# To subscribers of the xforms list from "T.C. Zhao" <tc_zhao@yahoo.com> :
You need to set image->modified = 1 if data has changed.
This was not documented clearly in the documentation.
--- brandym@sbox.tu-graz.ac.at wrote:
> # To subscribers of the xforms list from brandym@sbox.tu-graz.ac.at :
>
> Hi !
>
> I experienced some strange behaviour in xforms 0.89 using
> flimage_display().
>
> I try to display an image which has been capture by a frame grabber
> using a canvas. Here's my source
>
>
> /*********************************************/
>
> FL_IMAGE *myimage;
> unsigned char *image;
>
> // here's some init and
> // the allocation of image according to
> // the frame size of the grabber
>
>
> while(stay_in_this_loop)
> {
> image=grabimage(); // get a new frame
>
> if(!(myimage=flimage_alloc()))
> exit(-1);
>
> myimage->type=FL_IMAGE_GRAY;
> myimage->w=IMAGE_WIDTH;
> myimage->h=IMAGE_HEIGHT;
> flimage_getmem(myimage);
>
> for(row=0;row<IMAGE_HEIGHT;row++)
> for(col=0;col<IMAGE_WIDTH;col++)
> {
> myimage->gray[row][col]=(unsigned char)image[row*IMAGE_WIDTH+col];
> }
>
> if(flimage_sdisplay(myimage, FL_ObjWin(canvas))<0)
> exit(-2);
>
> flimage_free(myimage);
>
>
> do_some_gui_things();
> }
> /*********************************************************/
>
> This way it works once. I then tried to copy a new image from the
> grabber device into the (unsigned char *) image and wanted it
> to be displayed again - did NOT work !
> It seems to me as if a initialised FL_IMAGE structure can be
> displayed once,
> but if you do any changes to the gray-level data the changes can't
> be redisplayed.
> So what I'm doing no is to allocate/free the FL_IMAGE struct every
> time
> a new frame arrives from the grabber.
> Is there a faster/more efficient way to do this ? What am I doing
> wrong :(
>
> Thank you !
>
> Markus
> _________________________________________________
> To unsubscribe, send the message "unsubscribe" to
> xforms-request@bob.usuhs.mil or see
> http://bob.usuhs.mil/mailserv/xforms.html
> XForms Home Page: http://world.std.com/~xforms
> List Archive: http://bob.usuhs.mil/mailserv/list-archives/
>
>
__________________________________________________
Do You Yahoo!?
Talk to your friends online with Yahoo! Messenger.
http://im.yahoo.com
_________________________________________________
To unsubscribe, send the message "unsubscribe" to
xforms-request@bob.usuhs.mil or see
http://bob.usuhs.mil/mailserv/xforms.html
XForms Home Page: http://world.std.com/~xforms
List Archive: http://bob.usuhs.mil/mailserv/list-archives/
This archive was generated by hypermail 2b29 : Wed Feb 02 2000 - 09:58:23 EST