Apply same fix from foxy

CHANGELOG.rst

@@ -2,6 +2,10 @@
 Changelog
 =========
 
+[unreleased]
+============
+* fix: LaserScan is not properly aligned with generated point cloud
+
 ouster_ros v0.12.0
 ==================
 * [BREAKING]: updated ouster_client to the release of ``20231031`` [v0.10.0]; changes listed below.

ouster-ros/package.xml

@@ -2,7 +2,7 @@
 <?xml-model href="http://download.ros.org/schema/package_format2.xsd" schematypens="http://www.w3.org/2001/XMLSchema"?>
 <package format="3">
   <name>ouster_ros</name>
-  <version>0.12.0</version>
+  <version>0.12.1</version>
   <description>Ouster ROS2 driver</description>
   <maintainer email="[email protected]">ouster developers</maintainer>
   <license file="LICENSE">BSD</license>

ouster-ros/src/os_ros.cpp

@@ -180,7 +180,8 @@ sensor_msgs::msg::LaserScan lidar_scan_to_laser_scan_msg(
     msg.intensities.resize(ls.w);
 
     for (auto v = 0; v < ls.w; ++v) {
-        auto v_shift = (ls.w / 2 - 1 - v - pixel_shift_by_row[ring]) % ls.w;
+        auto sign = v < ls.w / 2 ? -1 : +1;
+        auto v_shift = (ls.w / 2 - 1 - v + sign * pixel_shift_by_row[ring]) % ls.w;
         auto src_idx = ring * ls.w + v_shift;
         msg.ranges[v] = rg[src_idx] * ouster::sensor::range_unit;
         msg.intensities[v] = static_cast<float>(sg[src_idx]);