Class Transformer

Inheritance Relationships

Derived Types

Class Documentation

class Transformer

A base class for transformers.

Instantiations of this class implement an interface to get transforms from certain types of frames (e.g. TF, WGS84) to other types of frames.

Subclassed by swri_transform_util::UtmTransformer, swri_transform_util::Wgs84Transformer

Public Functions

Transformer()
virtual ~Transformer() = default
void Initialize(std::shared_ptr<tf2_ros::Buffer> tf, std::shared_ptr<LocalXyWgs84Util> xy_util)

Initialize the Transformer from a tf::TransformListener.

Parameters:

tf – A shared pointer to a tf::TransformListener that the Transformer wraps. It is recommended that every Transformer in a node use the same tf::TransformListener to reduce redundant computation.

virtual std::map<std::string, std::vector<std::string>> Supports() const = 0

Get a map of the transforms supported by this Transformer

Returns:

A map from source frame IDs to list of destination frame IDs. A source->destination entry does not imply that the inverse transform is supported as well.

virtual bool GetTransform(const std::string &target_frame, const std::string &source_frame, const tf2::TimePoint &time, Transform &transform) = 0

Get a swri_transform_util::Transform

Gets the swri_transform_util::Transform that transforms coordinates from the source_frame into the target_frame. If the transform is not available, return false.

Parameters:

  • target_frame – [in] Destination frame for transform

  • source_frame – [in] Source frame for transform

  • time – [in] Time that the transform is valid for. To get the most recent transform, use tf2::TimePoint(0)

  • transform – [out] Output container for the transform

Returns:

True if the transform was found, false if no transform between the specified frames is available for the specified time.

Protected Functions

virtual bool Initialize()
virtual bool GetTransform(const std::string &target_frame, const std::string &source_frame, const tf2::TimePoint &time, geometry_msgs::msg::TransformStamped &transform) const

Protected Attributes

bool initialized_
std::shared_ptr<tf2_ros::Buffer> tf_buffer_
std::shared_ptr<LocalXyWgs84Util> local_xy_util_
rclcpp::Logger logger_