genesys: Add option to get a raw scan ignoring offsets

backend/genesys.cc

@@ -5823,6 +5823,18 @@ init_options (Genesys_Scanner * s)
   s->opt[OPT_FORCE_CALIBRATION].cap =
     SANE_CAP_SOFT_DETECT | SANE_CAP_SOFT_SELECT | SANE_CAP_ADVANCED;
 
+    // ignore offsets option
+    s->opt[OPT_IGNORE_OFFSETS].name = "ignore-internal-offsets";
+    s->opt[OPT_IGNORE_OFFSETS].title = SANE_I18N("Ignore internal offsets");
+    s->opt[OPT_IGNORE_OFFSETS].desc =
+        SANE_I18N("Acquires the image including the internal calibration areas of the scanner");
+    s->opt[OPT_IGNORE_OFFSETS].type = SANE_TYPE_BUTTON;
+    s->opt[OPT_IGNORE_OFFSETS].unit = SANE_UNIT_NONE;
+    s->opt[OPT_IGNORE_OFFSETS].size = 0;
+    s->opt[OPT_IGNORE_OFFSETS].constraint_type = SANE_CONSTRAINT_NONE;
+    s->opt[OPT_IGNORE_OFFSETS].cap = SANE_CAP_SOFT_DETECT | SANE_CAP_SOFT_SELECT |
+                                     SANE_CAP_ADVANCED;
+
   RIE (calc_parameters (s));
 
   DBGCOMPLETED;
@@ -7112,6 +7124,10 @@ set_option_value (Genesys_Scanner * s, int option, void *val,
       *myinfo |= SANE_INFO_RELOAD_PARAMS | SANE_INFO_RELOAD_OPTIONS;
       break;
 
+        case OPT_IGNORE_OFFSETS: {
+            s->dev->ignore_offsets = true;
+            break;
+        }
     default:
       DBG(DBG_warn, "%s: can't set unknown option %d\n", __func__, option);
     }

backend/genesys.h

@@ -142,6 +142,7 @@ enum Genesys_Option
   OPT_CALIBRATE,
   OPT_CLEAR_CALIBRATION,
   OPT_FORCE_CALIBRATION,
+  OPT_IGNORE_OFFSETS,
 
   /* must come last: */
   NUM_OPTIONS

backend/genesys_gl843.cc

@@ -3037,16 +3037,26 @@ gl843_init_regs_for_scan (Genesys_Device * dev, const Genesys_Sensor& sensor)
   move_dpi = dev->motor.base_ydpi;
 
   flags = 0;
+
     if (dev->settings.scan_method == ScanMethod::TRANSPARENCY ||
         dev->settings.scan_method == ScanMethod::TRANSPARENCY_INFRARED)
-  {
+    {
         // note: move_to_ta() function has already been called and the sensor is at the
         // transparency adapter
-        move = SANE_UNFIX(dev->model->y_offset_ta) - SANE_UNFIX(dev->model->y_offset_sensor_to_ta);
-    flags |= SCAN_FLAG_USE_XPA;
-  }
-  else
-    move = SANE_UNFIX(dev->model->y_offset);
+        if (dev->ignore_offsets) {
+            move = 0;
+        } else {
+            move = SANE_UNFIX(dev->model->y_offset_ta) -
+                   SANE_UNFIX(dev->model->y_offset_sensor_to_ta);
+        }
+        flags |= SCAN_FLAG_USE_XPA;
+    } else {
+        if (dev->ignore_offsets) {
+            move = 0;
+        } else {
+            move = SANE_UNFIX(dev->model->y_offset);
+        }
+    }
 
   move += dev->settings.tl_y;
   move = (move * move_dpi) / MM_PER_INCH;

backend/genesys_low.h

@@ -1512,6 +1512,10 @@ struct Genesys_Device
 
     // if enabled, no calibration data will be loaded or saved to files
     SANE_Int force_calibration = 0;
+    // if enabled, will ignore the scan offsets and start scanning at true origin. This allows
+    // acquiring the positions of the black and white strips and the actual scan area
+    bool ignore_offsets = false;
+
     Genesys_Model *model = nullptr;
 
     Genesys_Register_Set reg;