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/java/org/photonvision/SimVisionTarget.java

@@ -0,0 +1,51 @@
+/*
+ * 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/>.
+ */
+
+package org.photonvision;
+
+import edu.wpi.first.wpilibj.geometry.Pose2d;
+
+public class SimVisionTarget {
+    Pose2d targetPos;
+    double targetWidthMeters;
+    double targetHeightMeters;
+    double targetHeightAboveGroundMeters;
+    double targetInfill_pct;
+    double tgtAreaMeters2;
+
+    /**
+    * Describes a vision target located somewhere on the field that your SimVisionSystem can detect.
+    *
+    * @param targetPos Pose2d of the target on the field. Define it such that, if you are standing on
+    *     the middle of the field facing the target, the Y axis points to your left, and the X axis
+    *     points away from you.
+    * @param targetHeightAboveGroundMeters Height of the target above the field plane, in meters.
+    * @param targetWidthMeters Width of the outter bounding box of the target in meters.
+    * @param targetHeightMeters Pair Height of the outter bounding box of the target in meters.
+    */
+    public SimVisionTarget(
+            Pose2d targetPos,
+            double targetHeightAboveGroundMeters,
+            double targetWidthMeters,
+            double targetHeightMeters) {
+        this.targetPos = targetPos;
+        this.targetHeightAboveGroundMeters = targetHeightAboveGroundMeters;
+        this.targetWidthMeters = targetWidthMeters;
+        this.targetHeightMeters = targetHeightMeters;
+        this.tgtAreaMeters2 = targetWidthMeters * targetHeightMeters;
+    }
+}