Add PointCloudPacked iterators

include/ignition/msgs/PointCloudPackedUtils.hh

@@ -0,0 +1,138 @@
+/*
+ * Copyright (C) 2022 Open Source Robotics Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+*/
+
+// Inspired by
+// https://github.com/ros/common_msgs/blob/275b09a/sensor_msgs/include/sensor_msgs/point_cloud2_iterator.h
+
+#ifndef IGNITION_MSGS_POINTCLOUDPACKEDUTILS_HH_
+#define IGNITION_MSGS_POINTCLOUDPACKEDUTILS_HH_
+
+#include <ignition/msgs/pointcloud_packed.pb.h>
+
+#include <cstdarg>
+#include <sstream>
+#include <string>
+#include <vector>
+
+#include "ignition/msgs/config.hh"
+#include "ignition/msgs/detail/PointCloudPackedUtils.hh"
+
+namespace ignition
+{
+namespace msgs
+{
+/// \brief Class that can iterate over a PointCloudPacked message.
+///
+/// E.g, you create your message and reserve space for data as follows:
+/// \verbatim
+/// ignition::msgs::PointCloudPacked pcMsg;
+/// ignition::msgs::InitPointCloudPacked(pcMsg, "my_new_frame", false,
+///     {{"a", PointCloudPacked::Field::FLOAT32}});
+/// pcMsg.mutable_data()->resize(numPts * pcMsg.point_step());
+/// \endverbatim
+///
+/// For iterating over "a", you do :
+///
+/// \verbatim
+/// ignition::msgs::PointCloudPackedIterator<float> iterA(pcMsg, "a");
+/// \endverbatim
+///
+/// And then access it through iterA[0] or *iterA.
+///
+/// For iterating over RGBA, you can access each element as uint8_t:
+///
+/// \verbatim
+/// ignition::msgs::PointCloudPackedIterator<uint8_t> iterR(pcMsg, "r");
+/// ignition::msgs::PointCloudPackedIterator<uint8_t> iterG(pcMsg, "g");
+/// ignition::msgs::PointCloudPackedIterator<uint8_t> iterB(pcMsg, "b");
+/// ignition::msgs::PointCloudPackedIterator<uint8_t> iterA(pcMsg, "a");
+/// \endverbatim
+///
+/// \tparam FieldType Type of the element being iterated upon
+template<typename FieldType>
+class PointCloudPackedIterator
+  : public PointCloudPackedIteratorBase<
+    FieldType, FieldType, char, PointCloudPacked, PointCloudPackedIterator>
+{
+  // Documentation inherited
+  public: PointCloudPackedIterator(PointCloudPacked &_cloudMsg,
+    const std::string &_fieldName)
+      : PointCloudPackedIteratorBase<FieldType, FieldType, char,
+        PointCloudPacked, PointCloudPackedIterator>
+        ::PointCloudPackedIteratorBase(_cloudMsg, _fieldName)
+  {
+  }
+};
+
+/// \brief Same as a PointCloudPackedIterator but for const data
+/// \tparam FieldType Type of the element being iterated upon
+template<typename FieldType>
+class PointCloudPackedConstIterator
+  : public PointCloudPackedIteratorBase<
+    FieldType, const FieldType, const char, const PointCloudPacked,
+    PointCloudPackedConstIterator>
+{
+  public: PointCloudPackedConstIterator(
+      const PointCloudPacked &_cloudMsg,
+      const std::string &_fieldName)
+    : PointCloudPackedIteratorBase<FieldType, const FieldType, const char,
+        const PointCloudPacked,
+        PointCloudPackedConstIterator
+    >::PointCloudPackedIteratorBase(_cloudMsg, _fieldName)
+    {
+    }
+};
+
+/// \brief Return the size of a datatype (which is an enum of
+/// ignition::msgs::PointCloudPacked::Field) in bytes.
+/// \param[in] _dataType One of the enums of
+///            ignition::msgs::PointCloudPacked::Field
+/// \return Size in bytes. Returns -1 if the type is unknown.
+inline int sizeOfPointField(
+    PointCloudPacked::Field::DataType _dataType)
+{
+  if ((_dataType == PointCloudPacked::Field::INT8) ||
+      (_dataType == PointCloudPacked::Field::UINT8))
+  {
+    return 1;
+  }
+  else if ((_dataType == PointCloudPacked::Field::INT16) ||
+           (_dataType == PointCloudPacked::Field::UINT16))
+  {
+    return 2;
+  }
+  else if ((_dataType == PointCloudPacked::Field::INT32) ||
+           (_dataType == PointCloudPacked::Field::UINT32) ||
+           (_dataType == PointCloudPacked::Field::FLOAT32))
+  {
+    return 4;
+  }
+  else if (_dataType == PointCloudPacked::Field::FLOAT64)
+  {
+    return 8;
+  }
+  else
+  {
+    std::cerr << "PointCloudPacked::Field of type [" << _dataType
+              << "] does not exist" << std::endl;
+  }
+  return -1;
+}
+}
+}
+
+#endif