[sane-devel] custom gamma tables and xscanimage

[Henning Meier-Geinitz]

Hi,

On Mon, Feb 11, 2002 at 07:59:04PM +0100, Jaeger, Gerhard wrote:
> I'm currently implementing a custom gamma table support
> for the Plustek backend, not a thing so far BUT
> when will xscanimage update the changes a user made
> or does it never update on its own, do I need an extra
> button to submit the changes?
> 
> Any hints are welcome - the SANE_GET_OPTIONS/SET_OPTIONS
> stuff is implementend, but never called for gamma tables...

sane_control_option with SANE_ACTION_SET_VALUE is called once:
before the actual scan starts. See src/gtk_glue.c:

/* Ensure sure the device has up-to-date option values.  Except for
   vectors, all option values are kept current.  Vectors are
   downloaded into the device during this call.  */
void
gsg_sync (GSGDialog *dialog)


The SANE_ACTION_GET_VALUE is called when building the gtk_gamma_curve
widget:

static GtkWidget*
curve_new (GSGDialog *dialog, int optnum)

Called by 

static void
vector_new (GSGDialog * dialog, GtkWidget *vbox, int num_vopts, int *vopts)

hth,
  Henning