Merge changes I3e764082,I73bfde64,I94fd3166

* changes:
  Account for delayed U in using localizer
  Add interface for target selector
  Add basic line-following drivetrain
diff --git a/aos/vision/blob/contour.h b/aos/vision/blob/contour.h
index 9cd1400..bbd59a9 100644
--- a/aos/vision/blob/contour.h
+++ b/aos/vision/blob/contour.h
@@ -25,6 +25,7 @@
   ContourNode *pappend(int x, int y, AnalysisAllocator *alloc) {
     return alloc->cons_obj<ContourNode>(x, y, this);
   }
+  void set_point(Point new_pt) { pt = new_pt; }
 
   Point pt;
   ContourNode *next;
diff --git a/aos/vision/blob/range_image.cc b/aos/vision/blob/range_image.cc
index 946859d..c01a919 100644
--- a/aos/vision/blob/range_image.cc
+++ b/aos/vision/blob/range_image.cc
@@ -69,17 +69,17 @@
   RangeImage rimg = MergeRangeImage(blobl);
   int minx = rimg.ranges()[0][0].st;
   int maxx = 0;
-  for (const auto &range : rimg.ranges()) {
-    for (const auto &span : range) {
+  for (const std::vector<ImageRange> &range : rimg.ranges()) {
+    for (const ImageRange &span : range) {
       if (span.st < minx) minx = span.st;
       if (span.ed > maxx) maxx = span.ed;
     }
   }
   printf("maxx: %d minx: %d\n", maxx, minx);
   char buf[maxx - minx];
-  for (const auto &range : rimg.ranges()) {
+  for (const std::vector<ImageRange> &range : rimg.ranges()) {
     int i = minx;
-    for (const auto &span : range) {
+    for (const ImageRange &span : range) {
       for (; i < span.st; ++i) buf[i - minx] = ' ';
       for (; i < span.ed; ++i) buf[i - minx] = '#';
     }
diff --git a/frc971/control_loops/drivetrain/libspline.cc b/frc971/control_loops/drivetrain/libspline.cc
index f931e59..1d7aa0b 100644
--- a/frc971/control_loops/drivetrain/libspline.cc
+++ b/frc971/control_loops/drivetrain/libspline.cc
@@ -197,9 +197,9 @@
   void TrajectoryGetPlanXVA(::std::vector<::Eigen::Matrix<double, 3, 1>> *vec,
                             double *X, double *V, double *A) {
     for (size_t i = 0; i < vec->size(); ++i) {
-      X[i] = (*vec)[0][0];
-      V[i] = (*vec)[0][1];
-      A[i] = (*vec)[0][2];
+      X[i] = (*vec)[i][0];
+      V[i] = (*vec)[i][1];
+      A[i] = (*vec)[i][2];
     }
   }
 
diff --git a/motors/print/BUILD b/motors/print/BUILD
index 26ee976..26d8e45 100644
--- a/motors/print/BUILD
+++ b/motors/print/BUILD
@@ -8,6 +8,7 @@
     restricted_to = mcu_cpus,
     visibility = ["//visibility:public"],
     deps = [
+        "//aos/containers:sized_array",
         "//motors/core",
         "//third_party/GSL",
     ],
diff --git a/motors/print/print.h b/motors/print/print.h
index d51a2c3..89da913 100644
--- a/motors/print/print.h
+++ b/motors/print/print.h
@@ -3,6 +3,7 @@
 
 #include <memory>
 
+#include "aos/containers/sized_array.h"
 #include "motors/core/kinetis.h"
 #include "third_party/GSL/include/gsl/gsl"
 
@@ -29,6 +30,11 @@
   // Writes something to a separate debug stream. Some implementations will
   // always ignore this, and others will ignore it under some conditions.
   virtual int WriteDebug(gsl::span<const char> buffer) { return buffer.size(); }
+
+  // Reads any characters which are available (never blocks).
+  //
+  // The default never returns any data.
+  virtual aos::SizedArray<char, 4> ReadStdin() { return {}; }
 };
 
 // A trivial printing "implementation" which simply does nothing. This is used
diff --git a/motors/print/usb.h b/motors/print/usb.h
index 7e63184..981c5d3 100644
--- a/motors/print/usb.h
+++ b/motors/print/usb.h
@@ -28,6 +28,12 @@
     return debug_tty_->Write(buffer.data(), buffer.size());
   }
 
+  aos::SizedArray<char, 4> ReadStdin() override {
+    aos::SizedArray<char, 4> result;
+    result.set_size(stdout_tty_->Read(result.data(), result.max_size()));
+    return result;
+  }
+
  private:
   teensy::AcmTty *const stdout_tty_;
   teensy::AcmTty *const debug_tty_;
@@ -50,6 +56,12 @@
     return debug_tty_.Write(buffer.data(), buffer.size());
   }
 
+  aos::SizedArray<char, 4> ReadStdin() override {
+    aos::SizedArray<char, 4> result;
+    result.set_size(stdout_tty_.Read(result.data(), result.max_size()));
+    return result;
+  }
+
  private:
   teensy::UsbDevice usb_device_;
   teensy::AcmTty stdout_tty_;
diff --git a/y2019/jevois/spi.cc b/y2019/jevois/spi.cc
index 2d3e2f2..b6e6632 100644
--- a/y2019/jevois/spi.cc
+++ b/y2019/jevois/spi.cc
@@ -252,6 +252,8 @@
     memcpy(remaining_space.data(), &realtime_now, sizeof(realtime_now));
     remaining_space = remaining_space.subspan(sizeof(realtime_now));
   }
+  memcpy(remaining_space.data(), &message.camera_command, 1);
+  remaining_space = remaining_space.subspan(1);
   {
     uint16_t crc = jevois_crc_init();
     crc = jevois_crc_update(crc, transfer.data(),
@@ -281,6 +283,8 @@
         aos::realtime_clock::duration(realtime_now));
     remaining_input = remaining_input.subspan(sizeof(realtime_now));
   }
+  memcpy(&message.camera_command, remaining_input.data(), 1);
+  remaining_input = remaining_input.subspan(1);
   {
     uint16_t calculated_crc = jevois_crc_init();
     calculated_crc =
diff --git a/y2019/jevois/spi_test.cc b/y2019/jevois/spi_test.cc
index 8f08fcb..32551db 100644
--- a/y2019/jevois/spi_test.cc
+++ b/y2019/jevois/spi_test.cc
@@ -107,7 +107,28 @@
 
 // Tests packing and then unpacking an empty message.
 TEST(SpiToTeensyPackTest, Empty) {
+  RoborioToTeensy input_message{};
+  const SpiTransfer transfer = SpiPackToTeensy(input_message);
+  const auto output_message = SpiUnpackToTeensy(transfer);
+  ASSERT_TRUE(output_message);
+  EXPECT_EQ(input_message, output_message.value());
+}
+
+// Tests packing and then unpacking a message with all the fields set.
+TEST(SpiToTeensyPackTest, Full) {
   RoborioToTeensy input_message;
+  input_message.beacon_brightness[0] = 9;
+  input_message.beacon_brightness[1] = 7;
+  input_message.beacon_brightness[2] = 1;
+  input_message.light_rings[0] = 1;
+  input_message.light_rings[1] = 0;
+  input_message.light_rings[2] = 0;
+  input_message.light_rings[3] = 1;
+  input_message.light_rings[4] = 0;
+  input_message.realtime_now =
+      aos::realtime_clock::epoch() + std::chrono::seconds(971254);
+  input_message.camera_command = CameraCommand::kUsb;
+
   const SpiTransfer transfer = SpiPackToTeensy(input_message);
   const auto output_message = SpiUnpackToTeensy(transfer);
   ASSERT_TRUE(output_message);
diff --git a/y2019/jevois/structures.h b/y2019/jevois/structures.h
index 28da405..1f10dc0 100644
--- a/y2019/jevois/structures.h
+++ b/y2019/jevois/structures.h
@@ -106,17 +106,17 @@
   camera_duration age;
 };
 
+enum class CameraCommand : char {
+  // Stay in normal mode.
+  kNormal,
+  // Go to camera passthrough mode.
+  kCameraPassthrough,
+  // Go to being a useful USB device.
+  kUsb,
+};
+
 // This is all the information sent from the Teensy to each camera.
 struct CameraCalibration {
-  enum class CameraCommand : char {
-    // Stay in normal mode.
-    kNormal,
-    // Go to camera passthrough mode.
-    kCameraPassthrough,
-    // Go to being a useful USB device.
-    kUsb,
-  };
-
   bool operator==(const CameraCalibration &other) const {
     if (other.calibration != calibration) {
       return false;
@@ -139,6 +139,9 @@
   // The calibration matrix. This defines where the camera is pointing.
   //
   // TODO(Parker): What are the details on how this is defined?
+  // [0][0]: mount_angle
+  // [0][1]: focal_length
+  // [0][2]: barrel_mount
   Eigen::Matrix<float, 3, 4> calibration;
 
   // A local timestamp from the Teensy. This starts at 0 when the Teensy is
@@ -194,6 +197,9 @@
 
   // The current time.
   aos::realtime_clock::time_point realtime_now;
+
+  // A command to send to all the cameras.
+  CameraCommand camera_command;
 };
 
 }  // namespace jevois
diff --git a/y2019/jevois/teensy.cc b/y2019/jevois/teensy.cc
index 44b2505..a3b93d2 100644
--- a/y2019/jevois/teensy.cc
+++ b/y2019/jevois/teensy.cc
@@ -577,7 +577,8 @@
 // claiming that it's impossible to queue up the first byte for the slave end of
 // an SPI connection properly. Instead, we just accept there will be a garbage
 // byte and the other end ignores it.
-__attribute__((unused)) void TransferData() {
+__attribute__((unused)) void TransferData(
+    frc971::motors::PrintingImplementation *printing) {
   Uarts *const uarts = Uarts::global_instance;
   std::array<CobsPacketizer<uart_to_teensy_size()>, 5> packetizers;
   std::array<TransmitBuffer, 5> transmit_buffers{
@@ -585,13 +586,18 @@
   FrameQueue frame_queue;
   aos::monotonic_clock::time_point last_camera_send =
       aos::monotonic_clock::min_time;
+  CameraCommand stdin_camera_command = CameraCommand::kNormal;
+  CameraCommand last_roborio_camera_command = CameraCommand::kNormal;
+
   bool first = true;
   while (true) {
     {
       const auto received_transfer = SpiQueue::global_instance->Tick();
       if (received_transfer) {
         const auto unpacked = SpiUnpackToTeensy(*received_transfer);
-        if (!unpacked) {
+        if (unpacked) {
+          last_roborio_camera_command = unpacked->camera_command;
+        } else {
           printf("UART decode error\n");
         }
       }
@@ -639,7 +645,11 @@
         CameraCalibration calibration{};
         calibration.teensy_now = aos::monotonic_clock::now();
         calibration.realtime_now = aos::realtime_clock::min_time;
-        calibration.camera_command = CameraCalibration::CameraCommand::kNormal;
+        if (last_roborio_camera_command != CameraCommand::kNormal) {
+          calibration.camera_command = last_roborio_camera_command;
+        } else {
+          calibration.camera_command = stdin_camera_command;
+        }
         // TODO(Brian): Actually fill out the calibration field.
         transmit_buffers[0].MaybeWritePacket(calibration);
         transmit_buffers[1].MaybeWritePacket(calibration);
@@ -652,6 +662,29 @@
       }
     }
 
+    {
+      const auto stdin_data = printing->ReadStdin();
+      if (!stdin_data.empty()) {
+        switch (stdin_data.back()) {
+          case 'p':
+            printf("Entering passthrough mode\n");
+            stdin_camera_command = CameraCommand::kCameraPassthrough;
+            break;
+          case 'u':
+            printf("Entering USB mode\n");
+            stdin_camera_command = CameraCommand::kUsb;
+            break;
+          case 'n':
+            printf("Entering normal mode\n");
+            stdin_camera_command = CameraCommand::kNormal;
+            break;
+          default:
+            printf("Unrecognized character\n");
+            break;
+        }
+      }
+    }
+
     first = false;
   }
 }
@@ -817,7 +850,7 @@
   NVIC_ENABLE_IRQ(IRQ_SPI0);
   NVIC_ENABLE_IRQ(IRQ_PORTA);
 
-  TransferData();
+  TransferData(printing.get());
 
   while (true) {
   }
diff --git a/y2019/jevois/uart_test.cc b/y2019/jevois/uart_test.cc
index 1e90d84..d669688 100644
--- a/y2019/jevois/uart_test.cc
+++ b/y2019/jevois/uart_test.cc
@@ -66,8 +66,7 @@
   input_message.teensy_now =
       aos::monotonic_clock::time_point(std::chrono::seconds(1678));
   input_message.realtime_now = aos::realtime_clock::min_time;
-  input_message.camera_command =
-      CameraCalibration::CameraCommand::kCameraPassthrough;
+  input_message.camera_command = CameraCommand::kCameraPassthrough;
   const UartToCameraBuffer buffer = UartPackToCamera(input_message);
   const auto output_message = UartUnpackToCamera(buffer);
   ASSERT_TRUE(output_message);
diff --git a/y2019/vision/BUILD b/y2019/vision/BUILD
index bdef187..7300850 100644
--- a/y2019/vision/BUILD
+++ b/y2019/vision/BUILD
@@ -90,7 +90,7 @@
 
 cc_binary(
     name = "global_calibration",
-    srcs = ["global_calibration.cc"],
+    srcs = ["global_calibration.cc", "constants_formatting.cc"],
     deps = [
          ":target_finder",
          "//aos/logging",
diff --git a/y2019/vision/constants.cc b/y2019/vision/constants.cc
index bf3953c..ea47dd7 100644
--- a/y2019/vision/constants.cc
+++ b/y2019/vision/constants.cc
@@ -3,29 +3,52 @@
 namespace y2019 {
 namespace vision {
 
-constexpr double kInchesToMeters = 0.0254;
+static constexpr double kInchesToMeters = 0.0254;
 
 CameraCalibration camera_4 = {
     {
-        3.50309 / 180.0 * M_PI, 593.557, -0.0487739 / 180.0 * M_PI,
+        3.73623 / 180.0 * M_PI, 588.1, 0.269291 / 180.0 * M_PI,
     },
     {
-        {{5.56082 / kInchesToMeters, 4.70235 / kInchesToMeters,
-          33.4998 / kInchesToMeters}},
-        22.2155 * M_PI / 180.0,
+        {{6.02674 * kInchesToMeters, 4.57805 * kInchesToMeters,
+          33.3849 * kInchesToMeters}},
+        22.4535 / 180.0 * M_PI,
     },
     {
         4,
-        {{12.5 / kInchesToMeters, 12.0 / kInchesToMeters}},
-        {{kInchesToMeters, 0.0}},
-        26.0,
+        {{12.5 * kInchesToMeters, 12 * kInchesToMeters}},
+        {{1 * kInchesToMeters, 0.0}},
+        26,
         "cam4_0/debug_viewer_jpeg_",
+        52,
+    }};
+
+CameraCalibration camera_5 = {
+    {
+        1.00774 / 180.0 * M_PI, 658.554, 2.43864 / 180.0 * M_PI,
+    },
+    {
+        {{5.51248 * kInchesToMeters, 2.04087 * kInchesToMeters,
+          33.2555 * kInchesToMeters}},
+        -13.1396 / 180.0 * M_PI,
+    },
+    {
+        5,
+        {{12.5 * kInchesToMeters, 0.5 * kInchesToMeters}},
+        {{1 * kInchesToMeters, 0.0}},
+        26,
+        "cam5_0/debug_viewer_jpeg_",
+        59,
     }};
 
 const CameraCalibration *GetCamera(int camera_id) {
   switch (camera_id) {
-  case 4: return &camera_4;
-  default: return nullptr;
+    case 4:
+      return &camera_4;
+    case 5:
+      return &camera_5;
+    default:
+      return nullptr;
   }
 }
 
diff --git a/y2019/vision/constants.h b/y2019/vision/constants.h
index cbad8bf..b33b045 100644
--- a/y2019/vision/constants.h
+++ b/y2019/vision/constants.h
@@ -10,6 +10,7 @@
 
 // Position of the idealized camera in 3d space.
 struct CameraGeometry {
+  static constexpr size_t kNumParams = 4;
   // In Meters from floor under imu center.
   std::array<double, 3> location{{0, 0, 0}};
   double heading = 0.0;
@@ -28,6 +29,8 @@
     out.heading = data[3];
     return out;
   }
+
+  void dump(std::basic_ostream<char> &o) const;
 };
 
 struct IntrinsicParams {
@@ -50,6 +53,7 @@
     out.barrel_mount = data[2];
     return out;
   }
+  void dump(std::basic_ostream<char> &o) const;
 };
 
 // Metadata about the calibration results (Should be good enough to reproduce).
@@ -62,6 +66,9 @@
   // This will multiply tape_measure_direction and thus has no units.
   double beginning_tape_measure_reading;
   const char *filename_prefix;
+  int num_images;
+
+  void dump(std::basic_ostream<char> &o) const;
 };
 
 struct CameraCalibration {
@@ -72,6 +79,8 @@
 
 const CameraCalibration *GetCamera(int camera_id);
 
+void DumpCameraConstants(int camera_id, const CameraCalibration &value);
+
 }  // namespace vision
 }  // namespace y2019
 
diff --git a/y2019/vision/constants_formatting.cc b/y2019/vision/constants_formatting.cc
new file mode 100644
index 0000000..74a9ed3
--- /dev/null
+++ b/y2019/vision/constants_formatting.cc
@@ -0,0 +1,98 @@
+#include "y2019/vision/constants.h"
+
+#include <fstream>
+#include <sstream>
+
+namespace y2019 {
+namespace vision {
+
+namespace {
+// 64 should be enough for any mortal.
+constexpr int kMaxNumCameras = 64;
+constexpr double kInchesToMeters = 0.0254;
+}  // namespace
+
+static std::string fmt_rad(double v) {
+  std::stringstream ss;
+  if (v == 0.0) {
+    ss << "0.0";
+  } else {
+    ss << v * 180.0 / M_PI << " / 180.0 * M_PI";
+  }
+  return ss.str();
+}
+
+static std::string fmt_meters(double v) {
+  if (v == 0.0) return "0.0";
+  if (v == 1.0) return "kInchesToMeters";
+  std::stringstream ss;
+  ss << v / kInchesToMeters << " * kInchesToMeters";
+  return ss.str();
+}
+
+void IntrinsicParams::dump(std::basic_ostream<char> &o) const {
+  o << "    {\n        " << fmt_rad(mount_angle) << ", " << focal_length;
+  o << ", " << fmt_rad(barrel_mount) << ",\n    },\n";
+}
+
+void CameraGeometry::dump(std::basic_ostream<char> &o) const {
+  o << "{{{" << fmt_meters(location[0]) << ", " << fmt_meters(location[1])
+    << ", " << fmt_meters(location[2]) << "}}," << fmt_rad(heading) << ",},";
+}
+
+void DatasetInfo::dump(std::basic_ostream<char> &o) const {
+  o << "{\n"
+    << camera_id << ", "
+    << "{{" << fmt_meters(to_tape_measure_start[0]) << ", "
+    << fmt_meters(to_tape_measure_start[1]) << "}},\n"
+    << "{{" << fmt_meters(tape_measure_direction[0]) << ", "
+    << fmt_meters(tape_measure_direction[1]) << "}},\n"
+    << beginning_tape_measure_reading << ",\n"
+    << "\"" << filename_prefix << "\",\n"
+    << num_images << ",\n}";
+}
+
+void DumpCameraConstants(int camera_id, const CameraCalibration &value) {
+  std::ofstream o("y2019/vision/constants.cc");
+  o << R"(#include "y2019/vision/constants.h"
+
+namespace y2019 {
+namespace vision {
+
+static constexpr double kInchesToMeters = 0.0254;
+)";
+
+  // Go through all the cameras and either use the existing compiled-in
+  // calibration data or the new data which was passed in.
+  for (int i = 0; i < kMaxNumCameras; ++i) {
+    auto *params = (i == camera_id) ? &value : GetCamera(i);
+    if (params) {
+      o << "\nCameraCalibration camera_" << i << " = {\n";
+      params->intrinsics.dump(o);
+      params->geometry.dump(o);
+      params->dataset.dump(o);
+      o << "};\n";
+    }
+  }
+
+  o << R"(
+const CameraCalibration *GetCamera(int camera_id) {
+  switch (camera_id) {
+)";
+  for (int i = 0; i < kMaxNumCameras; ++i) {
+    if (i == camera_id || GetCamera(i) != nullptr) {
+      o << "  case " << i << ": return &camera_" << i << ";\n";
+    }
+  }
+  o << R"(  default: return nullptr;
+  }
+}
+
+}  // namespace vision
+}  // namespace y2019
+)";
+  o.close();
+}
+
+}  // namespace vision
+}  // namespace y2019
diff --git a/y2019/vision/debug_serial.cc b/y2019/vision/debug_serial.cc
index a095b14..857f20f 100644
--- a/y2019/vision/debug_serial.cc
+++ b/y2019/vision/debug_serial.cc
@@ -68,10 +68,9 @@
       if (n >= 1) {
         CameraCalibration calibration{};
         if (data[0] == 'p') {
-          calibration.camera_command =
-              CameraCalibration::CameraCommand::kCameraPassthrough;
+          calibration.camera_command = CameraCommand::kCameraPassthrough;
         } else {
-          calibration.camera_command = CameraCalibration::CameraCommand::kUsb;
+          calibration.camera_command = CameraCommand::kUsb;
         }
         if (write(itsDev, "\0", 1) == 1) {
           const auto out_data = frc971::jevois::UartPackToCamera(calibration);
diff --git a/y2019/vision/debug_viewer.cc b/y2019/vision/debug_viewer.cc
index 4f43c9a..533dcf6 100644
--- a/y2019/vision/debug_viewer.cc
+++ b/y2019/vision/debug_viewer.cc
@@ -92,10 +92,23 @@
     // Find polygons from blobs.
     std::vector<std::vector<Segment<2>>> raw_polys;
     for (const RangeImage &blob : imgs) {
+      // Convert blobs to contours in the corrected space.
+      ContourNode* contour = finder_.GetContour(blob);
+      if (draw_contours_) {
+        DrawContour(contour, {255, 0, 0});
+      }
+      finder_.UnWarpContour(contour);
+      if (draw_contours_) {
+        DrawContour(contour, {0, 0, 255});
+      }
+
+      // Process to polygons.
       std::vector<Segment<2>> polygon =
-          finder_.FillPolygon(blob, draw_raw_poly_);
+          finder_.FillPolygon(contour, draw_raw_poly_);
       if (polygon.empty()) {
-        DrawBlob(blob, {255, 0, 0});
+        if (!draw_contours_) {
+          DrawBlob(blob, {255, 0, 0});
+        }
       } else {
         raw_polys.push_back(polygon);
         if (draw_select_blob_) {
@@ -168,7 +181,21 @@
       } else if (key == 'b') {
         draw_raw_poly_ = !draw_raw_poly_;
       } else if (key == 'n') {
+        draw_contours_ = !draw_contours_;
+      } else if (key == 'm') {
         draw_select_blob_ = !draw_select_blob_;
+      } else if (key == 'h') {
+        printf("Key Mappings:\n");
+        printf(" z: Toggle drawing final target pose.\n");
+        printf(" x: Toggle drawing re-projected targets and print solver results.\n");
+        printf(" c: Toggle drawing proposed target groupings.\n");
+        printf(" v: Toggle drawing ordered target components.\n");
+        printf(" b: Toggle drawing proposed target components.\n");
+        printf(" n: Toggle drawing countours before and after warping.\n");
+        printf(" m: Toggle drawing raw blob data (may need to change image to toggle a redraw).\n");
+        printf(" h: Print this message.\n");
+        printf(" a: May log camera image to /tmp/debug_viewer_jpeg_<#>.yuyv"
+        printf(" q: Exit the application.\n");
       } else if (key == 'q') {
         printf("User requested shutdown.\n");
         exit(0);
@@ -178,6 +205,17 @@
     };
   }
 
+  void DrawContour(ContourNode *contour, PixelRef color) {
+    if (viewer_) {
+      for (ContourNode *node = contour; node->next != contour;) {
+        Vector<2> a(node->pt.x, node->pt.y);
+        Vector<2> b(node->next->pt.x, node->next->pt.y);
+        overlay_.AddLine(a, b, color);
+        node = node->next;
+      }
+    }
+  }
+
   void DrawComponent(const TargetComponent &comp, PixelRef top_color,
                      PixelRef bot_color, PixelRef in_color,
                      PixelRef out_color) {
@@ -252,6 +290,7 @@
   BlobList imgs_last_;
   ImageFormat fmt_last_;
   bool draw_select_blob_ = false;
+  bool draw_contours_ = false;
   bool draw_raw_poly_ = false;
   bool draw_components_ = false;
   bool draw_raw_target_ = false;
diff --git a/y2019/vision/global_calibration.cc b/y2019/vision/global_calibration.cc
index e92ae56..bf64310 100644
--- a/y2019/vision/global_calibration.cc
+++ b/y2019/vision/global_calibration.cc
@@ -42,17 +42,34 @@
   return new T(std::move(t));
 }
 
-std::array<double, 3> GetError(const double *const extrinsics,
+std::array<double, 3> GetError(const DatasetInfo &info,
+                               const double *const extrinsics,
                                const double *const geometry, int i) {
-  auto ex = ExtrinsicParams::get(extrinsics);
+  auto extrinsic_params = ExtrinsicParams::get(extrinsics);
+  auto geo = CameraGeometry::get(geometry);
 
-  double s = sin(geometry[2] + ex.r2);
-  double c = cos(geometry[2] + ex.r2);
+  const double s = sin(geo.heading + extrinsic_params.r2);
+  const double c = cos(geo.heading + extrinsic_params.r2);
 
-  // TODO: Generalize this from being just for a single calibration.
-  double dx = 12.5 + 26.0 + i - (geometry[0] + c * ex.z) / kInchesToMeters;
-  double dy = 12.0 - (geometry[1] + s * ex.z) / kInchesToMeters;
-  double dz = 28.5 - (geometry[3] + ex.y) / kInchesToMeters;
+  // Take the tape measure starting point (this will be at the perimeter of the
+  // robot), add the offset to the first sample, and then add the per sample
+  // offset.
+  const double dx =
+      (info.to_tape_measure_start[0] +
+       (info.beginning_tape_measure_reading + i) *
+           info.tape_measure_direction[0]) /
+          kInchesToMeters -
+      (geo.location[0] + c * extrinsic_params.z) / kInchesToMeters;
+  const double dy =
+      (info.to_tape_measure_start[1] +
+       (info.beginning_tape_measure_reading + i) *
+           info.tape_measure_direction[1]) /
+          kInchesToMeters -
+      (geo.location[1] + s * extrinsic_params.z) / kInchesToMeters;
+
+  constexpr double kCalibrationTargetHeight = 28.5;
+  const double dz = kCalibrationTargetHeight -
+                    (geo.location[2] + extrinsic_params.y) / kInchesToMeters;
   return {{dx, dy, dz}};
 }
 
@@ -61,6 +78,19 @@
   (void)argv;
   using namespace y2019::vision;
   // gflags::ParseCommandLineFlags(&argc, &argv, false);
+
+  int camera_id = 5;
+  const char *base_directory = "/home/parker/data/frc/2019_calibration/";
+
+  DatasetInfo info = {
+      camera_id,
+      {{12.5 * kInchesToMeters, 0.5 * kInchesToMeters}},
+      {{kInchesToMeters, 0.0}},
+      26,
+      "cam5_0/debug_viewer_jpeg_",
+      59,
+  };
+
   ::aos::logging::Init();
   ::aos::logging::AddImplementation(
       new ::aos::logging::StreamLogImplementation(stderr));
@@ -77,9 +107,8 @@
   double intrinsics[IntrinsicParams::kNumParams];
   IntrinsicParams().set(&intrinsics[0]);
 
-  // To know the meaning, see the printout below...
-  constexpr size_t GeometrykNumParams = 4;
-  double geometry[GeometrykNumParams] = {0, 0, 0, 0};
+  double geometry[CameraGeometry::kNumParams];
+  CameraGeometry().set(&geometry[0]);
 
   Solver::Options options;
   options.minimizer_progress_to_stdout = false;
@@ -91,11 +120,10 @@
   std::cout << "fl = " << intrinsics_.focal_length << ";\n";
   std::cout << "error = " << summary.final_cost << ";\n";
 
-  int nimgs = 56;
-  for (int i = 0; i < nimgs; ++i) {
-    auto frame = aos::vision::LoadFile(
-        "/home/parker/data/frc/2019_calibration/cam4_0/debug_viewer_jpeg_" +
-        std::to_string(i) + ".yuyv");
+  for (int i = 0; i < info.num_images; ++i) {
+    auto frame = aos::vision::LoadFile(std::string(base_directory) +
+                                       info.filename_prefix +
+                                       std::to_string(i) + ".yuyv");
 
     aos::vision::ImageFormat fmt{640, 480};
     aos::vision::BlobList imgs = aos::vision::FindBlobs(
@@ -105,7 +133,10 @@
     bool verbose = false;
     std::vector<std::vector<Segment<2>>> raw_polys;
     for (const RangeImage &blob : imgs) {
-      std::vector<Segment<2>> polygon = finder_.FillPolygon(blob, verbose);
+      // Convert blobs to contours in the corrected space.
+      ContourNode* contour = finder_.GetContour(blob);
+      finder_.UnWarpContour(contour);
+      std::vector<Segment<2>> polygon = finder_.FillPolygon(contour, verbose);
       if (polygon.empty()) {
       } else {
         raw_polys.push_back(polygon);
@@ -138,8 +169,8 @@
                                     const double *const extrinsics,
                                     double *residual) {
           auto in = IntrinsicParams::get(intrinsics);
-          auto ex = ExtrinsicParams::get(extrinsics);
-          auto pt = targ - Project(temp, in, ex);
+          auto extrinsic_params = ExtrinsicParams::get(extrinsics);
+          auto pt = targ - Project(temp, in, extrinsic_params);
           residual[0] = pt.x();
           residual[1] = pt.y();
           return true;
@@ -152,9 +183,9 @@
             NULL, &intrinsics[0], extrinsics);
       }
 
-      auto ftor = [i](const double *const extrinsics,
-                      const double *const geometry, double *residual) {
-        auto err = GetError(extrinsics, geometry, i);
+      auto ftor = [&info, i](const double *const extrinsics,
+                             const double *const geometry, double *residual) {
+        auto err = GetError(info, extrinsics, geometry, i);
         residual[0] = 32.0 * err[0];
         residual[1] = 32.0 * err[1];
         residual[2] = 32.0 * err[2];
@@ -164,7 +195,7 @@
       problem.AddResidualBlock(
           new NumericDiffCostFunction<decltype(ftor), CENTRAL, 3,
                                       ExtrinsicParams::kNumParams,
-                                      GeometrykNumParams>(
+                                      CameraGeometry::kNumParams>(
               new decltype(ftor)(std::move(ftor))),
           NULL, extrinsics, &geometry[0]);
     }
@@ -177,14 +208,18 @@
   {
     std::cout << summary.BriefReport() << "\n";
     auto intrinsics_ = IntrinsicParams::get(&intrinsics[0]);
+    auto geometry_ = CameraGeometry::get(&geometry[0]);
     std::cout << "rup = " << intrinsics_.mount_angle * 180 / M_PI << ";\n";
     std::cout << "fl = " << intrinsics_.focal_length << ";\n";
     std::cout << "error = " << summary.final_cost << ";\n";
 
-    std::cout << "camera_height = " << geometry[3] / kInchesToMeters << "\n";
-    std::cout << "camera_angle = " << geometry[2] * 180 / M_PI << "\n";
-    std::cout << "camera_x = " << geometry[0] / kInchesToMeters << "\n";
-    std::cout << "camera_y = " << geometry[1] / kInchesToMeters << "\n";
+    std::cout << "camera_angle = " << geometry_.heading * 180 / M_PI << "\n";
+    std::cout << "camera_x = " << geometry_.location[0] / kInchesToMeters
+              << "\n";
+    std::cout << "camera_y = " << geometry_.location[1] / kInchesToMeters
+              << "\n";
+    std::cout << "camera_z = " << geometry_.location[2] / kInchesToMeters
+              << "\n";
     std::cout << "camera_barrel = " << intrinsics_.barrel_mount * 180.0 / M_PI
               << "\n";
 
@@ -194,7 +229,7 @@
 
       auto extn = ExtrinsicParams::get(data);
 
-      auto err = GetError(data, &geometry[0], i);
+      auto err = GetError(info, data, &geometry[0], i);
 
       std::cout << i << ", ";
       std::cout << extn.z / kInchesToMeters << ", ";
@@ -208,6 +243,12 @@
       std::cout << err[2] << "\n";
     }
   }
+
+  CameraCalibration results;
+  results.dataset = info;
+  results.intrinsics = IntrinsicParams::get(&intrinsics[0]);
+  results.geometry = CameraGeometry::get(&geometry[0]);
+  DumpCameraConstants(camera_id, results);
 }
 
 }  // namespace y2019
diff --git a/y2019/vision/target_finder.cc b/y2019/vision/target_finder.cc
index f69e987..b46d802 100644
--- a/y2019/vision/target_finder.cc
+++ b/y2019/vision/target_finder.cc
@@ -33,39 +33,96 @@
       imgs->end());
 }
 
+ContourNode* TargetFinder::GetContour(const RangeImage &blob) {
+  alloc_.reset();
+  return RangeImgToContour(blob, &alloc_);
+}
+
+// TODO(ben): These values will be moved into the constants.h file.
+namespace {
+
+constexpr double f_x = 481.4957;
+constexpr double c_x = 341.215;
+constexpr double f_y = 484.314;
+constexpr double c_y = 251.29;
+
+constexpr double f_x_prime = 363.1424;
+constexpr double c_x_prime = 337.9895;
+constexpr double f_y_prime = 366.4837;
+constexpr double c_y_prime = 240.0702;
+
+constexpr double k_1 = -0.2739;
+constexpr double k_2 = 0.01583;
+constexpr double k_3 = 0.04201;
+
+constexpr int iterations = 7;
+
+}
+
+Point UnWarpPoint(const Point &point, int iterations) {
+  const double x0 = ((double)point.x - c_x) / f_x;
+  const double y0 = ((double)point.y - c_y) / f_y;
+  double x = x0;
+  double y = y0;
+  for (int i = 0; i < iterations; i++) {
+    const double r_sqr = x * x + y * y;
+    const double coeff =
+        1.0 + r_sqr * (k_1 + k_2 * r_sqr * (1.0 + k_3 * r_sqr));
+    x = x0 / coeff;
+    y = y0 / coeff;
+  }
+  double nx = x * f_x_prime + c_x_prime;
+  double ny = y * f_y_prime + c_y_prime;
+  Point p = {static_cast<int>(nx), static_cast<int>(ny)};
+  return p;
+}
+
+void TargetFinder::UnWarpContour(ContourNode *start) const {
+  ContourNode *node = start;
+  while (node->next != start) {
+    node->set_point(UnWarpPoint(node->pt, iterations));
+    node = node->next;
+  }
+  node->set_point(UnWarpPoint(node->pt, iterations));
+}
+
 // TODO: Try hierarchical merge for this.
 // Convert blobs into polygons.
 std::vector<aos::vision::Segment<2>> TargetFinder::FillPolygon(
-    const RangeImage &blob, bool verbose) {
+    ContourNode* start, bool verbose) {
   if (verbose) printf("Process Polygon.\n");
-  alloc_.reset();
-  auto *st = RangeImgToContour(blob, &alloc_);
 
   struct Pt {
     float x;
     float y;
   };
-  std::vector<Pt> pts;
+  std::vector<Pt> points;
 
   // Collect all slopes from the contour.
-  auto opt = st->pt;
-  for (auto *node = st; node->next != st;) {
+  Point previous_point = start->pt;
+  for (ContourNode *node = start; node->next != start;) {
     node = node->next;
 
-    auto npt = node->pt;
+    Point current_point = node->pt;
 
-    pts.push_back(
-        {static_cast<float>(npt.x - opt.x), static_cast<float>(npt.y - opt.y)});
+    points.push_back({static_cast<float>(current_point.x - previous_point.x),
+                      static_cast<float>(current_point.y - previous_point.y)});
 
-    opt = npt;
+    previous_point = current_point;
   }
 
-  const int n = pts.size();
-  auto get_pt = [&](int i) { return pts[(i + n * 2) % n]; };
+  const int num_points = points.size();
+  auto get_pt = [&points, num_points](int i) {
+    return points[(i + num_points * 2) % num_points];
+  };
 
-  std::vector<Pt> pts_new = pts;
-  auto run_box_filter = [&](int window_size) {
-    for (size_t i = 0; i < pts.size(); ++i) {
+  std::vector<Pt> filtered_points = points;
+  // Three box filter makith a guassian?
+  // Run gaussian filter over the slopes 3 times.  That'll get us pretty close
+  // to running a gausian over it.
+  for (int k = 0; k < 3; ++k) {
+    const int window_size = 2;
+    for (size_t i = 0; i < points.size(); ++i) {
       Pt a{0.0, 0.0};
       for (int j = -window_size; j <= window_size; ++j) {
         Pt p = get_pt(j + i);
@@ -75,25 +132,20 @@
       a.x /= (window_size * 2 + 1);
       a.y /= (window_size * 2 + 1);
 
-      float scale = 1.0 + (i / float(pts.size() * 10));
+      const float scale = 1.0 + (i / float(points.size() * 10));
       a.x *= scale;
       a.y *= scale;
-      pts_new[i] = a;
+      filtered_points[i] = a;
     }
-    pts = pts_new;
-  };
-  // Three box filter makith a guassian?
-  // Run gaussian filter over the slopes.
-  run_box_filter(2);
-  run_box_filter(2);
-  run_box_filter(2);
+    points = filtered_points;
+  }
 
   // Heuristic which says if a particular slope is part of a corner.
   auto is_corner = [&](size_t i) {
-    Pt a = get_pt(i - 3);
-    Pt b = get_pt(i + 3);
-    double dx = (a.x - b.x);
-    double dy = (a.y - b.y);
+    const Pt a = get_pt(i - 3);
+    const Pt b = get_pt(i + 3);
+    const double dx = (a.x - b.x);
+    const double dy = (a.y - b.y);
     return dx * dx + dy * dy > 0.25;
   };
 
@@ -102,11 +154,11 @@
   // Find all centers of corners.
   // Because they round, multiple points may be a corner.
   std::vector<size_t> edges;
-  size_t kBad = pts.size() + 10;
+  size_t kBad = points.size() + 10;
   size_t prev_up = kBad;
   size_t wrapped_n = prev_up;
 
-  for (size_t i = 0; i < pts.size(); ++i) {
+  for (size_t i = 0; i < points.size(); ++i) {
     bool v = is_corner(i);
     if (prev_v && !v) {
       if (prev_up == kBad) {
@@ -122,7 +174,7 @@
   }
 
   if (wrapped_n != kBad) {
-    edges.push_back(((prev_up + pts.size() + wrapped_n - 1) / 2) % pts.size());
+    edges.push_back(((prev_up + points.size() + wrapped_n - 1) / 2) % points.size());
   }
 
   if (verbose) printf("Edge Count (%zu).\n", edges.size());
@@ -133,7 +185,7 @@
   {
     std::vector<ContourNode *> segments_all;
 
-    for (ContourNode *node = st; node->next != st;) {
+    for (ContourNode *node = start; node->next != start;) {
       node = node->next;
       segments_all.push_back(node);
     }
@@ -147,12 +199,13 @@
   std::vector<Segment<2>> seg_list;
   if (segments.size() == 4) {
     for (size_t i = 0; i < segments.size(); ++i) {
-      auto *ed = segments[(i + 1) % segments.size()];
-      auto *st = segments[i];
+      ContourNode *segment_end = segments[(i + 1) % segments.size()];
+      ContourNode *segment_start = segments[i];
       float mx = 0.0;
       float my = 0.0;
       int n = 0;
-      for (auto *node = st; node != ed; node = node->next) {
+      for (ContourNode *node = segment_start; node != segment_end;
+           node = node->next) {
         mx += node->pt.x;
         my += node->pt.y;
         ++n;
@@ -164,26 +217,27 @@
       float xx = 0.0;
       float xy = 0.0;
       float yy = 0.0;
-      for (auto *node = st; node != ed; node = node->next) {
-        float x = node->pt.x - mx;
-        float y = node->pt.y - my;
+      for (ContourNode *node = segment_start; node != segment_end;
+           node = node->next) {
+        const float x = node->pt.x - mx;
+        const float y = node->pt.y - my;
         xx += x * x;
         xy += x * y;
         yy += y * y;
       }
 
       // TODO: Extract common to hierarchical merge.
-      float neg_b_over_2 = (xx + yy) / 2.0;
-      float c = (xx * yy - xy * xy);
+      const float neg_b_over_2 = (xx + yy) / 2.0;
+      const float c = (xx * yy - xy * xy);
 
-      float sqr = sqrt(neg_b_over_2 * neg_b_over_2 - c);
+      const float sqr = sqrt(neg_b_over_2 * neg_b_over_2 - c);
 
       {
-        float lam = neg_b_over_2 + sqr;
+        const float lam = neg_b_over_2 + sqr;
         float x = xy;
         float y = lam - xx;
 
-        float norm = sqrt(x * x + y * y);
+        const float norm = hypot(x, y);
         x /= norm;
         y /= norm;
 
@@ -212,7 +266,7 @@
     const std::vector<std::vector<Segment<2>>> &seg_list) {
   std::vector<TargetComponent> list;
   TargetComponent new_target;
-  for (const auto &poly : seg_list) {
+  for (const std::vector<Segment<2>> &poly : seg_list) {
     // Reject missized pollygons for now. Maybe rectify them here in the future;
     if (poly.size() != 4) continue;
     std::vector<Vector<2>> corners;
diff --git a/y2019/vision/target_finder.h b/y2019/vision/target_finder.h
index 633733a..bdf67f2 100644
--- a/y2019/vision/target_finder.h
+++ b/y2019/vision/target_finder.h
@@ -4,6 +4,7 @@
 #include "aos/vision/blob/region_alloc.h"
 #include "aos/vision/blob/threshold.h"
 #include "aos/vision/blob/transpose.h"
+#include "aos/vision/blob/contour.h"
 #include "aos/vision/debug/overlay.h"
 #include "aos/vision/math/vector.h"
 #include "y2019/vision/target_types.h"
@@ -15,6 +16,7 @@
 using aos::vision::RangeImage;
 using aos::vision::BlobList;
 using aos::vision::Vector;
+using aos::vision::ContourNode;
 
 class TargetFinder {
  public:
@@ -28,8 +30,11 @@
   // filter out obvious or durranged blobs.
   void PreFilter(BlobList *imgs);
 
+  ContourNode* GetContour(const RangeImage &blob);
+  void UnWarpContour(ContourNode* start) const;
+
   // Turn a blob into a polgygon.
-  std::vector<aos::vision::Segment<2>> FillPolygon(const RangeImage &blob,
+  std::vector<aos::vision::Segment<2>> FillPolygon(ContourNode *start,
                                                    bool verbose);
 
   // Turn a bloblist into components of a target.
@@ -57,6 +62,7 @@
   const Target &GetTemplateTarget() { return target_template_; }
 
   const IntrinsicParams &intrinsics() const { return intrinsics_; }
+  IntrinsicParams *mutable_intrinsics() { return &intrinsics_; }
 
  private:
   // Find a loosly connected target.
diff --git a/y2019/vision/target_sender.cc b/y2019/vision/target_sender.cc
index be56e91..2c7d8e2 100644
--- a/y2019/vision/target_sender.cc
+++ b/y2019/vision/target_sender.cc
@@ -275,7 +275,7 @@
   (void)argc;
   (void)argv;
   using namespace y2019::vision;
-  using frc971::jevois::CameraCalibration;
+  using frc971::jevois::CameraCommand;
   // gflags::ParseCommandLineFlags(&argc, &argv, false);
   ::aos::logging::Init();
   ::aos::logging::AddImplementation(
@@ -309,9 +309,11 @@
     bool verbose = false;
     std::vector<std::vector<Segment<2>>> raw_polys;
     for (const RangeImage &blob : imgs) {
-      std::vector<Segment<2>> polygon = finder_.FillPolygon(blob, verbose);
-      if (polygon.empty()) {
-      } else {
+      // Convert blobs to contours in the corrected space.
+      ContourNode* contour = finder_.GetContour(blob);
+      finder_.UnWarpContour(contour);
+      std::vector<Segment<2>> polygon = finder_.FillPolygon(contour, verbose);
+      if (!polygon.empty()) {
         raw_polys.push_back(polygon);
       }
     }
@@ -381,12 +383,17 @@
               frc971::jevois::UartUnpackToCamera(packet);
           if (calibration_question) {
             const auto &calibration = *calibration_question;
+            IntrinsicParams *intrinsics = finder_.mutable_intrinsics();
+            intrinsics->mount_angle = calibration.calibration(0, 0);
+            intrinsics->focal_length = calibration.calibration(0, 1);
+            intrinsics->barrel_mount = calibration.calibration(0, 2);
+
             switch (calibration.camera_command) {
-              case CameraCalibration::CameraCommand::kNormal:
+              case CameraCommand::kNormal:
                 break;
-              case CameraCalibration::CameraCommand::kUsb:
+              case CameraCommand::kUsb:
                 return 0;
-              case CameraCalibration::CameraCommand::kCameraPassthrough:
+              case CameraCommand::kCameraPassthrough:
                 return system("touch /tmp/do_not_export_sd_card");
             }
           } else {
diff --git a/y2019/wpilib_interface.cc b/y2019/wpilib_interface.cc
index 29377c8..02269eb 100644
--- a/y2019/wpilib_interface.cc
+++ b/y2019/wpilib_interface.cc
@@ -279,10 +279,26 @@
     spi_->SetMSBFirst();
   }
 
+  void set_activate_usb(std::unique_ptr<frc::DigitalInput> activate_usb) {
+    activate_usb_ = std::move(activate_usb);
+  }
+
+  void set_activate_passthrough(
+      std::unique_ptr<frc::DigitalInput> activate_passthrough) {
+    activate_passthrough_ = std::move(activate_passthrough);
+  }
+
   void DoSpiTransaction() {
     using namespace frc971::jevois;
     RoborioToTeensy to_teensy{};
     to_teensy.realtime_now = aos::realtime_clock::now();
+    if (activate_usb_ && !activate_usb_->Get()) {
+      to_teensy.camera_command = CameraCommand::kUsb;
+    } else if (activate_passthrough_ && !activate_passthrough_->Get()) {
+      to_teensy.camera_command = CameraCommand::kCameraPassthrough;
+    } else {
+      to_teensy.camera_command = CameraCommand::kNormal;
+    }
 
     std::array<char, spi_transfer_size() + 1> to_send{};
     {
@@ -343,6 +359,9 @@
   frc::SPI *spi_ = nullptr;
   ::std::unique_ptr<frc::SPI> dummy_spi_;
 
+  std::unique_ptr<frc::DigitalInput> activate_usb_;
+  std::unique_ptr<frc::DigitalInput> activate_passthrough_;
+
   frc971::wpilib::SpiRxClearer rx_clearer_;
 };
 
@@ -553,6 +572,9 @@
     frc::SPI camera_spi(frc::SPI::Port::kOnboardCS3);
     camera_reader.set_spi(&camera_spi);
     camera_reader.SetDummySPI(frc::SPI::Port::kOnboardCS2);
+    // Austin says 8, 9, 24, and 25 are good options to choose from for these.
+    camera_reader.set_activate_usb(make_unique<frc::DigitalInput>(24));
+    camera_reader.set_activate_passthrough(make_unique<frc::DigitalInput>(25));
 
     auto imu_trigger = make_unique<frc::DigitalInput>(0);
     ::frc971::wpilib::ADIS16448 imu(frc::SPI::Port::kOnboardCS1,