genesys: Use common code path to compute session optical_pixels_raw

backend/genesys_gl846.cc

@@ -708,18 +708,15 @@ static void gl846_init_optical_regs_scan(Genesys_Device* dev, const Genesys_Sens
         start |= 1;
     }
     unsigned startx = start + sensor.CCD_start_xoffset * ccd_pixels_per_system_pixel;
-    unsigned endx = startx + session.optical_pixels;
+    unsigned endx = startx + session.optical_pixels_raw;
 
     // compute pixel coordinate in the given dpihw space, taking segments into account
     startx /= session.hwdpi_divisor * session.segment_count;
     endx /= session.hwdpi_divisor * session.segment_count;
-    dev->deseg.pixel_groups = (endx - startx) / ccd_pixels_per_system_pixel;
-    dev->deseg.conseq_pixel_dist_bytes = 0;
+    dev->deseg.pixel_groups = session.optical_pixels /
+            (session.hwdpi_divisor * session.segment_count * ccd_pixels_per_system_pixel);
     dev->deseg.skip_bytes = 0;
 
-  /* use a segcnt rounded to next even number */
-     endx += ((session.conseq_pixel_dist_bytes + 1) & 0xfffe) * (session.segment_count - 1) * ccd_pixels_per_system_pixel;
-
     gl846_set_fe(dev, sensor, AFE_SET);
 
   /* enable shading */

backend/genesys_gl847.cc

@@ -724,21 +724,15 @@ static void gl847_init_optical_regs_scan(Genesys_Device* dev, const Genesys_Sens
 
     // start and end coordinate in optical dpi coordinates
     unsigned startx = start + sensor.CCD_start_xoffset * ccd_pixels_per_system_pixel;
-    unsigned endx = startx + session.optical_pixels;
-
-  /* sensors are built from 600 dpi segments for LiDE 100/200
-   * and 1200 dpi for the 700F */
+    unsigned endx = startx + session.optical_pixels_raw;
 
     // compute pixel coordinate in the given dpihw space, taking segments into account
     startx /= session.hwdpi_divisor * session.segment_count;
     endx /= session.hwdpi_divisor * session.segment_count;
-    dev->deseg.pixel_groups = (endx - startx) / ccd_pixels_per_system_pixel;
-    dev->deseg.conseq_pixel_dist_bytes = 0;
+    dev->deseg.pixel_groups = session.optical_pixels /
+            (session.hwdpi_divisor * session.segment_count * ccd_pixels_per_system_pixel);
     dev->deseg.skip_bytes = 0;
 
-  /* use a segcnt rounded to next even number */
-    endx += ((session.conseq_pixel_dist_bytes + 1) & 0xfffe) * (session.segment_count - 1) * ccd_pixels_per_system_pixel;
-
     gl847_set_fe(dev, sensor, AFE_SET);
 
   /* enable shading */

backend/genesys_low.cc

@@ -1324,17 +1324,24 @@ void compute_session(Genesys_Device* dev, ScanSession& s, const Genesys_Sensor&
         s.segment_count = sensor_profile->get_segment_count();
     }
 
+    s.optical_pixels_raw = s.optical_pixels;
     s.conseq_pixel_dist_bytes = 0;
 
     if (dev->model->asic_type == AsicType::GL845 ||
         dev->model->asic_type == AsicType::GL846 ||
         dev->model->asic_type == AsicType::GL847)
     {
-        // in case of multi-segments sensor, we have to add the witdh of the sensor crossed by the
-        // scan area
         if (s.segment_count > 1) {
             s.conseq_pixel_dist_bytes = sensor_profile->segment_size;
-            // TODO: apply to optical_pixels_raw before the multiply below
+
+            // in case of multi-segments sensor, we have to add the width of the sensor crossed by
+            // the scan area
+            unsigned extra_segment_scan_area = align_multiple_ceil(s.conseq_pixel_dist_bytes, 2);
+            extra_segment_scan_area *= s.segment_count - 1;
+            extra_segment_scan_area *= s.hwdpi_divisor * s.segment_count;
+            extra_segment_scan_area *= ccd_pixels_per_system_pixel;
+
+            s.optical_pixels_raw += extra_segment_scan_area;
             s.conseq_pixel_dist_bytes = multiply_by_depth_ceil(s.conseq_pixel_dist_bytes,
                                                                s.params.depth);
         }
@@ -2018,6 +2025,7 @@ void debug_dump(unsigned level, const ScanSession& session)
     DBG(level, "    ccd_size_divisor : %d\n", session.ccd_size_divisor);
     DBG(level, "    optical_resolution : %d\n", session.optical_resolution);
     DBG(level, "    optical_pixels : %d\n", session.optical_pixels);
+    DBG(level, "    optical_pixels_raw : %d\n", session.optical_pixels_raw);
     DBG(level, "    output_resolution : %d\n", session.output_resolution);
     DBG(level, "    output_pixels : %d\n", session.output_pixels);
     DBG(level, "    output_line_bytes : %d\n", session.output_line_bytes);

backend/genesys_low.h

@@ -649,6 +649,16 @@ inline T abs_diff(T a, T b)
     }
 }
 
+inline uint64_t align_multiple_floor(uint64_t x, uint64_t multiple)
+{
+    return (x / multiple) * multiple;
+}
+
+inline uint64_t align_multiple_ceil(uint64_t x, uint64_t multiple)
+{
+    return ((x + multiple - 1) / multiple) * multiple;
+}
+
 inline unsigned multiply_by_depth_ceil(unsigned pixels, unsigned depth)
 {
     if (depth == 1) {

backend/genesys_settings.h

@@ -227,9 +227,13 @@ struct ScanSession {
     // the optical resolution of the scanner.
     unsigned optical_resolution = 0;
 
-    // the number of pixels at the optical resolution.
+    // the number of pixels at the optical resolution, not including segmentation overhead.
     unsigned optical_pixels = 0;
 
+    // the number of pixels at the optical resolution, including segmentation overhead.
+    // only on gl846, g847
+    unsigned optical_pixels_raw = 0;
+
     // the resolution of the output data.
     // gl843-only
     unsigned output_resolution = 0;