addition ring

ViewController.m

//
//  ViewController.m
//  AdditoinRing
//
//  Created by Mizushima Yusuke on 8/22/15.
//  Copyright (c) 2015 Yusuke Mizusima. All rights reserved.
//

#import "ViewController.h"
@import SpriteKit;

@interface ViewController ()
@property (nonatomic, weak) SKScene *scene;
@property (nonatomic, weak) SKNode *ring;
@property (nonatomic, weak) SKLabelNode *valueLabel;
@property (nonatomic) int count;
@property (nonatomic) float ringW;
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    [self setupScene];
    [self createAdditionRing];
    [self updateFormula];
    [self createButton];
}

- (void)setupScene {
    SKView *sv = [[SKView alloc] initWithFrame:self.view.bounds];
    SKScene *s = [SKScene sceneWithSize:sv.frame.size];
    s.backgroundColor = [UIColor colorWithHue:0.7 saturation:0.3 brightness:0.3 alpha:1];
    [sv presentScene:s];
    
    [self.view addSubview:sv];
    self.scene = s;
}

- (void)createAdditionRing {
    CGPoint o = CGPointMake(CGRectGetMidX(self.view.bounds), 400);
    
    SKShapeNode *ring = [SKShapeNode shapeNodeWithCircleOfRadius:CGRectGetMidX(self.view.bounds) * 0.8];
    ring.fillColor = [UIColor colorWithHue:0.5 saturation:0.3 brightness:0.3 alpha:1];
    ring.lineWidth = 0;
    ring.position = o;
    [self.scene addChild:ring];
    self.ring = ring;
    
    [self.scene addChild:[self mylabel:@"+" p:CGPointMake(o.x - 60, o.y)]];
    [self.scene addChild:[self mylabel:@"=" p:CGPointMake(o.x + 60, o.y)]];
    
    NSString *valY = [NSString stringWithFormat:@"%d", arc4random() % 10];
    SKLabelNode *val = [self mylabel:valY p:CGPointMake(o.x, o.y)];
    [self.scene addChild:val];
    self.valueLabel = val;
}


typedef struct {int y; int ringVal[8];} NumberSet;
- (void)updateFormula {
    
    [self.ring removeAllChildren];
    self.ringW = 0;
    self.ring.zRotation = 0;
    
    // A. 2 + 1 = 3
    // B. 3 + 4 = 7
    // C. 2 + 7 = 9
    // D. 5 + 3 = 8
    // E. 6 + 0 = 6
    NumberSet s[] = {
        {.y=1, .ringVal={1,2,6,4,5,3,8,7}},
        {.y=4, .ringVal={3,2,6,4,7,1,8,9}},
        {.y=7, .ringVal={2,3,6,7,9,8,5,1}},
        {.y=3, .ringVal={2,0,6,7,5,8,1,3}},
        {.y=0, .ringVal={2,6,1,5,8,6,3,1}},
    };
    
    NumberSet q = s[self.count];
    
    self.valueLabel.text = [NSString stringWithFormat:@"%d", q.y];
    
    float dw = M_PI / 4.0;
    float r = 114;
    for (int i=0; i<8; i++) {
        float x = r * cos(dw * i);
        float y = r * sin(dw * i);
        NSString *s = [NSString stringWithFormat:@"%d", q.ringVal[i]];
        SKLabelNode* l = [self mylabel:s p:CGPointMake(x, y)];
        [self.ring addChild:l];
    }
    
    self.count = (self.count + 1) % 5;
}

- (SKLabelNode *)mylabel:(NSString *)text p:(CGPoint)p {
    
    float fontSize = 60;
    NSString *fontName = [[UIFont boldSystemFontOfSize:40] fontName];
    
    SKLabelNode *l = [SKLabelNode labelNodeWithText:text];
    l.fontName = fontName;
    l.fontSize = fontSize;
    l.position = p;
    l.verticalAlignmentMode = SKLabelVerticalAlignmentModeCenter;
    return l;
};

- (void)createButton {
    UIButton *btn = [UIButton buttonWithType:UIButtonTypeSystem];
    [btn setTitle:@"OK" forState:UIControlStateNormal];
    btn.titleLabel.font = [UIFont systemFontOfSize:40];
    [btn setTintColor:[UIColor whiteColor]];
    [btn sizeToFit];
    btn.center = CGPointMake(CGRectGetMidX(self.view.bounds), CGRectGetMaxY(self.view.bounds) - 200);
    [self.view addSubview:btn];
    
    [btn addTarget:self action:@selector(next) forControlEvents:UIControlEventTouchUpInside];
}

- (void)next {
    [self updateFormula];
}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    self.ringW += M_PI / 4.0;
    [self.ring runAction:[SKAction rotateToAngle:self.ringW duration:0.3 shortestUnitArc:NO]];
    [self.ring.children enumerateObjectsUsingBlock:^(SKNode *n, NSUInteger idx, BOOL *stop) {
        [n runAction:[SKAction rotateToAngle:-self.ringW duration:0.3 shortestUnitArc:NO]];
    }];
}

@end