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Animating car Marker movement returns to north when stopped

I am animating car moving on a street with real time location updates. While moving it positions correctly towards the direction, but when the movement stops the car is facing to true north and the bearing returns 0.0 no matter which direction I am. Follow the code I'm using:
public static void animateMarker(Marker marker, Location destination) {
if (marker != null) {
LatLng startPosition = marker.getPosition();
LatLng endPosition = new LatLng(destination.getLatitude(), destination.getLongitude());
float startRotation = marker.getRotation();
LatLngInterpolator latLngInterpolator = new LatLngInterpolator.LinearFixed();
ValueAnimator valueAnimator = ValueAnimator.ofFloat(0, 1);
valueAnimator.setDuration(1000); // duration 1 second
valueAnimator.setInterpolator(new LinearInterpolator());
valueAnimator.addUpdateListener(animation -> {
try {
float v = animation.getAnimatedFraction();
LatLng newPosition = latLngInterpolator.interpolate(v, startPosition, endPosition);
marker.setPosition(newPosition);
marker.setRotation(computeRotation(v, startRotation, destination.getBearing()));
} catch (Exception ex) { }
});
valueAnimator.start();
}
}
private static float computeRotation(float fraction, float start, float end) {
float normalizeEnd = end - start; // rotate start to 0
float normalizedEndAbs = (normalizeEnd + 360) % 360;
float direction = (normalizedEndAbs > 180) ? -1 : 1; // -1 = anticlockwise, 1 = clockwise
float rotation;
if (direction > 0) {
rotation = normalizedEndAbs;
} else {
rotation = normalizedEndAbs - 360;
}
float result = fraction * rotation + start;
return (result + 360) % 360;
}
how to solve this?

Android: how to Zoom using camera2 API

I am new to android development and i am creating app that deals with camera but i am having problem with the zoom in function. I am using camera2 code sample from google, i modified bit using solutions from here but still it is not working.
public float finger_spacing = 0;
public int zoom_level = 1;
.
.
.
public boolean onTouch(View v, MotionEvent event) {
try {
Activity activity = getActivity();
CameraManager manager = (CameraManager) activity.getSystemService(Context.CAMERA_SERVICE);
CameraCharacteristics characteristics = manager.getCameraCharacteristics(mCameraId);
float maxzoom = (characteristics.get(CameraCharacteristics.SCALER_AVAILABLE_MAX_DIGITAL_ZOOM))*10;
Rect m = characteristics.get(CameraCharacteristics.SENSOR_INFO_ACTIVE_ARRAY_SIZE);
int action = event.getAction();
float current_finger_spacing;
if (event.getPointerCount() > 1) {
// Multi touch logic
current_finger_spacing = getFingerSpacing(event);
if(finger_spacing != 0){
if(current_finger_spacing > finger_spacing && maxzoom > zoom_level){
zoom_level++;
}
else if (current_finger_spacing < finger_spacing && zoom_level > 1){
zoom_level--;
}
int minW = (int) (m.width() / maxzoom);
int minH = (int) (m.height() / maxzoom);
int difW = m.width() - minW;
int difH = m.height() - minH;
int cropW = difW /100 *(int)zoom_level;
int cropH = difH /100 *(int)zoom_level;
cropW -= cropW & 3;
cropH -= cropH & 3;
Rect zoom = new Rect(cropW, cropH, m.width() - cropW, m.height() - cropH);
mPreviewRequestBuilder.set(CaptureRequest.SCALER_CROP_REGION, zoom);
}
finger_spacing = current_finger_spacing;
}
else{
if (action == MotionEvent.ACTION_UP) {
//single touch logic
}
}
try {
mCaptureSession.setRepeatingRequest(mPreviewRequestBuilder.build(), mCaptureCallback,
null);
}
catch (CameraAccessException e) {
e.printStackTrace();
}
catch (NullPointerException ex)
{
ex.printStackTrace();
}
}
catch (CameraAccessException e)
{
throw new RuntimeException("can not access camera.", e);
}
return true;
}
//Determine the space between the first two fingers
#SuppressWarnings("deprecation")
private float getFingerSpacing(MotionEvent event) {
float x = event.getX(0) - event.getX(1);
float y = event.getY(0) - event.getY(1);
return (float) Math.sqrt(x * x + y * y);
}
I have added this in the end of Camera2BasicFragment class but it changes nothing.

Images are not resizing after dynamically adding Imageviews in relative layout

I am trying to create photo collage app. Here I am dynamically adding imageviews in relative layout by passing array of positions for creating grid. Grids are successfully created. But when I add images, the images aren't scaled properly or not fitting to entire imageview's area. Also when I add touch listener on images, images are moviing outside the area of imageview.Please help me in this.Thanks in advance Here is my code
public void drawGrids() {
Resources res = getResources();
int Rid = c.id;
TypedArray ta = res.obtainTypedArray(Rid);
int n = ta.length();
String[][] array = new String[n][];
for (int i = 0; i < n; ++i) {
int id = ta.getResourceId(i, 0);
if (id > 0) {
array[i] = res.getStringArray(id);
Log.e(" array", "" + i + " " + Arrays.toString(array[i]));
String[] values = Arrays.toString(array[i]).replaceAll("[\\[\\]\\s]", "").split(","); // extracting each element from array
final int position = i;
limit = position+1;
float x = Float.parseFloat(values[0]);
float y = Float.parseFloat(values[1]);
float w = Float.parseFloat(values[2]);
float h = Float.parseFloat(values[3]);
Log.e(" x:", "" + x);
Log.e(" y:", "" + y);
Log.e(" w:", "" + w);
Log.e(" h:", "" + h);
img1 = new ImageView(getActivity());
img1.setImageResource(R.drawable.button_background);
params = new RelativeLayout.LayoutParams((int) ((Screen_width * w) - padding), (int) ((Screen_height * h) - padding));
// x= x* Screen_width
// y= y* Screen_height
params.leftMargin = (int) ((Screen_width * x) + padding);
params.topMargin = (int) ((Screen_height * y) + padding);
params.rightMargin = padding;
params.bottomMargin = padding;
Log.e(" px(x):", "" + (int) (Screen_width * x));
Log.e(" px(y):", "" + (int) (Screen_height * y));
Log.e(" px(w):", "" + (int) (Screen_width * w));
Log.e("px(h)", "" + (int) (Screen_height * h));
if(!mSelectedImages.isEmpty()) {
onPickedSuccessfully(mSelectedImages);
}
else {
img1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Log.e("clicked", "" + position);
onClickPickImageMultipleWithLimit(img1);
}
});
}
IMGS.add(img1); // arraylist of imageview
root1.addView(img1, params);
createPreview();
} else {
// something wrong with the XML
}
}
ta.recycle();
}
public void onPickedSuccessfully(ArrayList<ImageEntry> images) { // selected images path are to be fetched here
mSelectedImages = images;
handler.post(new Runnable() {
#Override
public void run() {
for (j = 0; j <IMGS.size(); j++) {
final ImageView child=IMGS.get(j);
child.onTouchListener(new MultiTouchListener);// multitouch listener for zooming and scrolling picked image
Log.e("w n h", "" + child.getWidth() + " " + child.getHeight());
int areaheight = child.getWidth();
int areawidth = child.getHeight();
BitmapFactory.Options bmOptions = new BitmapFactory.Options();
oldBitmap = BitmapFactory.decodeFile(String.valueOf(mSelectedImages.get(j)), bmOptions);//decodeFile(String.valueOf(mSelectedImages.get(j)));
int height = oldBitmap.getHeight(), width = oldBitmap.getWidth();
Log.e(" b width and height ", "" + oldBitmap.getWidth() + " " + oldBitmap.getHeight());
Log.e(" area width and height ", "" + areawidth + " " + areaheight);
Bitmap scaledBitmap;
if (areaheight > areawidth) {
// portrait
float ratio = (float) height / areaheight;
height = areaheight;
width = (int) (width / ratio);
scaledBitmap = Bitmap.createScaledBitmap(oldBitmap, width, height, true);
Log.e("porait scaled w ht ", "" + scaledBitmap.getWidth() + " " + scaledBitmap.getHeight());
} else if (areawidth > areaheight) {
//landscape
float ratio = (float) width / areawidth;
width = areawidth;
height = (int) (height / ratio);
scaledBitmap = Bitmap.createScaledBitmap(oldBitmap, width, height, true);
Log.e("landscape scaled w ht ", "" + scaledBitmap.getWidth() + " " + scaledBitmap.getHeight());
} else {
// square
height = areaheight;
width = areawidth;
scaledBitmap = Bitmap.createScaledBitmap(oldBitmap, width, height, true);
Log.e("square scaled w ht ", "" + scaledBitmap.getWidth() + " " + scaledBitmap.getHeight());
}
child.setImageBitmap(scaledBitmap);
}
}
});

In your case you need to add line:
img1.setScaleType(ImageView.ScaleType.CENTER_CROP); // or CENTER_INSIDE, or FIT_CENTER, or for example FIT_XY
after:
img1.setImageResource(R.drawable.button_background);
Thus, you will provide scaling for all images that will be set into your ImageView. You can read more about scaleType here and here

Rather than use ImageView and setOnTouchListener, you may try this custom view.
public class ScaleImageView extends ImageView {
private ScaleGestureDetector mScaleDetector;
private float mScaleFactor = 1.0f;
private float x = 0;
private float y = 0;
private float tx = 0;
private float ty = 0;
private float dx = 0;
private float dy = 0;
private int scrollLimitX = 0;
private int scrollLimitY = 0;
private boolean justScaled = false;
public ScaleImageView(Context context) {
super(context);
mScaleDetector = new ScaleGestureDetector(context, new ScaleListener());
}
public ScaleImageView(Context context, AttributeSet attrs) {
super(context, attrs);
mScaleDetector = new ScaleGestureDetector(context, new ScaleListener());
}
#SuppressLint("ClickableViewAccessibility")
#Override
public boolean onTouchEvent(MotionEvent ev) {
if(ev.getPointerCount() == 1){
switch(ev.getAction()){
case MotionEvent.ACTION_DOWN:
tx = ev.getX();
ty = ev.getY();
break;
case MotionEvent.ACTION_MOVE:
if(!justScaled){
dx = tx - ev.getX();
dy = ty - ev.getY();
tx -= dx;
ty -= dy;
int scrollX = (int)(this.getScrollX()/mScaleFactor);
int scrollY = (int)(this.getScrollY()/mScaleFactor);
if(Math.abs(scrollX+dx) > scrollLimitX) dx = 0;
if(Math.abs(scrollY+dy) > scrollLimitY) dy = 0;
this.scrollBy((int)(dx*mScaleFactor), (int)(dy*mScaleFactor));
}
break;
case MotionEvent.ACTION_UP:
justScaled = false;
break;
}
}else if(ev.getPointerCount() == 2){
justScaled = true;
mScaleDetector.onTouchEvent(ev);
}
return super.onTouchEvent(ev);
}
#Override
public void onDraw(Canvas canvas) {
x = this.getWidth()/2;
y = this.getHeight()/2;
canvas.scale(mScaleFactor, mScaleFactor, x ,y);
int scrollX = (int)(this.getScrollX()/mScaleFactor);
int scrollY = (int)(this.getScrollY()/mScaleFactor);
if(Math.abs(scrollX) > scrollLimitX) dx = scrollLimitX - scrollX; else dx = 0;
if(Math.abs(scrollY) > scrollLimitY) dy = scrollLimitY - scrollY; else dy = 0;
this.scrollBy((int)(dx*mScaleFactor), (int)(dy*mScaleFactor));
super.onDraw(canvas);
}
public void setScaleFactor(float mfactor){
this.mScaleFactor = mfactor;
}
public float getScaleFactor(){
return this.mScaleFactor;
}
public void setScrollLimit(int x, int y){
this.scrollLimitX = x/2;
this.scrollLimitY = y/2;
}
private class ScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener {
#Override
public boolean onScale(ScaleGestureDetector detector) {
mScaleFactor *= detector.getScaleFactor();
mScaleFactor = Math.max(1.0f, Math.min(mScaleFactor, 5.0f));
ScaleImageView.this.invalidate();
return true;
}
}
}
To limit the image that at least one corner is inside the view:
// zoomImg is the Bitmap.
// mZoomImage is the ScaleImageView.
float scaleFactor = Math.min((float)(mZoomImage.getWidth())/zoomImg.getWidth(), (float)(mZoomImage.getHeight())/zoomImg.getHeight());
mZoomImage.setScrollLimit((int)(zoomImg.getWidth()*scaleFactor), (int)(zoomImg.getHeight()*scaleFactor));
Hope this is helpful!

Issue with my game Joystick

I'm working in a spaceship first person view game. I have a joystick, and when i move the joystick i can move all the objects (asteroids) of the screen simulating that the spaceship is being moved with the joystick.
The game works fine, but now i have a problem. If you are pressing the joystick in the max left position and then you do ACTION_UP and then instantly ACTION_DOWN in the joystick again but in the max right position, the spaceship starts moving to the right at max speed. It is hard to explain it. For example, If you press the joystick in max left position the spaceship is moving -20px per frame to the left and if you press the joystick in the max right position, the spaceship moves to the right +20px per frame.
So, now, if i do a fast max left and max right touch on the joystick, the spaceship does this movement: -20....+20
It is not reallistic movement.
I want to get this movement: -20 -17 -14 -9 -5 0 +5 +9 +14 +17 +20.... I mean a more reallistic spaceship movement. But the problem is that i am not a math or physics expert, and i dont have any idea of how to get that kind of functionality in this joystick... any help will be very grateful.
Here you can find a demo project with the joystick: https://mega.co.nz/#!cp5FhYIT!dM88qx_xQdyhED9fX_4xeJ9ciQYJirUlNzEi-KOzU2k
This is the joystick code, i found it in google and works very well except for the non realistic movement that i described before:
public class Joystick extends View {
public static final int INVALID_POINTER = -1;
private JoystickMovedListener moveListener;
//# of pixels movement required between reporting to the listener
private float moveResolution;
//Max range of movement in user coordinate system
private float movementRange;
//Last touch point in view coordinates
private int pointerId = INVALID_POINTER;
private float touchX;
private float touchY;
private float touchXDelayedMovement;
private float touchYDelayedMovement;
//Handle center in view coordinates
private float handleX;
private float handleY;
//Last reported position in view coordinates (allows different reporting sensitivities)
private float reportX;
private float reportY;
//Center of the view in view coordinates
private int cX;
private int cY;
//Size of the view in view coordinates
private int dimX;
private int dimY;
private int innerPadding;
private int bgRadius;
private int handleRadius;
private int movementRadius;
private int handleInnerBoundaries;
//Cartesian coordinates of last touch point - joystick center is (0,0)
private int cartX;
private int cartY;
//User coordinates of last touch point
private int userX;
private int userY;
//Offset co-ordinates (used when touch events are received from parent's coordinate origin)
private int offsetX;
private int offsetY;
private Paint bgPaint;
private Paint handlePaint;
boolean disabled;
Handler handler;
Handler handlerDelayedMovement;
public Joystick(Context context) {
super(context);
initJoystickView();
}
private void initJoystickView() {
setFocusable(true);
handlePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
handlePaint.setColor(Color.RED);
handlePaint.setStrokeWidth(1);
handlePaint.setStyle(Paint.Style.FILL_AND_STROKE);
bgPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
bgPaint.setColor(Color.DKGRAY);
bgPaint.setStrokeWidth(1);
bgPaint.setStyle(Paint.Style.FILL_AND_STROKE);
this.moveResolution = 1.0f;
handler = new Handler();
handlerDelayedMovement = new Handler();
}
public void setMovementRange(float movementRange) {
this.movementRange = movementRange;
}
public void setOnJostickMovedListener(JoystickMovedListener listener) {
this.moveListener = listener;
}
#Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
super.onLayout(changed, left, top, right, bottom);
int d = Math.min(getMeasuredWidth(), getMeasuredHeight());
dimX = d;
dimY = d;
cX = d / 2;
cY = d / 2;
bgRadius = dimX/2 - innerPadding;
handleRadius = (int)(d * 0.2);
handleInnerBoundaries = handleRadius;
movementRadius = Math.min(cX, cY) - handleInnerBoundaries;
}
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// Here we make sure that we have a perfect circle
int measuredWidth = measure(widthMeasureSpec);
int measuredHeight = measure(heightMeasureSpec);
setMeasuredDimension(measuredWidth, measuredHeight);
}
private int measure(int measureSpec) {
int result = 0;
// Decode the measurement specifications.
int specMode = MeasureSpec.getMode(measureSpec);
int specSize = MeasureSpec.getSize(measureSpec);
if (specMode == MeasureSpec.UNSPECIFIED) {
result = 200; // Return a default size of 200 if no bounds are specified.
} else {
result = specSize; // As you want to fill the available space always return the full available bounds.
}
return result;
}
#Override
protected void onDraw(Canvas canvas) {
canvas.save();
// Draw the background
canvas.drawCircle(cX, cY, bgRadius, bgPaint);
// Draw the handle
handleX = touchX + cX;
handleY = touchY + cY;
canvas.drawCircle(handleX, handleY, handleRadius, handlePaint);
canvas.restore();
}
public void setPointerId(int id) {
this.pointerId = id;
}
public int getPointerId() {
return pointerId;
}
#Override
public boolean onTouchEvent(MotionEvent ev) {
final int action = ev.getAction();
switch (action & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_MOVE: {
if (disabled==true)
break;
return processMoveEvent(ev);
}
case MotionEvent.ACTION_CANCEL:
case MotionEvent.ACTION_UP: {
if ( pointerId != INVALID_POINTER ) {
returnHandleToCenter();
returnHandleToCenterDelayedMovement();
setPointerId(INVALID_POINTER);
}
break;
}
case MotionEvent.ACTION_POINTER_UP: {
if ( pointerId != INVALID_POINTER ) {
final int pointerIndex = (action & MotionEvent.ACTION_POINTER_INDEX_MASK) >> MotionEvent.ACTION_POINTER_INDEX_SHIFT;
final int pointerId = ev.getPointerId(pointerIndex);
if ( pointerId == this.pointerId ) {
returnHandleToCenter();
returnHandleToCenterDelayedMovement();
setPointerId(INVALID_POINTER);
return true;
}
}
break;
}
case MotionEvent.ACTION_DOWN: {
handlerDelayedMovement.removeCallbacksAndMessages(null);
if ( pointerId == INVALID_POINTER ) {
int x = (int) ev.getX();
if ( x >= offsetX && x < offsetX + dimX ) {
setPointerId(ev.getPointerId(0));
if (disabled==true){
return true;
}
return processMoveEvent(ev);
}
}
break;
}
case MotionEvent.ACTION_POINTER_DOWN: {
if ( pointerId == INVALID_POINTER ) {
final int pointerIndex = (action & MotionEvent.ACTION_POINTER_INDEX_MASK) >> MotionEvent.ACTION_POINTER_INDEX_SHIFT;
final int pointerId = ev.getPointerId(pointerIndex);
int x = (int) ev.getX(pointerId);
if ( x >= offsetX && x < offsetX + dimX ) {
setPointerId(pointerId);
return true;
}
}
break;
}
}
return false;
}
private boolean processMoveEvent(MotionEvent ev) {
if ( pointerId != INVALID_POINTER ) {
final int pointerIndex = ev.findPointerIndex(pointerId);
// Translate touch position to center of view
float x = ev.getX(pointerIndex);
touchX = x - cX - offsetX;
float y = ev.getY(pointerIndex);
touchY = y - cY - offsetY;
reportOnMoved();
invalidate();
return true;
}
return false;
}
private void reportOnMoved() {
//constraint circle
float diffX = touchX;
float diffY = touchY;
double radial = Math.sqrt((diffX*diffX) + (diffY*diffY));
if ( radial > movementRadius ) {
touchX = (int)((diffX / radial) * movementRadius);
touchY = (int)((diffY / radial) * movementRadius);
}
//We calc user coordinates
//First convert to cartesian coordinates
cartX = (int)(touchX / movementRadius * movementRange);
cartY = (int)(touchY / movementRadius * movementRange);
//Cartesian Coordinates
userX = cartX;
userY = cartY;
if (moveListener != null) {
boolean rx = Math.abs(touchX - reportX) >= moveResolution;
boolean ry = Math.abs(touchY - reportY) >= moveResolution;
if (rx || ry) {
this.reportX = touchX;
this.reportY = touchY;
moveListener.OnMoved(userX, userY);
}
}
}
private void reportOnMovedDelayedMovement() {
//constraint circle
float diffX = touchXDelayedMovement;
float diffY = touchYDelayedMovement;
double radial = Math.sqrt((diffX*diffX) + (diffY*diffY));
if ( radial > movementRadius ) {
touchXDelayedMovement = (int)((diffX / radial) * movementRadius);
touchYDelayedMovement = (int)((diffY / radial) * movementRadius);
}
//We calc user coordinates
//First convert to cartesian coordinates
cartX = (int)(touchXDelayedMovement / movementRadius * movementRange);
cartY = (int)(touchYDelayedMovement / movementRadius * movementRange);
//Cartesian Coordinates
userX = cartX;
userY = cartY;
if (moveListener != null) {
boolean rx = Math.abs(touchXDelayedMovement - reportX) >= moveResolution;
boolean ry = Math.abs(touchYDelayedMovement - reportY) >= moveResolution;
if (rx || ry) {
this.reportX = touchXDelayedMovement;
this.reportY = touchYDelayedMovement;
moveListener.OnMoved(userX, userY);
}
}
}
private void returnHandleToCenter() {
final int numberOfFrames = 5;
final double intervalsX = (0 - touchX) / numberOfFrames;
final double intervalsY = (0 - touchY) / numberOfFrames;
handler.removeCallbacksAndMessages(null);
for (int i = 0; i < numberOfFrames; i++) {
final int j = i;
handler.postDelayed(new Runnable() {
#Override
public void run() {
touchX += intervalsX;
touchY += intervalsY;
//reportOnMoved();
invalidate();
if (moveListener != null && j == numberOfFrames - 1) {
moveListener.OnReturnedToCenter();
}
}
}, i * 10);
}
if (moveListener != null) {
moveListener.OnReleased();
}
}
private void returnHandleToCenterDelayedMovement() {
final int numberOfFrames = 25;
touchXDelayedMovement=touchX;
touchYDelayedMovement=touchY;
final double intervalsX = (0 - touchXDelayedMovement) / numberOfFrames;
final double intervalsY = (0 - touchYDelayedMovement) / numberOfFrames;
handlerDelayedMovement.removeCallbacksAndMessages(null);
for (int i = 0; i < numberOfFrames; i++) {
handlerDelayedMovement.postDelayed(new Runnable() {
#Override
public void run() {
touchXDelayedMovement += intervalsX;
touchYDelayedMovement += intervalsY;
reportOnMovedDelayedMovement();
}
}, i * 50);
}
}
public void setInnerPadding(int innerPadding){
this.innerPadding=innerPadding;
}
public void disable(){
disabled=true;
}
public void enable(){
disabled=false;
}
public interface JoystickMovedListener {
public void OnMoved(int pan, int tilt);
public void OnReleased();
public void OnReturnedToCenter();
}
}
You must do this in the class that will use the joystick:
private JoystickMovedListener joystickListener = new JoystickMovedListener() {
#Override
public void OnMoved(int pan, int tilt) {
//here i move the objects in the game
}
}
#Override
public void OnReleased() {}
public void OnReturnedToCenter() {};
};
joystickOnScreen = new Joystick(this);
joystickOnScreen.setMovementRange(screenHeight/50);
joystickOnScreen.setInnerPadding(screenHeight/30);
joystickOnScreen.setOnJostickMovedListener(joystickListener);
RelativeLayout.LayoutParams joystickParams = new RelativeLayout.LayoutParams(sh/3, sh/3);
joystickParams.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);
joystickParams.addRule(RelativeLayout.ALIGN_PARENT_LEFT);
joystickParams.setMargins(sh/100, 0, 0, sh/100);
joystickOnScreen.setLayoutParams(joystickParams);
joystickOnScreen.setAlpha(0.3f);

I will not implement the changes for you but hopefully this answer can help you towards implementing this on your own.
With your current implementation you are updating the object position (x, y) each frame. To get the more realistic physics that you want, you need to store and update velocity as well (vx, vy).
Add two new variables, vx and vy (with initial values of zero) in the objects that you are currently updating the position for. The joystick should control the change of the velocity instead of the position. Change the code that updates the positions x and y, to update the velocities vx and vy instead. When the joystick is max left, you can for example set vx = vx - 3.
After the velocity is updated, you need to update the position using the velocity variables. For example, set the position x = x + vx. Ideally you want this to happen in a different method that runs even if you don't move the joystick, but to keep it simple you can do this update right after the update of the velocity variables.
With this implementation you will get a more realistic game physics. As a next step you might want to add limits on the velocity to not move too fast. This can be done with an if-statement where you check that the value is not too big before adding more to it, or too smal before subtracting from it. Good luck!

Moving the camera using a touch input Cocos2D android

I'm trying to make a camera for an android app that moves by dragging on the touch screen to drag the camera across. I'm using the Cocos2D engine for my development.
The problem is, whenever you moved your finger on the screen, everything on the screen just disappears instead of moving.
My code is below, I hope someone can help me with this :) Thanks for your time.
#Override
public boolean ccTouchesMoved(MotionEvent event)
{
CGPoint location = CCDirector.sharedDirector().convertToGL(CGPoint.ccp(event.getX(), event.getY()));
CGPoint movement = CGPoint.ccpSub(location, previousLocation);
previousLocation = location;
//Update the camera
float[] x = new float[1];
float[] y = new float[1];
float[] z = new float[1];
this.getCamera().getCenter(x, y, z);
CameraPos.x = x[0];
CameraPos.y = y[0];
this.getCamera().getEye(x, y, z);
movement.x = 2 * movement.x * (1 + (z[0]/832));
movement.y = 2 * movement.y * (1 + (z[0]/832));
CameraPos.x = CameraPos.x - Math.round(movement.x);
CameraPos.y = CameraPos.y - Math.round(movement.y);
this.getCamera().setCenter(CameraPos.x, CameraPos.y, 0);
this.getCamera().setEye(CameraPos.x, CameraPos.y, z[0]);
return true;
}

Its fine I got it working nevertheless.
For any who want to know this, I created a class called CameraControls that controls the basic functions of the camera. It isnt finished yet (I'll probably update the code as I make changes such as zoom functionality) but this one allows me to track the touch input perfectly.
import org.cocos2d.nodes.CCDirector;
import org.cocos2d.types.CGPoint;
import org.cocos2d.types.CGSize;
public class CameraControls {
CGSize winSize = CCDirector.sharedDirector().displaySize();
CGPoint CameraPos = CGPoint.ccp(winSize.width, winSize.height);
CGPoint previousLocation;
double minX;
double maxX;
double minY;
double maxY;
public CameraControls(World world)
{
this.loadCamera(world);
}
public void setCameraLimit(float minX, float maxX, float minY, float maxY)
{
this.minX = minX;
this.maxX = maxX;
this.minY = minY;
this.maxY = maxY;
}
public void loadCamera(World world)
{
float[] x = new float[1];
float[] y = new float[1];
float[] z = new float[1];
world.getCamera().getCenter(x, y, z);
CameraPos.x = x[0];
CameraPos.y = y[0];
}
public void trackTouchMovement(CGPoint location, World world)
{
if(previousLocation == null)
{
previousLocation = location;
}
CGPoint movement = CGPoint.ccpSub(previousLocation, location);
previousLocation = location;
float[] x1 = new float[1];
float[] y1 = new float[1];
float[] z1 = new float[1];
world.getCamera().getEye(x1, y1, z1);
CameraPos.x = CameraPos.x + movement.x;
CameraPos.y = CameraPos.y + movement.y;
try
{
if(CameraPos.x >= maxX || CameraPos.x <= minX || CameraPos.y >= maxY || CameraPos.y <= minY)
{
CameraPos = CGPoint.ccpSub(CameraPos, movement);
}
}
catch (NullPointerException e)
{
System.out.println("Invalid values for camera Limits. No Limits applied.");
}
world.getCamera().setCenter(CameraPos.x, CameraPos.y, 0);
world.getCamera().setEye(CameraPos.x, CameraPos.y, z1[0]);
}
public void storePositionAsPrevious(CGPoint pos)
{
previousLocation = pos;
}
public void resetPrevious()
{
previousLocation = null;
}
}
Now that I have a class, I simply create an instance of CameraControls in my class and then do the necessary configuration.
CameraControls camera = new CameraControls(this);
In this case, I want the total area my camera can view to be 3 x the width of the camera, and 3 times the height of the camera, so I set the limits of the camera as the negative width of the camera, the width of the camera, the negative height of the camera and the height of the camera, as the camera starts at (0, 0).
camera.setCameraLimit(-winSize.width, winSize.width, -winSize.height, winSize.height);
Finally, I just add the necessary method calling in ccTouchesBegan, ccTouchesMoved and ccTouchesEnded
#Override
public boolean ccTouchesMoved(MotionEvent event)
{
CGPoint location = CCDirector.sharedDirector().convertToGL(CGPoint.ccp(event.getX(), event.getY()));
camera.trackTouchMovement(location, this);
return true;
}
#Override
public boolean ccTouchesEnded(MotionEvent event)
{
camera.resetPrevious();
return true;
}
#Override
public boolean ccTouchesBegan(MotionEvent event)
{
CGPoint location = CCDirector.sharedDirector().convertToGL(CGPoint.ccp(event.getX(), event.getY()));
camera.storePositionAsPrevious(location);
return true;
}