我有一个要在其中添加box2d主体的桶。不是放在整个铲斗上,而是放在左侧,右侧和底部,这样我就可以将球扔进铲斗中。
这是我的水桶。我在水桶的左侧和右侧添加了box2d主体。像这样
这对我来说很好,但是当我在底部添加主体时,我的游戏崩溃了。
这是我的代码,用于在存储桶中添加2个主体以及注释底部主体。
-(b2Body *) createBucket
{
CCSprite* bucket = [CCSprite spriteWithFile:@"simple-bucket-md.png"];
[self addChild:bucket z:3];
b2Body* b_bucket;
//set this to avoid updating this object in the tick schedule
bucket.userData = (void *)YES;
b2BodyDef bodyDef;
bodyDef.type = b2_staticBody;
CGPoint startPos = ccp(400,150);
bodyDef.position = [self toMeters:startPos];
bodyDef.userData = bucket;
bodyDef.gravityScale = 0;
b2PolygonShape dynamicBox;
//----------------------------------
// THis IS body for Left Side
//----------------------------------
int num = 5;
b2Vec2 verts[] = {
b2Vec2(-29.1f / PTM_RATIO, 25.0f / PTM_RATIO),
b2Vec2(-25.4f / PTM_RATIO, -14.9f / PTM_RATIO),
b2Vec2(-18.7f / PTM_RATIO, -14.9f / PTM_RATIO),
b2Vec2(-21.8f / PTM_RATIO, 26.7f / PTM_RATIO),
b2Vec2(-28.9f / PTM_RATIO, 25.1f / PTM_RATIO)
};
dynamicBox.Set(verts, num);
b2FixtureDef fixtureDef;
fixtureDef.shape = &dynamicBox;
fixtureDef.friction = 0.7;
fixtureDef.density = 10.0f;
fixtureDef.restitution = 0.7;
b_bucket = world->CreateBody(&bodyDef);
b_bucket->CreateFixture(&fixtureDef);
//----------------------------------
// THis IS body for Right Side
//----------------------------------
int num1 = 5;
b2Vec2 verts1[] = {
b2Vec2(16.8f / PTM_RATIO, 27.0f / PTM_RATIO),
b2Vec2(15.9f / PTM_RATIO, -11.5f / PTM_RATIO),
b2Vec2(22.1f / PTM_RATIO, -10.7f / PTM_RATIO),
b2Vec2(24.6f / PTM_RATIO, 26.9f / PTM_RATIO),
b2Vec2(16.9f / PTM_RATIO, 26.7f / PTM_RATIO)
};
dynamicBox.Set(verts1, num1);
fixtureDef.shape = &dynamicBox;
b_bucket-> CreateFixture(&fixtureDef);
//----------------------------------
// THis IS body for Bottom
//----------------------------------
/*
int num2 = 5;
b2Vec2 verts2[] = {
b2Vec2(-23.0f / PTM_RATIO, -21.6f / PTM_RATIO),
b2Vec2(18.9f / PTM_RATIO, -21.0f / PTM_RATIO),
b2Vec2(18.2f / PTM_RATIO, -26.1f / PTM_RATIO),
b2Vec2(-22.8f / PTM_RATIO, -25.9f / PTM_RATIO),
b2Vec2(-23.0f / PTM_RATIO, -21.7f / PTM_RATIO)
};
dynamicBox.Set(verts2, num2);
fixtureDef.shape = &dynamicBox;
b_bucket-> CreateFixture(&fixtureDef);
*/
return b_bucket;
}
最佳答案
您的顶点是顺时针排序的,而它们应该是逆时针的。
您必须创建具有逆时针缠绕(CCW)的多边形。我们必须小心,因为CCW的概念是相对于右手坐标系,z轴指向平面之外。根据坐标系统的约定,这可能在屏幕上显示为顺时针方向。
同样,为了创建4个面的多边形(看来您正在尝试),您仅需要4个顶点。尝试这样的事情。
int num2 = 4;
b2Vec2 verts2[] = {
b2Vec2(-22.8f / PTM_RATIO, -25.9f / PTM_RATIO),
b2Vec2(18.2f / PTM_RATIO, -26.1f / PTM_RATIO),
b2Vec2(18.9f / PTM_RATIO, -21.0f / PTM_RATIO),
b2Vec2(-23.0f / PTM_RATIO, -21.6f / PTM_RATIO)
};
dynamicBox.Set(verts2, num2);
fixtureDef.shape = &dynamicBox;
b_bucket-> CreateFixture(&fixtureDef);
请注意,您也可以删除横向实体的第五个顶点。
关于ios - 在Sprite Cocos2d上添加box2d主体,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/19582260/