短冊切りにした丸を上下にシェイクするiPhoneアプリのサンプルコードを描いてみます。
#import “ViewController.h”
@import SpriteKit;
@interface ShakeScene : SKScene
@end
@implementation ShakeScene
– (void)didMoveToView:(SKView *)view
{
self.backgroundColor = [SKColor colorWithWhite:0.6 alpha:1];
self.physicsBody = [SKPhysicsBody bodyWithEdgeLoopFromRect:self.frame];
[self createBar];
}
– (void)createBar
{
float r = 140;
CGPoint o = CGPointMake(CGRectGetMidX(self.frame), CGRectGetMidY(self.frame));
for (int i=0; i<30; i++) {
float x = i * 10 – r;
float h = sqrtf(powf(r, 2) – powf(x, 2));
SKSpriteNode *bar = [SKSpriteNode spriteNodeWithColor:[SKColor purpleColor] size:CGSizeMake(9, r * 2.0)];
bar.name = @”bar”;
bar.position = CGPointMake(x + o.x, o.y);
[self addChild:bar];
SKSpriteNode *yellow = [SKSpriteNode spriteNodeWithColor:[SKColor yellowColor] size:CGSizeMake(8, h * 2.0)];
[bar addChild:yellow];
bar.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:bar.size];
for (int i=0; i<1; i++) {
SKPhysicsJointSpring *spring = [SKPhysicsJointSpring jointWithBodyA:bar.physicsBody bodyB:self.physicsBody anchorA:bar.position anchorB:CGPointMake(bar.position.x, bar.position.y + (i==0 ? 200 : –200))];
spring.frequency = 0.8;
spring.damping = 0.3;
[self.physicsWorld addJoint:spring];
}
}
}
– (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
CGPoint p = [[touches anyObject] locationInNode:self];
[self enumerateChildNodesWithName:@”bar” usingBlock:^(SKNode *node, BOOL *stop) {
if ([node containsPoint:p]) {
[node.physicsBody applyImpulse:CGVectorMake(0, 20)];
}
}];
}
@end
@interface ViewController ()
@end
@implementation ViewController
– (void)viewDidLoad
{
[super viewDidLoad];
SKView *spriteView = [[SKView alloc] initWithFrame:self.view.bounds];
[self.view addSubview:spriteView];
SKScene *scene = [[ShakeScene alloc] initWithSize:spriteView.frame.size];
[spriteView presentScene:scene];
}
@end