Setting up Blob detector and viewer code in y2022

Includes viewer with SIFT code stripped out, since we're not using it
in y2022.

Change-Id: Id56e9e5c868a1d730dcfb433d5e4868898a6f011
Signed-off-by: Jim Ostrowski <yimmy13@gmail.com>
diff --git a/y2022/vision/camera_reader_main.cc b/y2022/vision/camera_reader_main.cc
new file mode 100644
index 0000000..ee65cfe
--- /dev/null
+++ b/y2022/vision/camera_reader_main.cc
@@ -0,0 +1,58 @@
+#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 //y2022/vision:camera_reader -- --config y2022/config.json
+//   --override_hostname pi-7971-1  --ignore_timestamps true
+DEFINE_string(config, "config.json", "Path to the config file to use.");
+DEFINE_uint32(exposure, 5, "Exposure time, in 100us increments");
+
+namespace y2022 {
+namespace vision {
+namespace {
+
+using namespace frc971::vision;
+
+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);
+
+  v4l2_reader.SetExposure(FLAGS_exposure);
+
+  event_loop.Run();
+}
+
+}  // namespace
+}  // namespace vision
+}  // namespace y2022
+
+int main(int argc, char **argv) {
+  aos::InitGoogle(&argc, &argv);
+  y2022::vision::CameraReaderMain();
+}