Develop Reference

How to draw an arrow,put on frame and display in real time?

I need to create four arrow (up, down, left and right) and put them on frame in real time.I am doing some work with real time image processing and based on the results of function i need to show the arrow in real time on frame. After getting a frame from:
public Mat onCameraFrame(CameraBridgeViewBase.CvCameraViewFrame inputFrame) {
mRgba = inputFrame.rgba();
mGray = inputFrame.gray();
if(state){
myTask= new MyTask();
myTask.execute(mRgba);
//need to write method to display arrow
return mRgba;
}
return mRgba;
}
It call async task to do the method recognize and set which arrow need to be displayed.For now it return 1 if started frame and other frames are the same.I need to know how to make an arrow and display it on the frame.I will later make an algorithm to determent for direction so lets assume when return is 1 i need to display up arrow in the frame.
My asynctask is:
class MyTask extends AsyncTask<Mat, Void, Integer> {
#Override
protected void onPreExecute() {
super.onPreExecute();
}
#Override
protected Integer doInBackground(Mat... mats) {
if(!isCancelled())
return recognize(mats[0]);
else return 0;
}
#Override
protected void onPostExecute(Integer integer) {
super.onPostExecute(integer);
directionOfCamera=integer;
}
#Override
protected void onCancelled() {
super.onCancelled();
}
}
The method recognize is:
public int recognize(Mat inputFrame) {
if (startedFrame){
deskriptor.detect(inputFrame,keypoints1);
deskriptor.compute(inputFrame,keypoints1,deskriptor1);
startedFrame=false;
return 0;
}
deskriptor.detect(inputFrame,keypoints2);
Size size;
size=keypoints2.size();
if(size.height!= 0) {
deskriptor.compute(inputFrame,keypoints2,deskriptor2);
List<MatOfDMatch> matches = new LinkedList<MatOfDMatch>();
matcher.knnMatch(deskriptor1, deskriptor2, matches,2);
//Calculating good match list...
LinkedList<DMatch> goodMatchesList = new LinkedList<DMatch>();
for (int i = 0; i < matches.size(); i++) {
MatOfDMatch matofDMatch = matches.get(i);
DMatch[] dmatcharray = matofDMatch.toArray();
DMatch m1 = dmatcharray[0];
DMatch m2 = dmatcharray[1];
if (m1.distance <= m2.distance * nndrRatio) {
goodMatchesList.addLast(m1);
}
}
if (goodMatchesList.size() >= 7) {
List<KeyPoint> controlKeypointlist = keypoints1.toList();
List<KeyPoint> liveKeypointlist = keypoints2.toList();
LinkedList<Point> objectPoints = new LinkedList<>();
LinkedList<Point> scenePoints = new LinkedList<>();
for (int i = 0; i < goodMatchesList.size(); i++) {
objectPoints.addLast(controlKeypointlist.get(goodMatchesList.get(i).queryIdx).pt);
scenePoints.addLast(liveKeypointlist.get(goodMatchesList.get(i).trainIdx).pt);
}
MatOfPoint2f objMatOfPoint2f = new MatOfPoint2f();
objMatOfPoint2f.fromList(objectPoints);
MatOfPoint2f scnMatOfPoint2f = new MatOfPoint2f();
scnMatOfPoint2f.fromList(scenePoints);
return 1;
}
}
return 0;
}
Basically it should look like this:
If there is any code missing that helps, let me know and I add it.

As a solution - draw arrows in Adobe After Effects
and use this AirBnB library to implement it

Setting ImageView in JavaFX based on a gif animation

I am fairly new to programming and have recently encountered a problem that I have not found a solution for online. I have created an ImageView in FXML and gave it an FXid of "gif1". I am using code from this stackoverflow post but I tried modifying it so that it would fit my needs. I put the entirety of the code in a separate java file that I called "Gif.java". Typically, "Gif.java" uses an hbox and other non applicable methods to set the ImageView. I removed those because I will be using an existing FXML document so there is no need to create a new one. In my code, I call on "Gif.java" and expect a returned ImageView. However, when I set my ImageView (gif1) to the returned ImageView, it doesn't update on the screen.
Here is the link to the gif post: How I can stop an animated GIF in JavaFX?
Here is my code that I use to update gif1:
#FXML
private void setUp(){
Gif newGif = new Gif("rightrock.gif"); // Creates object newGif and passes through path to gif
gif1 = newGif.returnImage2(); // Sets gif1 to returned ImageView
}
Here is the return code in Gif.java:
public class Gif{
private Animation ani;
private ImageView test;
public Gif(String image) {
// TODO: provide gif file, ie exchange banana.gif with your file
ani = new AnimatedGif(getClass().getResource(image).toExternalForm(), 1000);
ani.setCycleCount(1);
ani.play();
Button btPause = new Button( "Pause");
btPause.setOnAction( e -> ani.pause());
Button btResume = new Button( "Resume");
btResume.setOnAction( e -> ani.play());
}
public void returnImage(ImageView x){
test = x; // Sets ImageView test to parameter x
}
public ImageView returnImage2() {
return test; // Return instance field test
}
public static void main(String[] args) {
launch(args);
}
public class AnimatedGif extends Animation {
public AnimatedGif( String filename, double durationMs) {
GifDecoder d = new GifDecoder();
d.read( filename);
Image[] sequence = new Image[ d.getFrameCount()];
for( int i=0; i < d.getFrameCount(); i++) {
WritableImage wimg = null;
BufferedImage bimg = d.getFrame(i);
sequence[i] = SwingFXUtils.toFXImage( bimg, wimg);
}
super.init( sequence, durationMs);
}
}
public class Animation extends Transition {
private ImageView imageView;
private int count;
private int lastIndex;
private Image[] sequence;
private Animation() {
}
public Animation( Image[] sequence, double durationMs) {
init( sequence, durationMs);
}
private void init( Image[] sequence, double durationMs) {
this.imageView = new ImageView(sequence[0]);
this.sequence = sequence;
this.count = sequence.length;
setCycleCount(1);
setCycleDuration(Duration.millis(durationMs));
setInterpolator(Interpolator.LINEAR);
}
protected void interpolate(double k) {
final int index = Math.min((int) Math.floor(k * count), count - 1);
if (index != lastIndex) {
imageView.setImage(sequence[index]);
lastIndex = index;
}
}
public ImageView getView() {
returnImage(imageView); // This runs returnImage with the ImageView that I want to set
return imageView;
}
}
Any help would be greatly appreciated!

Java Android Augmented Reality Application Image Coordinates

i am currently new to augmented reality programming and i would like to ask a question regarding the cameraView. My objective is to display an clickable imageButton at a specific real-life coordinate and display it in a cameraView. In this case, the thing that i want to display inside my cameraView(Which is a world) is my button. I tried using Wikitude/ AndAR/ Layar API before i decided that it was a hassle to call its permission for usage and I am currently using DroidAR as a library and reference. However i can't seem to find a way to display what i want correctly. I would like to seek help regarding this issue. Please advise me or guide me the correct way to achieve it. Thank you very much ! Below are my current codes using the droidAR library SDK.
public class DisplayAR extends Setup {
private static final float MIN_DIST = 15f;
private static final float MAX_DIST = 55f;
private Button b = null;
protected static final String LOG_TAG = "StaticDemoSetup";
World world;
GLCamera camera;
private TimeModifier timeModifier;
#Override
public void _a_initFieldsIfNecessary() {
// allow the user to send error reports to the developer:
}
#Override
public void _b_addWorldsToRenderer(GL1Renderer renderer,
GLFactory objectFactory, GeoObj currentPosition) {
camera = new GLCamera(new Vec(0, 0, 1));
world = new World(camera);
timeModifier = new TimeModifier(1);
RenderList l = new RenderList();
timeModifier.setChild(l);
world.add(timeModifier);
initI9Tests(world);
addTestGeoObj(world, camera);
renderer.addRenderElement(world);
}
private void addTestGeoObj(World w, GLCamera c) {
GeoObj o = new GeoObj();
w.add(o);
}
private void initI9Tests(World w) {
{
// transform android ui elements into opengl models:
b = new Button(getActivity());
b.setText("L.311");
MeshComponent button = GLFactory.getInstance().newTexturedSquare("buttonId", IO.loadBitmapFromView(b));
button.addChild(new AnimationFaceToCamera(camera, 0.5f));
button.setScale(new Vec(10, 10, 10));
button.setColor(Color.red());
button.setOnClickCommand(new CommandShowToast(getActivity(), "THIS IS L.311"));
GeoObj treangleGeo = new GeoObj();
treangleGeo.setVirtualPosition(new Vec(MIN_DIST, MAX_DIST, 0.0f));
treangleGeo.setComp(button);
w.add(treangleGeo);
}
}
#Override
public void _c_addActionsToEvents(EventManager eventManager,
CustomGLSurfaceView arView, SystemUpdater updater) {
ActionWASDMovement wasdAction = new ActionWASDMovement(camera, 25f,
50f, 20f);
ActionRotateCameraBuffered rotateAction = new ActionRotateCameraBuffered(
camera);
eventManager.addOnLocationChangedAction(new ActionCalcRelativePos(
world, camera));
updater.addObjectToUpdateCycle(wasdAction);
updater.addObjectToUpdateCycle(rotateAction);
arView.addOnTouchMoveAction(wasdAction);
eventManager.addOnOrientationChangedAction(rotateAction);
eventManager.addOnTrackballAction(new ActionMoveCameraBuffered(camera,
5, 25));
}
#Override
public void _d_addElementsToUpdateThread(SystemUpdater worldUpdater) {
// add the created world to be updated:
worldUpdater.addObjectToUpdateCycle(world);
}
#Override
public void _e2_addElementsToGuiSetup(GuiSetup guiSetup, Activity activity) {
guiSetup.setBottomMinimumHeight(50);
guiSetup.setBottomViewCentered();
}
}

try to use wikitude library for augmented reality at www.wikitude.com it has sample example simpleArbrowser is what u wanted

GameLoop Thread occasionally slow

For the game I'm currently writing for Android devices, I've got a class called RenderView, which is a Thread and updates and renders everything. Occasionally the class logs the message "Game thread is only updating the update method and is not rendering anything". The game is running at 30 fps on my nexus s. And I get the message a couple of times throughout the session. Could someone tell me how I could optimize the class or if I'm forgetting something or that it's totally normal?
Here's my code:
public class RenderView extends SurfaceView implements Runnable {
public final String classTAG = this.getClass().getSimpleName();
Game game;
Bitmap framebuffer;
Thread gameloop;
SurfaceHolder holder;
boolean running;
int sleepTime;
int numberOfFramesSkipped;
long beginTime;
long endTime;
long lastTime;
int differenceTime;
int framePeriod;
Canvas canvas;
int frameCount;
WSLog gameEngineLog;
public RenderView(Game game, Bitmap framebuffer) {
super(game);
this.game = game;
this.framebuffer = framebuffer;
this.holder = getHolder();
framePeriod = 1000/game.getFramesPerSecond();
lastTime = System.currentTimeMillis();
gameEngineLog = game.getGameEngineLog();
}
#Override
public void run() {
while(running == true) {
if(holder.getSurface().isValid()) {
beginTime = System.currentTimeMillis();
numberOfFramesSkipped = 0;
game.getCurrentScreen().update();
game.getCurrentScreen().render(); // Draw out everything to the current virtual screen (the bitmap)
game.getGraphics().renderFrameBuffer(); // Actually draw everything to the real screen (combine both bitmaps)
canvas = holder.lockCanvas();
if(canvas != null) { // Fix for mysterious bug ( FATAL EXCEPTION: Thread)
// The viewing area of our virtual screen on our real screen
canvas.drawBitmap(framebuffer, null, game.getWSScreen().getGameScreenextendeddst(), null);
holder.unlockCanvasAndPost(canvas);
}
else {
gameEngineLog.e(classTAG, "Surface has not been created or otherwise cannot be edited");
}
endTime = System.currentTimeMillis();;
differenceTime = (int) (endTime - beginTime);
sleepTime = (int) (framePeriod - differenceTime);
if(sleepTime > 0) {
try {
Thread.sleep(sleepTime);
} catch (InterruptedException exception) {
exception.printStackTrace();
}
}
else {
while(sleepTime < 0 && numberOfFramesSkipped < game.getMaxFrameSkippes()) {
gameEngineLog.d(classTAG, "Game thread is only updating the update method and is not rendering anything");
try {
Thread.sleep(5);
}
catch (InterruptedException exception) {
exception.printStackTrace();
}
game.getCurrentScreen().update();
sleepTime += framePeriod;
numberOfFramesSkipped++;
}
}
// Frame Per Second Count
frameCount++;
if(lastTime + 1000 < System.currentTimeMillis()) {
game.getGameEngineLog().d(classTAG, "REAL FPS: " + frameCount);
lastTime = System.currentTimeMillis();
frameCount = 0;
}
}
}
}
public void resume() {
running = true;
gameloop = new Thread(this);
gameloop.start();
}
public void pause() {
running = false;
while(running == true) {
try {
gameloop.join();
running = false;
}
catch (InterruptedException e) {
}
}
gameloop = null;
}
}
Here's the code for the Graphics class (the getGraphics() just return an graphics object):
public class Graphics {
public final String classTAG = this.getClass().getSimpleName();
Game game;
Canvas frameBuffer;
Canvas canvasGameScreenextended;
Canvas canvasGameScreen; // Used for customeScreen
Bitmap gameScreenextended;
Bitmap gameScreen;
Rect gameScreendst;
Rect gameScreenextendeddst;
WSLog gameEngineLog;
Graphics(Game game, Bitmap framebuffer, Bitmap gameScreen) {
this.game = game;
// Initialize canvases to render to
frameBuffer = new Canvas(framebuffer);
canvasGameScreen = new Canvas(gameScreen);
// Initialize images to be rendered to our composition
this.gameScreen = gameScreen;
// Set up the Log
gameEngineLog = game.getGameEngineLog();
}
public void resetCanvasGameScreenextended() {
// This method has to be called each time the screen scaling type changes
canvasGameScreenextended = new Canvas(game.getWSScreen().getGameScreenextended());
gameScreenextended = game.getWSScreen().getGameScreenextended();
}
public Canvas getCanvasGameScreenextended() {
return canvasGameScreenextended;
}
public Canvas getCanvasGameScreen() {
return canvasGameScreen;
}
public void renderFrameBuffer() {
// Composition
// First layer (bottom)
frameBuffer.drawBitmap(gameScreen, null, game.getWSScreen().getGameScreendst(), null);
// Second layer (top)
frameBuffer.drawBitmap(gameScreenextended, null, game.getWSScreen().getGameScreenextendeddst(), null);
}
public void clearFrameBuffer() {
canvasGameScreen.drawColor(Color.BLACK);
//canvasGameScreenextended.drawColor(Color.BLACK);
gameScreenextended.eraseColor(Color.TRANSPARENT); // Make top layer transparent
}
}
Here's the code for the screen class (the getCurrentScreen() method returns a screen object):
public class Screen {
public final String classTAG = this.getClass().getSimpleName();
protected final Game game;
protected final Graphics graphics;
protected Screen(Game game) {
this.game = game;
this.graphics = game.getGraphics();
//game.getInput().reset();
}
public void update() {
}
public void render() {
}
/** Initialize all the sensory that should be used within this screen.*/
public void resume() {
}
public void pause() {
game.getInput().useAccelerometer(false);
game.getInput().useKeyboard(false);
game.getInput().useTouchscreen(false);
}
public void onDispose() {
game.getGraphics().clearFrameBuffer();
}
public void setScreenResizeType(int screenResizeType) {
}
The Screen class is extended and the render() method is shadowed with methods like:
graphics.getCanvasGameScreen().drawRect(play, red);
The funny thing is, when I override the render() method and don't place any code in it, the logger fires constantly with the message: "Game thread is only updating the update method and is not rendering anything". What kind of sorcery is this?!
Help is hugely appreciated!

As far as I understand from your updated post, there is no rendering problem actually. Instead, your code mistakenly prints that message.
This is because you check if(sleepTime > 0) , so if the rendering is very fast and sleepTime is zero, you get that message. Just change it to if(sleepTime >= 0).

Eclipse RCP application - custom splash screen

I'm currently developing an Eclipse RCP application, in which I'm trying to implement a custom splash screen handler, sporting a progress bar (behavior similar to the default progress bar you can define in the .product definition) and multiple cycling background images.
After editing the extensions of the main application plugin this way:
[...]
<!-- install custom splash handler -->
<extension point="org.eclipse.ui.splashHandlers">
<splashHandler
class="com.example.application.splash.SlideShowSplashHandler"
id="splash.slideshow">
</splashHandler>
<splashHandlerProductBinding
productId="com.example.application.product"
splashId="com.example.application.splash.slideshow">
</splashHandlerProductBinding>
</extension>
<!-- define images (in plugin root directory) to be shown -->
<extension point="com.example.application.splashExtension">
<splashExtension id="01" image="01_Splash2Ag.bmp"></splashExtension>
<splashExtension id="02" image="02_Splash3Ag.bmp"></splashExtension>
<splashExtension id="00" image="00_Splash1Ag.bmp"></splashExtension>
</extension>
[...]
I'm trying to implement the custom splashscreen handler class:
public class SlideShowSplashHandler extends AbstractSplashHandler {
private List<Image> fImageList;
private ProgressBar fBar;
private final static String F_SPLASH_EXTENSION_ID = "com.example.application.splashExtension"; //NON-NLS-1
private final static String F_ELEMENT_IMAGE = "image"; //NON-NLS-1
private int imageIdx = 0;
public SlideShowSplashHandler() {
fImageList = new ArrayList<Image>(5);
}
/* (non-Javadoc)
* #see org.eclipse.ui.splash.AbstractSplashHandler#init(org.eclipse.swt.widgets.Shell)
*/
public void init(Shell splash) {
// Store the shell
super.init(splash);
// Force shell to inherit the splash background
getSplash().setBackgroundMode(SWT.INHERIT_DEFAULT);
// Load all splash extensions
loadSplashExtensions();
// If no splash extensions were loaded abort the splash handler
if (hasSplashExtensions() == false) return;
// Create UI
createUI(splash);
}
private boolean hasSplashExtensions() {
if (fImageList.isEmpty()) {
return false;
} else {
return true;
}
}
#Override
public IProgressMonitor getBundleProgressMonitor() {
return new NullProgressMonitor() {
#Override
public void beginTask(String name, final int totalWork) {
getSplash().getDisplay().syncExec(new Runnable() {
public void run() {
fBar.setSelection(50);
}
});
}
#Override
public void subTask(String name) {
getSplash().getDisplay().syncExec(new Runnable() {
public void run() {
if (fBar.getSelection() < 100) fBar.setSelection(fBar.getSelection() + 10);
if (imageIdx >= fImageList.size()) imageIdx = 0;
Image image = fImageList.get(imageIdx++);
getSplash().setBackgroundImage(image);
getSplash().setRedraw(true);
getSplash().redraw();
}
});
}
};
}
private void createUI(Shell shell) {
Composite container = new Composite(shell, SWT.NONE);
container.setLayout(new GridLayout(1, false));
container.setLocation(5, 374);
container.setSize(480, 15);
/* Progress Bar */
fBar = new ProgressBar(container, SWT.HORIZONTAL);
fBar.setLayoutData(new GridData(SWT.FILL, SWT.BEGINNING, true, false));
((GridData) fBar.getLayoutData()).heightHint = 13;
fBar.setMaximum(100);
fBar.setSelection(25);
/* Version Label */
Label versionLabel = new Label(container, SWT.NONE);
versionLabel.setLayoutData(new GridData(SWT.END, SWT.BEGINNING, true, false));
//versionLabel.setFont(fVersionFont);
//versionLabel.setForeground(fVersionColor);
//versionLabel.setText(NLS.bind(Messages.SplashHandler_BUILD, "2.1 Nightly")); //$NON-NLS-1$
/* Layout All */
shell.layout(true, true);
}
private void loadSplashExtensions() {
// Get all splash handler extensions
IExtension[] extensions = Platform.getExtensionRegistry()
.getExtensionPoint(F_SPLASH_EXTENSION_ID).getExtensions();
// Process all splash handler extensions
for (int i = 0; i < extensions.length; i++) {
processSplashExtension(extensions[i]);
}
}
/**
* Parse the extension points with the images filename.
*/
private void processSplashExtension(IExtension extension) {
// Get all splash handler configuration elements
IConfigurationElement[] elements = extension.getConfigurationElements();
// Process all splash handler configuration elements
for (int j = 0; j < elements.length; j++) {
processSplashElements(elements[j]);
}
}
/**
* Create the images defined as extension points
*/
private void processSplashElements(IConfigurationElement configurationElement) {
String name = configurationElement.getAttribute(F_ELEMENT_IMAGE);
ImageDescriptor descriptor = Activator.getImageDescriptor("/"+name);
if (descriptor != null) {
Image image = descriptor.createImage();
if (image !=null) {
fImageList.add(image);
}
}
}
public void dispose() {
super.dispose();
// Check to see if any images were defined
if ((fImageList == null) ||
fImageList.isEmpty()) {
return;
}
// Dispose of all the images
Iterator<Image> iterator = fImageList.iterator();
while (iterator.hasNext()) {
Image image = iterator.next();
image.dispose();
}
}
}
Problem is that the progress bar just works, while the images are not shown. While debugging I could verify that the images are actually found and loaded, and correctly set in the shell; the shell just seems to not being redrawn. Am i missing something?=

I could solve the problem on linux and windows, but it did not work on macos/cocoa (in which the splash screen is looking "scrambled" on each image slideshow iteration).
Is was very simple indeed, just attaching an extra Composite between the splash shell and the container containing the widgets; then change the background image on the newly create container object.
private void createUI(Shell shell) {
Composite bgcontainer = new Composite(shell, SWT.NONE); // new
[...]
Composite container = new Composite(bgcontainer, SWT.NONE);
[...]
fBar = new ProgressBar(container, SWT.HORIZONTAL);
[...]
Label versionLabel = new Label(container, SWT.NONE);
versionLabel.setLayoutData(new GridData(SWT.END, SWT.BEGINNING, true, false));
shell.layout(true, true);
}
#Override public IProgressMonitor getBundleProgressMonitor() {
return new NullProgressMonitor() {
#Override public void beginTask(String name, final int totalWork) {
getSplash().getDisplay().syncExec(new Runnable() {
public void run() {
if (fBar != null) fBar.setSelection(40);
Image image = fImageList.get(imageIdx++);
bgcontainer.setBackgroundImage(image);
bgcontainer.setRedraw(true);
bgcontainer.update();
}
});
}
#Override public void subTask(String name) {
final String n = name;
getSplash().getDisplay().syncExec(new Runnable() {
String taskname = n;
public void run() {
if (fBar != null && fBar.getSelection() < 100)
fBar.setSelection(fBar.getSelection() + 10);
if (fBar.getSelection() == 60 || fBar.getSelection() == 80) {
if (imageIdx >= fImageList.size()) imageIdx = 0;
Image image = fImageList.get(imageIdx++);
bgcontainer.setBackgroundImage(image);
bgcontainer.setRedraw(true);
bgcontainer.update();
}
}
});
}
};
}

I haven't tried your code, but when you make changes to a Control, it is not enough to call Control.redraw(), but you must also call Control.update().
Control.redraw() requests that a control should be redrawn, Control.update() actually redraws it. The later is needed when your code runs on the UI thread!