重力箱

ダイアルで重力の方向を操作するiPhoneアプリのサンプルコードを描いてみます。

#import “ViewController.h”

#import <SpriteKit/SpriteKit.h>

@interface GravityScene : SKScene

@end

@implementation GravityScene

– (void)didMoveToView:(SKView *)view

{

//    self.physicsWorld.speed = 0.5;

    [self createWall];

    [self createDoor];

    [self createDial];

    [self createChips];

}

– (void)createWall

{

    self.physicsBody = [SKPhysicsBody bodyWithEdgeLoopFromRect:self.frame];

    self.physicsBody.dynamic = NO;

}

– (void)createDoor

{

    UIBezierPath *path = [UIBezierPath bezierPathWithRect:self.frame];

    [path appendPath:[UIBezierPath bezierPathWithArcCenter:CGPointMake(160, 250) radius:140 startAngle:0 endAngle:2*M_PI clockwise:NO]];

    path.usesEvenOddFillRule = YES;

    

    SKShapeNode *door = [SKShapeNode node];

    door.path = path.CGPath;

    door.fillColor = [SKColor lightGrayColor];

    door.zPosition = 1;

    [self addChild:door];

}

– (void)createDial

{

    UIBezierPath *path = [UIBezierPath bezierPathWithOvalInRect:CGRectMake(-40, –40, 80, 80)];

    SKShapeNode *dial = [SKShapeNode node];

    dial.name = @”dial”;

    dial.path = path.CGPath;

    dial.position = CGPointMake(270, 50);

    dial.lineWidth = 5;

    dial.strokeColor = [SKColor redColor];

    dial.zPosition = 2;

    [self addChild:dial];

    

    SKLabelNode *arrow = [SKLabelNode node];

    arrow.text = @”↓”;

    arrow.fontColor = [SKColor redColor];

    arrow.verticalAlignmentMode = SKLabelVerticalAlignmentModeCenter;

    arrow.horizontalAlignmentMode = SKLabelHorizontalAlignmentModeCenter;

    [dial addChild:arrow];

}

– (void)createChips

{

    for (int i=0; i<100; i++) {

        float x = (i % 10) * 30 + arc4random() % 5;

        float y = (i / 10) * 30;

        SKSpriteNode *node = [SKSpriteNode spriteNodeWithColor:[SKColor colorWithHue:i*0.01 saturation:0.7 brightness:0.9 alpha:1.0] size:CGSizeMake(5, 5)];

        node.position = CGPointMake(x, y);

        [self addChild:node];

        

        node.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:node.size];

    }

}

– (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event

{

    CGPoint p = [[touches anyObject] locationInNode:self];

    SKNode *dial = [self childNodeWithName:@”dial”];

    if ([dial containsPoint:p]) {

        float dx = p.x – dial.position.x;

        float dy = p.y – dial.position.y;

        float angle = atan2f(dx, -dy);

        [dial runAction:[SKAction rotateToAngle:angle duration:0.2]];

        angle -= M_PI_2;

        self.physicsWorld.gravity = CGVectorMake(cos(angle), sin(angle));

    }

}

@end

@interface ViewController ()

@end

@implementation ViewController

– (void)viewDidLoad

{

    [super viewDidLoad];

    

    SKView *spriteView = [[SKView alloc] initWithFrame:self.view.bounds];

    [self.view addSubview:spriteView];

    

    SKScene *scene = [[GravityScene alloc] initWithSize:spriteView.frame.size];

    [spriteView presentScene:scene];

}

@end