Add constants.h which contains the result of calibration.

Change-Id: Ia7f76ff9bd549728c40888e800ebc266769525db
diff --git a/y2019/vision/constants.h b/y2019/vision/constants.h
new file mode 100644
index 0000000..cbad8bf
--- /dev/null
+++ b/y2019/vision/constants.h
@@ -0,0 +1,78 @@
+#ifndef _Y2019_VISION_CONSTANTS_H_
+#define _Y2019_VISION_CONSTANTS_H_
+
+#include <math.h>
+#include <array>
+#include <string>
+
+namespace y2019 {
+namespace vision {
+
+// Position of the idealized camera in 3d space.
+struct CameraGeometry {
+  // In Meters from floor under imu center.
+  std::array<double, 3> location{{0, 0, 0}};
+  double heading = 0.0;
+
+  void set(double *data) {
+    location[0] = data[0];
+    location[1] = data[1];
+    location[2] = data[2];
+    heading = data[3];
+  }
+  static CameraGeometry get(const double *data) {
+    CameraGeometry out;
+    out.location[0] = data[0];
+    out.location[1] = data[1];
+    out.location[2] = data[2];
+    out.heading = data[3];
+    return out;
+  }
+};
+
+struct IntrinsicParams {
+  static constexpr size_t kNumParams = 3;
+
+  double mount_angle = 0.819433 / 180.0 * M_PI;  // 9.32615 / 180.0 * M_PI;
+  double focal_length = 666.763;                 // 734.328;
+  // This is a final rotation where the camera isn't straight.
+  double barrel_mount = 2.72086 / 180.0 * M_PI;
+
+  void set(double *data) {
+    data[0] = mount_angle;
+    data[1] = focal_length;
+    data[2] = barrel_mount;
+  }
+  static IntrinsicParams get(const double *data) {
+    IntrinsicParams out;
+    out.mount_angle = data[0];
+    out.focal_length = data[1];
+    out.barrel_mount = data[2];
+    return out;
+  }
+};
+
+// Metadata about the calibration results (Should be good enough to reproduce).
+struct DatasetInfo {
+  int camera_id;
+  // In meters from IMU start.
+  std::array<double, 2> to_tape_measure_start;
+  // In meters,
+  std::array<double, 2> tape_measure_direction;
+  // This will multiply tape_measure_direction and thus has no units.
+  double beginning_tape_measure_reading;
+  const char *filename_prefix;
+};
+
+struct CameraCalibration {
+  IntrinsicParams intrinsics;
+  CameraGeometry geometry;
+  DatasetInfo dataset;
+};
+
+const CameraCalibration *GetCamera(int camera_id);
+
+}  // namespace vision
+}  // namespace y2019
+
+#endif  // _Y2019_VISION_CONSTANTS_H_