- tuned HP2300C geometry

- added a safeguard against negative values when moving to scan target,
	  due to failed start position detection

ChangeLog

@@ -1,3 +1,9 @@
+2006-05-15  Stéphane Voltz <stefdev@modulonet.fr> 
+
+        * backend/genesys_devices.c backend/genesys_gl646.c: tuned HP 2300
+	  geometry description and added a safeguard against failed origin
+	  detection
+
 2006-05-14  m. allan noah <anoah AT pfeiffer DOT edu>
 	* backend/fujitsu*: rewritten backend, supports many more scanners
 	  with much better usb support and less model-specific code.

backend/genesys_devices.c

@@ -539,9 +539,9 @@ static Genesys_Model hp2300c_model = {
   {16, 8, 0},			/* possible depths in color mode */
 
   SANE_FIX (-2.0),		/* Start of scan area in mm (x_offset) */
-  SANE_FIX (-2.0),		/* Start of scan area in mm (y_offset) */
+  SANE_FIX (0.0),		/* Start of scan area in mm (y_offset) */
   SANE_FIX (215.9),		/* Size of scan area in mm (x) */
-  SANE_FIX (297.1),		/* Size of scan area in mm (y) */
+  SANE_FIX (295.0),		/* Size of scan area in mm (y) */
 
   SANE_FIX (0.0),		/* Start of white strip in mm (y) */
   SANE_FIX (1.0),		/* Start of black mark in mm (x) */

backend/genesys_gl646.c

@@ -2729,9 +2729,9 @@ gl646_init_regs_for_scan (Genesys_Device * dev)
   if (channels > 1)
     {
       max_shift = dev->model->ld_shift_r;
-      if (dev->model->ld_shift_b > max_shift)
+      if ((unsigned int)dev->model->ld_shift_b > max_shift)
 	max_shift = dev->model->ld_shift_b;
-      if (dev->model->ld_shift_g > max_shift)
+      if ((unsigned int)dev->model->ld_shift_g > max_shift)
 	max_shift = dev->model->ld_shift_g;
       max_shift =
 	(max_shift * dev->settings.yres) / dev->motor.base_ydpi;
@@ -2947,6 +2947,13 @@ gl646_init_regs_for_scan (Genesys_Device * dev)
   DBG (DBG_info, "gl646_init_regs_for_scan: move=%d steps\n", move);
 
   move += (SANE_UNFIX (dev->model->y_offset) * move_dpi) / MM_PER_INCH;
+  if (move < 0)
+    {
+      DBG (DBG_error,
+	   "gl646_init_regs_for_scan: overriding negative move value %d\n",
+	   move);
+      move = 1;
+    }
   DBG (DBG_info, "gl646_init_regs_for_scan: move=%d steps\n", move);
 
   /* add tl_y to base movement */