Cocos2d 2.x: understanding ccBezierConfig beheaviour

问题

I am on this since a while and time ago I asked a question and a user kindly replied to me explaning that there is this plugin tool that I can use to create quick bezier curves prototypes.

I tried and produced this:

I thought it would be perfectly translated in this ccBezierConfig:

ccBezierConfig bezier;
self.position = CGPointMake(-10.0f, 400.0f);
bezier.controlPoint_1 = CGPointMake(160, 190.0f);
bezier.controlPoint_2 = CGPointMake(200, 190.0f);
bezier.endPosition =CGPointMake(340.0f,280.0f);

id bezierForward = [CCBezierBy actionWithDuration:3 bezier:bezier];    
[self runAction: [CCSequence actions:
                  bezierForward, [CCHide action],
                  nil]];

Unfortunately the path I get is not quiet what I was expecting. The character starts to move from the top left corner of the screen and then just goes up and I don't see the movement I expected.

Any explanation on what am I doing wrong?

Btw.. I am using Cocos2d 2.0 on iOS 6.0, retina display iPod touch 4th generation.

EDIT:

Another example..

I thought that this configuration would do like in this and then do the symmetric thing from the end to the start but "upside down".

Any suggestions on what am I doing wrong?

    ccBezierConfig bezier;

     self.position = CGPointMake(0.0f, 150.0f);
     bezier.controlPoint_1 = CGPointMake(-20.0f, 290.0f);
     bezier.controlPoint_2 = CGPointMake(260, 290.0f);
     bezier.endPosition =CGPointMake(340.0f,150.0f);

    id bezierForward = [CCBezierBy actionWithDuration:3 bezier:bezier];


    ccBezierConfig bezier2;
    bezier2.controlPoint_1 = CGPointMake(340.0f, 10.0f);
    bezier2.controlPoint_2 = CGPointMake(80, 10.0f);
    bezier2.endPosition =CGPointMake(-20.0f,150.0f);

    id bezierReturn = [CCBezierBy actionWithDuration:3 bezier:bezier2];


    [self runAction: [CCSequence actions:
                      bezierForward, bezierReturn, [CCHide action],
                      nil]];

回答1:

I was using CCBezierBy but the examples are based on a CCBezierTo formula. Hence everything works as excpected if I use CCBezierTo instaed of CCBezierBy.

来源：https://stackoverflow.com/questions/14589474/cocos2d-2-x-understanding-ccbezierconfig-beheaviour

标签

ios

cocos2d-iphone

bezier