在Cocos2d中使用CCSprites

Question

我想知道是否有人知道我如何将CCSprite附加到cpConstraint并使用物理更新。下面是我的代码:

upper = [game.spaceManager addPolyAt:cpv(70,195) mass:300 rotation:0 numPoints:6 points:cpv(2,12), cpv(28,8), cpv(33,0), cpv(36,-10), cpv(-33,-10), cpv(-20,8)];
upper->collision_type = kTireCollisionType;
cpShape *lower = [game.spaceManager addPolyAt:cpv(70,125) mass:300 rotation:0 numPoints:7 points:cpv(34,8), cpv(31,0), cpv(25,-9), cpv(7,-13), cpv(-20,-8), cpv(-30,0), cpv(-35,8)];
lower->collision_type = kTireCollisionType;
//HIT POINT
cpShape *sensor = [game.spaceManager addCircleAt:cpv(70,160) mass:10 radius:10];
sensor->sensor = YES;
sensor->collision_type = kScoreCollisionType;
cpShape *sensor2 = [game.spaceManager addCircleAt:cpv(70, 160) mass:10 radius:10];
sensor2->sensor = YES;
//Combine them into one body!
[game.spaceManager combineShapes:upper, lower, sensor, sensor2, nil];
//The "rope"
cpVect a1 = cpv(0,30);      //Local coordinates of tire
cpVect a2 = cpv(70,320);    //World coordinates (staticBody is at (0,0))
//calculate the length of the rope
float max = cpvdist(cpBodyLocal2World(upper->body, a1), a2);
cpConstraint *rope = [game.spaceManager addSlideToBody:upper->body fromBody:game.spaceManager.staticBody toBodyAnchor:a1 fromBodyAnchor:a2 minLength:1 maxLength:max];
cpConstraintNode *ropeNode = [cpConstraintNode nodeWithConstraint:rope];
ropeNode.color = ccBLUE;
[game addChild:ropeNode];
//Attach a sprite to the sensor, lucky for us it's exactly in the center
//of the tire... otherwise this wouldn't work
[game addChild:[super initWithShape:sensor file:@"TractorTireFront.png"] z:3];
[game addChild:[cpCCSprite spriteWithShape:sensor2 file:@"TractorTireBack.png"] z:1];
ivGame = game;
//Free the shape when we are released
self.spaceManager = game.spaceManager;
self.autoFreeShape = YES;
[self schedule:@selector(step:) interval:.1];
return self;

init方法的代码。我在屏幕上有一个轮胎，正如你所看到的，有一个cpConstraint作为绳子，悬挂在屏幕的顶部，并连接到轮胎的顶部。我想以某种方式将CCSprite附加到此约束并使其随轮胎的摆动而更新，或者如果有另一种方法使用CCSprite并使其随轮胎的摆动而更新。

我使用cocos2d + spaceManager。我听过有人说，只要使用CCSprite和更新它与轮胎运动，但我不熟悉cocos2d或spaceManger来完成这一点，所以如果有人有一些代码片段或教程告诉我如何做到这一点，我会非常感激。

Answer 1

我不知道花栗鼠但是你可以在tick方法中输入

-(void) tick() {
// not sure how you get position in chipmunk, somehow convert it to cgPoint
CGPoint * p = ccp(cpConstraint->position.x, cpConstraint->position.y);
//find out the offset of the tire compared to the cpConstraint then add it to p
p = ccp(p.x + offset.x, p.y + offset.y);
//assign it to your CCSprite
sprite.position = p;
}

初始化CCSprite

CCSprite * s = [CCSprite spritreWithFile:"picture.png"];
//add to CCLayer with is self here
[self addChild:s];