On Wed, May 10, 2006 at 09:29:31AM -0700, temp temp wrote:
> I have a problem creating a function that will draw the contents of a buffer
> into a drawing area.
>
> Here is the function I call when I want to draw the contents of "buffer" into
> the drawingarea designated by "area":
>
> int draw_in_widget(GtkWidget *area,unsigned char* buffer,int img_height,int
> img_width,bool is_rgb)
> {
> //conversion BGR->RGB
> if(!is_rgb)
> {
> unsigned char tmp;
> for(int i=0;i<img_width*img_height;i++)
> {
> tmp = buffer[3*i];//B->tmp
> buffer[3*i] = buffer[3*i+2];//R->B
> buffer[3*i+2] = tmp;//tmp->R
> }
> }
>
> gpointer destroy_fn_data;
> int area_width=area->allocation.width;
> int area_height=area->allocation.height;
>
> GdkPixbuf *pixbuf_dest=gdk_pixbuf_new(GDK_COLORSPACE_RGB,FALSE,8,
> area_width,area_height);
> GdkPixbuf
> *pixbuf_src=gdk_pixbuf_new_from_data(buffer,GDK_COLORSPACE_RGB,FALSE,8,
> img_width,img_height,img_width*3,NULL,destroy_fn_data);
> GdkGC *gc=area->style->fg_gc[GTK_STATE_NORMAL];
> double scale_x=(double)area_width/img_width;
> double scale_y=(double)area_height/img_height;
>
> gtk_widget_queue_draw(area);
You should not call gtk_widget_queue_draw() on a widget in
its expose handler. I wonder how the redrawing ever stops
when each redraw attempts to invoke another redraw...
> gdk_pixbuf_scale(pixbuf_src,pixbuf_dest,0,0,area_width,area_height,
> 0,0,scale_x,scale_y,GDK_INTERP_TILES);
>
> gdk_draw_pixbuf(area->window,gc,pixbuf_dest,
> 0,0,0,0,area_width,area_height,GDK_RGB_DITHER_NORMAL,0,0);
>
> gdk_pixbuf_unref(pixbuf_src);
> gdk_pixbuf_unref(pixbuf_dest);
> return(0);
> }
>
>
> The function adapts the size of the image contained in the buffer (of size
> 3*img_height*img_width) to the size of the drawing area.
>
> My problem is that this function only works when placed in a
> "on_drawingarea1_expose_event" handler.
To invoke redraw of a widget call
gtk_widget_queue_draw(widget);
As a result, the expose handler will be called (somewhat
later when the main loop comes to that).
Yeti
--
Anonyms eat their boogers.
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