * 2 *
Math.PI;
int iw = images[i].Width;
int ih = images[i].Height;
double r = radius + (radius / 3) * Math.Sin (f * 2 *
Math.PI);
int xpos = (int) Math.Floor (xmid + r * Math.Cos (ang) -
iw / 2 + 0.5);
int ypos = (int) Math.Floor (ymid + r * Math.Sin (ang) -
ih / 2 + 0.5);
double k = (i % 2 == 1) ? Math.Sin (f * 2 * Math.PI) :
Math.Cos (f * 2 * Math.PI);
k = 2 * k * k;
k = Math.Max (0.25, k);
Rectangle r1, r2, dest;
r1 = new Rectangle (xpos, ypos,(int) (iw * k),
(int) (ih * k));
/* FIXME: Why is that code not working (in the original gtk-demo it works
r2 = new Rectangle (0, 0, backWidth, backHeight);
dest = new Rectangle (0, 0, 0, 0);
r1.Intersect (r2, dest);
images[i].Composite (frame, dest.x, dest.y, dest.width,
dest.height, xpos, ypos, k, k,
InterpType.Nearest, (int) ((i % 2 == 1)
? Math.Max (127, Math.Abs (255 * Math.Sin (f *
2 * Math.PI)))
: Math.Max (127, Math.Abs (255 * Math.Cos (f *
2 * Math.PI)))));
*/
images[i].Composite (frame, r1.X, r1.Y, r1.Width,
r1.Height, xpos, ypos, k, k,
InterpType.Nearest, (int) ((i % 2 == 1)
? Math.Max (127, Math.Abs (255 * Math.Sin (f *
2 * Math.PI)))
: Math.Max (127, Math.Abs (255 * Math.Cos (f *
2 * Math.PI)))));
}
drawingArea.QueueDraw ();
frameNum++;
return true;
}
public DemoPixbuf () : base ("Gdk Pixbuf Demo")
{
this.DeleteEvent += new DeleteEventHandler (OnWindowDelete);
try
{
LoadPixbuf ();
} catch (Exception e)
{
using (MessageDialog md = new MessageDialog (this,
DialogFlags.DestroyWithParent,
MessageType.Error,
ButtonsType.Close,
"Error: \n" + e.Message)) {
md.Run ();
md.Hide ();
}
throw;
}
frame = new Pixbuf (Colorspace.Rgb, true, 8, backWidth,
backHeight);
drawingArea = new DrawingArea ();
drawingArea.ExposeEvent += new ExposeEventHandler (Expose);
Add (drawingArea);
GLib.Timeout.Add (FrameDelay, new GLib.TimeoutHandler(timeout));
this.SetDefaultSize (backWidth, backHeight);
// this.Resizable = false;
ShowAll ();
}
void OnWindowDelete (object obj, DeleteEventArgs args)
{
this.Hide ();
this.Destroy ();
args.RetVal = true;
}
}
}