genesys: Reduce duplication in channel count and depth calculation

2019-08-17 11:51:34 +03:00 · 2019-08-17 11:51:34 +03:00 · f2871ca81d
commit f2871ca81d
--- a/backend/genesys.cc
+++ b/backend/genesys.cc
@ -1382,7 +1382,6 @@ static void genesys_coarse_calibration(Genesys_Device* dev, Genesys_Sensor& sens
  int size;
  int black_pixels;
  int white_average;
-  int channels;
  uint8_t offset[4] = { 0xa0, 0x00, 0xa0, 0x40 };	/* first value isn't used */
  uint16_t white[12], dark[12];
  int i, j;
@ -1390,10 +1389,7 @@ static void genesys_coarse_calibration(Genesys_Device* dev, Genesys_Sensor& sens
  black_pixels = sensor.black_pixels
    * dev->settings.xres / sensor.optical_res;

-  if (dev->settings.scan_mode == ScanColorMode::COLOR_SINGLE_PASS)
-    channels = 3;
-  else
-    channels = 1;
+    unsigned channels = dev->settings.get_channels();

  DBG(DBG_info, "channels %d y_size %d xres %d\n", channels, dev->model->y_size,
      dev->settings.xres);
--- a/backend/genesys_gl124.cc
+++ b/backend/genesys_gl124.cc
@ -1272,8 +1272,6 @@ static void gl124_init_scan_regs(Genesys_Device* dev, const Genesys_Sensor& sens
 static void
 gl124_calculate_current_setup (Genesys_Device * dev, const Genesys_Sensor& sensor)
 {
-  int channels;
-  int depth;
  int start;

  int used_res;
@ -1289,17 +1287,6 @@ gl124_calculate_current_setup (Genesys_Device * dev, const Genesys_Sensor& senso
    DBG(DBG_info, "%s ", __func__);
    debug_dump(DBG_info, dev->settings);

-  /* channels */
-  if (dev->settings.scan_mode == ScanColorMode::COLOR_SINGLE_PASS)
-    channels = 3;
-  else
-    channels = 1;
-
-  /* depth */
-  depth = dev->settings.depth;
-  if (dev->settings.scan_mode == ScanColorMode::LINEART)
-    depth = 1;
-
  /* start */
  start = SANE_UNFIX (dev->model->x_offset);
  start += dev->settings.tl_x;
@ -1312,8 +1299,8 @@ gl124_calculate_current_setup (Genesys_Device * dev, const Genesys_Sensor& senso
    session.params.starty = 0; // not used
    session.params.pixels = dev->settings.pixels;
    session.params.lines = dev->settings.lines;
-    session.params.depth = depth;
-    session.params.channels = channels;
+    session.params.depth = dev->settings.get_depth();
+    session.params.channels = dev->settings.get_channels();
    session.params.scan_method = dev->settings.scan_method;
    session.params.scan_mode = dev->settings.scan_mode;
    session.params.color_filter = dev->settings.color_filter;
@ -1877,14 +1864,6 @@ static void gl124_init_regs_for_coarse_calibration(Genesys_Device* dev,
                                                   Genesys_Register_Set& regs)
 {
    DBG_HELPER(dbg);
-  uint8_t channels;
-
-  /* set line size */
-    if (dev->settings.scan_mode == ScanColorMode::COLOR_SINGLE_PASS) {
-        channels = 3;
-    } else {
-        channels = 1;
-    }

    ScanSession session;
    session.params.xres = dev->settings.xres;
@ -1894,7 +1873,7 @@ static void gl124_init_regs_for_coarse_calibration(Genesys_Device* dev,
    session.params.pixels = sensor.optical_res / sensor.ccd_pixels_per_system_pixel();
    session.params.lines = 20;
    session.params.depth = 16;
-    session.params.channels = channels;
+    session.params.channels = dev->settings.get_channels();
    session.params.scan_method = dev->settings.scan_method;
    session.params.scan_mode = dev->settings.scan_mode;
    session.params.color_filter = dev->settings.color_filter;
@ -2009,26 +1988,13 @@ static void gl124_wait_for_motor_stop(Genesys_Device* dev)
 static void gl124_init_regs_for_scan(Genesys_Device* dev, const Genesys_Sensor& sensor)
 {
    DBG_HELPER(dbg);
-  int channels;
  int flags;
-  int depth;
  float move;
  int move_dpi;
  float start;

    debug_dump(DBG_info, dev->settings);

-  /* channels */
-  if (dev->settings.scan_mode == ScanColorMode::COLOR_SINGLE_PASS)
-    channels = 3;
-  else
-    channels = 1;
-
-  /* depth */
-  depth = dev->settings.depth;
-  if (dev->settings.scan_mode == ScanColorMode::LINEART)
-    depth = 1;
-
  /* y (motor) distance to move to reach scanned area */
  move_dpi = dev->motor.base_ydpi/4;
  move = SANE_UNFIX (dev->model->y_offset);
@ -2036,8 +2002,7 @@ static void gl124_init_regs_for_scan(Genesys_Device* dev, const Genesys_Sensor&
  move = (move * move_dpi) / MM_PER_INCH;
  DBG (DBG_info, "%s: move=%f steps\n", __func__, move);

-  if(channels*dev->settings.yres>=600 && move>700)
-    {
+    if (dev->settings.get_channels() * dev->settings.yres >= 600 && move > 700) {
        gl124_feed(dev, move-500, SANE_FALSE);
      move=500;
    }
@ -2065,8 +2030,8 @@ static void gl124_init_regs_for_scan(Genesys_Device* dev, const Genesys_Sensor&
    session.params.starty = move;
    session.params.pixels = dev->settings.pixels;
    session.params.lines = dev->settings.lines;
-    session.params.depth = depth;
-    session.params.channels = channels;
+    session.params.depth = dev->settings.get_depth();
+    session.params.channels = dev->settings.get_channels();
    session.params.scan_method = dev->settings.scan_method;
    session.params.scan_mode = dev->settings.scan_mode;
    session.params.color_filter = dev->settings.color_filter;
--- a/backend/genesys_gl646.cc
+++ b/backend/genesys_gl646.cc
@ -2217,19 +2217,9 @@ static void setup_for_scan(Genesys_Device* dev,
 {
    DBG_HELPER(dbg);
  SANE_Int depth;
-  int channels;

    debug_dump(DBG_info, dev->settings);

-  if (settings.scan_mode == ScanColorMode::COLOR_SINGLE_PASS)
-    {
-      channels = 3;
-    }
-  else
-    {
-      channels = 1;
-    }
-
  depth=settings.depth;
  if (settings.scan_mode == ScanColorMode::LINEART)
    {
@ -2283,7 +2273,7 @@ static void setup_for_scan(Genesys_Device* dev,
    session.params.pixels = settings.pixels;
    session.params.lines = settings.lines;
    session.params.depth = depth;
-    session.params.channels = channels;
+    session.params.channels = settings.get_channels();
    session.params.scan_method = dev->settings.scan_method;
    session.params.scan_mode = settings.scan_mode;
    session.params.color_filter = settings.color_filter;
@ -2367,7 +2357,6 @@ static SensorExposure gl646_led_calibration(Genesys_Device* dev, const Genesys_S
  int total_size;
  unsigned int i, j;
  int val;
-  unsigned int channels;
  int avg[3], avga, avge;
  int turn;
  uint16_t expr, expg, expb;
@ -2376,15 +2365,15 @@ static SensorExposure gl646_led_calibration(Genesys_Device* dev, const Genesys_S

  SANE_Bool acceptable = SANE_FALSE;

+    unsigned channels = dev->settings.get_channels();
+
  /* get led calibration resolution */
  if (dev->settings.scan_mode == ScanColorMode::COLOR_SINGLE_PASS)
    {
-      channels = 3;
      settings.scan_mode = ScanColorMode::COLOR_SINGLE_PASS;
    }
  else
    {
-      channels = 1;
      settings.scan_mode = ScanColorMode::GRAY;
    }
  resolution = get_closest_resolution(dev->model->ccd_type, sensor.optical_res, channels);
@ -3357,13 +3346,12 @@ static void simple_scan(Genesys_Device* dev, const Genesys_Sensor& sensor,
        lines = dev->reg.get24(REG_LINCNT) + 1;
    }
  size = lines * settings.pixels;
-  if (settings.depth == 16)
-    bpp = 2;
-  else
-    bpp = 1;
-  size *= bpp;
-  if (settings.scan_mode == ScanColorMode::COLOR_SINGLE_PASS)
-    size *= 3;
+    if (settings.depth == 16) {
+        bpp = 2;
+    } else {
+        bpp = 1;
+    }
+    size *= bpp * settings.get_channels();
  data.clear();
  data.resize(size);

@ -3732,12 +3720,7 @@ gl646_is_compatible_calibration (Genesys_Device * dev, const Genesys_Sensor& sen
  /* build minimal current_setup for calibration cache use only, it will be better
   * computed when during setup for scan
   */
-  if (dev->settings.scan_mode == ScanColorMode::COLOR_SINGLE_PASS)
-    {
-        dev->session.params.channels = 3;
-    } else {
-        dev->session.params.channels = 1;
-    }
+    dev->session.params.channels = dev->settings.get_channels();
  dev->current_setup.xres = dev->settings.xres;

    DBG(DBG_io, "%s: requested=(%d,%f), tested=(%d,%f)\n", __func__,
--- a/backend/genesys_gl841.cc
+++ b/backend/genesys_gl841.cc
@ -2035,8 +2035,6 @@ dummy \ scanned lines

 static void gl841_calculate_current_setup(Genesys_Device * dev, const Genesys_Sensor& sensor)
 {
-  int channels;
-  int depth;
  int start;

  int used_res;
@ -2056,17 +2054,6 @@ static void gl841_calculate_current_setup(Genesys_Device * dev, const Genesys_Se
    DBG(DBG_info, "%s ", __func__);
    debug_dump(DBG_info, dev->settings);

-/* channels */
-  if (dev->settings.scan_mode == ScanColorMode::COLOR_SINGLE_PASS)
-    channels = 3;
-  else
-    channels = 1;
-
-/* depth */
-  depth = dev->settings.depth;
-  if (dev->settings.scan_mode == ScanColorMode::LINEART)
-      depth = 1;
-
 /* start */
  start = SANE_UNFIX (dev->model->x_offset);

@ -2081,8 +2068,8 @@ static void gl841_calculate_current_setup(Genesys_Device * dev, const Genesys_Se
    session.params.starty = 0; // not used
    session.params.pixels = dev->settings.pixels;
    session.params.lines = dev->settings.lines;
-    session.params.depth = depth;
-    session.params.channels = channels;
+    session.params.depth = dev->settings.get_depth();
+    session.params.channels = dev->settings.get_channels();
    session.params.scan_method = dev->settings.scan_method;
    session.params.scan_mode = dev->settings.scan_mode;
    session.params.color_filter = dev->settings.color_filter;
@ -2956,14 +2943,6 @@ static void gl841_init_regs_for_coarse_calibration(Genesys_Device* dev,
                                                   Genesys_Register_Set& regs)
 {
    DBG_HELPER(dbg);
-  uint8_t channels;
-
-  /* set line size */
-  if (dev->settings.scan_mode == ScanColorMode::COLOR_SINGLE_PASS)
-    channels = 3;
-  else {
-    channels = 1;
-  }

    ScanSession session;
    session.params.xres = dev->settings.xres;
@ -2973,7 +2952,7 @@ static void gl841_init_regs_for_coarse_calibration(Genesys_Device* dev,
    session.params.pixels = sensor.optical_res / sensor.ccd_pixels_per_system_pixel();
    session.params.lines = 20;
    session.params.depth = 16;
-    session.params.channels = channels;
+    session.params.channels = dev->settings.get_channels();
    session.params.scan_method = dev->settings.scan_method;
    session.params.scan_mode = dev->settings.scan_mode;
    session.params.color_filter = dev->settings.color_filter;
@ -3061,27 +3040,13 @@ static void gl841_init_regs_for_shading(Genesys_Device* dev, const Genesys_Senso
 static void gl841_init_regs_for_scan(Genesys_Device* dev, const Genesys_Sensor& sensor)
 {
    DBG_HELPER(dbg);
-  int channels;
  int flags;
-  int depth;
  float move;
  int move_dpi;
  float start;

    debug_dump(DBG_info, dev->settings);

-/* channels */
-  if (dev->settings.scan_mode == ScanColorMode::COLOR_SINGLE_PASS)
-    channels = 3;
-  else
-    channels = 1;
-
-/* depth */
-  depth = dev->settings.depth;
-  if (dev->settings.scan_mode == ScanColorMode::LINEART)
-      depth = 1;
-
-
  /* steps to move to reach scanning area:
     - first we move to physical start of scanning
     either by a fixed steps amount from the black strip
@ -3157,8 +3122,8 @@ static void gl841_init_regs_for_scan(Genesys_Device* dev, const Genesys_Sensor&
    session.params.starty = move;
    session.params.pixels = dev->settings.pixels;
    session.params.lines = dev->settings.lines;
-    session.params.depth = depth;
-    session.params.channels = channels;
+    session.params.depth = dev->settings.get_depth();
+    session.params.channels = dev->settings.get_channels();
    session.params.scan_method = dev->settings.scan_method;
    session.params.scan_mode = dev->settings.scan_mode;
    session.params.color_filter = dev->settings.color_filter;
--- a/backend/genesys_gl843.cc
+++ b/backend/genesys_gl843.cc
@ -1403,8 +1403,6 @@ static void gl843_init_scan_regs(Genesys_Device* dev, const Genesys_Sensor& sens
 static void
 gl843_calculate_current_setup(Genesys_Device * dev, const Genesys_Sensor& sensor)
 {
-  int channels;
-  int depth;
  int start;

  int used_res;
@ -1423,18 +1421,6 @@ gl843_calculate_current_setup(Genesys_Device * dev, const Genesys_Sensor& sensor
  /* we have 2 domains for ccd: xres below or above half ccd max dpi */
  unsigned ccd_size_divisor = sensor.get_ccd_size_divisor_for_dpi(dev->settings.xres);

-  /* channels */
-  if (dev->settings.scan_mode == ScanColorMode::COLOR_SINGLE_PASS)
-    channels = 3;
-  else
-    channels = 1;
-
-  /* depth */
-  depth = dev->settings.depth;
-    if (dev->settings.scan_mode == ScanColorMode::LINEART) {
-        depth = 1;
-    }
-
    if (dev->settings.scan_method == ScanMethod::TRANSPARENCY ||
        dev->settings.scan_method == ScanMethod::TRANSPARENCY_INFRARED)
    {
@ -1460,8 +1446,8 @@ gl843_calculate_current_setup(Genesys_Device * dev, const Genesys_Sensor& sensor
    session.params.starty = 0; // not used
    session.params.pixels = dev->settings.pixels;
    session.params.lines = dev->settings.lines;
-    session.params.depth = depth;
-    session.params.channels = channels;
+    session.params.depth = dev->settings.get_depth();
+    session.params.channels = dev->settings.get_channels();
    session.params.scan_method = dev->settings.scan_method;
    session.params.scan_mode = dev->settings.scan_mode;
    session.params.color_filter = dev->settings.color_filter;
@ -2298,13 +2284,6 @@ static void gl843_init_regs_for_coarse_calibration(Genesys_Device* dev,
                                                   Genesys_Register_Set& regs)
 {
    DBG_HELPER(dbg);
-  uint8_t channels;
-
-  /* set line size */
-  if (dev->settings.scan_mode == ScanColorMode::COLOR_SINGLE_PASS)
-    channels = 3;
-  else
-    channels = 1;

  int flags = SCAN_FLAG_DISABLE_SHADING |
              SCAN_FLAG_DISABLE_GAMMA |
@ -2324,7 +2303,7 @@ static void gl843_init_regs_for_coarse_calibration(Genesys_Device* dev,
    session.params.pixels = sensor.optical_res / sensor.ccd_pixels_per_system_pixel();
    session.params.lines = 20;
    session.params.depth = 16;
-    session.params.channels = channels;
+    session.params.channels = dev->settings.get_channels();
    session.params.scan_method = dev->settings.scan_method;
    session.params.scan_mode = dev->settings.scan_mode;
    session.params.color_filter = dev->settings.color_filter;
@ -2516,26 +2495,13 @@ static void gl843_init_regs_for_shading(Genesys_Device* dev, const Genesys_Senso
 static void gl843_init_regs_for_scan(Genesys_Device* dev, const Genesys_Sensor& sensor)
 {
    DBG_HELPER(dbg);
-  int channels;
  int flags;
-  int depth;
  float move;
  int move_dpi;
  float start;

    debug_dump(DBG_info, dev->settings);

-  /* channels */
-  if (dev->settings.scan_mode == ScanColorMode::COLOR_SINGLE_PASS)
-    channels = 3;
-  else
-    channels = 1;
-
-  /* depth */
-  depth = dev->settings.depth;
-  if (dev->settings.scan_mode == ScanColorMode::LINEART)
-    depth = 1;
-
  move_dpi = dev->motor.base_ydpi;

  flags = 0;
@ -2597,8 +2563,8 @@ static void gl843_init_regs_for_scan(Genesys_Device* dev, const Genesys_Sensor&
    session.params.starty = move;
    session.params.pixels = dev->settings.pixels;
    session.params.lines = dev->settings.lines;
-    session.params.depth = depth;
-    session.params.channels = channels;
+    session.params.depth = dev->settings.get_depth();
+    session.params.channels = dev->settings.get_channels();
    session.params.scan_method = dev->settings.scan_method;
    session.params.scan_mode = dev->settings.scan_mode;
    session.params.color_filter = dev->settings.color_filter;
--- a/backend/genesys_gl846.cc
+++ b/backend/genesys_gl846.cc
@ -1139,8 +1139,6 @@ static void gl846_init_scan_regs(Genesys_Device* dev, const Genesys_Sensor& sens
 static void
 gl846_calculate_current_setup(Genesys_Device * dev, const Genesys_Sensor& sensor)
 {
-  int channels;
-  int depth;
  int start;

  int used_res;
@ -1158,17 +1156,6 @@ gl846_calculate_current_setup(Genesys_Device * dev, const Genesys_Sensor& sensor
    DBG(DBG_info, "%s ", __func__);
    debug_dump(DBG_info, dev->settings);

-  /* channels */
-  if (dev->settings.scan_mode == ScanColorMode::COLOR_SINGLE_PASS)
-    channels = 3;
-  else
-    channels = 1;
-
-  /* depth */
-  depth = dev->settings.depth;
-  if (dev->settings.scan_mode == ScanColorMode::LINEART)
-    depth = 1;
-
  /* start */
  start = SANE_UNFIX (dev->model->x_offset);
  start += dev->settings.tl_x;
@ -1181,8 +1168,8 @@ gl846_calculate_current_setup(Genesys_Device * dev, const Genesys_Sensor& sensor
    session.params.starty = 0; // not used
    session.params.pixels = dev->settings.pixels;
    session.params.lines = dev->settings.lines;
-    session.params.depth = depth;
-    session.params.channels = channels;
+    session.params.depth = dev->settings.get_depth();
+    session.params.channels = dev->settings.get_channels();
    session.params.scan_method = dev->settings.scan_method;
    session.params.scan_mode = dev->settings.scan_mode;
    session.params.color_filter = dev->settings.color_filter;
@ -1563,14 +1550,6 @@ static void gl846_init_regs_for_coarse_calibration(Genesys_Device* dev,
                                                   Genesys_Register_Set& regs)
 {
    DBG_HELPER(dbg);
-  uint8_t channels;
-
-  /* set line size */
-  if (dev->settings.scan_mode == ScanColorMode::COLOR_SINGLE_PASS)
-    channels = 3;
-  else {
-    channels = 1;
-  }

    ScanSession session;
    session.params.xres = dev->settings.xres;
@ -1580,7 +1559,7 @@ static void gl846_init_regs_for_coarse_calibration(Genesys_Device* dev,
    session.params.pixels = sensor.optical_res / sensor.ccd_pixels_per_system_pixel();
    session.params.lines = 20;
    session.params.depth = 16;
-    session.params.channels = channels;
+    session.params.channels = dev->settings.get_channels();
    session.params.scan_method = dev->settings.scan_method;
    session.params.scan_mode = dev->settings.scan_mode;
    session.params.color_filter = dev->settings.color_filter;
@ -1735,27 +1714,13 @@ static void gl846_init_regs_for_shading(Genesys_Device* dev, const Genesys_Senso
 static void gl846_init_regs_for_scan(Genesys_Device* dev, const Genesys_Sensor& sensor)
 {
    DBG_HELPER(dbg);
-  int channels;
  int flags;
-  int depth;
  float move;
  int move_dpi;
  float start;

    debug_dump(DBG_info, dev->settings);

- /* channels */
-  if (dev->settings.scan_mode == ScanColorMode::COLOR_SINGLE_PASS)
-    channels = 3;
-  else
-    channels = 1;
-
-  /* depth */
-  depth = dev->settings.depth;
-  if (dev->settings.scan_mode == ScanColorMode::LINEART)
-    depth = 1;
-
-
  /* steps to move to reach scanning area:
     - first we move to physical start of scanning
     either by a fixed steps amount from the black strip
@ -1788,7 +1753,7 @@ static void gl846_init_regs_for_scan(Genesys_Device* dev, const Genesys_Sensor&
   * computing acceleration/deceleration distance for scan
   * resolution. So leave a remainder for it so scan makes the final
   * move tuning */
-  if(channels*dev->settings.yres>=600 && move>700)
+    if (dev->settings.get_channels() * dev->settings.yres >= 600 && move > 700)
    {
        gl846_feed(dev, move-500);
      move=500;
@ -1821,8 +1786,8 @@ static void gl846_init_regs_for_scan(Genesys_Device* dev, const Genesys_Sensor&
    session.params.starty = move;
    session.params.pixels = dev->settings.pixels;
    session.params.lines = dev->settings.lines;
-    session.params.depth = depth;
-    session.params.channels = channels;
+    session.params.depth = dev->settings.get_depth();
+    session.params.channels = dev->settings.get_channels();
    session.params.scan_method = dev->settings.scan_method;
    session.params.scan_mode = dev->settings.scan_mode;
    session.params.color_filter = dev->settings.color_filter;
--- a/backend/genesys_gl847.cc
+++ b/backend/genesys_gl847.cc
@ -1155,8 +1155,6 @@ static void gl847_init_scan_regs(Genesys_Device* dev, const Genesys_Sensor& sens
 static void
 gl847_calculate_current_setup(Genesys_Device * dev, const Genesys_Sensor& sensor)
 {
-  int channels;
-  int depth;
  int start;

  int used_res;
@ -1174,17 +1172,6 @@ gl847_calculate_current_setup(Genesys_Device * dev, const Genesys_Sensor& sensor
    DBG(DBG_info, "%s ", __func__);
    debug_dump(DBG_info, dev->settings);

-  /* channels */
-  if (dev->settings.scan_mode == ScanColorMode::COLOR_SINGLE_PASS)
-    channels = 3;
-  else
-    channels = 1;
-
-  /* depth */
-  depth = dev->settings.depth;
-  if (dev->settings.scan_mode == ScanColorMode::LINEART)
-    depth = 1;
-
  /* start */
  start = SANE_UNFIX (dev->model->x_offset);
  start += dev->settings.tl_x;
@ -1197,8 +1184,8 @@ gl847_calculate_current_setup(Genesys_Device * dev, const Genesys_Sensor& sensor
    session.params.starty = 0; // not used
    session.params.pixels = dev->settings.pixels;
    session.params.lines = dev->settings.lines;
-    session.params.depth = depth;
-    session.params.channels = channels;
+    session.params.depth = dev->settings.get_depth();
+    session.params.channels = dev->settings.get_channels();
    session.params.scan_method = dev->settings.scan_method;
    session.params.scan_mode = dev->settings.scan_mode;
    session.params.color_filter = dev->settings.color_filter;
@ -1620,14 +1607,6 @@ static void gl847_init_regs_for_coarse_calibration(Genesys_Device* dev,
                                                   Genesys_Register_Set& regs)
 {
    DBG_HELPER(dbg);
-  uint8_t channels;
-
-  /* set line size */
-  if (dev->settings.scan_mode == ScanColorMode::COLOR_SINGLE_PASS)
-    channels = 3;
-  else {
-    channels = 1;
-  }

    ScanSession session;
    session.params.xres = dev->settings.xres;
@ -1637,7 +1616,7 @@ static void gl847_init_regs_for_coarse_calibration(Genesys_Device* dev,
    session.params.pixels = sensor.optical_res / sensor.ccd_pixels_per_system_pixel();
    session.params.lines = 20;
    session.params.depth = 16;
-    session.params.channels = channels;
+    session.params.channels = dev->settings.get_channels();
    session.params.scan_method = dev->settings.scan_method;
    session.params.scan_mode = dev->settings.scan_mode;
    session.params.color_filter = dev->settings.color_filter;
@ -1791,27 +1770,13 @@ static void gl847_init_regs_for_shading(Genesys_Device* dev, const Genesys_Senso
 static void gl847_init_regs_for_scan(Genesys_Device* dev, const Genesys_Sensor& sensor)
 {
    DBG_HELPER(dbg);
-  int channels;
  int flags;
-  int depth;
  float move;
  int move_dpi;
  float start;

    debug_dump(DBG_info, dev->settings);

- /* channels */
-  if (dev->settings.scan_mode == ScanColorMode::COLOR_SINGLE_PASS)
-    channels = 3;
-  else
-    channels = 1;
-
-  /* depth */
-  depth = dev->settings.depth;
-  if (dev->settings.scan_mode == ScanColorMode::LINEART)
-    depth = 1;
-
-
  /* steps to move to reach scanning area:
     - first we move to physical start of scanning
     either by a fixed steps amount from the black strip
@ -1844,8 +1809,7 @@ static void gl847_init_regs_for_scan(Genesys_Device* dev, const Genesys_Sensor&
   * computing acceleration/deceleration distance for scan
   * resolution. So leave a remainder for it so scan makes the final
   * move tuning */
-  if(channels*dev->settings.yres>=600 && move>700)
-    {
+    if (dev->settings.get_channels() * dev->settings.yres >= 600 && move > 700) {
        gl847_feed(dev, move-500);
      move=500;
    }
@ -1877,8 +1841,8 @@ static void gl847_init_regs_for_scan(Genesys_Device* dev, const Genesys_Sensor&
    session.params.starty = move;
    session.params.pixels = dev->settings.pixels;
    session.params.lines = dev->settings.lines;
-    session.params.depth = depth;
-    session.params.channels = channels;
+    session.params.depth = dev->settings.get_depth();
+    session.params.channels = dev->settings.get_channels();
    session.params.scan_method = dev->settings.scan_method;
    session.params.scan_mode = dev->settings.scan_mode;
    session.params.color_filter = dev->settings.color_filter;
--- a/backend/genesys_settings.h
+++ b/backend/genesys_settings.h
@ -95,6 +95,21 @@ struct Genesys_Settings

    // cache entries expiration time
    int expiration_time = 0;
+
+    unsigned get_channels() const
+    {
+        if (scan_mode == ScanColorMode::COLOR_SINGLE_PASS)
+            return 3;
+        return 1;
+    }
+
+    unsigned get_depth() const
+    {
+        if (scan_mode == ScanColorMode::LINEART)
+            return 1;
+        return depth;
+    }
+
 };

 struct SetupParams {