四角をジェットコースターのループみたいにクルクルっと飛ばすiPhoneアプリのサンプルコードを描いてみます。
#import “ViewController.h”
#import <SpriteKit/SpriteKit.h>
@interface LoopScene : SKScene
@end
@implementation LoopScene
– (void)didMoveToView:(SKView *)view
{
self.backgroundColor = [SKColor lightGrayColor];
self.physicsWorld.gravity = CGVectorMake(0, 0);
[self createLoop];
}
– (void)createLoop
{
UIBezierPath *pathA = [UIBezierPath bezierPathWithArcCenter:CGPointZero radius:50 startAngle:0 endAngle:M_PI clockwise:NO];
SKShapeNode *loopA = [SKShapeNode node];
loopA.path = pathA.CGPath;
loopA.position = CGPointMake(100, 200);
[self addChild:loopA];
loopA.physicsBody = [SKPhysicsBody bodyWithEdgeChainFromPath:pathA.CGPath];
loopA.physicsBody.dynamic = NO;
UIBezierPath *pathB = [UIBezierPath bezierPathWithArcCenter:CGPointZero radius:50 startAngle:0 endAngle:M_PI clockwise:YES];
SKShapeNode *loopB = [SKShapeNode node];
loopB.path = pathB.CGPath;
loopB.position = CGPointMake(180, 300);
[self addChild:loopB];
loopB.physicsBody = [SKPhysicsBody bodyWithEdgeChainFromPath:pathB.CGPath];
loopB.physicsBody.dynamic = NO;
UIBezierPath *pathC = [UIBezierPath bezierPathWithArcCenter:CGPointZero radius:50 startAngle:0.5*M_PI endAngle:2.0*M_PI clockwise:YES];
SKShapeNode *loopC = [SKShapeNode node];
loopC.path = pathC.CGPath;
loopC.position = CGPointMake(195, 100);
[self addChild:loopC];
loopC.physicsBody = [SKPhysicsBody bodyWithEdgeChainFromPath:pathC.CGPath];
loopC.physicsBody.dynamic = NO;
}
– (SKNode *)createBall
{
SKSpriteNode *ball = [SKSpriteNode spriteNodeWithColor:[SKColor colorWithHue:0.1 * (arc4random()%10) saturation:0.8 brightness:1.0 alpha:1.0] size:CGSizeMake(20, 20)];
ball.name = @”ball”;
ball.position = CGPointMake(60, 400);
[self addChild:ball];
ball.physicsBody = [SKPhysicsBody bodyWithCircleOfRadius:10];
ball.physicsBody.linearDamping = 0;
ball.physicsBody.angularDamping = 0;
ball.physicsBody.friction = 0.1;
ball.physicsBody.collisionBitMask = 0x2;
ball.physicsBody.categoryBitMask = 0x1;
return ball;
}
– (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
SKNode *ball = [self createBall];
[ball.physicsBody applyImpulse:CGVectorMake(0, –10)];
}
– (void)didSimulatePhysics
{
[self enumerateChildNodesWithName:@”ball” usingBlock:^(SKNode *node, BOOL *stop) {
if(node.position.x > 350) {
[node removeFromParent];
}
}];
}
@end
@interface ViewController ()
@end
@implementation ViewController
– (void)viewDidLoad
{
[super viewDidLoad];
SKView *spriteView = [[SKView alloc] initWithFrame:self.view.bounds];
[self.view addSubview:spriteView];
SKScene *scene = [[LoopScene alloc] initWithSize:spriteView.frame.size];
[spriteView presentScene:scene];
}
– (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
@end