I'm making a game using Libgdx, I need to know if the user is using two fingers and if they are placed in the correct position. One finger should be on the right side of the screen and the other in the left side of the screen.
the easiest solution without using any listeners is to just iterate over some count of pointers and calling simple Gdx.input.isTouched() - you have to set some "maximum pointers count" but hey - peoples usually has only 20 fingers :)
final int MAX_NUMBER_OF_POINTERS = 20;
int pointers = 0;
for(int i = 0; i < MAX_NUMBER_OF_POINTERS; i++)
{
if( Gdx.input.isTouched(i) ) pointers++;
}
System.out.println( pointers );
due to reference:
Whether the screen is currently touched by the pointer with the given index. Pointers are indexed from 0 to n. The pointer id identifies the order in which the fingers went down on the screen, e.g. 0 is the first finger, 1 is the second and so on. When two fingers are touched down and the first one is lifted the second one keeps its index. If another finger is placed on the touch screen the first free index will be used.
you can also easily the position of touching pointer by using Gdx.input.getX() and Gdx.input.getY() like
final int MAX_NUMBER_OF_POINTERS = 20;
int pointers = 0;
for(int i = 0; i < MAX_NUMBER_OF_POINTERS; i++)
{
if( Gdx.input.isTouched(i) )
{
x = Gdx.input.getX(i);
y = Gdx.input.getY(i)
}
}
and then you can for example put it into array
How to detect number of fingers being used?
You can do it with MotionEvent with getPointerCount()
You can detect how many fingers are on the screen doing this :
int PointerCount = event.getPointerCount();
I need to know if the user is using two fingers and if they are placed in the correct position
You can get the X,Y and compare it.
#Override
public boolean onTouch(View v, MotionEvent event) {
int x = event.getX();
int y = event.getY();
return true;
}
For more information you can check MotionEvent Documentation so you can get there what you want.
Both GestureListener and InputProcessor have the touchDown method. This has the x and y value for each finger on the screen (pointer). Implement either one of these and you can override the touchdown to suit your needs. This is a great tutorial to start with. Hope this helps.
Related
I have implemented a ZoomViewGroup, which is capable of scrolling infinitely in all directions and also zooming infinitely while still delivering all touch events correctly offset to its child Views.
But when it comes to multi-touch, only the first pointer is offset correctly, and all others are pointing to a wrong location, and thats because there is the scaling factor I have to take care of. (As pointer 0 has a different offset from its original location than pointer 1 or 2, when scaling_factor != 1.0f)
I am saving my transformation in a Matrix, so it's easy to calculate the coordinates from screen to workspace and back using matrix.mapPoints(..) and the matrix inverse.
When I draw the child views, I can just apply the transformation matrix like this:
protected void dispatchDraw(Canvas canvas)
{
canvas.save();
canvas.concat(transformation_matrix);
super.dispatchDraw(canvas);
canvas.restore();
}
Same with touch events:
float[] touch_array = new float[2];
public boolean dispatchTouchEvent(MotionEvent event)
{
touch_array[0] = event.getX();
touch_array[1] = event.getY();
transformation_matrix.mapPoints(touch_array);
event.setLocation(touch_array[0], touch_array[1]);
return super.dispatchTouchEvent(event);
}
But MotionEvent.setLocation(float x, float y) does actually offset all pointers by the same amount. If we zoomed by 2.0f the offset is different for each pointer, so I have to be able to do something like MotionEvent.setLoction(int pointer_index, float x, float y) for each one individually. Is there anything I can do to achieve this?
EDIT: The only solution I know (and searched for) so far is to create a new MotionEvent with the new coordinates.
--
You can get all pointers (fingers touching) positions trough the methods getX(int pointerId)/getY(int).
You can get all on screen pointers trough the getPointerCount()
So to parse multi-touch you must do something like:
public boolean dispatchTouchEvent(MotionEvent event)
{
for(int i = 0; i < event.getPointerCount(); i++){
touch_array[0] = event.getX(i);
touch_array[1] = event.getY(i);
transformation_matrix.mapPoints(touch_array);
MotionEvent copy = MotionEvent.obtainNoHistory(event);
copy.setLocation(touch_array[0], touch_array[1]);
boolean handled = super.dispatchTouchEvent(copy);
copy.recycle();
if(handled) return true;
}
return false;
}
Also note that I created a copy of the MotionEvent object, so childrem can modify it without breaking the position trough the for.
Sorry, just now I noticed your last statement, you must copy the event to a new MotionEvent, so the childrem can parse itself and do its works, copying also will make your code safe of modifications, it's a bad idea to change the MotionEvent directly since it can break a for loop in any dispatch method.
I am using libgdx for easy 3D game, I need check model is clicked.
It is my code:
public int getObject (int screenX, int screenY) {
Ray ray = cam.getPickRay(screenX, screenY);
int result = -1;
float distance = -1;
for (int i = 0; i < rooms.size; ++i) {
final GameObject instance = rooms.get(i);
instance.transform.getTranslation(position);
position.add(instance.center);
final float len = ray.direction.dot(position.x-ray.origin.x, position.y-ray.origin.y, position.z-ray.origin.z);
if (len < 0f)
continue;
float dist2 = position.dst2(ray.origin.x+ray.direction.x*len, ray.origin.y+ray.direction.y*len, ray.origin.z+ray.direction.z*len);
if (distance >= 0f && dist2 > distance)
continue;
if (dist2 <= instance.radius * instance.radius ) {
result = i;
distance = dist2;
}
}
return result;
}
It it sometimes work.
Is is my model:
http://www6.zippyshare.com/v/97501566/file.html
What do I wrong?
Any help for me?
I am new with libgdx.
When was I press 1 it lights, but when I waas press 2, 1 lights too (instead 2)...
I didn't fully analyze your code nor do I know what It it sometimes work. actually means (e.g. in which circumstances doesn't it work?) but you're using a bounding sphere for detecting whether the object has been clicked or not.
Assuming your calculations are correct (as I said, I didn't check them in depth) you still can have false positives or negatives since the only shape which is perfectly represented by a bounding sphere is ... well... a sphere.
That might be the source for click detection to work "sometimes".
If that is the case and you want more accurate detection you should either use different bound volumes, bounding volumne hierarchies or a rendering based approach (i.e. render the object id into some buffer, which would allow for pixel perfect selection).
UPDATE:
From your post update it seems that bounding spheres are not the problem here, since they should not overlap, unless your data is wrong - which you should check/debug.
So the problem might actually lie in your calculations. From the documentation it looks like the ray you get is projected into the scene (i.e. into world space) so you'd need to transform your objects' center into worldspace as well.
You're currently only applying the position but ignore rotation and scale thus the resulting position might be wrong. I'm sure there's some built-in transform code, so instead of transforming manually you should use that. Please check the docs on how to do that.
In the game i'm building, I have made a basic collision detection system.
My current method is explained below:
I workout where the player will be in the next step of the game:
double checkforx = x+vx;
double checkfory = y+vy;
I then check for a collision with blocks (1) in mapArray.
public static Boolean checkForMapCollisions(double character_x,double character_y){
//First find our position in the map so we can check for things...
int map_x = (int) Math.round((character_x-10)/20);
int map_y = (int) Math.round((character_y-10)/20);
//Now find out where our bottom corner is on the map
int map_ex = (int) Math.round((character_x+10)/20);
int map_ey = (int) Math.round((character_y+10)/20);
//Now check if there's anything in the way of our character being there...
try{
for(int y = map_y; y <= map_ey; y++){
for(int x = map_x; x <= map_ex; x++){
if (levelArray[y][x] == 1){
return true;
}
}
}
}catch (Exception e){
System.out.println("Player outside the map");
}
return false;
}
If true is returned {nothing}
If false is returned {Player physics}
I need the player to be able to land on a block and then be able to walk around but I cannot find and adequate tutorial for this.
Can someone give me an idea on how to run my collision detection and/or movement?
There are 2 parts to this question. Collision detection, meaning determining whether a volume is touching or intersecting another volume. The second is collision response. Collision response is the physics portion.
I'll cover collision detection here as that's primarily what you asked about.
Ddefine a class for the map like so:
int emptyTile = 0;
//this assumes level is not a ragged array.
public boolean inBounds(int x, int y){
return x>-1 && y>-1 && x<levelArray[0].length && y<levelArray.length;
}
public boolean checkForCollisions(Rectangle rectangle){
boolean wasCollision = false;
for(int x=0;x<rectangle.width && !wasCollision;x++){
int x2 = x+rectangle.x;
for(int y=0;y<rectangle.height && !wasCollision;y++){
int y2 = y+rectangle.y;
if(inBounds(x2,y2) && levelArray[y2][x2] != emptyTile){
//collision, notify listeners.
wasCollision=true;
}
}
}
}
Do not make your methods static. You probably want more than one instance of a level right? Static is for when you need to share state which remains constant across multiple instances of a class. Level data will surely not remain constant for every level.
Instead of passing in a coordinate, try passing in an entire rectangle. This rectangle will be the bounding box of your character (the bounding box is also sometimes referred to as AABB, which means Axis-aligned bounding box, just FYI in case you're reading tutorials online for this sort of thing.) Let your Sprite class decide what its bounding rectangle is, that's not the map class's responsibility. All the map should be used for is maybe rendering, and whether a rectangle is overlapping tiles which are not empty.
I am sorry for a very shitty explanation but here is my github code and it will help better.
https://github.com/Quillion/Engine
Just to explain what I do. I have character object (https://github.com/Quillion/Engine/blob/master/QMControls.java) and it has vectors and a boolean called standing. Every time boolean standing is false. Then we pass it to the engine to check for collision, if collision happens then standing is true and y vector is 0. As to x vector whenever you press any arrow keys you make the xvector of the object to whatever value you want. And in the update loop you displace the given box by the amount of speed.
I found this article: http://android-developers.blogspot.ca/2010/06/making-sense-of-multitouch.html which helped my understanding but I'm still not sure how to do what I'm trying to do.
In my game, I have a virtual analog stick and some buttons. Only 2 fingers will ever register at once. This is what I want. One for the analog stick and one for a button.
The main thing I'm unsure of is, say I put a finger down on the analog stick and move it around, then put a finger on the button, then release the button, the analog stick should keep moving to my first finger.
And vice versa, if the button touches first and then the analog stick, if I let go of the analog stick the button should still be pushed down.
Do touch pointers work in this fashion on Android, as in, once I put my finger down, regardless of any other fingers I put up or down, it will remember my first finger in order and give it a down, move move move up events?
Thanks
Ideally I wish I had a function like this:
void onTouch(int fingerID, int action, int x, int y)
{
}
Where each finger that is put down will receive down, move and up event when that finger goes up.
The game is a racing game so they need to be able to steer and push gas at the same time.
My problem is similar to this
identified multi touch pointer in action_move
Edit:
I have this code:
private void onTouch(int finger, int action, float x, float y)
{
if(action == MotionEvent.ACTION_DOWN || action == MotionEvent.ACTION_POINTER_DOWN)
{
createInput(finger, x, y);
}
else if(action == MotionEvent.ACTION_MOVE)
{
inputMove(finger, x, y);
}
else if(action == MotionEvent.ACTION_UP || action == MotionEvent.ACTION_POINTER_UP)
{
destroyInput(finger, x, y);
}
}
public void onTouch(MotionEvent ev)
{
final int pointerCount = ev.getPointerCount();
for (int p = 0; p < pointerCount; p++) {
onTouch(ev.getPointerId(p), ev.getAction(), ev.getX(p), ev.getY(p));
}
}
But it only works for the first one.
So from the examples given right in the MotionEvent class:
public boolean onTouch(MotionEvent ev) {
final int pointerCount = ev.getPointerCount();
for (int p = 0; p < pointerCount; p++) {
onTouch(ev.getPointerId(p), ev.getAction(), ev.getX(p), ev.getY(p));
}
return true;
}
You could take a look at the way the pinch is handled in AChartEngine for zoom. See this code, starting at line 80. It may look complex at the beginning, but it may help you on handling more use cases.
I am working on a game in which you are a simple circle that fires bullets and its multiplayer and so on. Well, I am trying to make boundaries sort of like a maze type thing that u have to go through I have tried collision detection like this:
public void checkCollisions(){
Rectangle r1 = bo.getBounds();
Rectangle d = p.getBounds();
if (d.intersects(r1))
border = true;
}
And basically if border = true then i stop the character from moving. I have 2 problems when i do this,
He doesnt stop just goes REALLY slow.
He stays at the REALLY slow state even off the border.
I use border like this:
boolean border = false;
then in my paint method i state this:
if (border)
p.dx = 0;
p.dy = 0;
p represents the Guy class :P
More of the dx and dy:
public void keyPressed(KeyEvent e) {
int key = e.getKeyCode();
if (key == KeyEvent.VK_A)
dx = -2;
if (key == KeyEvent.VK_D)
dx = 2;
if (key == KeyEvent.VK_W)
dy = -2;
if (key == KeyEvent.VK_S)
dy = 2;
and for keyReleased i just change the value of dx and dy to 0
also for how the guy moves:
public void move() {
x = x + dx;
y = y + dy;
}
Please help me figure out why this isn't working.
OK, I still think a full restructuring of your game logic is in order, but I think I can shed light as to what's going on. Let's look at the various places where things are happening:
PAINT: On the Swing thread, when paint() is called, you see if there were collisions and if so zero out the speeds (assuming you fix that if block).
KEY: On the Swing thread, when a key is pressed, you set the speed according to the key pressed.
CHECK: At some unknown point, you check for collisions and record whether there was one.
MOVE: At some unknown point, you update your "guy's" position with the speed.
So here's the problem: in Java, just like any other program, you get multiple key pressed events when you're holding down a key. There will be a short delay between the first and second, and then they will repeat rapidly. Try it in a text box in your browser, the same behaviour occurs there.
So how does that affect you? Well, you're probably getting into a scenario like this:
PAINT -> speed set to zero
KEY -> speed set back to -2
MOVE -> guy is moved -2
CHECK -> border = false
PAINT -> speed set to zero again
Really, if you restructure the code so that you get a game loop that looks something like this:
public void runGame() {
while(true) {
updateSpeeds();
updatePositionFromSpeed();
repaint();
}
}
Where updateSpeeds() would instead query whether the key is down or up and also compute whether the guy could move in that direction, and updatePositionFromSpeed() would update the guy's position. Then paint() would rely only on the guy's x and y coordinates, would not write to them, and would not need to know about the speed.
here's a very easy solution.
Here's a bit of my pseudo code.
if(player.getBounds().intersects(wall.getBounds())){
//Go Back to prior position, regardless of direction coming from. Since the reverse velocity X and velocity Y directions are taken care off
x -= velX;
y -= velY;
//Then Stop at that prior position to make next move
velX = 0;
velY = 0;
}