How to use and create and handle Model class in IOS? - iphone

i want to increment and decrement a variable trough out the application as i am using that in many views of the application. I am working on a game for iOS. I want to store the score in a variable and when the user start playing game there are two or three points where the users can loose the score like -1 before start playing the game even. Suppose i am giving the user three options for something if he choose first then he move to the next step if he will return back and want to choose second option he will have to bear -1 from his score and again if he go for third same process will be followed.

I think you only have to make singleton class to solve this
follow the answer What should my Objective-C singleton look like? it have the idea of singleton

Related

Identifying unity gameObjects (pre-runtime) to save/load their data

I pretty much already made a little quest game for Android, and it only just occurred to me that I have to save player's progress.
I have a lot of interactive game objects (they share a script InteractiveObject that I made), which has an integer "CurrentPosition" parameter, that tracks how the player interacted with it. I need to save that parameter for all of those game objects.
What I figured I will do is pass this data to some "manager" singleton class after every interaction, and compile it into the list.. only I have nothing to identify those game objects by. GetInstanceID is unique, but not persistent, so its useless for this purpose.
Of course, I could just add "ID" parameter ty my script, and fill it by-hand in editor.. but that seems to be a suboptimal solution. There are a lot of those objects.
Any suggestions?
You need to somehow "register" your buttons
This is basically the same idea as "give them all an ID manually" except replace manually with "using code."
The first problem you have is that all of your buttons are hand-placed in your scene and all of their interactions are done by hand and all of this was done manually with no regard to "I'm going to need to be able to identify these later" which is how you've ended up here.
Option 1:
Have your code create, place, and name your buttons. As your code is yours it will just automatically generate the required ID and retrieve the state from the save file because you built it to handle this requirement from the get-go.
As you haven't already set your project up this way, this will be a lot of work spent refactoring your project to do it this way.
Option 2:
Do it manually as you stated you don't want to do. You may have to decide that this is the least work-intensive solution that is also reliable.
Option 3:
Create a class that all it does is have a registerButton function that shoves the buttons into an array so that they have an index ID value. When your buttons run their Start() method (if they do not have a Monobehavior script yet, give them one for this purpose) calls this registerButton method, which returns an ID (its literally just the button's index in the all_the_buttons array). Use this as your serialization ID.
Note that while this is deterministic (in that the buttons will register themselves in the same order every time) it occurs in an unknown order. If you delete, clone, create, or move the button around in the scene hierarchy, you will affect what IDs your buttons have, possibly invalidating any existing save files.
you can use playerprefs to save the game data , take a look at this link https://docs.unity3d.com/ScriptReference/PlayerPrefs.html

Determine if Game has been Launched for the First Time - Cocos2d

I know this is probably very easy, but I want to add sprites in game that tell you have to play the game ONLY on the first launch. If the game is launched a second, third fourth, fifth, time etc. I do not want those instructions to appear again.
Could someone lead me in the right direction or give me an example?
I was thinking of adding a boolean "isFirstLaunch" then putting it in AppDelegate in "applicationDidFinishLaunching" then checking it in my game scene to see if it is true, but I'm not completely sure.
Any help?
Thanks!
Just use the default preferences. If the app doesn't find the file = first time, if the app does find the file = not first time. I did something like this when I was programming LustCalc. Look for NSUserDefaults... something. Sorry I did this a long time ago.
Found this:
Best way to check if an iPhone app is running for the first time
as a side note, if you don't use synchronize, the iphone decide when to store the preferences, usally after a minute or two: if the app quits in the meantime, no preferences get saved. So you should sync only when you quit the app and at exceptional times.

iOS frame by frame animation, by script

There are a few SO questions regarding frame by frame animation (such as frame by frame animation and other similar questions), however I feel mine is different so here goes.
This is partially a design question from someone with very little ios experience.
I'm not sure "frame by frame" is the correct description of what I want to do so let me describe that. Basically, I have a "script" of an animated movie and I'd like to play this script.
This script is a json file which describes a set of scenes. In each scene there are a few elements such as a background image, a list of actors with their positions and a background sound clip. Further, for each actor and background there's an image file that represents it. (it's a bit more complex - each actor has a "behavior" such as how it blinks, how he talks etc). So my job is to follow the given script referencing actors and background and with every frame, place the actors in their designated position, draw the correct background and play the sound file.
The movie may be paused, scrubbed forward or backward similar to youtube's movie player functionality.
Most of the questions I've seen which refer to frame-by-frame animation have different requirements than I do (I'll list some more requirements later). They usually suggest to use animationImages property of a UIImageView. This is fine for animating a button or a checkbox but they all assume there's a short and predefined set of images that need to be played.
If I were to go with animationImages I'd have to pre-create all the images up front and my pure guess is that it won't scale (think about 30fps for one minute, you get 60*30=1800 images. Plus the scrub and pause/play abilities seem challenging in this case).
So I'm looking for the right way to do this. My instinct, and I'm learning more as I go, is that there are probably three or four main ways to achieve this.
By using Core Animations and defining "keypoints" and animated transitions b/w those keypoints. For example if an actor needs to be at point A at time t1 and point B at time t2 then all I need to do it animate what's in between. I've done something similar in ActionScript in the past and it was nice but was particularly challenging to implement the scrub action and keep everytyhing in sync so I'm not a big fan of the approach. Imagine that you have to implement a pause in the middle of an animation or scrub to a middle of an animation. It's doable but not pleasant.
Set a timer for, say 30 times a second and on every tick consult the model (the model is the script json file along with the description of the actors and the backgrounds) and draw what needs to be drawn at this time. Use Quartz 2D's API and drawRect. This is probably the simple approach and but I don't have enough experience to tell how well it's going to work on different devices, probably CPU wise, it all depends on the amount of calculations I need to make on each tick and the amount of effort it takes ios to draw everything. I don't have a hunch.
Similar to 2, but use OpenGL to draw. I prefer 2 b/c the API is easier but perhaps resource wise OpenGL is more suitable.
Use a game framework such as cocos2d which I'd never used before but seems to be solving more or less similar problems. They seem to have a nice API so I'd be happy if I could find all my requirements answered by them.
Atop of the requirements I'd just described (play a movie given it's "script" file and a description of the actors, backgrounds and sounds), there's another set of requirements -
The movie needs to be played in full screen mode or partial screen mode (where the rest of the screen is dedicated to other controls)
I'm starting with the iphone by naturally an ipad should follow.
I'd like to be able to create a thumbnail of this movie for local phone use (display it in a gallery in my application). The thumbnail may just be the first frame of the movie.
I want to be able to "export" the result as a movie, something that could be easily uploaded to youtube or facebook.
So the big question here is whether any of the suggested 1-4 implementations I have in mind (or others you might suggest) can somehow export such a movie.
If all four fail on the movie export task then I have an alternative in mind. The alternative is to use a server which runs ffmpeg and which accept a bundle of all the movie images (I'd have to draw them in the phone and upload them to the sever by their sequence) and then the server would compile all the images with their soundtrack to a single movie.
Obviously to keep things simple I'd prefer to do this server-less, i.e. be able to export the movie from the iphone but if that's too much to ask then the last requirement would be to at least be able to export the set of all images (keyframes in the movie) so I can bundle them and upload to a server.
The length of the movie is supposed to be a one or two minutes. I hope the question wasn't too long and that it's clear...
Thanks!
well written question. for your video export needs check out AVFoundation (available as of iOS 4). If I were going to implement this, I'd try #1 or #4. I think #1 might be the quickest to just try out, but that's probably because I don't have any experience with cocos2d. I think you will be able to pause and scrub CoreAnimation: check out the CAMediaTiming protocol it adopts.
Ran, you do have a number of options. You are not going to find a "complete solution" but it will be possible to make use of existing libraries in order to skip a bunch of implementation and performance issues. You can of course try to build this whole thing in OpenGL, but my advice is that you go with another approach. What I suggest is that you render the entire "video" frame by frame on the device based on your json settings. That basically comes down to setting up your scene elements and then determining the positions of each element for times [0, 1, 2] where each number indicates a frame at some framerate (15, 20, or 24 FPS would be more than enough). First off, please have a look at my library for non-trivial iOS animations, in it you will find a class named AVOfflineComposition that does the "comp items and save to a file on disk" step. Obviously, this class does not do everything you need, but it is a good starting point for the basic logic of creating a comp of N elements and writing the results out to a video file. The point of creating a comp is that all of your code that reads settings and places objects at a specific spot in the comp can be run in an offline mode and the result you get at the end is a video file. Compare this to all the details involved with maintaining all theses elements in memory and then going forward more quickly or slowly depending on how quickly everything is running.
The next step will be to create 1 audio file that is the length that the "movie" of all the comped frames and have it include any sounds at specific times. This basically means mixing the audio at runtime and saving the results to an output file so that the results are easy to play with AVAudioPlayer. You can have a look at some very simple PCM mixer code that I wrote for this type of thing. But, you might want to consider a more complete audio engine like theamazingaudioengine.
Once you have an audio file and a movie file, these can be played together and kept in sync quite easily using the AVAnimatorMedia class. Take a look at this AVSync example for source code that shows a tightly synced example of playing a video and showing a movie.
Your last requirement can be implemented with the AVAssetWriterConvertFromMaxvid class, it implements logic that will read a .mvid movie file and write it as a h.264 encoded video using the h.264 encoder hardware on the iPhone or iPad. With this code, you will not need to write a ffmpeg based server module. Also, that would not work anyway because it would take too long to upload all the uncompressed video to your server. You need to compress the video to h.264 before it can be uploaded or emailed from the app.

iPhone Smooth Transition from One Video To Another

I have to figure out the best way to transition from one video to the next
BASIC IDEA: An example would be that there is a video of a person walking.....the user taps the video and a seamless transition occurs to a video of a person running (over simplified example)
My first thought was to create 2 movie players and use transitions between the 2 view elements. But movie-player doesn't support that.
stopping the current video, loading new content, and then starting it is a solution but not very elegant. We are making a interactive sales tool for our reps and we want this to look as professional as possible.
CURRENT THOUGHT: If there was some sample code for AVPlayer, it would seem I could use AVVideoComposition to switch between videos? But details on how that might happen don't seem to be currently available.
POSSIBLE CLUE: I figured this would be easy as I bought an app called Live Cams HD that shows 16 different video feeds at once.
Any ideas? Thanks in advance!
Steve, the short answer is that you are not going to be able to get the kind of results you want using AVPlayer. The h.264 video logic included in iOS is really great at playing video and video/audio together, but it really sucks at starting/stopping and switching from one clip to another. The reason is that there is a lot of buffering that needs to happen to load up and start playing a h.264 video in hardware. Basically, you need to roll your own code that sets UIImage/CGImageRef for your views in a way that makes it easy to switch from one clip to another by simply switching from one array of UIImage objects to another. Of course, that is easy to say yet not so easy to implement.
What I would suggest is that you evaluate existing code that already implements this logic instead of rolling your own. For example, have a look at this StreetFighter demo app. It shows how a very simple game like iPhone UI can be constructed using a series of clips that show a character doing a kick, a punch, or throwing a fireball. The results looks like this:
I also wrote up a blog post about seamless-video-looping-on-ios. You can of course roll your own code to do all this, but I would suggest reading more about my library at the linked website as it will save you a lot of time.
After the first video has played every frame except the last one, you quickly swap to a view with an image of the last frame (basically the last frame) and then you transition into a view with the an image of the first frame of the next video and start up that one.
Or you could create a animation with all your frames (programming your videos), that will make it customizable, but the quality will probably not be as good and the cpu usage can spike, so you will have to make a call on that one.

How to replace an invisible UIButton to play different sounds

I'll try and be as precise as possible here!
Basically, I have an app in the AppStore which is a soundboard. It works great and we've shifted a few copies.
My client now wants to include random sounds when the character's face is clicked on TouchDown. I've got that working fine, using an array.
However, he now wants the button to return, let's say, 10 sounds BEFORE playing random sounds from another batch of 10.
So, in theory, you'd have to hit the button at least 10 times to hear the other sounds.
I was trying to think of a way of counting the number of clicks, to then use a different array of sounds.
Is that even possible?
Any help would be greatly appreciated!
How about using a variable to track number of button taps?