Split camera_reader into a lib and main

Change-Id: If3ace42d69d4abf2aea501457e7c0757426688c4
Signed-off-by: James Kuszmaul <jabukuszmaul@gmail.com>
diff --git a/y2020/vision/BUILD b/y2020/vision/BUILD
index b43829d..7f57e3a 100644
--- a/y2020/vision/BUILD
+++ b/y2020/vision/BUILD
@@ -39,8 +39,25 @@
 cc_binary(
     name = "camera_reader",
     srcs = [
+        "camera_reader_main.cc",
+    ],
+    target_compatible_with = ["@platforms//os:linux"],
+    visibility = ["//y2020:__subpackages__"],
+    deps = [
+        ":camera_reader_lib",
+        "//aos:init",
+        "//aos/events:shm_event_loop",
+    ],
+)
+
+cc_library(
+    name = "camera_reader_lib",
+    srcs = [
         "camera_reader.cc",
     ],
+    hdrs = [
+        "camera_reader.h",
+    ],
     data = [
         "//y2020:config",
     ],
@@ -50,8 +67,7 @@
         ":v4l2_reader",
         ":vision_fbs",
         "//aos:flatbuffer_merge",
-        "//aos:init",
-        "//aos/events:shm_event_loop",
+        "//aos/events:event_loop",
         "//aos/network:team_number",
         "//third_party:opencv",
         "//y2020/vision/sift:sift971",
diff --git a/y2020/vision/camera_reader.cc b/y2020/vision/camera_reader.cc
index b13c19c..64e7948 100644
--- a/y2020/vision/camera_reader.cc
+++ b/y2020/vision/camera_reader.cc
@@ -1,12 +1,13 @@
+#include "y2020/vision/camera_reader.h"
+
 #include <math.h>
 
 #include <opencv2/calib3d.hpp>
 #include <opencv2/features2d.hpp>
 #include <opencv2/imgproc.hpp>
 
-#include "aos/events/shm_event_loop.h"
+#include "aos/events/event_loop.h"
 #include "aos/flatbuffer_merge.h"
-#include "aos/init.h"
 #include "aos/network/team_number.h"
 #include "y2020/vision/sift/sift971.h"
 #include "y2020/vision/sift/sift_generated.h"
@@ -15,10 +16,6 @@
 #include "y2020/vision/v4l2_reader.h"
 #include "y2020/vision/vision_generated.h"
 
-// config used to allow running camera_reader independently.  E.g.,
-// bazel run //y2020/vision:camera_reader -- --config y2020/config.json
-//   --override_hostname pi-7971-1  --ignore_timestamps true
-DEFINE_string(config, "config.json", "Path to the config file to use.");
 DEFINE_bool(skip_sift, false,
             "If true don't run any feature extraction.  Just forward images.");
 DEFINE_bool(ransac_pose, false,
@@ -28,156 +25,6 @@
 
 namespace frc971 {
 namespace vision {
-namespace {
-
-class CameraReader {
- public:
-  CameraReader(aos::EventLoop *event_loop,
-               const sift::TrainingData *training_data, V4L2Reader *reader,
-               const cv::Ptr<cv::flann::IndexParams> &index_params,
-               const cv::Ptr<cv::flann::SearchParams> &search_params)
-      : event_loop_(event_loop),
-        training_data_(training_data),
-        camera_calibration_(FindCameraCalibration()),
-        reader_(reader),
-        image_sender_(event_loop->MakeSender<CameraImage>("/camera")),
-        result_sender_(
-            event_loop->MakeSender<sift::ImageMatchResult>("/camera")),
-        detailed_result_sender_(
-            event_loop->MakeSender<sift::ImageMatchResult>("/camera/detailed")),
-        read_image_timer_(event_loop->AddTimer([this]() { ReadImage(); })) {
-    for (int ii = 0; ii < number_training_images(); ++ii) {
-      matchers_.push_back(cv::FlannBasedMatcher(index_params, search_params));
-      prev_camera_field_R_vec_list_.push_back(cv::Mat::zeros(3, 1, CV_32F));
-      prev_camera_field_T_list_.push_back(cv::Mat::zeros(3, 1, CV_32F));
-    }
-    CopyTrainingFeatures();
-
-    for (auto &matcher : matchers_) {
-      matcher.train();
-    }
-
-    event_loop->OnRun(
-        [this]() { read_image_timer_->Setup(event_loop_->monotonic_now()); });
-  }
-
- private:
-  const sift::CameraCalibration *FindCameraCalibration() const;
-
-  // Copies the information from training_data_ into matcher_.
-  void CopyTrainingFeatures();
-  // Processes an image (including sending the results).
-  void ProcessImage(const CameraImage &image);
-  // Reads an image, and then performs all of our processing on it.
-  void ReadImage();
-
-  flatbuffers::Offset<
-      flatbuffers::Vector<flatbuffers::Offset<sift::ImageMatch>>>
-  PackImageMatches(flatbuffers::FlatBufferBuilder *fbb,
-                   const std::vector<std::vector<cv::DMatch>> &matches);
-  flatbuffers::Offset<flatbuffers::Vector<flatbuffers::Offset<sift::Feature>>>
-  PackFeatures(flatbuffers::FlatBufferBuilder *fbb,
-               const std::vector<cv::KeyPoint> &keypoints,
-               const cv::Mat &descriptors);
-
-  void SendImageMatchResult(const CameraImage &image,
-                            const std::vector<cv::KeyPoint> &keypoints,
-                            const cv::Mat &descriptors,
-                            const std::vector<std::vector<cv::DMatch>> &matches,
-                            const std::vector<cv::Mat> &camera_target_list,
-                            const std::vector<cv::Mat> &field_camera_list,
-                            const std::vector<cv::Point2f> &target_point_vector,
-                            const std::vector<float> &target_radius_vector,
-                            const std::vector<int> &training_image_indices,
-                            const std::vector<int> &homography_feature_counts,
-                            aos::Sender<sift::ImageMatchResult> *result_sender,
-                            bool send_details);
-
-  // Returns the 2D (image) location for the specified training feature.
-  cv::Point2f Training2dPoint(int training_image_index,
-                              int feature_index) const {
-    const float x = training_data_->images()
-                        ->Get(training_image_index)
-                        ->features()
-                        ->Get(feature_index)
-                        ->x();
-    const float y = training_data_->images()
-                        ->Get(training_image_index)
-                        ->features()
-                        ->Get(feature_index)
-                        ->y();
-    return cv::Point2f(x, y);
-  }
-
-  // Returns the 3D location for the specified training feature.
-  cv::Point3f Training3dPoint(int training_image_index,
-                              int feature_index) const {
-    const sift::KeypointFieldLocation *const location =
-        training_data_->images()
-            ->Get(training_image_index)
-            ->features()
-            ->Get(feature_index)
-            ->field_location();
-    return cv::Point3f(location->x(), location->y(), location->z());
-  }
-
-  const sift::TransformationMatrix *FieldToTarget(int training_image_index) {
-    return training_data_->images()
-        ->Get(training_image_index)
-        ->field_to_target();
-  }
-
-  void TargetLocation(int training_image_index, cv::Point2f &target_location,
-                      float &target_radius) {
-    target_location.x =
-        training_data_->images()->Get(training_image_index)->target_point_x();
-    target_location.y =
-        training_data_->images()->Get(training_image_index)->target_point_y();
-    target_radius = training_data_->images()
-                        ->Get(training_image_index)
-                        ->target_point_radius();
-  }
-
-  int number_training_images() const {
-    return training_data_->images()->size();
-  }
-
-  cv::Mat CameraIntrinsics() const {
-    const cv::Mat result(3, 3, CV_32F,
-                         const_cast<void *>(static_cast<const void *>(
-                             camera_calibration_->intrinsics()->data())));
-    CHECK_EQ(result.total(), camera_calibration_->intrinsics()->size());
-    return result;
-  }
-
-  cv::Mat CameraDistCoeffs() const {
-    const cv::Mat result(5, 1, CV_32F,
-                         const_cast<void *>(static_cast<const void *>(
-                             camera_calibration_->dist_coeffs()->data())));
-    CHECK_EQ(result.total(), camera_calibration_->dist_coeffs()->size());
-    return result;
-  }
-
-  aos::EventLoop *const event_loop_;
-  const sift::TrainingData *const training_data_;
-  const sift::CameraCalibration *const camera_calibration_;
-  V4L2Reader *const reader_;
-  std::vector<cv::FlannBasedMatcher> matchers_;
-  aos::Sender<CameraImage> image_sender_;
-  aos::Sender<sift::ImageMatchResult> result_sender_;
-  aos::SendFailureCounter result_failure_counter_;
-  aos::Sender<sift::ImageMatchResult> detailed_result_sender_;
-  // We schedule this immediately to read an image. Having it on a timer means
-  // other things can run on the event loop in between.
-  aos::TimerHandler *const read_image_timer_;
-
-  // Storage for when we want to use the previous estimates of pose
-  std::vector<cv::Mat> prev_camera_field_R_vec_list_;
-  std::vector<cv::Mat> prev_camera_field_T_list_;
-
-  const std::unique_ptr<frc971::vision::SIFT971_Impl> sift_{
-      new frc971::vision::SIFT971_Impl()};
-};
 
 const sift::CameraCalibration *CameraReader::FindCameraCalibration() const {
   const std::string_view node_name = event_loop_->node()->name()->string_view();
@@ -694,43 +541,5 @@
   return fbb->CreateVector(features_vector);
 }
 
-void CameraReaderMain() {
-  aos::FlatbufferDetachedBuffer<aos::Configuration> config =
-      aos::configuration::ReadConfig(FLAGS_config);
-
-  const aos::FlatbufferSpan<sift::TrainingData> training_data(
-      SiftTrainingData());
-  CHECK(training_data.Verify());
-
-  const auto index_params = cv::makePtr<cv::flann::IndexParams>();
-  index_params->setAlgorithm(cvflann::FLANN_INDEX_KDTREE);
-  index_params->setInt("trees", 5);
-  const auto search_params =
-      cv::makePtr<cv::flann::SearchParams>(/* checks */ 50);
-  cv::FlannBasedMatcher matcher(index_params, search_params);
-
-  aos::ShmEventLoop event_loop(&config.message());
-
-  // First, log the data for future reference.
-  {
-    aos::Sender<sift::TrainingData> training_data_sender =
-        event_loop.MakeSender<sift::TrainingData>("/camera");
-    CHECK_EQ(training_data_sender.Send(training_data),
-             aos::RawSender::Error::kOk);
-  }
-
-  V4L2Reader v4l2_reader(&event_loop, "/dev/video0");
-  CameraReader camera_reader(&event_loop, &training_data.message(),
-                             &v4l2_reader, index_params, search_params);
-
-  event_loop.Run();
-}
-
-}  // namespace
 }  // namespace vision
 }  // namespace frc971
-
-int main(int argc, char **argv) {
-  aos::InitGoogle(&argc, &argv);
-  frc971::vision::CameraReaderMain();
-}
diff --git a/y2020/vision/camera_reader.h b/y2020/vision/camera_reader.h
new file mode 100644
index 0000000..c05ebea
--- /dev/null
+++ b/y2020/vision/camera_reader.h
@@ -0,0 +1,174 @@
+#ifndef Y2020_VISION_CAMERA_READER_H_
+#define Y2020_VISION_CAMERA_READER_H_
+
+#include <math.h>
+
+#include <opencv2/calib3d.hpp>
+#include <opencv2/features2d.hpp>
+#include <opencv2/imgproc.hpp>
+
+#include "aos/events/event_loop.h"
+#include "aos/flatbuffer_merge.h"
+#include "aos/network/team_number.h"
+#include "y2020/vision/sift/sift971.h"
+#include "y2020/vision/sift/sift_generated.h"
+#include "y2020/vision/sift/sift_training_generated.h"
+#include "y2020/vision/tools/python_code/sift_training_data.h"
+#include "y2020/vision/v4l2_reader.h"
+#include "y2020/vision/vision_generated.h"
+
+namespace frc971 {
+namespace vision {
+
+class CameraReader {
+ public:
+  CameraReader(aos::EventLoop *event_loop,
+               const sift::TrainingData *training_data, V4L2Reader *reader,
+               const cv::Ptr<cv::flann::IndexParams> &index_params,
+               const cv::Ptr<cv::flann::SearchParams> &search_params)
+      : event_loop_(event_loop),
+        training_data_(training_data),
+        camera_calibration_(FindCameraCalibration()),
+        reader_(reader),
+        image_sender_(event_loop->MakeSender<CameraImage>("/camera")),
+        result_sender_(
+            event_loop->MakeSender<sift::ImageMatchResult>("/camera")),
+        detailed_result_sender_(
+            event_loop->MakeSender<sift::ImageMatchResult>("/camera/detailed")),
+        read_image_timer_(event_loop->AddTimer([this]() { ReadImage(); })) {
+    for (int ii = 0; ii < number_training_images(); ++ii) {
+      matchers_.push_back(cv::FlannBasedMatcher(index_params, search_params));
+      prev_camera_field_R_vec_list_.push_back(cv::Mat::zeros(3, 1, CV_32F));
+      prev_camera_field_T_list_.push_back(cv::Mat::zeros(3, 1, CV_32F));
+    }
+    CopyTrainingFeatures();
+
+    for (auto &matcher : matchers_) {
+      matcher.train();
+    }
+
+    event_loop->OnRun(
+        [this]() { read_image_timer_->Setup(event_loop_->monotonic_now()); });
+  }
+
+ private:
+  const sift::CameraCalibration *FindCameraCalibration() const;
+
+  // Copies the information from training_data_ into matcher_.
+  void CopyTrainingFeatures();
+  // Processes an image (including sending the results).
+  void ProcessImage(const CameraImage &image);
+  // Reads an image, and then performs all of our processing on it.
+  void ReadImage();
+
+  flatbuffers::Offset<
+      flatbuffers::Vector<flatbuffers::Offset<sift::ImageMatch>>>
+  PackImageMatches(flatbuffers::FlatBufferBuilder *fbb,
+                   const std::vector<std::vector<cv::DMatch>> &matches);
+  flatbuffers::Offset<flatbuffers::Vector<flatbuffers::Offset<sift::Feature>>>
+  PackFeatures(flatbuffers::FlatBufferBuilder *fbb,
+               const std::vector<cv::KeyPoint> &keypoints,
+               const cv::Mat &descriptors);
+
+  void SendImageMatchResult(const CameraImage &image,
+                            const std::vector<cv::KeyPoint> &keypoints,
+                            const cv::Mat &descriptors,
+                            const std::vector<std::vector<cv::DMatch>> &matches,
+                            const std::vector<cv::Mat> &camera_target_list,
+                            const std::vector<cv::Mat> &field_camera_list,
+                            const std::vector<cv::Point2f> &target_point_vector,
+                            const std::vector<float> &target_radius_vector,
+                            const std::vector<int> &training_image_indices,
+                            const std::vector<int> &homography_feature_counts,
+                            aos::Sender<sift::ImageMatchResult> *result_sender,
+                            bool send_details);
+
+  // Returns the 2D (image) location for the specified training feature.
+  cv::Point2f Training2dPoint(int training_image_index,
+                              int feature_index) const {
+    const float x = training_data_->images()
+                        ->Get(training_image_index)
+                        ->features()
+                        ->Get(feature_index)
+                        ->x();
+    const float y = training_data_->images()
+                        ->Get(training_image_index)
+                        ->features()
+                        ->Get(feature_index)
+                        ->y();
+    return cv::Point2f(x, y);
+  }
+
+  // Returns the 3D location for the specified training feature.
+  cv::Point3f Training3dPoint(int training_image_index,
+                              int feature_index) const {
+    const sift::KeypointFieldLocation *const location =
+        training_data_->images()
+            ->Get(training_image_index)
+            ->features()
+            ->Get(feature_index)
+            ->field_location();
+    return cv::Point3f(location->x(), location->y(), location->z());
+  }
+
+  const sift::TransformationMatrix *FieldToTarget(int training_image_index) {
+    return training_data_->images()
+        ->Get(training_image_index)
+        ->field_to_target();
+  }
+
+  void TargetLocation(int training_image_index, cv::Point2f &target_location,
+                      float &target_radius) {
+    target_location.x =
+        training_data_->images()->Get(training_image_index)->target_point_x();
+    target_location.y =
+        training_data_->images()->Get(training_image_index)->target_point_y();
+    target_radius = training_data_->images()
+                        ->Get(training_image_index)
+                        ->target_point_radius();
+  }
+
+  int number_training_images() const {
+    return training_data_->images()->size();
+  }
+
+  cv::Mat CameraIntrinsics() const {
+    const cv::Mat result(3, 3, CV_32F,
+                         const_cast<void *>(static_cast<const void *>(
+                             camera_calibration_->intrinsics()->data())));
+    CHECK_EQ(result.total(), camera_calibration_->intrinsics()->size());
+    return result;
+  }
+
+  cv::Mat CameraDistCoeffs() const {
+    const cv::Mat result(5, 1, CV_32F,
+                         const_cast<void *>(static_cast<const void *>(
+                             camera_calibration_->dist_coeffs()->data())));
+    CHECK_EQ(result.total(), camera_calibration_->dist_coeffs()->size());
+    return result;
+  }
+
+  aos::EventLoop *const event_loop_;
+  const sift::TrainingData *const training_data_;
+  const sift::CameraCalibration *const camera_calibration_;
+  V4L2Reader *const reader_;
+  std::vector<cv::FlannBasedMatcher> matchers_;
+  aos::Sender<CameraImage> image_sender_;
+  aos::Sender<sift::ImageMatchResult> result_sender_;
+  aos::SendFailureCounter result_failure_counter_;
+  aos::Sender<sift::ImageMatchResult> detailed_result_sender_;
+  // We schedule this immediately to read an image. Having it on a timer means
+  // other things can run on the event loop in between.
+  aos::TimerHandler *const read_image_timer_;
+
+  // Storage for when we want to use the previous estimates of pose
+  std::vector<cv::Mat> prev_camera_field_R_vec_list_;
+  std::vector<cv::Mat> prev_camera_field_T_list_;
+
+  const std::unique_ptr<frc971::vision::SIFT971_Impl> sift_{
+      new frc971::vision::SIFT971_Impl()};
+};
+
+}  // namespace vision
+}  // namespace frc971
+#endif  // Y2020_VISION_CAMERA_READER_H_
diff --git a/y2020/vision/camera_reader_main.cc b/y2020/vision/camera_reader_main.cc
new file mode 100644
index 0000000..c7fec43
--- /dev/null
+++ b/y2020/vision/camera_reader_main.cc
@@ -0,0 +1,52 @@
+#include "aos/events/shm_event_loop.h"
+#include "aos/init.h"
+#include "y2020/vision/camera_reader.h"
+
+// config used to allow running camera_reader independently.  E.g.,
+// bazel run //y2020/vision:camera_reader -- --config y2020/config.json
+//   --override_hostname pi-7971-1  --ignore_timestamps true
+DEFINE_string(config, "config.json", "Path to the config file to use.");
+namespace frc971 {
+namespace vision {
+namespace {
+
+void CameraReaderMain() {
+  aos::FlatbufferDetachedBuffer<aos::Configuration> config =
+      aos::configuration::ReadConfig(FLAGS_config);
+
+  const aos::FlatbufferSpan<sift::TrainingData> training_data(
+      SiftTrainingData());
+  CHECK(training_data.Verify());
+
+  const auto index_params = cv::makePtr<cv::flann::IndexParams>();
+  index_params->setAlgorithm(cvflann::FLANN_INDEX_KDTREE);
+  index_params->setInt("trees", 5);
+  const auto search_params =
+      cv::makePtr<cv::flann::SearchParams>(/* checks */ 50);
+  cv::FlannBasedMatcher matcher(index_params, search_params);
+
+  aos::ShmEventLoop event_loop(&config.message());
+
+  // First, log the data for future reference.
+  {
+    aos::Sender<sift::TrainingData> training_data_sender =
+        event_loop.MakeSender<sift::TrainingData>("/camera");
+    CHECK_EQ(training_data_sender.Send(training_data),
+             aos::RawSender::Error::kOk);
+  }
+
+  V4L2Reader v4l2_reader(&event_loop, "/dev/video0");
+  CameraReader camera_reader(&event_loop, &training_data.message(),
+                             &v4l2_reader, index_params, search_params);
+
+  event_loop.Run();
+}
+
+}  // namespace
+}  // namespace vision
+}  // namespace frc971
+
+int main(int argc, char **argv) {
+  aos::InitGoogle(&argc, &argv);
+  frc971::vision::CameraReaderMain();
+}