Draw a random line.Set CGPoint nil ? - Objective C

Question

Hi, I use ccTouchesBegan and ccTouchesEnded to draw a line. I want to draw a line when i drag the cursor(or finger) on screen. That mean, when i release the cursor, it will draw a line with the first point is the position which i has a first touch (ccTouchesBegan) and last point which i have when release (ccTouchesEnded). Here is my code:

CGPoint first;
CGPoint last;

- (BOOL)ccTouchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    UITouch *touch = [touches anyObject];
    last.x = 0; // this is the problem
    last.y = 0; 

    first = [[Director sharedDirector] convertCoordinate:[touch locationInView:
                                                                 [touch view]]];

    return kEventHandled;
}

- (BOOL)ccTouchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
    UITouch *touch = [touches anyObject];
    last = [[Director sharedDirector] convertCoordinate:[touch locationInView:
                                                               [touch view]]];
    [self draw];// this command will draw the lines.

    return kEventHandled;
}

-(void)draw
{ 
    glColor4f(0.8, 1.0, 0.76, 1.0); 
    glLineWidth(2.0f); 
    // first- CGPoint when ccTouchesBegan is called,
    // last - CGPoint when ccTouchesEnded is called 
    drawLine(first, last);
}

I used cocos 2d.

But the problem is that tt always return to 0, that means, it always turn back to the left corner when i has a TouchesBegan. I try to set nil, like this: last = nil or last.x = nil; last.y = nil; But they do not work.

Answer 1

You mean when the line gets drawn it is always from your last position to (0,0)? Is each of your functions beeing called ccTouchesBegan and ccTouchesEnded? And did you check the values used for drawing the line?

Answer 2

Here is draw() function:

    -(void)draw{ 

    glColor4f(0.8, 1.0, 0.76, 1.0); 

    glLineWidth(2.0f); 

    drawLine(first, last);//first- CGPoint when ccTouchesBegan is called, last - CGPoint when ccTouchesEnded is called 

    }

I used cocos 2d.

I'm sorry. I afraid that there are too many code, that will make you confused