Create timesync JNI for testing client (#1433)

photon-lib/src/test/java/org/photonvision/PhotonCameraTest.java

@@ -24,12 +24,25 @@
 
 package org.photonvision;
 
+import edu.wpi.first.hal.HAL;
+import edu.wpi.first.networktables.NetworkTableInstance;
+import edu.wpi.first.networktables.NetworkTablesJNI;
+import edu.wpi.first.wpilibj.Timer;
+import java.io.IOException;
 import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
 import org.photonvision.common.dataflow.structures.Packet;
+import org.photonvision.jni.PhotonTargetingJniLoader;
+import org.photonvision.jni.WpilibLoader;
 import org.photonvision.targeting.PhotonPipelineResult;
 
 class PhotonCameraTest {
+    @BeforeAll
+    public static void load_wpilib() {
+        WpilibLoader.loadLibraries();
+    }
+
     @Test
     public void testEmpty() {
         Assertions.assertDoesNotThrow(
@@ -40,4 +53,43 @@ class PhotonCameraTest {
                     PhotonPipelineResult.photonStruct.pack(packet, ret);
                 });
     }
+
+    // Just a smoketest for dev use -- don't run by default
+    @Test
+    public void testTimeSyncServerWithPhotonCamera() throws InterruptedException, IOException {
+        load_wpilib();
+        PhotonTargetingJniLoader.load();
+
+        HAL.initialize(500, 0);
+
+        NetworkTableInstance.getDefault().stopClient();
+        NetworkTableInstance.getDefault().startServer();
+
+        var camera = new PhotonCamera("Arducam_OV2311_USB_Camera");
+        PhotonCamera.setVersionCheckEnabled(false);
+
+        for (int i = 0; i < 5; i++) {
+            Thread.sleep(500);
+
+            var res = camera.getLatestResult();
+            var captureTime = res.getTimestampSeconds();
+            var now = Timer.getFPGATimestamp();
+
+            // expectTrue(captureTime < now);
+
+            System.out.println(
+                    "sequence "
+                            + res.metadata.sequenceID
+                            + " image capture "
+                            + captureTime
+                            + " received at "
+                            + res.getTimestampSeconds()
+                            + " now: "
+                            + NetworkTablesJNI.now() / 1e6
+                            + " time since last pong: "
+                            + res.metadata.timeSinceLastPong / 1e6);
+        }
+
+        HAL.shutdown();
+    }
 }