How to draw an arbitrary curve in cocos2dx

Question

I'm working on a game based on cocos2dx, now I need to draw an arbitrary curve as the finger moves on the screen,then the curve will become the path along which my hero walks.Any idea will be appreciated.

Answer 1

Curve is connected line.
so you can draw curve using connected line.

Accumulate the points in cctouchesmove/cctouchemove event function.
Make line sprite, add and draw them.

and also cocos2d-x have curve classes. if you use them, you can run action easily.

CCCardinalSplineTo
CCCardinalSplineBy
CCCatmullRomTo
CCCatmullRomBy
CCBezierBy
CCBezierTo

And for drawing, this is sample code.

void HelloWorld::draw()  
{  
    // move to 50,50 since the "by" path will start at 50,50  
    kmGLPushMatrix();
    kmGLTranslatef(50, 50, 0);
    ccDrawCardinalSpline(m_pArray, 7, 100);

    kmGLPopMatrix();

    CCSize s = CCDirector::sharedDirector()->getWinSize();  

    kmGLPushMatrix();  
    kmGLTranslatef(s.width/2, 50, 0);  
    ccDrawCardinalSpline(m_pArray, 1, 100);  
    kmGLPopMatrix();  
}