About CCTouches!

cocos2d-x C++
#1

I test the CCTouch, then I find the m_nViewId is always 0, why?? thanks!

#2

It is useless, we will delete it.

#3

#737 is created for it.

#4

How can I distinguish these points?

#5

On android, points are put into CCSet in sequence, CCSet0] means the first touch, CCSet1] is the second, and so on.
I am not sure if it is true on iOS.

#6

I first put oen finger, then I put second finger! Then I uplift the first finger. In the ccTouchesEnded(), the pTouches->count() == 1. through the pTouches, I don’t know the first finger or second finger!?

#7

Yes, you are right. Android have a pid point which touch is operated, we don’t translate this message. I don’t know if iOS has this feature, we should keep all platforms have the same feature.

Why do you need it?

#8

On iOS its possible to identify each touch by its addres in memory (for one touch its always the same).

UITouch* touch;
touchId = reinterpret_cast(touch);

#9

Yes, how bright you are. You can use in the same way. The address of each touch keeps the same in its life cycle.

#10

thanks!

#11

I believe UITouch objects on iPhone have a ‘hash’ property that returns a unique identifier for them. Safer to use than the memory address

#12

I have this same problem and need to track CCTouches by hash. How can I create the hash instead of using memory address?

Thanks
ML

#13

May be you can put the values into you hash table.
Why do you need hash?

#14

Hi, just putting multi touch into my game and came across this problem too. The ID/index of the UITouch is not in the CCSet class.

@Minggo, it is needed for a case like this: Say you are moving three sprites around the screen using three fingers, I receive a CCSet with three CCTouch items in it (one CCTouch for each finger). Then I take a finger off the screen so I have two left, I now receive a CCSet with two CCTouch items (two pairs of coordinates), I can’t tell which finger disappeared! I could “guess” which finger disappeared by checking old coordinates but I might get it wrong if for example if all the fingers were close to each other when one was removed.

At the moment I am using the address of the “CCTouch**" to determine which finger disappeared. This works due to the code in Cocos2d’s Eagleview.mm but I think this could break in a future version of Cocos2D-X. Ideally the real UITouch’s ID should be passed onto the CCTouch class.
The code in Eagleview.mm currently looks like this:-
<pre>

  • touchesBegan:touches withEvent:event
    {
    cocos2d::CCSet set;
    cocos2d::CCTouch**pTouch;
    for (UITouch touch in touches) {
    NSNumber    index = (NSNumber*)CFDictionaryGetValue(touchesIntergerDict, touch);
    int unUsedIndex = 0;
    // it is a new touch
    if (! index) {
    unUsedIndex = [self getUnUsedIndex];
    // The touches is more than MAX_TOUCHES ?
    if (unUsedIndex -1) {
    return;
    }

          pTouch = s\_pTouches[unUsedIndex] = new cocos2d::CCTouch();
      float x = [touch locationInView: [touch view]].x;
      float y = [touch locationInView: [touch view]].y;
      pTouch-\>SetTouchInfo(0, x, y);

      CFDictionaryAddValue(touchesIntergerDict, touch, [NSNumber numberWithInt:unUsedIndex]);

      set.addObject(pTouch);
  }

    }

    if (set.count() 0)
    return;
    cocos2d::CCDirector::sharedDirector()>getOpenGLView>touchesBegan;
    }
    </pre>
    You can see it uses the UITouch index itself in the line “NSNumber **index = CFDictionaryGetValue;”.

The code to pass on the index would be like this:-
** in the above Eagleview.mm touchesDown, the line “pTouch~~>SetTouchInfo;” needs to become "pTouch~~>SetTouchInfo(0, x, y, index);”. And the same for the touchesMoved, touchesEnded, touchesCancelled functions.
* The SetTouchInfo function in the class CCTouch header file, needs an extra int iIndex parameter like “void SetTouchInfo(int nViewId, float x, float y, int iIndex)”.
* And class CCTouch, in the header file, needs a variable “int m_iIndex;”
* And the code in the CCTouch class function SetTouchInfo needs the line “m_iIndex = iIndex;” adding. e.g:-

class CCTouch : public CCObject
{
public:
    CCTouch() {}
    CCTouch(int nViewId, float x, float y) : m_nViewId(nViewId), m_point(x, y), m_prevPoint(x, y) {}

    CCPoint locationInView(int nViewId) {CC_UNUSED_PARAM(nViewId); return m_point; }
    CCPoint previousLocationInView(int nViewId) {CC_UNUSED_PARAM(nViewId); return m_prevPoint; }
    int view() { return m_nViewId; }

    void SetTouchInfo(int nViewId, float x, float y, int iIndex)              // <- added "int iIndex"
    {
        m_nViewId   = nViewId;
        m_prevPoint = m_point;
        m_point.x   = x;
        m_point.y   = y;
        m_iIndex = iIndex;                  // <- added
    }

private:
    int     m_nViewId;
    CCPoint m_point;
    CCPoint m_prevPoint;
    int m_iIndex;                               // <- added
};

I did the above in the iPhone iOS Cocos2d-x version, it is the same sort of thing on Android ( “int pid = event.getPointerId(i);” in calls to “public boolean onTouchEvent(MotionEvent event)” ).

#15

Ok, could you pull a request by github?

#16

OK, pull request sent.