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/include/photonlib/SimVisionTarget.h

@@ -0,0 +1,45 @@
+/*
+ * 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/>.
+ */
+
+#pragma once
+
+#include <frc/geometry/Pose2d.h>
+#include <units/area.h>
+#include <units/length.h>
+
+namespace photonlib {
+
+/**
+ * Represents a target on the field which the vision processing system could
+ * detect.
+ */
+class SimVisionTarget {
+ public:
+  explicit SimVisionTarget(frc::Pose2d& targetPos,
+                           units::meter_t targetHeightAboveGround,
+                           units::meter_t targetWidth,
+                           units::meter_t targetHeight);
+
+  frc::Pose2d targetPos;
+  units::meter_t targetHeightAboveGround;
+  units::meter_t targetWidth;
+  units::meter_t targetHeight;
+  double targetInfill_pct;
+  units::square_meter_t tgtArea;
+};
+
+}  // namespace photonlib