We throw the puck in iOS eight

Before creating a casual game for iOS, it would be nice to answer the question: - Why?
Three options:

• Cut money;
• To please relatives;
• Fuck knows, but thought burns the body from the inside.

I think in the coming years, the correct answer is the third.
And, I will not argue and teach - I will tell you how I make applications.
The development guru silently clicks the plus and walk away. The rest follow me to remember school and table hockey.
And yes, the uniqueness of the topic is that in each sentence the words begin with different letters.
The article has nine pictures and half a minute of funny animation.

1. The idea

The choice of tools depends on it. My ideas as smartphone users are straightforward. Because - no extra tools for development, except for the library of sound reproduction. I borrow resources from the network. Ringtones, design, images, code examples. Everything has already been created before us. Copyright - like in hockey or football. Let's say Messi invented a new feint. You can copy it without transferring money to the author.
Okay. As an example of the game, I chose table hockey.

2. Start of the project

Figure 2. In Xcode, I’m looking for a new project.

By the way, I have fat fingers. So, only the iPad mode is suitable for the game. This greatly facilitates the work. In addition, I prohibit screen rotation, allowing only portrait orientation. Long live the portrait, here you have hockey, not ballet.
With the choice of the name of the application there is no difficulty - Hockey 2015 . Names of sports are profitable. As for the money, I, of course, misled. I would like the future opus to bring satisfaction, both spiritual and material. I already wrote here about my game Biathlon 2014. Every year - almost a thousand bucks. Buy during the World Cup, the Olympics, the cup stages. Who! Norwegians, Germans, Czechs, French, Russians, Italians.
I think my future hockey is waiting for something similar just because of the name.

I choose the icon. Not as important as the name. The main thing is to enjoy it yourself.

Figure 3. Whoever guesses what kind of hockey player he is, the prize is 1 dollar.

As a result, we get a blank for a future game that displays a bright gray screen. The project has two main files that I can edit.

• ViewController.xib
• ViewController.m

And I won’t, bad tone. Good tone is not too lazy and create another class of the ViewController type. For example, named PlayViewController.


Figure 4. Add a new PlayViewController.

The project has two new files that I can always edit.

• PlayViewController.xib
• PlayViewController.m

3. Still images

I place the still images using the editor in the file PlayViewController.xib.
First, you need to create, steal or borrow the pictures. Milfgard made images of the ice field, hockey players, and goalkeepers . In Mosigre there are. For which I without asking placed the Mosigra name label in the center of the field. The puck is from the net. Photos of the faces of hockey players - nhl.com. Buttons - from the designers of Zeptolab. Hockey sounds - from the Ice Rage app.
Now you can place the images in the xib file editor. It's simple - all pictures are displayed by the UIImageView element.


Figure 5. Hockey field and scoreboard in the Xcode editor.

If in the future you need animation of statically defined elements - it does not matter. I give the element a name. Now it can be programmed to move, extinguish, rotate, mock as you like.

Example, declare the scoreBoard element (black scoreboard in the picture) in the file PlayViewController.m

   IBOutlet UIImageView *scoreBoard;

The IBOutlet keyword means that in the XIB editor you can assign a scoreBoard identifier to any item.
I assign a mouse in the editor.

Now I can move the picture deep up so that it does not block the hockey field.

  scoreBoard.center = CGPointMake(384, -1000);

I remind you, 384 is the center of the iPad screen in width, -1000 is something outside the device. After the command is executed, the scoreboard will fly up beyond the boundaries of the screen.

If you want to move a group of pictures - they must be combined. Get an element of type UIView to move a group of pictures and labels into it.

Figure 6. So, unnecessary elements are removed from the ice.

Now we’ll place the hockey players here to teach them how to move.

4. Transformable images

We place one hockey player programmatically in the file PlayViewController.m

   UIImageView *player =  [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"player_1.png"]];
    float rPlayer = 150.0;
   player.frame = CGRectMake(0, 0, rPlayer, rPlayer);
    player.center = CGPointMake(100, 500);
    [self.view addSubview:player];
 

Figure 7. A hockey player appeared on the court.

In the future, I will move and rotate it. Like this.

    player.center = CGPointMake(xnew, ynew); // перемещаю в точку (xnew=100, ynew=440)
    player.transform = CGAffineTransformMakeRotation(alpha); // кручу хоккеиста на угол (alpha=2.0) в радианах
 

Figure 8. The hockey player left for another place and turned around.

There are many hockey players, but I am alone. We place all 12 players using an array.

    NSMutableArray *players;
    players = [[NSMutableArray alloc] init];
    shadows = [[NSMutableArray alloc] init];
    for (int k=0; k<12; k++) {
        UIImageView *p =  [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"player_1"]];
        p.frame = CGRectMake(0, 0, cellDx, cellDx);
        float x = xp[k];
        float y = yp[k];
        p.center = CGPointMake(x, y);
        p.transform = CGAffineTransformMakeRotation(ap[k]);
        [players addObject:p];
        p = [players objectAtIndex:k];   // так можем получить доступ к любому из 12 хоккеистов
        [self.view addSubview:p];
    }
  

5. Numerical methods in hockey

Hockey, like life, depends on time.
It is necessary to have a time counter. The event that the program will trigger 3,000 times per minute.

     NSTimer *pauseTimer;
    time = 0;
    deltaTime = 1.0/50.0;
    pauseTimer = [NSTimer scheduledTimerWithTimeInterval:deltaTime  target:self selector:@selector(timerFunction) userInfo:nil repeats:YES];
- (void) timerFunction
{
// мы здесь бываем 50 раз в секунду
    time = time + deltaTime;
    [self renderPuck];
    [self renderPlayers];
    [self puckMoving:deltaTime];
}
    

So, all that remains for me is to paint the puckMoving function. In it I will check the collision of the puck and hockey players. Mathematically, the puck is defined by a circle with a radius of 21 pixels. Each hockey player has two circles - a larger (radius of 25 pixels) body. Smaller (5 pixel radius) - a club.

Feature below, comments inside.

Inside the function, the Vector class is used.

When numerically modeling the movement of the puck, there is one trick. 50 times per second is not enough for simulation accuracy. I use an elementary trick - I’ll double the number of calls to puckMoving, breaking the time step into ten accordingly.

- (void) timerFunction
{
// мы здесь бываем 50 раз в секунду
    time = time + deltaTime;
    [self renderPuck];
    [self renderPlayers];
    for (int k=0; k<10; k++)  [self puckMoving:deltaTime/10.0];
}
    

We look what happened

6. Statistics know everything

Russians and Americans love statistics. Therefore, I organized a tournament of the six best teams in the world.
Real players from nhl.com, goals, goals, points, all stars of the tournament.

7. Testing

Apple allows 1,000 testers at the app revision stage.



Thank you for reading.