Add support for OpenCV to Java wrappers.

java/java.gradle

@@ -21,6 +21,11 @@ sourceSets {
     }
 }
 
+dependencies {
+    compile 'org.opencv:opencv-java:3.1.0'
+    runtime 'org.opencv:opencv-java:3.1.0'
+}
+
 jar {
     description = 'Generates CameraServer jar, with the JNI shared libraries embedded'
     baseName = 'cameraserver'
@@ -85,7 +90,7 @@ task jniHeadersCameraServer {
         exec {
             executable org.gradle.internal.jvm.Jvm.current().getExecutable('javah')
             args '-d', outputFolder
-            args '-classpath', sourceSets.main.output.classesDir
+            args '-classpath', sourceSets.main.runtimeClasspath.asPath
             args 'edu.wpi.cameraserver.CameraServerJNI'
         }
     }

java/lib/CameraServerJNI.cpp

@@ -521,6 +521,20 @@ JNIEXPORT void JNICALL Java_edu_wpi_cameraserver_CameraServerJNI_releaseSource
   CheckStatus(env, status);
 }
 
+/*
+ * Class:     edu_wpi_cameraserver_CameraServerJNI
+ * Method:    putSourceFrame
+ * Signature: (IJ)V
+ */
+JNIEXPORT void JNICALL Java_edu_wpi_cameraserver_CameraServerJNI_putSourceFrame
+  (JNIEnv *env, jclass, jint source, jlong imageNativeObj)
+{
+  cv::Mat& image = *((cv::Mat*)imageNativeObj);
+  CS_Status status;
+  cs::PutSourceFrame(source, image, &status);
+  CheckStatus(env, status);
+}
+
 /*
  * Class:     edu_wpi_cameraserver_CameraServerJNI
  * Method:    notifySourceError
@@ -716,6 +730,21 @@ JNIEXPORT void JNICALL Java_edu_wpi_cameraserver_CameraServerJNI_releaseSink
   CheckStatus(env, status);
 }
 
+/*
+ * Class:     edu_wpi_cameraserver_CameraServerJNI
+ * Method:    grabSinkFrame
+ * Signature: (IJ)J
+ */
+JNIEXPORT jlong JNICALL Java_edu_wpi_cameraserver_CameraServerJNI_grabSinkFrame
+  (JNIEnv *env, jclass, jint sink, jlong imageNativeObj)
+{
+  cv::Mat& image = *((cv::Mat*)imageNativeObj);
+  CS_Status status;
+  auto rv = cs::GrabSinkFrame(sink, image, &status);
+  CheckStatus(env, status);
+  return rv;
+}
+
 /*
  * Class:     edu_wpi_cameraserver_CameraServerJNI
  * Method:    getSinkError

java/src/edu/wpi/cameraserver/CameraServerJNI.java

@@ -116,7 +116,7 @@ public class CameraServerJNI {
   //
   // OpenCV Source Functions
   //
-  //public static native void putSourceFrame(int source, CvMat image);
+  public static native void putSourceFrame(int source, long imageNativeObj);
   public static native void notifySourceError(int source, String msg);
   public static native void setSourceConnected(int source, boolean connected);
   public static native int createSourceProperty(int source, String name, int type);
@@ -149,7 +149,7 @@ public class CameraServerJNI {
   //
   // OpenCV Sink Functions
   //
-  //public static native int grabSinkFrame(int sink, CvMat image);
+  public static native long grabSinkFrame(int sink, long imageNativeObj);
   public static native String getSinkError(int sink);
   public static native void setSinkEnabled(int sink, boolean enabled);
 

java/src/edu/wpi/cameraserver/CvSink.java

@@ -7,6 +7,8 @@
 
 package edu.wpi.cameraserver;
 
+import org.opencv.core.Mat;
+
 /// A sink for user code to accept video frames as OpenCV images.
 public class CvSink extends VideoSink {
   /// Create a sink for accepting OpenCV images.
@@ -33,9 +35,9 @@ public class CvSink extends VideoSink {
   /// Wait for the next frame and get the image.
   /// @return Frame time, or 0 on error (call GetError() to obtain the error
   ///         message);
-  //public long grabFrame(CvMat image) {
-  //  return CameraServerJNI.grabSinkFrame(m_handle, image);
-  //}
+  public long grabFrame(Mat image) {
+    return CameraServerJNI.grabSinkFrame(m_handle, image.nativeObj);
+  }
 
   /// Get error string.  Call this if WaitForFrame() returns 0 to determine
   /// what the error is.

java/src/edu/wpi/cameraserver/CvSource.java

@@ -7,6 +7,8 @@
 
 package edu.wpi.cameraserver;
 
+import org.opencv.core.Mat;
+
 /// A source that represents a video camera.
 public class CvSource extends VideoSource {
   /// Create an OpenCV source.
@@ -28,7 +30,9 @@ public class CvSource extends VideoSource {
 
   /// Put an OpenCV image and notify sinks.
   /// @param image OpenCV image
-  //public void putFrame(Mat image);
+  public void putFrame(Mat image) {
+    CameraServerJNI.putSourceFrame(m_handle, image.nativeObj);
+  }
 
   /// Signal sinks that an error has occurred.  This should be called instead
   /// of NotifyFrame when an error occurs.