我有一个带钟摆的工作时钟,但摆臂不能正确缩放。这是缩放之前的样子...
然后,缩放后...
钟面按比例缩小,摆臂(绿线)也按比例缩小,但看起来它围绕它的中心点而不是面中心的支点按比例缩小。我可以通过设置秋千来修复这种缩放,anchorPoint
使其向一端而不是中心缩放......
swing.anchorPoint = CGPointMake(0, 0.5);
但这样做会导致钟摆不摆动。(我认为是因为物理力被施加到摇摆上anchorPoint
,如果我将它移动到一端,它就会位于固定的销锚上)。
我怎样才能让手臂朝着支点缩放并仍然允许它摆动?
这是代码...
// in my SKScene
ClockFace *face = [ClockFace face]; // just an SKNode subclass
face.name = @"face";
face.position = CGPointMake(150, 150);
[self addChild:face];
// add the pendulum
SKSpriteNode *fulcrum = [SKSpriteNode spriteNodeWithColor:[UIColor redColor] size:CGSizeMake(5, 5)];
[face addChild:fulcrum];
fulcrum.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:fulcrum.frame.size];
fulcrum.physicsBody.dynamic = NO;
SKSpriteNode *swing = [SKSpriteNode spriteNodeWithColor:[UIColor greenColor] size:CGSizeMake(190, 2)];
[face addChild:swing];
swing.position = CGPointMake(95, 0);
swing.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:swing.frame.size];
SKPhysicsJointPin *pinJoint = [SKPhysicsJointPin jointWithBodyA:fulcrum.physicsBody bodyB:swing.physicsBody anchor:face.position];
[self.physicsWorld addJoint:pinJoint];