Adds a class that can build a points processing pipeline out of a Lua configuration. (#94)

cartographer/io/CMakeLists.txt

@@ -48,6 +48,18 @@ google_library(io_points_processor
     io_points_batch
 )
 
+google_library(io_points_processor_pipeline_builder
+  SRCS
+    points_processor_pipeline_builder.cc
+  HDRS
+    points_processor_pipeline_builder.h
+  DEPENDS
+    common_lua_parameter_dictionary
+    common_make_unique
+    io_null_points_processor
+    io_points_processor
+)
+
 google_library(io_xray_points_processor
   USES_CAIRO
   USES_EIGEN
@@ -56,6 +68,8 @@ google_library(io_xray_points_processor
   HDRS
     xray_points_processor.h
   DEPENDS
+    common_lua_parameter_dictionary
+    common_make_unique
     common_math
     io_cairo_types
     io_points_processor
@@ -70,6 +84,8 @@ google_library(io_xyz_writing_points_processor
   HDRS
     xyz_writing_points_processor.h
   DEPENDS
+    common_lua_parameter_dictionary
+    common_make_unique
     io_points_processor
 )
 

cartographer/io/points_processor_pipeline_builder.cc

@@ -0,0 +1,65 @@
+/*
+ * Copyright 2016 The Cartographer Authors
+ *
+ * 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.
+ */
+
+#include "cartographer/io/points_processor_pipeline_builder.h"
+
+#include "cartographer/common/make_unique.h"
+#include "cartographer/io/null_points_processor.h"
+
+namespace cartographer {
+namespace io {
+
+PointsProcessorPipelineBuilder::PointsProcessorPipelineBuilder() {}
+
+PointsProcessorPipelineBuilder* PointsProcessorPipelineBuilder::instance() {
+  static PointsProcessorPipelineBuilder instance;
+  return &instance;
+}
+
+void PointsProcessorPipelineBuilder::RegisterType(const std::string& name,
+                                                  FactoryFunction factory) {
+  CHECK(factories_.count(name) == 0) << "A points processor with named '"
+                                     << name
+                                     << "' has already been registered.";
+  factories_[name] = factory;
+}
+
+std::vector<std::unique_ptr<PointsProcessor>>
+PointsProcessorPipelineBuilder::CreatePipeline(
+    common::LuaParameterDictionary* const dictionary) const {
+  std::vector<std::unique_ptr<PointsProcessor>> pipeline;
+  // The last consumer in the pipeline must exist, so that the one created after
+  // it (and being before it in the pipeline) has a valid 'next' to point to.
+  // The last consumer will just drop all points.
+  pipeline.emplace_back(common::make_unique<NullPointsProcessor>());
+
+  std::vector<std::unique_ptr<common::LuaParameterDictionary>> configurations =
+      dictionary->GetArrayValuesAsDictionaries();
+
+  // We construct the pipeline starting at the back.
+  for (auto it = configurations.rbegin(); it != configurations.rend(); it++) {
+    const string action = (*it)->GetString("action");
+    auto factory_it = factories_.find(action);
+    CHECK(factory_it != factories_.end())
+        << "Unknown action '" << action
+        << "'. Did you register the correspoinding PointsProcessor?";
+    pipeline.push_back(factory_it->second(it->get(), pipeline.back().get()));
+  }
+  return pipeline;
+}
+
+}  // namespace io
+}  // namespace cartographer

cartographer/io/points_processor_pipeline_builder.h

@@ -0,0 +1,70 @@
+/*
+ * Copyright 2016 The Cartographer Authors
+ *
+ * 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.
+ */
+
+#ifndef CARTOGRAPHER_IO_POINTS_PROCESSOR_PIPELINE_BUILDER_H_
+#define CARTOGRAPHER_IO_POINTS_PROCESSOR_PIPELINE_BUILDER_H_
+
+#include <string>
+#include <unordered_map>
+#include <vector>
+
+#include "cartographer/common/lua_parameter_dictionary.h"
+#include "cartographer/io/points_processor.h"
+
+namespace cartographer {
+namespace io {
+
+// Singleton that knows how to build a points processor pipeline out of a Lua
+// configuration. You can register new classes with this instance that must
+// define its name and a way to build itself out of a LuaParameterDictionary.
+// See the various 'PointsProcessor's for examples.
+class PointsProcessorPipelineBuilder {
+ public:
+  PointsProcessorPipelineBuilder(const PointsProcessorPipelineBuilder&) =
+      delete;
+  PointsProcessorPipelineBuilder& operator=(
+      const PointsProcessorPipelineBuilder&) = delete;
+
+  static PointsProcessorPipelineBuilder* instance();
+
+  template <typename PointsProcessorType>
+  void Register() {
+    instance()->RegisterType(
+        PointsProcessorType::kConfigurationFileActionName,
+        [](common::LuaParameterDictionary* const dictionary,
+           PointsProcessor* const next) -> std::unique_ptr<PointsProcessor> {
+          return PointsProcessorType::FromDictionary(dictionary, next);
+        });
+  }
+
+  std::vector<std::unique_ptr<PointsProcessor>> CreatePipeline(
+      common::LuaParameterDictionary* dictionary) const;
+
+ private:
+  using FactoryFunction = std::function<std::unique_ptr<PointsProcessor>(
+      common::LuaParameterDictionary*, PointsProcessor* next)>;
+
+  PointsProcessorPipelineBuilder();
+
+  void RegisterType(const std::string& name, FactoryFunction factory);
+
+  std::unordered_map<std::string, FactoryFunction> factories_;
+};
+
+}  // namespace io
+}  // namespace cartographer
+
+#endif  // CARTOGRAPHER_IO_POINTS_PROCESSOR_PIPELINE_BUILDER_H_

cartographer/io/xray_points_processor.cc

@@ -21,6 +21,8 @@
 
 #include "Eigen/Core"
 #include "cairo/cairo.h"
+#include "cartographer/common/lua_parameter_dictionary.h"
+#include "cartographer/common/make_unique.h"
 #include "cartographer/common/math.h"
 #include "cartographer/io/cairo_types.h"
 #include "cartographer/mapping_3d/hybrid_grid.h"
@@ -83,6 +85,15 @@ XRayPointsProcessor::XRayPointsProcessor(const double voxel_size,
       transform_(transform),
       voxels_(voxel_size, Eigen::Vector3f::Zero()) {}
 
+std::unique_ptr<XRayPointsProcessor> XRayPointsProcessor::FromDictionary(
+    common::LuaParameterDictionary* dictionary, PointsProcessor* next) {
+  return common::make_unique<XRayPointsProcessor>(
+      dictionary->GetDouble("voxel_size"),
+      transform::FromDictionary(dictionary->GetDictionary("transform").get())
+          .cast<float>(),
+      dictionary->GetString("filename"), next);
+}
+
 void XRayPointsProcessor::Process(std::unique_ptr<PointsBatch> batch) {
   for (const auto& point : batch->points) {
     const Eigen::Vector3f camera_point = transform_ * point;

cartographer/io/xray_points_processor.h

@@ -17,6 +17,7 @@
 #ifndef CARTOGRAPHER_IO_XRAY_POINTS_PROCESSOR_H_
 #define CARTOGRAPHER_IO_XRAY_POINTS_PROCESSOR_H_
 
+#include "cartographer/common/lua_parameter_dictionary.h"
 #include "cartographer/io/points_processor.h"
 #include "cartographer/mapping_3d/hybrid_grid.h"
 #include "cartographer/transform/rigid_transform.h"
@@ -30,9 +31,14 @@ namespace io {
 // combined into a movie.
 class XRayPointsProcessor : public PointsProcessor {
  public:
+  constexpr static const char* kConfigurationFileActionName =
+      "write_xray_image";
   XRayPointsProcessor(double voxel_size, const transform::Rigid3f& transform,
                       const string& output_filename, PointsProcessor* next);
 
+  static std::unique_ptr<XRayPointsProcessor> FromDictionary(
+      common::LuaParameterDictionary* dictionary, PointsProcessor* next);
+
   ~XRayPointsProcessor() override {}
 
   void Process(std::unique_ptr<PointsBatch> batch) override;

cartographer/io/xyz_writing_points_processor.cc

@@ -2,6 +2,7 @@
 
 #include <iomanip>
 
+#include "cartographer/common/make_unique.h"
 #include "glog/logging.h"
 
 namespace cartographer {
@@ -21,6 +22,14 @@ XyzWriterPointsProcessor::XyzWriterPointsProcessor(const string& filename,
   file_ << std::setprecision(6);
 }
 
+std::unique_ptr<XyzWriterPointsProcessor>
+XyzWriterPointsProcessor::FromDictionary(
+    common::LuaParameterDictionary* const dictionary,
+    PointsProcessor* const next) {
+  return common::make_unique<XyzWriterPointsProcessor>(
+      dictionary->GetString("filename"), next);
+}
+
 PointsProcessor::FlushResult XyzWriterPointsProcessor::Flush() {
   file_.close();
   CHECK(file_) << "Writing XYZ file failed.";

cartographer/io/xyz_writing_points_processor.h

@@ -20,6 +20,7 @@
 #include <fstream>
 #include <string>
 
+#include "cartographer/common/lua_parameter_dictionary.h"
 #include "cartographer/io/points_processor.h"
 
 namespace cartographer {
@@ -28,7 +29,13 @@ namespace io {
 // Writes ASCII xyz points.
 class XyzWriterPointsProcessor : public PointsProcessor {
  public:
+  constexpr static const char* kConfigurationFileActionName = "write_xyz";
+
   XyzWriterPointsProcessor(const string& filename, PointsProcessor* next);
+
+  static std::unique_ptr<XyzWriterPointsProcessor> FromDictionary(
+      common::LuaParameterDictionary* dictionary, PointsProcessor* next);
+
   ~XyzWriterPointsProcessor() override {}
 
   XyzWriterPointsProcessor(const XyzWriterPointsProcessor&) = delete;

scripts/update_cmakelists.py

@@ -231,8 +231,8 @@ def RunOnDirectory(root):
     for c in sorted(mains):
       # Binaries do not get their full subpath appended, but we prepend
       # 'cartographer' to distinguish them after installation. So,
-      # 'io/asset_writer_main.cc' will generate a binary called
+      # 'io/assets_writer_main.cc' will generate a binary called
-      # 'cartographer_asset_writer'.
+      # 'cartographer_assets_writer'.
       name = "cartographer_" + path.basename(path.splitext(c)[0][:-5])
       AddTarget("google_binary", name, directory, [c], [])