Android pinch zoom on Camera delay - android

I have a custom surfaceview for my CameraPreview in my app, and I am trying to implement Pinch zoom, by implementing these two methods:
#Override
public boolean onTouchEvent(MotionEvent event) {
Camera camera = getCamera();
if (camera == null) {
return true;
}
Camera.Parameters params = camera.getParameters();
int action = event.getAction();
if (event.getPointerCount() > 1) {
if (action == MotionEvent.ACTION_POINTER_DOWN) {
MCLog.v(TAG, "Single ");
mDist = getFingerSpacing(event);
MCLog.w(TAG, "Original distance " + mDist);
} else if (action == MotionEvent.ACTION_MOVE && params.isZoomSupported()) {
camera.cancelAutoFocus();
handleZoom(event, params);
}
} else {
if (action == MotionEvent.ACTION_UP) {
mFirstTime = false;
handleFocus(event, params);
}
}
return true;
}
private void handleZoom(MotionEvent event, Camera.Parameters params) {
if(mFirstTime) {
mDist = getFingerSpacing(event);
mFirstTime = false;
return;
}
List<Integer> zoomRatios = params.getZoomRatios();
int maxZoom = params.getMaxZoom();
int zoom = params.getZoom();
double spacing = getFingerSpacing(event);
MCLog.w(TAG, String.format("Old zoom is: %s", zoom));
//Percentage of displacement
MCLog.w(TAG, String.format("Original distance is: %s, new displacement is %s", mDist, spacing));
double percentage = (mDist + spacing)/mDist;
if(mDist > spacing)
{
percentage *= -1;
}
MCLog.w(TAG, String.format("Percentage is: %s", percentage));
zoom = new Double(zoom + percentage).intValue();
MCLog.w(TAG, String.format("New zoom is: %s", zoom));
if (zoom > maxZoom) {
zoom = maxZoom;
}
if (zoom < 0) {
zoom = 0;
}
mDist = spacing;
params.setZoom(zoom);
if (mZoomListener != null) {
mZoomListener.onZoomChanged(zoomRatios.get(zoom));
}
getCamera().setParameters(params);
}
This seems to be working, however the zoom has some slight delay that gets longer the more I zoom into the image. Like I would stop pinching and the image would still keep zooming in.
I couldnt find any implementation for pinch zoom in the camera besides this one, so maybe this is doing something wrong.

Since you're seeing the logging continue after you lift your finger, that probably means you're not processing your touch event queue fast enough.
That setProperties call is not particularly fast.
So you'll need to rate-limit somehow, and drop touch events that you don't have time to handle. There are many options of varying kinds of tradeoffs.
I'm not very familiar with the input APIs, so not sure if there's some parameter you can just tweak to reduce the rate of calls - maybe just don't do anything unless the change in zoom is above dinner threshold, and then increase the threshold until the zooming doesn't lag?
Or you can send the zoom calls to another thread to actually invoke setParameters, and just drop a zoom call to the floor if that thread if already busy processing a previous call.
Or better, have a 'nextZoom' parameter that your zoom setting thread looks at once it finishes its prior call, and then just have the touch event handler update nextZoom on each invocation. The zoom setting thread then always checks if the value has changed once it finishes the last set call, and if so, sets it again.
Then you'll always get the newest zoom level, and they won't pile up either.

Related

Unity how can i swerve box with use joint?

I want to get an image like in the picture with code. I stacked boxes because i must add joint with code. I want to make the boxes look like this as the character slides left and right smoothly. And how can i smooth swerving control in unity for touch or mouse button?
I tried this codes for movement:
if (Input.touchCount > 0)
{
Touch touch = Input.GetTouch(0);
if (touch.phase == TouchPhase.Began)
firstPos = touch.position;
if (touch.phase == TouchPhase.Stationary || touch.phase == TouchPhase.Moved)
Swerving(touch.position);
}
private void Swerving(Vector2 touch)
{
endPos = touch;
float diff = endPos.x - firstPos.x;
transform.Translate(diff * Time.deltaTime * swerveSpeed, 0, 0);
}
But not smooth swerving.
I tried hinge joint for image. I tried random values to motor,spring etc. But it didnt work i have never used joints.
In general when dealing with physics you shouldn't use transform this break collision detection and other physics related things like your joints etc.
Try and rather go through the Rigidbody using e.g. Rigidbody.MovePosition (or accordingly Rigidbody2D.MovePosition if your are in 2D) within FixedUpdate like e.g.
// or Rigidbody2D depending on your needs
[SerializeField] private Rigidbody _rigidbody;
private Vector2 startPos;
private float movement;
private void Awake()
{
if(!_rigidbody) rigidbody = GetComponent<Rigidbody>();
}
// get user input in Update in general
private void Update()
{
if (Input.touchCount > 0)
{
var touch = Input.GetTouch(0);
switch(touch.phase)
{
case TouchPhase.Began:
startPos = touch.position;
movement = 0;
break;
case TouchPhase.Stationary:
case TouchPhase.Moved:
movement = touch.position.x - startPos.x;
break;
default:
movement = 0;
}
}
}
// Apply Physics in FixedUpdate!
private void FixedUpdate()
{
_rigidbody.MovePosition(_rigidbody.position + Vector3.right * movement * Time.deltaTime * swerveSpeed);
}
However, in general the touch is a 2D pixel space position which might be quite different on different devices.
I would rather translate it into a 3D world space position and use something like e.g.
[SerializeField] private Rigidbody _rigidbody;
[SerializeField] private Camera _mainCamera;
private float _offset;
private Plane? _hitPlane;
private Vector3 _targetPosition;
private void Awake()
{
if (!_rigidbody) _rigidbody = GetComponent<Rigidbody>();
if (!_mainCamera) _mainCamera = Camera.main;
}
// get user input in Update in general
private void Update()
{
_targetPosition = _rigidbody.position;
if (Input.touchCount <= 0)
{
return;
}
var touch = Input.GetTouch(0);
switch (touch.phase)
{
case TouchPhase.Began:
{
// Check if you are touching the character
var ray = _mainCamera.ScreenPointToRay(touch.position);
if (Physics.Raycast(ray, out var hit) && hit.rigidbody == _rigidbody)
{
// create a virtual plane parallel to the camera view
// passing the hit point
_hitPlane = new Plane(-ray.direction, hit.point);
// also store the offset from pivot to the hit point
// we only care about the X axis
_offset = (_rigidbody.position - hit.point).x;
}
break;
}
case TouchPhase.Stationary:
case TouchPhase.Moved:
{
if (_hitPlane.HasValue)
{
// now instead keep ray casting against that virtual plane
var ray = _mainCamera.ScreenPointToRay(touch.position);
if (_hitPlane.Value.Raycast(ray, out var distance))
{
var hitPoint = ray.GetPoint(distance);
_targetPosition.x = hitPoint.x + _offset;
}
}
break;
}
default:
_hitPlane = null;
break;
}
}
// Apply Physics in FixedUpdate!
private void FixedUpdate()
{
_rigidbody.MovePosition(_targetPosition);
}
this makes sure your character is definitely placed on the X axis where you are dragging it without any delays but still complying with physics

Multi-touch bug on my first Android game

Right now I've been developing a game which will make the character move up or down if either swipe up or down on the left side of the screen. Then, he can also, shoot projectiles if I tap the right side of the screen. I've succeeded on making it work but the problem is that the swipe function do not works while I tap the the right screen. Both only works if I do one of them. I cannot move the character if I am firing projectiles. Any suggestions? Appreciate it in advanced.
Here's the code:
For the swipe movement function:
void Swipe() {
if (Input.touchCount > 0) {
Touch t = Input.GetTouch(0);
if (t.phase == TouchPhase.Began)
{
lp = t.position;
fp = t.position;
text.text = fp.x.ToString();
}
else if (t.phase == TouchPhase.Ended)
{
lp = t.position;
//Swipe Up
if (fp.y < lp.y && fp.x < 400)
{
currentLane += 1;
}
//Swipe Down
else if (fp.y > lp.y && fp.x < 400)
{
currentLane -= 1;
}
}
}
}
And here's the code for the tap or firing projectiles function:
void FireBullets() {
interval += 2 * Time.deltaTime;
anim.SetBool("Attacking", firing);
if (Input.touchCount > 0 && interval > .75f) {
Vector3 bulletTouchPos;
Touch bulletT = Input.GetTouch(0);
bulletTouchPos = bulletT.position;
if (bulletT.phase == TouchPhase.Began) {
if (bulletTouchPos.x > 400)
{
interval = 0;
firing = true;
//Fire Bullets
Instantiate(bullets, new Vector3(transform.position.x + 1.2f, transform.position.y + .3f, transform.position.z), Quaternion.identity);
}
}
}else
{
firing = false;
}
}
Your lp and fp values don't care which finger is being checked.
If you want to detect multiple touch gestures at once, you need to discriminate your detection based on which finger that is.
You can do this by looking at the Touch.fingerId value, which is unique for each finger. Fingers are just an ID assigned to a given touching point as it moves across the screen in order to identify it from other touching points currently also on the screen.
You'll need to adjust your code to handle how to store the information you need in order to do what you need, but this should get you started.

android display a response while user performs a gesture

How to show a response while gesture input is in progress?
I'm using swipe down gesture to reload my WebView.
Using this for gesture detection:How to detect swipe direction between left/right and up/down
Problem
SimpleGestureListener captures the result of user input only. It cannot be used to show a response, e.g. animation, while the user is performing a gesture.
Imperfect inelegant solution:
flaw: Shows animation independent of SimpleOnGestureListener; a response to user gesture input is displayed and gesture input may still fail or vice versa.
private volatile float userTouchY = -1;
// translating WebView every onTouch event call is inefficient.
// only translate when translateYBy value is greater than a threshold.
private float translateYBy = 0;
/**
* Shift webView without animation.
* #param num
*/
private void __shiftWebViewDownBy(int num){
float current = webView.getY();
if(current >= webviewTranslationLimit) return;
current += num;
if(current> webviewTranslationLimit) current = webviewTranslationLimit;
webView.setY(current);
}
#Override
public boolean onTouch(View v, MotionEvent event) {
//Skip everything unless at the content top.
if(webView.getScrollY() > 0) return false;
int action = event.getAction();
if(action == MotionEvent.ACTION_MOVE){
float y = event.getY();
float dif = y - userTouchY;
if(dif < webviewTranslationLimit/10){
//dif less than screenHeight*1/40, ignore input
}else if(dif < -(webviewTranslationLimit/5)){
//swipe up
userTouchY = -1;//not swipe down cancelling
__shiftWebViewTopTo(0);
}else if(userTouchY < y) {
//swipe down
translateYBy += dif;
if(userTouchY == -1){
//userTouchY at the initial value, ignore for this once.
userTouchY = y;
}else{
userTouchY = y;
if(translateYBy > 5 ){
__shiftWebViewDownBy((int)translateYBy);
translateYBy = 0;
}
}
}
}else{
Log.d(TAG,"action not move:" +MotionEvent.actionToString(action));
// Webview shift down should only occur while moving
// Once finger is off,cancel
__shiftWebViewTopTo(0);
userTouchY = -1;
}
boolean result = gestureDetector.onTouchEvent(event);
return result;
}
Writing a GestureListener of a sort from scratch obviously solves the problem and I can simply use Toast to message the user for a failed gesture input, but there ought to be an easier, more readable solution.

How to use the mouse joint in Android?

I want to use the MouseJoint in Java for Android. I am new in box2d and cocos2d. I don't know how to use the mouse joint.
i recomend you to see this tutorial example. Copy from it (sorry i don't like broken links :) ) ...
you drag your body with the help of the MouseJoint, it will collide with the other bodys in the world and apply force to them.
Box2d - Manual - http://www.box2d.org/manual.html#_Toc258082974
8.10 Mouse Joint
The mouse joint is used in the testbed to manipulate bodies with the mouse. It attempts to drive a point on a body towards the current position of the cursor. There is no restriction on rotation.
The mouse joint definition has a target point, maximum force, frequency, and damping ratio. The target point initially coincides with the body’s anchor point. The maximum force is used to prevent violent reactions when multiple dynamic bodies interact. You can make this as large as you like. The frequency and damping ratio are used to create a spring/damper effect similar to the distance joint.
Many users have tried to adapt the mouse joint for game play. Users often want to achieve precise positioning and instantaneous response. The mouse joint doesn’t work very well in that context. You may wish to consider using kinematic bodies instead.
So let's start..
You have to create your PhysicWorld and at least one body in it. ( Checkout the PhysicExample how to.. )
- MouseJoint method
public MouseJoint createMouseJoint(AnimatedSprite box , float x, float y)
{
final Body boxBody =
this.mPhysicsWorld.getPhysicsConnectorManager().findBodyByShape(box);
Vector2 v = boxBody.getWorldPoint(
new Vector2(x/pixelToMeteRatio, y/pixelToMeteRatio)
);
MouseJointDef mjd = new MouseJointDef();
mjd.bodyA = groundBody;
mjd.bodyB = boxBody;
mjd.dampingRatio = 0.2f;
mjd.frequencyHz = 30;
mjd.maxForce = (float) (200.0f * boxBody.getMass());
mjd.collideConnected = true;
mjd.target.set(v);
return (MouseJoint) this.mPhysicsWorld.createJoint(mjd);
}
- Touching Body
we have to override our onAreaTouched method to create an MouseJoint anchor-point on the touch position.
MouseJoint mjActive = null;
private float pixelToMeteRatio = PhysicsConstants.PIXEL_TO_METER_RATIO_DEFAULT;
#Override
public boolean onAreaTouched(
final TouchEvent pSceneTouchEvent,
final ITouchArea pTouchArea ,
final float pTouchAreaLocalX,
final float pTouchAreaLocalY )
{
if(pSceneTouchEvent.getAction() == MotionEvent.ACTION_DOWN) {
this.runOnUpdateThread(new Runnable() {
#Override
public void run() {
final AnimatedSprite face = (AnimatedSprite)pTouchArea; //The touched body
//If we have a active MouseJoint, we are just moving arround don't create an 2nd one.
if( mjActive == null)
{
Vector2 vector = new Vector2(pTouchAreaLocalX/pixelToMeteRatio,pTouchAreaLocalY/pixelToMeteRatio);
//=====================================
// GROUNDBODY - Used for the MouseJoint
//=====================================
BodyDef groundBodyDef = new BodyDef();
groundBodyDef.position.set(vector);
groundBody = mPhysicsWorld.createBody(groundBodyDef);
//====================================
// CREATE THE MOUSEJOINT
//====================================
mjActive = PhysicsJumpExample.this.createMouseJoint(face, pTouchAreaLocalX, pTouchAreaLocalY);
}
}});
return true;
}
return false;
}
- Moving the body
We are moving our finger over the scene, so we have to move the MouseJoint too.
If we release the finger.. we must destroy the MouseJoint..
#Override
public boolean onSceneTouchEvent(final Scene pScene, final TouchEvent pSceneTouchEvent) {
if(this.mPhysicsWorld != null) {
if(pSceneTouchEvent.getAction() == MotionEvent.ACTION_MOVE) {
this.runOnUpdateThread(new Runnable() {
#Override
public void run() {
if( mjActive != null ){ //If the MJ is active move it ..
// =========================================
// MOVE THE MOUSEJOINT WITH THE FINGER..
// =========================================
Vecotr2 vec = new Vector2(pSceneTouchEvent.getX()/pixelToMeteRatio, pSceneTouchEvent.getY()/pixelToMeteRatio);
mjActive.setTarget(vec);
}
}});
return true;
}
//===========================================
// RELEASE THE FINGER FROM THE SCENE..
//===========================================
if( pSceneTouchEvent.getAction() == MotionEvent.ACTION_UP ||
pSceneTouchEvent.getAction() == MotionEvent.ACTION_CANCEL
) {
this.runOnUpdateThread(new Runnable() {
#Override
public void run() {
if( mjActive != null )
{
//======================================
// DESTROY OUR MOUSEJOINT
//======================================
PhysicsJumpExample.this.mPhysicsWorld.destroyJoint(mjActive);
PhysicsJumpExample.this.mPhysicsWorld.destroyBody(groundBody);
mjActive = null;
}
}});
return true;
}
return false;
}
FYI:
To fit your needs, you have to play with this settings ( in the createMouseJoint method )
mjd.dampingRatio = 0.2f;
mjd.frequencyHz = 30;
mjd.maxForce = (float) (200.0f * boxBody.getMass());

Android - Moving a single image

Can anyone help please.
Im writing a small Android game where the player is able to select a "barrier" and drag it accross the screen with their finger. I have the barriers drawn on the screen and I am able to drag it accross the screen.
My problem however is when I add more than 1 barrier, eg 3 barriers, and drag a barrier accross the screen, they all drag and they all drag to the same position. That is to say they all lie on top of each other, making it look as though there is only 1 barrier.
Here is my code, can anyone please tell me where I am going wrong/explain where I am going wrong.
public class MainGamePanel extends SurfaceView implements SurfaceHolder.Callback, SensorEventListener {
// Initialising the Barrier
private Barrier barrier[] = new Barrier[3];
// The Main Game Panel
public MainGamePanel(Context context) {
super(context);
// Adding a call-back (this) to the surfaceHolder to intercept events
getHolder().addCallback(this);
// Creating the Game items
// The starting coordinates of the Barrier
int x = 30;
int y = 270;
barrier[0] = new Barrier(BitmapFactory.decodeResource(getResources(), R.drawable.blue_barrier), x, y);
barrier[1] = new Barrier(BitmapFactory.decodeResource(getResources(), R.drawable.green_barrier), x + 15, y);
barrier[2] = new Barrier(BitmapFactory.decodeResource(getResources(), R.drawable.pink_barrier), x + 30, y);
// Create the Game Loop Thread
thread = new MainThread(getHolder(), this);
// Make the GamePanel focusable so it can handle events
setFocusable(true);
}
// Handles the touch events
public boolean onTouchEvent(MotionEvent event)
{
int eventAction = event.getAction();
int x = (int)event.getX();
int y = (int)event.getY();
switch (eventAction)
{
// Touch down so check if finger is on Barrier
case MotionEvent.ACTION_DOWN:
if (x > barrier[0].getX() && x < barrier[0].getX() + 8
&& y > barrier[0].getX() && y < barrier[0].getY() + 8)
{
barrier[0].isTouched();
}
else if (x > barrier[1].getX() && x < barrier[1].getX() + 8
&& y > barrier[1].getX() && y < barrier[1].getY() + 8)
{
barrier[1].isTouched();
}
else if (x > barrier[2].getX() && x < barrier[2].getX() + 8
&& y > barrier[2].getX() && y < barrier[2].getY() + 8)
{
barrier[2].isTouched();
}
break;
// Touch-drag with the Barrier
case MotionEvent.ACTION_MOVE:
// Move the Barrier the same as the finger
for (int i = 0; i < barrier.length; i++)
{
if (barrier[i] == barrier[0])
{
barrier[0].setX(x);
barrier[0].setY(y);
} // end if
else if (barrier[i] == barrier[1])
{
barrier[1].setX(x);
barrier[1].setY(y);
}
else if (barrier[i] == barrier[2])
{
barrier[2].setX(x);
barrier[2].setY(y);
} // end else if
} // end for
break;
case MotionEvent.ACTION_UP:
// Finger no longer on Barrier - Do Nothing
break;
}
return true;
}
// Render - Draws the Game Item Bitmaps to the screen
public void render(Canvas canvas)
{
// Set the background to white
canvas.drawColor(Color.WHITE);
barrier[0].draw(canvas);
barrier[1].draw(canvas);
barrier[2].draw(canvas);
}
// Update
// This is the Game's update method
// It iterates through all the Objects and calls their update() methods (if they have one)
public void update()
{
} // end update
In your barrier move code, you aren't checking a particular barrier is touched, so you're moving all of them to the same coordinates. The following loop does exactly the same thing as your current code:
// Move the Barrier the same as the finger
for (int i = 0; i < barrier.length; i++)
{
barrier[i].setX(x);
barrier[i].setY(y);
} //end for
To fix this, you need to check if the current barrier in the loop is the one that was touched, and can change that whole loop to something like:
// Move the Barrier the same as the finger
for (int i = 0; i < barrier.length; i++)
{
if (barrier[i].isTouched())
{
barrier[i].setX(x);
barrier[i].setY(y);
} // end if
} // end for
You would then need to make sure that you un-set the touched property in the ACTION_UP section. If you post your Barrier class definition I can probably help more.
I'm pretty sure your problem could be solved by making the barriers three separate objects instead of in an array.
As already pointed out, your code in handling the move is wrong because it moves all the Barriers to the same X,Y when it should only move the one that is touched.
Also, you are never resetting the isTouched on the objects in the Action up. When the user lifts their finger you should set them all to isTouched == false. If you don't do that then once you touch one it will always move to the X,Y.

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