指で描いた線の上をチャリンコが駆け下りていくようなiPhoneアプリを描いてみます。
動作イメージ
XcodeからiOS7 iPhone Simulatorで動かすとこんな感じになります。
サンプルコード
#import “ViewController.h”
#import <SpriteKit/SpriteKit.h>
@interface BicycleLine : SKScene
@property BOOL contentCreated;
@property UIBezierPath *path;
@end
@implementation BicycleLine
– (void)didMoveToView:(SKView *)view
{
if (!self.contentCreated) {
[self createSceneContents];
self.contentCreated = YES;
}
}
– (void)createSceneContents
{
self.backgroundColor = [SKColor purpleColor];
[self createBicycleNode];
[self updateGround];
SKLabelNode *start = [SKLabelNode node];
start.name = @”startBtn”;
start.text = @”Go!”;
start.position = CGPointMake(280, 20);
[self addChild:start];
}
– (void)createBicycleNode
{
SKSpriteNode *bicycleFrame = [SKSpriteNode spriteNodeWithImageNamed:@”bicycleframe”];
bicycleFrame.position = CGPointMake(260, 450);
bicycleFrame.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:bicycleFrame.size];
bicycleFrame.physicsBody.linearDamping = 5.0; // move slow
bicycleFrame.physicsBody.dynamic = NO;
bicycleFrame.name = @”bicycle”;
[self addChild:bicycleFrame];
CGPoint center[] = {
CGPointMake(bicycleFrame.position.x – bicycleFrame.size.width/2.0,
bicycleFrame.position.y – bicycleFrame.size.height/2.0),
CGPointMake(bicycleFrame.position.x + bicycleFrame.size.width/2.0,
bicycleFrame.position.y – bicycleFrame.size.height/2.0)
};
for (int i=0; i<2; i++) {
SKSpriteNode *tire = [SKSpriteNode spriteNodeWithImageNamed:@”tire”];
tire.position = CGPointMake(center[i].x, center[i].y);
tire.physicsBody = [SKPhysicsBody bodyWithCircleOfRadius:tire.size.width/2.0];
[self addChild:tire];
SKPhysicsJointPin *pin = [SKPhysicsJointPin jointWithBodyA:bicycleFrame.physicsBody bodyB:tire.physicsBody anchor:center[i]];
[self.physicsWorld addJoint:pin];
}
}
– (void)updateGround
{
SKShapeNode *ground = (SKShapeNode*)[self childNodeWithName:@”ground”];
if (!ground) {
ground = [SKShapeNode node];
ground.name = @”ground”;
ground.physicsBody.dynamic = NO;
[self addChild:ground];
}
if (!self.path) {
self.path = [UIBezierPath bezierPath];
}
ground.path = self.path.CGPath;
}
– (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
CGPoint p = [[touches anyObject] locationInNode:self];
if ([[self childNodeWithName:@”startBtn”] containsPoint:p]) {
SKNode *node = [self childNodeWithName:@”bicycle”];
node.physicsBody.dynamic = YES;
SKShapeNode *ground = (SKShapeNode*)[self childNodeWithName:@”ground”];
ground.physicsBody = [SKPhysicsBody bodyWithEdgeChainFromPath:self.path.CGPath];
} else {
self.path = [UIBezierPath bezierPath];
[self.path moveToPoint:p];
}
}
– (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
CGPoint p = [[touches anyObject] locationInNode:self];
[self.path addLineToPoint:p];
[self updateGround];
}
– (void)didSimulatePhysics
{
SKNode *node = [self childNodeWithName:@”bicycle”];
if (node.position.x < 0 || node.position.x > 320 || node.position.y < 0) {
[node removeFromParent];
[self createBicycleNode];
self.path = nil;
[self updateGround];
}
}
@end
@interface ViewController ()
@end
@implementation ViewController
– (void)viewDidLoad
{
[super viewDidLoad];
SKView *spriteView = [[SKView alloc] initWithFrame:self.view.bounds];
[self.view addSubview:spriteView];
SKScene *scene = [[BicycleLine alloc] initWithSize:self.view.bounds.size];
[spriteView presentScene:scene];
}
– (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
@end