falling down bridge

ViewController.mm

//
//  ViewController.m
//  FallingDownBridge
//
//  Created by MizushimaYusuke on 8/27/15.
//  Copyright (c) 2015 MizushimaYusuke. All rights reserved.
//

#import "ViewController.h"
@import SpriteKit;

typedef NS_ENUM(NSInteger, MyTapType) {
    STOP    = 0,
    START   = 1,
    JUMP    = 2,
    Air     = 3
};

@interface ViewController () <SKSceneDelegate, SKPhysicsContactDelegate>
@property (nonatomic, weak) SKScene *scene;
@property (nonatomic, weak) SKShapeNode *player;
@property (nonatomic) NSInteger tapType;
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    [self setupScene];
    [self createFloor];
    [self createPlayer];
    [self createBottom];
}

- (void)setupScene {
    SKView *sv = [[SKView alloc] initWithFrame:self.view.bounds];
    SKScene *s = [SKScene sceneWithSize:sv.frame.size];
    s.delegate = self;
    s.scene.physicsWorld.contactDelegate = self;
    [sv presentScene:s];
    s.backgroundColor = [self color:3];
    [self.view addSubview:sv];

    self.scene = s;
}

- (void)createFloor {
    float w = CGRectGetMaxX(self.view.bounds) / 3.0;
    float h = 10;
    for (int i=0; i<3; i++) {
        int color = (i==1) ? 2 : 1;
        CGSize size = CGSizeMake((i==1) ? w * 0.8 : w, h);
        SKSpriteNode *bar = [SKSpriteNode spriteNodeWithColor:[self color:color] size:size];
        bar.name = [NSString stringWithFormat:@"bar%d", i];
        bar.position = CGPointMake(w * i + w * 0.5, 100);
        bar.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:bar.size];
        bar.physicsBody.categoryBitMask = 1 << 1;
        bar.physicsBody.contactTestBitMask = 1 << 2;
        bar.physicsBody.dynamic = NO;
        [self.scene addChild:bar];
    }
}

- (void)createPlayer {
    float r = 30;
    SKShapeNode *p = [SKShapeNode shapeNodeWithCircleOfRadius:r];
    p.fillColor = [self color:0];
    p.position = CGPointMake(r, 300);
    
    SKSpriteNode *deco = [SKSpriteNode spriteNodeWithColor:[self color:1] size:CGSizeMake(10, 10)];
    deco.position = CGPointMake(r * 0.6, 0);
    [p addChild:deco];
    
    p.physicsBody = [SKPhysicsBody bodyWithCircleOfRadius:r];
    p.physicsBody.categoryBitMask = 1 << 2;
    p.physicsBody.restitution = 0;
    [self.scene addChild:p];
    self.player = p;
}

- (void)createBottom {
    float h = 50;
    float w = CGRectGetMaxX(self.view.bounds);
    SKSpriteNode *btm = [SKSpriteNode spriteNodeWithColor:[self color:4] size:CGSizeMake(w, h)];
    btm.position = CGPointMake(w * 0.5, h * 0.5);
    [self.scene addChild:btm];
}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
    if (self.tapType == STOP) {
        self.tapType = START;
    } else if (self.tapType == START) {
        self.tapType = JUMP;
    }
}

#define TopSpeed 3
- (void)update:(NSTimeInterval)currentTime forScene:(SKScene *)scene {
    
    if (self.tapType == STOP) return;
    
    if (fabs(self.player.physicsBody.angularVelocity) < TopSpeed) {
        [self.player.physicsBody applyTorque:-0.1];
    }
    
    if (self.tapType == JUMP) {
        self.tapType = Air;
        [self.player.physicsBody applyImpulse:CGVectorMake(0, 80)];
    }
    
    SKNode *mBar = [self.scene childNodeWithName:@"bar1"];
    mBar.physicsBody.velocity = CGVectorMake(0, MAX(mBar.physicsBody.velocity.dy, -1));
    
    if (self.player.position.y < -30) {
        [self.player removeFromParent];
        [self.scene.children enumerateObjectsUsingBlock:^(SKNode *n, NSUInteger idx, BOOL *stop) {
            if ([n.name hasPrefix:@"bar"]) [n removeFromParent];
        }];
        
        [self createPlayer];
        [self createFloor];
        self.tapType = STOP;
    }
}

- (void)didBeginContact:(SKPhysicsContact *)contact {
    for (SKNode *n in @[contact.bodyA.node, contact.bodyB.node]) {
        if ([n.name isEqual:@"bar1"] && !n.physicsBody.dynamic) {
            n.physicsBody.dynamic = YES;
            n.physicsBody.linearDamping = 1;
            n.physicsBody.allowsRotation = NO;
        }
    }
    
    if (self.tapType == Air) self.tapType = START;
}

#define ColorHex(rgb) [UIColor colorWithRed:((rgb & 0xFF0000)>>16)/255.0 green:((rgb & 0xFF00)>>8)/255.0 blue:(rgb & 0xFF)/255.0 alpha:1]
- (UIColor *)color:(int)i {
    if (i > 4) return nil;
    int code[] = {0x468966, 0xFFF0A5, 0xFFB03B, 0x26100B, 0x8E2800};
    return ColorHex(code[i]);
}

@end