goocanvas vs crcanvas,which better?
Program need to draw realtime lines on per frame,first time i use cairo_surface_create_similar and draw surface on the frame. (frame draw on GtkDrawingArea),this make fast on my pc and the Machine(use slitaz system),but when i use ubuntu on the machine,the Xorg process take 100% cpu,this make me craze,i still don't kown why. I want to use canvas to change this,there are some cairo canvas,goocanvas can be found in lib.gnome.org,it will be a part of gnome? goocanvas vs crcanvas ,which should i use? or somebody have a good method to do these. software do these: 1. capture frame from TV card by V4L2,and then change fmt from yuyv to gray. 2. draw gray frame to GtkDrawingarea by gdk_draw_gray to a GdkPixmap. 3. do some other things on the GdkPixmap,such as draw pixbuf and text,and then gdk_draw_drawable. 4. measure on the drawingarea.such as line,circle,ellipse,polygon,arrow,draw results on the frame. 5. do other things ,such as zoom,save as image,video. there are some problems: 1. can create cairo surface on GRAY picture,then i can draw something on it ? ___ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
Ho to implement new GSource?
Hello! I'm working on MT application, which perform some tasks in separated threads. My application also use GTK+ and it should work on Windows, so I need to deal somehow with running all functions, which change GUI from one thread. I run one thread with GTK's main loop and i want to implement new source, which will check GAsysnQueue for new elements (passed to it by other threads) and perform some actions (like updating progress bars). I went to GLib documentation and i stuck there. I'm unable to figure out how main loop works and how can I correctly implement new source type. I cannot use idle source, because I want to check my async queue more often. On the other hand I want to understand how main loop works in GLib. ___ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
Re: Ho to implement new GSource?
On Thu, 26 Mar 2009 12:17:17 +0100 Tomasz Jankowski tomc...@gmail.com wrote: Hello! I'm working on MT application, which perform some tasks in separated threads. My application also use GTK+ and it should work on Windows, so I need to deal somehow with running all functions, which change GUI from one thread. I run one thread with GTK's main loop and i want to implement new source, which will check GAsysnQueue for new elements (passed to it by other threads) and perform some actions (like updating progress bars). I went to GLib documentation and i stuck there. I'm unable to figure out how main loop works and how can I correctly implement new source type. I cannot use idle source, because I want to check my async queue more often. On the other hand I want to understand how main loop works in GLib. You can use g_idle_add(), and any custom GSource object you make is going to have to do something very similar. In unix what g_idle_add() does is put a byte in a pipe on which the main loop has a file descriptor poll. In windows I think it uses a windows thread event object. Instead of worker threads placing things in a GAsyncQueue, you can pass them as a data argument when they call g_idle_add(). Or if there is a special reason to do so you can pass the data onto a queue, and your idle function can pop it off again. Chris ___ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
Re: goocanvas vs crcanvas,which better?
Hi Chen, For the application that you described, using a canvas doesn't give you much and you can just as well create a cairo context and draw on the image directly. But there are a few things that you should be aware of: - Drawing overlays on av full realtime speed is going to take a lot of CPU no matter how fast you do it. - You should make sure to prepare all the data offline before you ship it off to the screen. Thus don't put the data from the frame grabber on the screen until after you have annotated it. - If the annotation is static, it certainly faster to prepare a transparent pixbuf and draw the annotation on the pixbuf and then simply merge the data from the frame grabber with the overlay mostly transparent pixbuf, and then ship the result of to display. - If you want the user to be able to interactively zoom the resulting pixbuf, you may want to have a look at my GtkImageViewer that creates such a zoomable interface for you. See the tutorial at: http://giv.sourceforge.net/gtk-image-viewer/ Regards, Dov 2009/3/26 chen zhixin thexin1...@gmail.com Program need to draw realtime lines on per frame,first time i use cairo_surface_create_similar and draw surface on the frame. (frame draw on GtkDrawingArea),this make fast on my pc and the Machine(use slitaz system),but when i use ubuntu on the machine,the Xorg process take 100% cpu,this make me craze,i still don't kown why. I want to use canvas to change this,there are some cairo canvas,goocanvas can be found in lib.gnome.org,it will be a part of gnome? goocanvas vs crcanvas ,which should i use? or somebody have a good method to do these. software do these: 1. capture frame from TV card by V4L2,and then change fmt from yuyv to gray. 2. draw gray frame to GtkDrawingarea by gdk_draw_gray to a GdkPixmap. 3. do some other things on the GdkPixmap,such as draw pixbuf and text,and then gdk_draw_drawable. 4. measure on the drawingarea.such as line,circle,ellipse,polygon,arrow,draw results on the frame. 5. do other things ,such as zoom,save as image,video. there are some problems: 1. can create cairo surface on GRAY picture,then i can draw something on it ? ___ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list ___ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
Re: goocanvas vs crcanvas,which better?
Hi, Dov. On Thursday 26 March 2009, Dov Grobgeld wrote: - If the annotation is static, it certainly faster to prepare a transparent pixbuf and draw the annotation on the pixbuf and then simply merge the data from the frame grabber with the overlay mostly transparent pixbuf, and then ship the result of to display. Is there standard facility for creating cairo context for pixbuf? Like gdk_cairo_create() for drawables. ___ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
Re: cairo context for pixbuf
- Original Message - Subject: Re: goocanvas vs crcanvas,which better? Is there standard facility for creating cairo context for pixbuf? Like gdk_cairo_create() for drawables. pixels = gdk_pixbuf_get_pixels (pixbuf); width = gdk_pixbuf_get_width (pixbuf); height = gdk_pixbuf_get_height (pixbuf); rowstride = gdk_pixbuf_get_rowstride (pixbuf); surface = cairo_image_surface_create_for_data ( pixels, CAIRO_FORMAT_ARGB32, width, height, rowstride ); This works if the the pixbuf has alpha; the only flaw is that the red and blue component are exchanged, so the function cairo_set_source_rgb (cr, red, green, blue); must be used as if it would be cairo_set_source_rgb (cr, blue, green, red); P.A. ___ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
Re: goocanvas vs crcanvas,which better?
The following does it: int img_width = gdk_pixbuf_get_width(pixbuf); int img_height = gdk_pixbuf_get_height(pixbuf); cairo_surface_t *surface = cairo_image_surface_create_for_data(gdk_pixbuf_get_pixels(pixbuf), CAIRO_FORMAT_ARGB32, img_width, img_height, gdk_pixbuf_get_rowstride(pixbuf)); You will have to swap R and B in calls to: cairo_set_source_rgba (cr, 0,0,1.0,0.5); when drawing though, as cairo and gdk_pixbuf have different ideas about their order. (These examples are copied from the GtkImageViewer tutorial.) Regards, Dov 2009/3/26 Alexander b3n...@yandex.ru Hi, Dov. On Thursday 26 March 2009, Dov Grobgeld wrote: - If the annotation is static, it certainly faster to prepare a transparent pixbuf and draw the annotation on the pixbuf and then simply merge the data from the frame grabber with the overlay mostly transparent pixbuf, and then ship the result of to display. Is there standard facility for creating cairo context for pixbuf? Like gdk_cairo_create() for drawables. ___ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list ___ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org http://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
