Develop Reference

2d unity , How to drag an object using touch/finger on x axis only

There's someone here can help me. Im new to unity. I was working on making objects moves only on x-axis / y-axis when the object touch and drag to the left the object moves to left and stops when the touch or removes on the object.
using UnityEngine;
using System.Collections;
public class MoveScriptVertical : MonoBehaviour
{
//touch offset allows ball not to shake when it start moving
float deltax,deltay;
Rigidbody2D rb;
bool moveAllowed = false;
void Start ()
{
rb = GetComponent<Rigidbody2D> ();
}
void Update ()
{
//touch event
if (Input.touchCount > 0)
{
Touch touch = Input.GetTouch (0);
//knowing the touch position
Vector2 touchPos = Camera.main.ScreenToWorldPoint(touch.position);
//touch phase
switch (touch.phase)
{
case TouchPhase.Began:
//if you touch the car
if (GetComponent<Collider2D> () == Physics2D.OverlapPoint (touchPos))
{
//get the offset between position you touch
deltax = touchPos.x - transform.position.x;
deltay = touchPos.y - transform.position.y;
//if touch began within the car collider
//then it is allowed to move
moveAllowed = true;
//restriction some rigidbody properties
rb.freezeRotation = true;
rb.velocity = new Vector2 (0, 0);
GetComponent<BoxCollider2D> ().sharedMaterial = null;
}
break;
//you move your finger
case TouchPhase.Moved:
//if you touches the car and move is allowed
if (GetComponent<Collider2D> () == Physics2D.OverlapPoint (touchPos) && moveAllowed)
rb.MovePosition (new Vector2 (0, touchPos.y - deltay));
break;
//you released your finger
case TouchPhase.Ended:
//restore intial parameters
//when touch is ended
moveAllowed = false;
rb.freezeRotation = true;
rb.gravityScale = 0;
PhysicsMaterial2D mat = new PhysicsMaterial2D ();
GetComponent<BoxCollider2D> ().sharedMaterial = mat;
break;
}
}
}
}

There are some libraries that allow you to have complex finger events, for instance Touchscript. If you choose this solution you will find tutorials online.
The most basic way is to use unity's Input class with a nice doc here: https://docs.unity3d.com/ScriptReference/Input.html
This allow you to know when a finger touched the screen or moved on the screen. It will give you x an y coordinate so if you just want to move along x you would use only the x value, and, for example translate your object with it using
transform.Translate(new Vector3(x, 0f, 0f));
Edit
Since you use touchscript, have a look at TransformGesture, it should allow you to handle many transform events. If you want to have more control, you can use PressGesture, PanGesture and ReleaseGesture instead

Random number generator with no duplicate

I am having a hard time trying to ensure no duplicates numbers appear in the following code below. I tried to create an ArrayList to add all the possible index of the array and then gradually remove the values of the array from the List as more elements are generated by the number generator. This; however, didnt work as I expected. I've been trying to think about it but Haven't been able to come up with a viable solution.
Random randGen = new Random();
public boolean onTouchEvent(MotionEvent touchevent) {
switch (touchevent.getAction()) {
case MotionEvent.ACTION_DOWN: {
x1 = touchevent.getX();
y1 = touchevent.getY();
break;
}
case MotionEvent.ACTION_UP: {
x2 = touchevent.getX();
y2 = touchevent.getY();
int maxLength=exampleArray.length;
List<Integer>indices=new ArrayList<Integer>(maxLength);
for(int i=0;i<maxLength;i++){
indices.add(i);
}
int randomApple = randGen.nextInt(exampleArray.length);
int randomNum=indices.get(randomApple) ;
indices.remove(randomApple);
textView.setText(exampleArray[randomNum]);
if (x1 < x2) {
}
if (x1 > x2) {
//textView.setText(exampleArray[randomNum]);
}
}
}
return false;
}

I think you are missing some steps and adding extraneous ones....
One simple way (if you don't care whether the numbers keep going up) is to keep adding a random positive value to a counter. That way the new counter will always be different.
If you do:
Another way to do this is to creating a list of numbers beforehand (either sequentially [1, 2, 3...] or you randomly add some amount to each new index [rnd1, rnd1 + rnd2, rnd1 + rnd2 + rnd3...]), randomizing the ordering by shuffling the numbers (click this!), and then simply iterating through the created array.

Android Multitouch Strange Behavior

After a lot of tinkering, I think I've finally come up with a good multitouch handling system for my android game. It makes use of Robert Greene's Input Pipeline, modified for use with multitouch. Right now, the code has a simple system that records which pointer ID is currently doing which action (right now just shooting and moving). Each pointer's state is kept in a Pointer class, which is just a simple encapsulation of whether it is down, and it's coordinates. The ID acts as the pointer array index.
This seems like it should work well in practice, but in game it behaves very erratic. When recording the pointer actions in LogCat, oftentimes Android will send an "UP" action when the pointer remains down, or just before a number of "MOVE" actions by the pointer. Because my code believes the pointer is up, the game doesn't respond to it.
This also happens with button presses like the shooting button. When the pointer comes down on the area (which right now is just simply the lower left region), Android will send multiple "UP" and "DOWN" actions even though the pointer remains down the whole time. I had a single touch movement system before and none of these problems happened.
Is this just an issue with how I am reacting to the events? Should I handle POINTER_DOWN and DOWN separately? Or should I detect which pointers are moving after the "UP" action to see which ones really are down despite what Android says?
Here's my current code in my thread which receives the input events from Android. Because it is a pipeline system, I have the events encapsulated in the InputObject which is somewhat similar to Robert Greene's. Maybe a new set of eyes can help me tell what's wrong? Thanks for any help!
private int inx, iny;
private int shootID;
public boolean shooting = false;
private int moveID;
public boolean moveDown = false;
private static final int MAX_POINTERS = 10;
private Pointer[] pointers = new Pointer[MAX_POINTERS];
public void inputTouch(InputObject in) {
switch(in.action) {
case MotionEvent.ACTION_DOWN:
case MotionEvent.ACTION_POINTER_DOWN:
pointers[in.pID].press(in.pX[in.actionIndex], in.pY[in.actionIndex]);
//Log.i("D", "DOWN");
break;
case MotionEvent.ACTION_MOVE:
for(int p = 0; p < in.pointCount; p++) {
int id = in.pointerIDs[p];
pointers[id].setCoord(in.pX[id], in.pY[id]);
}
//Log.i("D", "MOVE");
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_POINTER_UP:
pointers[in.pID].release();
if(shootID == in.pID) {
shooting = false;
}
if(moveID == in.pID) {
moveDown = false;
}
//Log.i("D", "UP");
break;
case MotionEvent.ACTION_CANCEL:
default:
break;
}
for(int ap = 0; ap < MAX_POINTERS; ap++) {
if(pointers[ap].down) {
if(pointers[ap].x < world.cam.pixelWidth / 4 &&
pointers[ap].y > world.cam.pixelHeight - (world.cam.pixelHeight / 4)) {
shootID = ap;
shooting = true;
} else {
inx = pointers[ap].x;
iny = pointers[ap].y;
moveID = ap;
moveDown = true;
}
}
}
StringBuilder sb = new StringBuilder();
for(int j = 0; j < 3; j++) {
sb.append("ID " + (j+1) + ": " + pointers[j].down + "[" + pointers[j].x + ", " + pointers[j].y + "]" + " | ");
}
//Log.i("D", sb.toString());
}

Hope you got the answer by now, but here''s my solution:
First of all, there's a couple of things to add in the InputHolder class:
-internal public fields for mPointerIndex = event.getPointerIndex and mPointerID = event.getPointerID(mPointerIndex) (these get assigned in the useEvent/useHistory)
-if you only need to track 2 touchpoints, you need to add mPointerIndex2, x2 and y2 aswell. Add more as you need to track more points.
-add definitions for the case where MotionEvent.ACTION_POINTER_2_UP/DOWN gets passed. Turns out, POINTER_1 is the same as POINTER_UP/DOWN! This really tripped me up because I was falling through the switch case to the default. I only caught this because I changed my default to -1 and saw it logged.
Depending on how you process the actions in your processInput(obj), you map these to different ints. In my case I used the obj.y to see if they where left/right touches and I only needed two points, so I mapped these to ACTION_TOUCH_POINTER_UP/DOWN instead of giving each touch it's own action int identifier.
-now, if you want to track multiple touch points, you would have to do the above and the below in a for loop over all entries in event.getPointerCount(). In my case I was only interested in the x/y of one other touchpoint, so I could get away with only doing a check after I had filled the first point and the other pointerindex was easy to deduce:
public void useEvent(MotionEvent event) {
eventType = EVENT_TYPE_TOUCH;
int a = event.getAction();
switch (a) {
case MotionEvent.ACTION_DOWN:
action = ACTION_TOUCH_DOWN;
break;
case MotionEvent.ACTION_POINTER_DOWN:
action = ACTION_TOUCH_POINTER_DOWN;
break;
case MotionEvent.ACTION_POINTER_2_DOWN:
action = ACTION_TOUCH_POINTER_DOWN;
break;
case MotionEvent.ACTION_MOVE:
action = ACTION_TOUCH_MOVE;
break;
case MotionEvent.ACTION_UP:
action = ACTION_TOUCH_UP;
break;
case MotionEvent.ACTION_POINTER_UP:
action = ACTION_TOUCH_POINTER_UP;
break;
case MotionEvent.ACTION_POINTER_2_UP:
action = ACTION_TOUCH_POINTER_UP;
break;
default:
action = -1;
}
time = event.getEventTime();
pointerIndex = (event.getAction() & MotionEvent.ACTION_POINTER_ID_MASK) >> MotionEvent.ACTION_POINTER_ID_SHIFT;
pointerID = event.getPointerId(pointerIndex);
x = (int) event.getX(pointerIndex);
y = (int) event.getY(pointerIndex);
if (event.getPointerCount() > 1)
{
pointerIndex2 = pointerIndex== 0 ? 1 : 0;
x2 = (int)event.getX(pointerIndex2);
y2 = (int)event.getY(pointerIndex2);
}
}
If you''re tracking more points, or need more information about each touchevent, you have to extend the for loop up over the action switch case.
Anyway, now you need two variables in your thread so you can keep track of your two touches: call 'em touchOneID and touchTwoID (or index). On an ACTION_POINTER_2_UP, the obj.mPointerID refers to the obj which is going UP! This means that the other touch will change it's ID! Keep track of this change, and you're sorted. The internal obj's mPointerID/Index will always be correct, you just have to track them correctly in your surfaceview's thread so you can act accordingly to when you get a POINTER_DOWN. In my case, I did a simple x position check to determine what to do in my ACTION_MOVE event which told me enough to correctly determine which x/y or x2/y2 I should use and how to use it. This meant less code to run and limits to the things I had to keep in memory, but it all depends on what and how much information you need.
Finally:
To be honest, if you handled the definitions correctly and assigned every MotionEvent and held them in the InputObject, you'd probably be fine. Hell, I think you can ignore and lose the whole switch case and just say obj.mAction = event.getAction() and handle these in your processInput(obj)!
Meaning, all those static ints he's remapping to in the InputHolder seem unnecessary, unless you really only need one or two touch definitions (which explains his mysterious standalone comment of "this app is only interested in down touches"). Getting rid of those statically defined ints also means you can just test against MotionEvent.ACTION_CODE instead of doing a lookup against InputHolder.TOUCH_ACTION_CODE.

Can i use motionEvent .getRawY() with View . getTop()?

Im making a program about the game Go and im trying to write some code to allow a person to place a bead, which really just shows an invisible bead. But after an hour of going back and forth with it i just cant seem to figure out why the Y coordinate of my motionevent always seems 2 rows down from where it needs to be.
My code for filling my array
for(int y=0; y< 9;y++)
{
for(int x=0;x<9;x++)
{
String name="Whitebead" + ((9*y)+x+2); //The +2 is because of a naming problem
WhitePieces[x][y]=(ImageView) findViewById(getResources().getIdentifier(name, "id", getPackageName()));
}
}
My code for handling motion events
#Override
public boolean onTouchEvent(MotionEvent e)
{
if(e.getAction() == MotionEvent.ACTION_DOWN)
{
float X=e.getRawX();
float Y=e.getRawY();
if(X>Board.getLeft() && X<Board.getRight())
if(Y< Board.getTop() && Y>Board.getBottom());
player1.placepiece(X, Y);
}
return super.onTouchEvent(e);
}
And finally my code that resolves which bead to what coordinate
public void placepiece(float X, float Y)
{
int[] pieceindex=resolvePiece(X,Y);
pieces[pieceindex[0]][pieceindex[1]].setVisibility(ImageView.VISIBLE);
}
private int[] resolvePiece(float x, float y) {
int Xindex=0;
int[] oldcoords= new int[2]; //cordinates are like so {xCoord, Ycoord}
int[] newcoords= new int[2];
oldcoords[0]=pieces[0][0].getLeft(); //set the oldcoordinates to the first index
oldcoords[1]=pieces[0][0].getTop();
for(int i=1; i<9;i++) //go through the 9 indexs to find the closest X value
{
newcoords[0]=pieces[i][0].getLeft();
newcoords[1]=pieces[i][0].getTop();
if(Math.abs((int)x-newcoords[0])<Math.abs((int)x-oldcoords[0]))
{
Xindex=i;
oldcoords[0]=newcoords[0];
}
}
int Yindex=0;
oldcoords[0]=pieces[0][0].getLeft(); //Reset oldcoords again
oldcoords[1]=pieces[0][0].getTop();
for(int n=1; n<9;n++) //Go through the 9 indexes for the closest Y value
{
newcoords[0]=pieces[0][n].getLeft();
newcoords[1]=pieces[0][n].getTop();
if(Math.abs((int)y-newcoords[1])<Math.abs((int)y-oldcoords[1]))
{
Yindex=n;
oldcoords[1]=newcoords[1];
}
}
int[] rInt= new int[]{Xindex,Yindex};
return rInt;
}
//////EDIT: Fixed
I figured it out, at the top of the android window is about and inch of space where the title and battery life and stuff go, when you get motion coordinates it takes in the whole screen, where .getTop() only gets from where linear layout Starts. SO instead of using .getTop or.getLeft i used .getLocationInWindow(oldcoord[]) and it places the info i needed into my oldcoord array.

//////EDIT: Fixed I figured it out, at the top of the android window is about and inch of space where the title and battery life and stuff go, when you get motion coordinates it takes in the whole screen, where .getTop() only gets from where linear layout Starts. SO instead of using .getTop or.getLeft i used .getLocationInWindow(oldcoord[]) and it places the info i needed into my oldcoord array.

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.