Develop Reference

Collision - recognizing when object has stopped colliding

What I mean is that when I collide with the side of an entity and want to jump, I cannot move right/left as I have a flag which prevents this when I collide with the entity on the right/left side, like so:
This is code code I use to detect collision:
public void onCollision(Wrapper wrapper) {
if (horizontal_velocity == 0 && vertical_velocity == 0) {
return;
}
Entity e1 = wrapper.thisEntity; //the object we are controlling
Entity e2 = wrapper.otherEntity; //the object we are impacting with
Rectangle rect1 = wrapper.thisEntityRectangle;
Rectangle rect2 = wrapper.otherEntityRectangle;
int e1y = (int) rect1.getY(), e1x = (int) rect1.getX(), e1w = (int) rect1.getWidth(), e1h = (int) rect1.getHeight();
int e2y = (int) rect2.getY(), e2x = (int) rect2.getX(), e2w = (int) rect2.getWidth(), e2h = (int) rect2.getHeight();
e1x += e1w / 2;
e1w /= 2;
e1y += e1h / 2;
e1h /= 2;
//horizontal interaction -- x
/* ---+\\\\\\+---
* |------|
* | |
* e1 | e2 | e1
* | |
* |------|
* ---+\\\\\\+---
*/
boolean touchingSide = false;
if(e1y > e2y && e1y < e2y + e2h) {
//touchingSide = true;
if(e1x > e2x - e1w && e1x < e2x) { //going right || hitting left side
collisionsHappening.put(wrapper.otherEntity.getID(), "right");
canMoveRight = false;
horizontal_velocity = 0;
setX(e2x - e1w*2);
}
if(e1x < e2x + e2w + e1w && e1x > e2x) { //going left || hitting right side
collisionsHappening.put(wrapper.otherEntity.getID(), "left");
canMoveLeft = false;
horizontal_velocity = 0;
setX(e2x + e2w);
}
}
//vertical interaction -- y
/*
* \| e1 |\
* \+--+------+--+\
* \\\\| |\\\\
* \\\\| e2 |\\\\
* \\\\| |\\\\
* \+--+------+--+\
* \| e1 |\
*
*/
if(e1x > e2x - e1w && e1x < e2x + e2w && !touchingSide) {
if(e1y + e1h > e2y && e1y < e2y) { //going down || hitting top side
collisionsHappening.put(wrapper.otherEntity.getID(), collisionsHappening.get(wrapper.otherEntity.getID()) + "|top");
setY(e2y - e1h * 2);
vertical_velocity = 0;
//readyNextTurn = true;
isFalling = false;
onGround = true;
}
if(e1y - e1h < e2y + e2h && e1y > e2y) { //going up || hitting bottom side
collisionsHappening.put(wrapper.otherEntity.getID(), collisionsHappening.get(wrapper.otherEntity.getID()) + "|bottom");
setY(e2y + e2h + e1h);
vertical_velocity = 0;
//readyNextTurn = true;
isFalling = false;
onGround = true;
}
}
}
..and where the code is affected by the canMoveRight and canMoveLeft flags:
public void key(int keyCode) {
try {
onEdge();
switch (keyList.get(keyCode)) {
...
case MOVE_RIGHT:
for(Entity e : objectsCollidingWith) { //check if still colliding, if not, reset variable canMoveLeft inorder to not impair movement
if(collisionsHappening.get(e.getID()) == "right") {
canMoveRightNextFrame = true;
}
}
canMoveLeft = true;
if (!canMoveRight && !canMoveRightNextFrame) break;
if(canMoveRightNextFrame) {
canMoveRightNextFrame = false;
System.out.println(canMoveRightNextFrame);
}
if (horizontal_velocity == 0) {
horizontal_velocity = getXDisplacement();
}
changeX(horizontal_velocity);
direction = "right";
//horizontal_velocity = 0;
break;
case MOVE_LEFT:
for(Entity e : objectsCollidingWith) { //check if still colliding, if not, reset variable canMoveLeft inorder to not impair movement
if(collisionsHappening.get(e.getID()) == "left") {
canMoveLeftNextFrame = true;
}
}
canMoveRight = true;
if (!canMoveLeft && !canMoveLeftNextFrame) {
break;
}
canMoveLeftNextFrame = canMoveLeftNextFrame ? true : false; //if true, make false
if (horizontal_velocity == 0) {
horizontal_velocity = getXDisplacement();
}
changeX(-horizontal_velocity);
direction = "left";
//horizontal_velocity = 0;
break;
case JUMP:
jump();
}
} catch (NullPointerException e) {
//ignore - a key with no action pressed
}
}
What I have tried
When I look for collisions - not react to them as shown in the above code - I tried to implement a HashMap in which I put a String - either "left" or "right" - to the key Entity.getID() which returns a unique name, like so (after the lines of code that are relevant are // <<<) :
public Wrapper[] collisions(Entity thisEntity) {
ArrayList<Wrapper> wrappers = new ArrayList<Wrapper>();
Player p = null;
boolean isPlayer = thisEntity instanceof Player;
boolean onGround = false;
if (isPlayer) {
p = (Player) thisEntity;
}
try {
for (Entity e : getLevel().getEntities()) {
if (!thisEntity.equals(e)) {
collisionsHappening.put(e.getID(), ""); // <<<
objectsCollidingWith.add(e); // <<<
if (thisEntity.getRect().intersects(e.getRect())) {
wrappers.add(new Wrapper(thisEntity, e, thisEntity.getRect(), e.getRect(),
thisEntity.getRect().intersection(e.getRect())));
onGround = true;
//collisionsHappening.put(e.getID(), true);
//System.out.println("collision between " + e.getID() + " + " + thisEntity.getID());
}
}
}
} catch (Exception e) {
e.printStackTrace();
}
if (isPlayer) {
p.isTouching = onGround;
if (onGround) {
//System.out.println(onGround);
}
}
//Entity[] result = list.toArray(new Entity[1]);
return wrappers.toArray(new Wrapper[0]);
}
This system relies on keeping a flag 1 frame after the collision ceases in-order to remove the flags canMoveRight or canMoveLeft in the lines of code
for(Entity e : objectsCollidingWith) { //check if still colliding, if not, reset variable canMoveLeft inorder to not impair movement
if(collisionsHappening.get(e.getID()) == "left") {
canMoveLeftNextFrame = true;
}
}
canMoveRight = true;
if (!canMoveLeft && !canMoveLeftNextFrame) {
break;
}
if(canMoveLeftNextFrame) {
canMoveLeftNextFrame = false; //if true, make false
}
...
...and same for the canMoveRight flag...
However, this does not work, and I still cannot move mid-jump after I "scrape" the edge of an Entity unless I move in the opposite direction to "reset" the flag for the desired direction (line: case MOVE_RIGHT: ... canMoveLeft = true; and case MOVE_LEFT: ... canMoveRight = true;), as seen in the animation.
So, to conclude:
How can I make this system work?
Is there a more efficient/better way of doing this kind of thing?
Do you recommend I redo my collision?
Thanks.

It is actually impossible to approach this problem in such an event driven way for a game more advanced then Snake. I recommend that you focus on a simple update loop which updates each entity. Each entity then updates their own velocity and then position. Then check for collision and handle response. The key event handlers should not have any logic and be simply changing flags which the entities can poll.
As for the the collision and response part, that is where the meat of a simple platform game engine lies, and there are many different approaches. In the modern world of off the shelf physics engines, e.g. Box2D, you could simply let the physics system handle things. But from the sounds of things, you are not looking for that and what you want is what I call logic based physics.
If your world and entities consist of axis aligned boxes, you can separate horizontal and vertical motion into two discrete steps, for each entity. For each axis, each object tries to move as far as it can for (depending on velocity and collisions) if the object hits something, generate a collision event and set the velocity to zero on that axis. Repeat for the other axis and you will have a simple platform game engine. For this method you will need to handle the state of two objects touching carefully due to floating point numerical error. I recommend doing collision detection with integers (in the scale of the screen coordinates).
If you are looking to have an environment and entities which are not restricted to the axis aligned boxes, then you will have to get more complex and no longer rely on simply handling X then Y movement to give you things like a box sliding on the floor or down a wall. In this case I suggest you keep track of what surface your entity is standing or walking on so that you can handle their movement differently in each state. When they are in the air, normal movement, but when they are on some surface, the movement is constrained to horizontal movement and the vertical position is adjusted to keep them on the surface. You then will need to detect when they change states.
I hope you find this helpful. It turns out that it is not an easy topic to Google. (Update loops, collision detection, physics of motion, numerical integration and the geometry of collision response are all easy to Google). Most programmers seem to just take the approach of keep fiddling with it till it works, and so it never gets documented well.
P.S. Implicit Euler integration method is fine for most games.

How to do collision detection with many walls (maze)?

In my game, the player navigates a maze. I can't figure out how to do proper collision detection with the walls. It is easy to do collision detection for staying in a certain area:
if (x > rightWallX - playerWidth) x = rightWallX - playerWidth;
if (x < leftWallX) x = leftWallX;
//...
But how would I do collision detection for many walls?
I can do plain collision detection without correction (like if (intersecting) return true;), but I can't correct this correctly. If I just store the old x and y and reset them, then
The object never actually touches the wall
If the object can go up but is blocked to the right, it won't go up, it will just not move.
How is collision detection in a maze done?

The easiest way, once you have solved collision detection, to fix the collision is to move the actor to the closest valid position to where the actor would be were it not for the object it collides with. This assumes no inertia, but it is sufficient for maze-like games or top-down map-crawling games.
If you want to simplify your calculations further, you can limit yourself to detecting if changing the actor's x or y coordinate would be better. If your actor has an axis-aligned rectangular hit-box and all obstacles are axis-aligned rectangular as well (the simplest case), this assumption is indeed correct. However, the results might not be satisfactory in some other cases (potential artifact: speed boost from gliding diagonal walls - not the case in most maze games).
Keep in mind multiple collisions could happen concurrently (pushing against two walls). If there are no sharp angles between two walls that an actor could both intersect (say, if all your obstacles are axis aligned and sufficiently spaced), fixing each collision in turn will suffice - just don't stop after the first collision.

You can use Rectangle.intersects() method:
public Rectangle Player(){
return new Rectangle(PlayerX,PlayerY,PlayerWidth,PlayerHeight);
//we do this for getting players x and y values every tick
}
if(Player().intersects(new Rectangle(0,0,100,50)))//if(player touching wall)
new Rectangle(0,0,100,50) is just an example you can change it.

Ok so i'm currently making a 2D top down view game and I'm not sure how you created your maze. However, in my game my Level is created from a Tile[][] tiles = new Tile[levelWidth][levelHeight]; array. The way i handled collision detection was by checking the surrounding tiles to see if they were solid.
This is my getTile method.
public Tile[][] getTile(int x, int y) {
if (x < 0 || x >= getWidth() || y < 0 || y >= getHeight()) {
return new VoidTile();
} else {
return tiles[x][y];
}
}
In my Tile.java class i have a isSolid() method which returns whether the tile is solid or not. All of my tiles extend my Tile.java so they inherit this method and I override it in their constructor. As i said previously, I am not sure whether or not you use the same style of level implementation as i do. However, It is good practice to do it this way :)
Personally, I am not a big fan of using the .intersects() and .contains() methods for Sprite collision detection. I mainly use them for buttons and alike.
Ok so,
In my player.java class i have a checkBlockedDirection(int x, int y) method and it looks like this.
public void checkBlockedDirection(int x, int y) {
boolean u = map.getTile(x, y - 1).isSolid();
boolean d = map.getTile(x, y + 1).isSolid();
boolean l = map.getTile(x - 1, y).isSolid();
boolean r = map.getTile(x + 1, y).isSolid();
if (u) {
uBlocked = true;
System.out.println("up tile blocked");
} else {
uBlocked = false;
}
if (d) {
dBlocked = true;
System.out.println("down tile blocked");
} else {
dBlocked = false;
}
if (l) {
lBlocked = true;
System.out.println("left tile blocked");
} else {
lBlocked = false;
}
if (r) {
rBlocked = true;
System.out.println("right tile blocked");
} else {
rBlocked = false;
}
}
Then in my player update method i have this
public void tick() {
float dx = 0;
float dy = 0;
if (input.up.isPressed()) {
direction = 0;
} else if (input.down.isPressed()) {
direction = 2;
} else if (input.left.isPressed()) {
direction = 3;
} else if (input.right.isPressed()) {
direction = 1;
} else {
direction = 4; // standing
}
checkBlockedDirection((int)x, (int)y);
if (input.up.isPressed() && y > 0 && !uBlocked) {
dy += -speed;
} else if (input.down.isPressed() && y < map.getHeight() - 1 && !dBlocked) {
dy += speed;
} else if (input.left.isPressed() && x > 0 && !lBlocked) {
dx += -speed;
} else if (input.right.isPressed() && x < map.getWidth() - 1 && !rBlocked) {
dx += speed;
}
x += dx;
y += dy;
}
Basically it just checks whether or not the blocks up, down, left, or right are solid. If they are solid then it wont move and if they arent solid then you can move in the desired direction.
Not sure if this helps or not but it's just my take on this kind of grid collision detection :)
Hope this helps :)
Enjoy

Making game gravity, everything goes way too quickly

So basically i'm currently working on a small project where the player will be able to fight stuff through move but the gravity is giving me kind of a problem. So basically, i got this method, checkGravity() which will check if isGravityApplicable() return true (does the entity's bottom collider(a Line2D) collide with one of the foothold?(another line2D))
If isGravityApplicable() returns true, then the gravity should be applied but the problem that i have is that anything above 1 pixel Y is way too quickly and even, moving the character by one pixel is extremely fast. I'm not sure whether i should fix my game loop or what?
public boolean isGravityApplicable() {
for (Line2D line : frame.getMap().getFootholds()) {
/*Does the bottom collider intersect the foothold?*/
/*v THIS CHECK DOESN'T WORK CORRECTLY FOR SOME REASONS v*/
if (!GraphicHelper.getLineCameraRelative(getBottomCollider(), frame.getCam()).intersectsLine(line)) {
return true;
}
/*Above check returned false, if the velocity.y is above 1, then it might
skip the line since it would be skipping 5 pixels for example at once.
this check should resolve that.*/
if (velocity.y > 0) {
Line2D collider = getPositionToVelocityCollider();
if (!collider.intersectsLine(line)) {
position.y = (int) line.getY1(); //Y1 or Y2, same sh*t.
return true;
}
}
}
return false;
}
public void checkGravity() {
if (isGravityApplicable()) {
if (isJumping) { //Player has jumped
velocity.y += 1;
velocity.y = velocity.y > TERMINAL_ACCELERATION ? (int) TERMINAL_ACCELERATION : velocity.y;
if (velocity.y < 0) {
isFalling = true;
}
} else if (isFalling) { //Player is currently falling but not from jumping. Most likely just spawned
velocity.y = 1;
/*Anything higher than 1 is WAY too quickly...*/
//velocity.y += 1;
//velocity.y = velocity.y > TERMINAL_VELOCITY ? (int) TERMINAL_VELOCITY : velocity.y;
} else if (isJumping && isFalling) { //Player has jumped and has reached its highest point, falling back down
velocity.y = 1;
/*Anything higher than 1 is WAY too quickly...*/
//velocity.y += 1;
//velocity.y = velocity.y > TERMINAL_VELOCITY ? (int) TERMINAL_VELOCITY : velocity.y;
} else { //Player hasn't jumped and has not started falling, he most likely just spawned
isFalling = true;
velocity.y = 1;
}
} else {
isFalling = false;
isJumping = false;
}
}
Thanks in advance. Oh and if there is anything i could of done better like the collisions which consist of simple lines all around the entities, please tell me. :) Thanks.

Nevermind guys, for some reason the update/tick method was called twice in the loop for some reasons. I guess i had a brain fart or something.

ACTION_DOWN or only ACTION_MOVE in onTouch()

onTouch method of my View:
public boolean onTouch(View view, MotionEvent event) {
Log.d("Touch", "Touch");
int mNewX = (int) Math.floor(event.getX());
int mNewY = (int) Math.floor(event.getY());
boolean isPositionFree = isPositionFree(mNewX, mNewY);
if (!isPositionFree) {
if (event.getAction() == MotionEvent.ACTION_DOWN) {
int i = 0;
for (Point point : points) {
if (point.spotted) {
points.remove(i);
invalidate();
break;
}
i++;
}
} else if (event.getAction() == MotionEvent.ACTION_MOVE) {
int i = 0;
for (Point point : points) {
if (point.spotted) {
points.remove(i);
Point p = new Point(mNewX, mNewY, point.TYPE);
points.add(i, p);
invalidate();
break;
}
i++;
}
}
}
}
There are multiple items in the canvas. Their positions are saved in "points". They get drawn to the canvas in a onDraw method via the position of those "points", means Point point.x and point.y.
Now, when I click an item (a point on the canvas), it should disappear.
Then, when the MotionEvent.ACTION_MOVE is true, I want to move the point, depending on the event.getX() and event.getY().
the method "isPositionFree(newX,newY)" checks if the point.x and point.y equals newX and newY (the position I just touched on the screen).
if the position is taken (means, there is an item where I just clicked), I'll get to the motionevent-IFs.
Here comes the problem:
my code removes the point before I can actually move it. I didnt find any way I could fix this problem for hours. :/ I find it difficult, since the onTouch is always called from the beginning, means ACTION_DOWN and ACTION_MOVE never take place at the same time.
Do you know any fix for this?
thanks in advance, Sebastian

Got it to work!
For everbody having the same issue, feel free to take this sample code as a help :)
Stuff I declared in the beginning
Vector<Point> points = new Vector<Point>();
Bitmap[] monsterTypes = new Bitmap[3];
Vector<Integer> distanceMovedX = new Vector<Integer>();
Vector<Integer> distanceMovedY = new Vector<Integer>();
int mNewX = -1;
int mNewY = -1;
OnTouch-Method
public boolean onTouch(View view, MotionEvent event) {
mNewX = (int) FloatMath.floor(event.getX());
mNewY = (int) FloatMath.floor(event.getY());
boolean touchedPoint = touchedPoint(mNewX, mNewY);
switch (event.getAction()) {
case MotionEvent.ACTION_MOVE:
distanceMovedX.add(mNewX);
distanceMovedY.add(mNewY);
break;
case MotionEvent.ACTION_UP:
isMoveEvent = isMoveEvent();
if (isMoveEvent) {
for (Point point : points) {
if (point.spotted) {
// Your code
}
i++;
}
} else {
if (touchedPoint) {
for (Point point : points) {
if (point.spotted) {
// Your code
}
}
}
}
distanceMovedX.clear();
distanceMovedY.clear();
return true;
}
return true;
}
touchedPoint-Method
public boolean touchedPoint(int mNewX, int mNewY) {
boolean touchedPoint = false;
int height = 0;
int width = 0;
for (Point point : points) {
height = monsterTypes[point.TYPE - 1].getHeight();
width = monsterTypes[point.TYPE - 1].getWidth();
if (point.x + width < mNewX || point.x > mNewX + width
|| point.y + height < mNewY || point.y > mNewY + height) {
touchedPoint = false;
point.spotted = false;
} else {
touchedPoint = true;
point.spotted = true;
return touchedPoint;
}
}
return touchedPoint;
}
isMoveEvent-Method
public boolean isMoveEvent() {
boolean isMoveEvent = false;
boolean isMoveEventX = false;
boolean isMoveEventY = false;
for (int i = 0; i <= (points.size() -1); i++) {
Log.d("point", "for loop entered");
if (!distanceMovedY.isEmpty()) {
Log.d("point.x", "distanceMovedY is not empty");
int dMY = distanceMovedY.get(distanceMovedY.size() - 1) - distanceMovedY.get(0);
if ((dMY > 50 || dMY <= 0) && dMY != 0) {
Log.d("point.y", "is move event");
Log.d("point.y", "dMY: " + dMY);
isMoveEventY = true;
} else {
Log.d("point.x", "is no move event");
Log.d("point.x", "dMY: " + dMY);
isMoveEvent = false;
return isMoveEvent;
}
}
if (!distanceMovedX.isEmpty()) {
Log.d("point.x", "distanceMovedX is not empty");
int dMX = distanceMovedX.get(distanceMovedX.size() - 1) - distanceMovedX.get(0);
if (dMX <= 50 && dMX >= -50 && dMX != 0) {
Log.d("point.x", "is move event");
Log.d("point.x", "dMX: " + dMX);
isMoveEventX = true;
} else {
Log.d("point.x", "is no move event");
Log.d("point.x", "dMX: " + dMX);
isMoveEvent = false;
return isMoveEvent;
}
}
if (isMoveEventX && isMoveEventY) {
Log.d("point", "is move event");
isMoveEvent = true;
return isMoveEvent;
}
}
Log.d("point", "is no move event");
return isMoveEvent;
}
Point Class
class Point {
int x, y;
int TYPE;
boolean spotted;
boolean halfSpotted;
public Point() {
}
public Point(int x, int y, int t) {
this.x = x;
this.y = y;
this.TYPE = t;
}
#Override
public String toString() {
return x + ", " + y;
}
}
EXPLANATION:
Point:
we got a class Point. All those points declared in the Vector are x- and y-coordinates on your canvas. They help us to check the position we clicked.
monsterTypes:
its the different graphics I use. If you only use one graphic that you draw onto the canvas, change it to your needs
distanceMovedX & Y:
saves all the X and Y Coordinates of your "ACTION_MOVE". From pos 0 (the first touched point) to pos Z (the last touched point, where ACTION_UP occurs). Though its not the original X and Y position. Its the result of posZ - pos0.
With these values you can determine, after what distance travelled you wanna invoke "onMove" and BELOW which distance "onClick" should be invoked.
mNewX & Y:
the currently position of your onTouch-Method. Everytime you move your finger, newX & Y become overwritten.
Methods:
onTouch():
First, we'll overwrite mNewX and Y to the current position touched. Then we check if we clicked on an existing spot (in my case some 48px*48px area)
Next we record the taken distance in ACTION_MOVE.
After that we continue with ACTION_UP, where we check if we just performed some moveEvent or clickEvent.
touchedPoint():
calculates if we touched some existing point on the canvas, or not. returns true or false
isMoveEvent():
checks if we moved the certain distance. in my case i wanna move down, 50px or more. though im not allowed to move sidewards -50px or +50px. If its NOT a move event, the last spot touched still has to be on the in the giving distance (in my case in the 48px*48px range of the point).
Thats it. took me days to only figure out that option ;/ ashamed of that ... though I coded it pretty fast, what makes me feeling better again :D

I'm just suggesting some walk-around :
Instead of removing the point when clicking it,
make a privata Point in your class, where you currently remove the point, just set your new Variable Point to the Point you would remove...
Then, after using it in action or action move, the last place you would use it,
check if your private variable is not null, if so, remove it, then, set it to null.

try using a switch case statement:
switch finger_action:
case(ACTION_MOVE)
{
//move code
return false;
}
case(ACTION_TOUCH)
{
//dissappear code
return false;
}
note the up above code is pseudo code, but what it does it checks to see if you are moving the dot before just touching it. this way the dot will attempt a move first instead of being removed first.
thanks,
Alex

Android Sprite Animation Move To position X (should be simple but, I'm stuck)

I'm trying to move sprites to stop the frames in center(or move them to certain x position) when right or left pressed on screen. There are 3 sprites created using box.java in the view, placed one after another with padding, stored in arraylist.
The problem: No smooth movement and doesn't stop in the center of each frames after movement has begun, sometimes all boxes are moving on top of each others, padding is totally lost. Please let me know what I'm doing wrong, thanks a lot!
//BEGINING OF BOX.JAVA >> The problem is in this class!
//This goes in Update();
private void boxMove()
{
int get_moved_pos = getMovedPos(); //get moved pos
int sprite_size = view.getSpriteSize(); //get sprite arraylist size
currentDirection = view.getDirection(); //get direction "left" or "right" from view
if(currentDirection == "right" && isMoving == false)
{
setSpriteMovedNext();
}else
if(currentDirection == "left" && isMoving == false)
{
setSpriteMovedPrev();
}
if(currentDirection != lastDirection)
{
lastDirection = currentDirection;
//MOVE RIGHT
if(currentDirection == "right" && get_moved_pos > 0) //move left and make sure that moved pos isn't overlapping / or moving to empty space
{
//Animate left until it reaches the new x position
if(x > get_new_pos_left)
{
x -= pSpeedX;
}
Log.d("RIGHT","POS: " + get_moved_pos);
}else
//MOVE LEFT
if(currentDirection == "left" && get_moved_pos < sprite_size-1) //move left and make sure that moved pos isn't overlapping / or moving to empty space
{
//Animate right until it reaches the new x position
if(x < get_new_pos_right)
{
x += pSpeedX;
}
}
}
}
//Call when screen is touched (in View.java), to set a new position to move to.
public void resetMoving()
{
isMoving = false;
this.lastDirection = "";
Log.d("RESET", "MOVING RESET");
}
public int getMovedPos()
{
return this.smoved_pos;
}
private void setSpriteMovedNext()
{
int get_max_moved = getMovedPos();
int s_size = view.getSpriteSize();
if (isMoving == false) //take a break between movements
{
if(get_max_moved < s_size-1)
{
Log.d("NEXT", "CALLED");
this.get_new_pos_right = x + view.getNextPosX(); //current x and next stop position
this.smoved_pos += 1;
this.isMoving = true; //set to avoid double touch
Log.d("NEXT", "X POS SET: " + get_max_moved);
}
}
}
private void setSpriteMovedPrev()
{
int get_max_moved = getMovedPos();
if (isMoving == false) //take a break between movements
{
if(get_max_moved > 0)
{
Log.d("PREV", "CALLED");
this.get_new_pos_left = x - view.getNextPosX(); //get current x pos and prev stop position
this.smoved_pos -= 1; //to limit the movements
this.isMoving = true; //set to avoid double touch
Log.d("PREV", "X POS SET: " + get_max_moved);
}
}
}
//END OF BOX.JAVA
//VIEW
//Add boxes
public void addBox()
{
int TOTAL_BOXES = 3;
int padding_left = 200;
int padding_tmp = this.getWidth()/2;
box.clear(); //clear old
//Box 1
box.add(new Boxes(box, this, "box1",
padding_tmp,
this.getHeight()/2,
boxSpriteImage, 1, 2, 0, 0));
padding_tmp += boxSpriteImage.getWidth()/TOTAL_BOXES + padding_left;
//Box 2
box.add(new Boxes(box, this, "box2",
padding_tmp,
this.getHeight()/2,
boxSpriteImage, 1, 2, 1, 1));
padding_tmp += boxSpriteImage.getWidth()/TOTAL_BOXES + padding_left;
//Box 3
box.add(new Boxes(box, this, "box3",
padding_tmp,
this.getHeight()/2,
boxSpriteImage, 1, 2, 2, 1));
}
public boolean onTouchEvent(MotionEvent event){
if (System.currentTimeMillis() - lastClick > 100){
lastClick = System.currentTimeMillis();
float x = event.getX();
float y = event.getY();
synchronized (getHolder())
{
if(isBoxWindow() == true)
{
if(x >= this.getWidth()/2)
{
Direction = "right";
}else
{
Direction = "left";
}
}
}
}
//called in box.java to get next x pos to move
public float getNextPosX()
{
int PADDING = 200; //padding between frames
next_pos_x = boxSprite.getWidth()/TOTAL_COLUMNS + PADDING;
return next_pos_x;
}

I think your error is in the if statements, where you compare currentDirection and lastDirection (I'm assuming that lastDirection is a String) with other Strings using the == operator. The == almost operator never works when you want to compare Objects for equality. You should use the equals() method.
For eg.
if(currentDirection != lastDirection)
should be written as:
if(!currentDirection.equals(lastDirection)
Make such changes in your code(They are needed at many places!) and I think your problem should be solved.
A good debugging practice would be logging data about your app, from each of the if blocks, to see if each of them is executed. You could have found out if your if statements are being executed.
EDIT: Why have you put this code?
if (System.currentTimeMillis() - lastClick > 100)
This means onTouchEvents are only interpreted after 100ms. remove it and check, probably that's what is causing the problem.

Alrite, decided to use onFling() method and call via View instead of adding the animations separately into the class itself, works really well when called box.get(i).update() in a loop of all added boxes, all of them animated equally. Thanks udiboy.