Adding in a stripped down camera_reader

This camera_reader will serve as routing point of images getting processed
on the pi's

Change-Id: I8e7472d44d6cfec1e8453be55f03234476f106a4
Signed-off-by: Jim Ostrowski <yimmy13@gmail.com>
diff --git a/y2022/vision/camera_reader.h b/y2022/vision/camera_reader.h
new file mode 100644
index 0000000..c302b15
--- /dev/null
+++ b/y2022/vision/camera_reader.h
@@ -0,0 +1,78 @@
+#ifndef Y2022_VISION_CAMERA_READER_H_
+#define Y2022_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 "frc971/vision/v4l2_reader.h"
+#include "frc971/vision/vision_generated.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"
+
+namespace y2022 {
+namespace vision {
+
+using namespace frc971::vision;
+
+// TODO<Jim/Milind>: Need to add in senders to send out the blob data/stats
+
+class CameraReader {
+ public:
+  CameraReader(aos::EventLoop *event_loop,
+               const sift::TrainingData *training_data, V4L2Reader *reader)
+      : event_loop_(event_loop),
+        training_data_(training_data),
+        camera_calibration_(FindCameraCalibration()),
+        reader_(reader),
+        image_sender_(event_loop->MakeSender<CameraImage>("/camera")),
+        read_image_timer_(event_loop->AddTimer([this]() { ReadImage(); })) {
+    event_loop->OnRun(
+        [this]() { read_image_timer_->Setup(event_loop_->monotonic_now()); });
+  }
+
+ private:
+  const sift::CameraCalibration *FindCameraCalibration() const;
+
+  // 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();
+
+  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_;
+  aos::Sender<CameraImage> image_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_;
+};
+
+}  // namespace vision
+}  // namespace y2022
+#endif  // Y2022_VISION_CAMERA_READER_H_