Add Photonlib (#231)

Merges Photonlib into Photonvision, along with the Photonlib code examples. Also creates a new PhotonTargeting library teams can depend on.

photon-lib/src/main/native/cpp/photonlib/PhotonPipelineResult.cpp

@@ -0,0 +1,67 @@
+/*
+ * Copyright (C) Photon Vision.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include "photonlib/PhotonPipelineResult.h"
+
+namespace photonlib {
+PhotonPipelineResult::PhotonPipelineResult(
+    units::second_t latency, wpi::ArrayRef<PhotonTrackedTarget> targets)
+    : latency(latency),
+      targets(targets.data(), targets.data() + targets.size()) {
+  hasTargets = targets.size() != 0;
+}
+
+bool PhotonPipelineResult::operator==(const PhotonPipelineResult& other) const {
+  return latency == other.latency && hasTargets == other.hasTargets &&
+         targets == other.targets;
+}
+
+bool PhotonPipelineResult::operator!=(const PhotonPipelineResult& other) const {
+  return !operator==(other);
+}
+
+Packet& operator<<(Packet& packet, const PhotonPipelineResult& result) {
+  // Encode latency, existence of targets, and number of targets.
+  packet << result.latency.to<double>() * 1000 << result.hasTargets
+         << static_cast<int8_t>(result.targets.size());
+
+  // Encode the information of each target.
+  for (auto& target : result.targets) packet << target;
+
+  // Return the packet
+  return packet;
+}
+
+Packet& operator>>(Packet& packet, PhotonPipelineResult& result) {
+  // Decode latency, existence of targets, and number of targets.
+  int8_t targetCount = 0;
+  double latencyMillis = 0;
+  packet >> latencyMillis >> result.hasTargets >> targetCount;
+  result.latency = units::second_t(latencyMillis / 1000.0);
+
+  result.targets.clear();
+
+  // Decode the information of each target.
+  for (int i = 0; i < targetCount; ++i) {
+    PhotonTrackedTarget target;
+    packet >> target;
+    result.targets.push_back(target);
+  }
+  return packet;
+}
+
+}  // namespace photonlib