First commit.

core/build.gradle

@@ -0,0 +1,11 @@
+apply plugin: "java"
+
+sourceCompatibility = 1.6
+[compileJava, compileTestJava]*.options*.encoding = 'UTF-8'
+
+sourceSets.main.java.srcDirs = [ "src/" ]
+
+
+eclipse.project {
+    name = appName + "-core"
+}

core/src/ve/ucv/ciens/icaro/ardemo/CustomPerspectiveCamera.java

@@ -0,0 +1,54 @@
+package ve.ucv.ciens.icaro.ardemo;
+
+import com.badlogic.gdx.graphics.PerspectiveCamera;
+import com.badlogic.gdx.math.Matrix4;
+import com.badlogic.gdx.math.Vector3;
+
+public class CustomPerspectiveCamera extends PerspectiveCamera{
+	private final Vector3 tmp = new Vector3();
+
+	public CustomPerspectiveCamera(float fieldOfView, float viewportWidth, float viewportHeight){
+		super(fieldOfView, viewportWidth, viewportHeight);
+		update();
+	}
+
+	public void update(Matrix4 customProjection){
+		this.update(customProjection, true);
+	}
+
+	public void update(Matrix4 customProjection, boolean updateFrustum){
+		projection.set(customProjection);
+		view.setToLookAt(position, tmp.set(position).add(direction), up);
+		combined.set(projection).mul(view);
+
+		if(updateFrustum){
+			invProjectionView.set(combined).inv();
+			frustum.update(invProjectionView);
+		}
+	}
+
+	public void setCustomARProjectionMatrix(final float focalPointX, final float focalPointY, final float cameraCenterX, final float cameraCenterY, final float near, final float far, final float w, final float h){
+		final float FAR_PLUS_NEAR = far + near;
+		final float FAR_LESS_NEAR = far - near;
+
+		projection.val[Matrix4.M00] = -2.0f * focalPointX / w;
+		projection.val[Matrix4.M10] = 0.0f;
+		projection.val[Matrix4.M20] = 0.0f;
+		projection.val[Matrix4.M30] = 0.0f;
+
+		projection.val[Matrix4.M01] = 0.0f;
+		projection.val[Matrix4.M11] = 2.0f * focalPointY / h;
+		projection.val[Matrix4.M21] = 0.0f;
+		projection.val[Matrix4.M31] = 0.0f;
+
+		projection.val[Matrix4.M02] = 2.0f * cameraCenterX / w - 1.0f;
+		projection.val[Matrix4.M12] = 2.0f * cameraCenterY / h - 1.0f;
+		projection.val[Matrix4.M22] = -FAR_PLUS_NEAR / FAR_LESS_NEAR;
+		projection.val[Matrix4.M32] = -1.0f;
+
+		projection.val[Matrix4.M03] = 0.0f;
+		projection.val[Matrix4.M13] = 0.0f;
+		projection.val[Matrix4.M23] = -2.0f * far * near / FAR_LESS_NEAR;
+		projection.val[Matrix4.M33] = 0.0f;
+	}
+}

core/src/ve/ucv/ciens/icaro/ardemo/EviDemo.java

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+package ve.ucv.ciens.icaro.ardemo;
+
+import ve.ucv.ciens.icaro.ardemo.ImageProcessor.CalibrationData;
+import ve.ucv.ciens.icaro.ardemo.ImageProcessor.MarkerData;
+
+import com.badlogic.gdx.ApplicationAdapter;
+import com.badlogic.gdx.Gdx;
+import com.badlogic.gdx.graphics.GL20;
+import com.badlogic.gdx.graphics.Pixmap;
+import com.badlogic.gdx.graphics.Texture;
+import com.badlogic.gdx.graphics.g2d.SpriteBatch;
+
+public class EviDemo extends ApplicationAdapter {
+	private static final String TAG = "NXTAR_ANDROID_MAIN";
+	private static final String CLASS_NAME = EviDemo.class.getSimpleName();
+
+	private ImageProcessor cvProc;
+	private Texture tex;
+	private Pixmap frame;
+	private SpriteBatch batch;
+	private MarkerData data;
+	private CalibrationData calib;
+
+	private float[][] calibrationSamples;
+	private int lastSampleTaken;
+
+	public EviDemo(ImageProcessor proc) {
+		super();
+		tex = null;
+		cvProc = proc;
+		frame = null;
+
+		lastSampleTaken = 0;
+
+		calibrationSamples = new float[ProjectConstants.CALIBRATION_SAMPLES][];
+		for(int i = 0; i < calibrationSamples.length; i++){
+			calibrationSamples[i] = new float[ProjectConstants.CALIBRATION_PATTERN_POINTS * 2];
+		}
+	}
+
+	@Override
+	public void create () {
+		batch = new SpriteBatch();
+	}
+
+	@Override
+	public void render () {
+		Gdx.gl.glClearColor(1, 0, 0, 1);
+		Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
+
+		if(cvProc.isCameraCalibrated()) {
+			data = cvProc.findMarkersInFrame();
+			if(data != null) {
+				frame = new Pixmap(data.outFrame, 0, data.outFrame.length);
+				tex = new Texture(frame);
+
+				batch.begin();
+				batch.draw(tex, 0, 0);
+				batch.end();
+
+				frame.dispose();
+				tex.dispose();
+			}
+		} else {
+			calib = cvProc.findCalibrationPattern();
+
+			if(calib != null){
+
+				if(!cvProc.isCameraCalibrated() && calib.calibrationPoints != null){
+					Gdx.app.log(TAG, CLASS_NAME + ".render(): Sample taken.");
+
+					// Save the calibration points to the samples array.
+					for(int i = 0; i < calib.calibrationPoints.length; i += 2){
+						Gdx.app.log(TAG, CLASS_NAME + ".render(): Value " + Integer.toString(i) + " = (" + Float.toString(calib.calibrationPoints[i]) + ", " + Float.toString(calib.calibrationPoints[i + 1]) + ")");
+						calibrationSamples[lastSampleTaken][i] = calib.calibrationPoints[i];
+						calibrationSamples[lastSampleTaken][i + 1] = calib.calibrationPoints[i + 1];
+					}
+
+					// Move to the next sample.
+					lastSampleTaken++;
+
+					// If enough samples has been taken then calibrate the camera.
+					if(lastSampleTaken == ProjectConstants.CALIBRATION_SAMPLES){
+						Gdx.app.log(TAG, CLASS_NAME + "render(): Last sample taken.");
+
+						cvProc.calibrateCamera(calibrationSamples);
+					}
+				}
+
+				frame = new Pixmap(calib.outFrame, 0, calib.outFrame.length);
+				tex = new Texture(frame);
+
+				batch.begin();
+				batch.draw(tex, 0, 0);
+				batch.end();
+
+				frame.dispose();
+				tex.dispose();
+			}
+		}
+	}
+}

core/src/ve/ucv/ciens/icaro/ardemo/ImageProcessor.java

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+package ve.ucv.ciens.icaro.ardemo;
+
+import com.badlogic.gdx.math.Matrix3;
+import com.badlogic.gdx.math.Vector3;
+
+public interface ImageProcessor {
+	public class MarkerData{
+		public byte[] outFrame;
+		public int[] markerCodes;
+		public Vector3[] translationVectors;
+		public Matrix3[] rotationMatrices;
+	}
+
+	public class CalibrationData{
+		public byte[] outFrame;
+		public float[] calibrationPoints;
+	}
+
+	/**
+	 * <p>Finds up to {@link ProjectConstants.MAXIMUM_NUMBER_OF_MARKERS} markers in the input
+	 * image and returns their codes and pose estimation in the CVMarkerData structure. The
+	 * markers are higlihted in the input image.</p>
+	 * 
+	 * @param frame The JPEG encoded input image.
+	 * @return A data structure containing the processed output image, the
+	 * detected marker codes and their respective locations.
+	 */
+	public MarkerData findMarkersInFrame();
+
+	/**
+	 * <p>Attempts to detect a checkerboard calibration pattern in the input image.
+	 * If the pattenr is found the method returns an image with the pattern
+	 * highlighted and the spatial location of the calibration points in the 
+	 * output data structure.</p>
+	 * 
+	 * @param frame The JPEG encoded input image.
+	 * @return A data structure containing the processed output image and the
+	 * location of the calibration points. If the pattern was not found, the returnd
+	 * calibration points array is null.
+	 */
+	public CalibrationData findCalibrationPattern();
+
+	/** 
+	 * <p>Obtains the intrinsic camera parameters necesary for calibration.</p>
+	 */
+	public boolean calibrateCamera(float[][] calibrationSamples);
+
+	/**
+	 * <p>Indicates if OpenCV has been sucessfully initialized and used
+	 * to obtain the camera parameters for calibration.</p>
+	 * 
+	 * @return True if and only if OpenCV initialized succesfully and calibrateCamera has been called previously.
+	 */
+	public boolean isCameraCalibrated();
+
+	public float getFocalPointX();
+	public float getFocalPointY();
+	public float getCameraCenterX();
+	public float getCameraCenterY();
+}

core/src/ve/ucv/ciens/icaro/ardemo/ProjectConstants.java

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+package ve.ucv.ciens.icaro.ardemo;
+
+public abstract class ProjectConstants{
+	public static final int     SERVICE_DISCOVERY_PORT     = 9988;
+	public static final int     VIDEO_STREAMING_PORT       = 9989;
+	public static final int     MOTOR_CONTROL_PORT         = 9990;
+	public static final int     SENSOR_REPORT_PORT         = 9991;
+	public static final int     APP_CONTROL_PORT           = 9992;
+	public static final String  MULTICAST_ADDRESS          = "230.0.0.1";
+
+	public static final int     EXIT_SUCCESS               = 0;
+	public static final int     EXIT_FAILURE               = 1;
+
+	public static final boolean DEBUG                      = false;
+
+	public static final int[]   POWERS_OF_2                = {64, 128, 256, 512, 1024, 2048};
+	public static final float   MAX_ABS_ROLL               = 60.0f;
+
+	public static final String  FONT_CHARS                 = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890:,";
+
+	public static final int     MAXIMUM_NUMBER_OF_MARKERS  = 5;
+	public static final int     CALIBRATION_PATTERN_POINTS = 54;
+	public static final int     CALIBRATION_SAMPLES        = 10;
+}