I've created a super simple count down application. You press a button, and the count down runs. The end result calculating looks like this:
10.0
9.999
9.998
...
And each whole number represents a second, so as you can imagine it runs fast.
While this loop runs, I have code in it to play a sound if it finds the current values to be 3.0 or 2.0 or 1.0 or 0.0.
Everything triggers and the sound plays, however it is glitchy as heck. About 80% of the time is triggers perfectly. The rest of the time it is either delayed by a fraction of a second or misses it completely. The sound effects are critical to the app.
I've used prepare to play properly and it did nothing to improve. My current implementation is using SKTAudio which I feel like is a bit overkill for my needs.
Any advice?
Please mind one moment - if you are using Double class to compare two values, you may find, that 2.0 value is not real 2.0, but 2.0000000001 for example. So, 2 and 2.0000001 are different values and your sound will no be played
Use may try smth. like
let checkValue: Double = 2 // your comparison value
let timerValue = 2.00000001 //for example
if (timerValue - Double(Int(timerValue))) == 0 && checkValue == timerValue {
print("Cool")
} else {
print("Not cool")
}
or almost the same
let checkValue: Double = 2 // your comparison value
let timerValue = 2.00000001 //for example
if timerValue == Double(Int(timerValue)) && timerValue == checkValue {
print("Cool")
} else {
print("Not cool")
}
Related
I am building a simple dice roll game.
The game cycle is like this:
1) Roll dice and move piece
2) Check if there is extra bonus moves, if Yes then move the piece
3) Check if piece has reached its destination, if Yes then Game ends
4) End turn
I built my Game loop using SKAction.run statements and append them into an array and then run them.
The actual code is very long, so I am providing only the basic flow here.
func runDiceRoll() {
// some SKActions
}
func checkExtraMoves() {
// run some SKActions depending on runDiceRoll() outcome
}
func checkStatus() {
// code to check if Game ends, depends on checkExtraMoves() outcome
}
func endTurn() {
// code to end the player's turn and give it to the other player
}
My game loop looks something like this
func runGameCycle() {
var actions = [SKAction]()
let actionRun = SKAction.run {runDiceRoll()}
let actionCheckExtraMoves = SKAction.run {checkExtraMoves()}
let actionCheckStatus = SKAction.run {checkStatus()}
let actionEndTurn = SKAction.run {endTurn()}
let actionWait = SKAction.wait(forDuration:2.0)
actions.append(actionRun)
actions.append(actionWait)
actions.append(actionCheckExtraMoves)
actions.append(actionCheckStatus)
actions.append(actionEndTurn)
piece.run(SKAction.sequence(actions))
}
If I remove the Wait action, then the game play is not correct.
I would prefer not to use a Wait duration because it is just an estimate that the preceeding actions will be completed in 2 seconds or less.
I think it would be better if all the actions waits for the preceeding action to complete before firing. I am not sure how to use a completion handler or DispatchQueue for such purposes.
Is there a better way, more foolproof way to write the game loop?
So I've just started trying out coding in swift and I'm creating an extremely basic app (purely to experiment and learn) where you click a button and two playing cards appear on the screen.
I'm trying to get it so that when the two playing cards are the same, the button to play again disables, the program pauses for a few seconds, then the button re-enables (so later I can add some 'win' text during the pause time).
Now the button and pausing fully works besides one problem. When testing, the program pauses and then when it finishes pausing the display then updates to show the two cards being equal. But while it pauses, it shows two random non equal cards.
I'm not sure why, seeing as the cards update before I check if they're equal, but I'm new to swift (literally last few days) so not sure how it works.
Any ideas? :)
#IBAction func playRoundTapped(sender: UIButton) {
// Change the card image each time the play button is pressed using a random number generator
self.firstCardImageView.image = UIImage(named: String(format: "card%i", arc4random_uniform(13)+1))
self.secondCardImageView.image = UIImage(named: String(format: "card%i", arc4random_uniform(13)+1))
// Check if the cards are equal
if firstCardImageView.image == secondCardImageView.image && firstCardImageView.image != "card" {
playRoundButton.userInteractionEnabled=false;
NSThread.sleepForTimeInterval(4)
playRoundButton.userInteractionEnabled=true;
}
}
Don't sleep in the main thread as this will stop all interactions with your app. You need to replace:
NSThread.sleepForTimeInterval(4)
playRoundButton.userInteractionEnabled=true;
with:
let enableTime = dispatch_time(DISPATCH_TIME_NOW, Int64(4 * Double(NSEC_PER_SEC)))
dispatch_after(enableTime, dispatch_get_main_queue()) {
playRoundButton.userInteractionEnabled=true;
}
First off, a better solution is not pausing at all and using dispatch_after to change the playRoundButton button state after 4 seconds.
If you want to stick with pausing, then you should give time for the UI to update itself before pausing. E.g.,
dispatch_async(dispatch_get_main_thread(), {
//Check if both cards are equal
if firstCardImageView.image == secondCardImageView.image && firstCardImageView.image != "card" {
playRoundButton.userInteractionEnabled=false;
NSThread.sleepForTimeInterval(4)
playRoundButton.userInteractionEnabled=true;
}
});
The fact is, when you assign a new image to your buttons, the button is actually redrawn on screen only at the next run-loop cycle, so if you pause before that is run, no visual change can be seen...
Keep in mind that pausing on the main thread will make your app unresponsive during that timeframe.
You're comparing two UIImage instances, which doesn't work with == because it will only compare the pointers. In your case, it would be much easier to compare the numbers that generated those images.
Other than that, you're pausing the main thread, which takes care of updating the user interface, so it doesn't actually get a chance to do so. One way to solve this problem is by using NSTimer.
#IBAction func playRoundTapped(sender: UIButton) {
let firstNumber = arc4random_uniform(13) + 1
let secondNumber = arc4random_uniform(13) + 1
firstCardImageView.image = UIImage(named: "card\(firstNumber)")
secondCardImageView.image = UIImage(named: "card\(secondNumber)")
if firstNumber == secondNumber {
playRoundButton.userInteractionEnabled = false;
NSTimer.scheduledTimerWithTimeInterval(4.0, target: self, selector: "enableButton", userInfo: nil, repeats: false)
}
}
func enableButton() {
playRoundButton.userInteractionEnabled = true;
}
Newbie to IOS programming - learning through Swift. I'm writing a simple "slot machine / dice game".
I'm trying to show the user a flashing sequence of rolls before the "actual" roll appears.
func doFancyDiceRoll() {
for x in 1...100 {
Die1.image = PipsImg[RollOne()]
Die2.image = PipsImg[RollOne()]
Die3.image = PipsImg[RollOne()]
}
}
Die1, etc., are defined as generic UIImage views.
In any case, I'm not seeing the 100x iterations, just the images at the end of the loop. I'm assuming that either it redraws "too fast" or that IOS is trying to be smart, and only draws the last images so as to conserve resources.
I'll wildly guess that I need to either implement some kind of delay here, or, IOS needs to be told to explicitly draw out my images, and not try to outthink my intent.
For the delay, I've seen something about NSTimer, but nothing I saw seems to simply say something like "pause for .05" second, and the whole construct was unclear as they were ObjC examples/conversions.
(Note: I've simplified things here --- normally, I would store the value of RollOne() so I can use it later. I also would like to make an array (or collection?) like Die[1].image, but that is another question.)
========== Edit =======
OK, so I'm following up with more of my original code, merged in with that of #doctordoder so we can discuss a bit better. Hopefully that is kosher. (If this appended question is too long, please advise me on the best way to post a lengthy follow-up directly.)
import UIKit
class ViewController: UIViewController {
//( stripping out stuff unneeded for discussion )
// refers to same label below - works but kosher??
#IBOutlet var btnRoll_x: UIView
#IBAction func btnRoll(sender: AnyObject) {
triggerRoll()
}
var timer : NSTimer? = nil
var rolls : Int = 0
func triggerRoll() {
//hiding is bad UI, but until i know how to "disable & dim"
btnRoll_x.hidden = true
timer = NSTimer.scheduledTimerWithTimeInterval(0.10, target: self, selector: "doFancyDiceRoll", userInfo: nil, repeats: true);
}
func doFancyDiceRoll() {
Die1.image = PipsImg[randomInt(6)]
Die2.image = PipsImg[randomInt(6)]
Die3.image = PipsImg[randomInt(6)]
if (++rolls > 10)
{
timer?.invalidate()
timer = nil
rolls = 0 // DCB added this presumed missing line
btnRoll_x.hidden = false //again, need to do this better
}
}
}
Hopefully, my implementation of the code is what would have been intended. I made some minor adjustments for (hopeful) clarity.
Good news is I have working code. I have just enough understanding to get in place, but I'm fuzzy on some details.
Here is what I (think I) know...
We declare an NSTImer object, and a roll counter at the main level of the class. I note that in my original version, I had the roll counter scoped within the rolling function itself. Took me a while to understand why it could not live in the DiceRoll loop itself, but now I do. I'm going to express it poorly, but since the timer is going to call DiceRoll multiple instances, it needs to live outside the function.
The button btnRoll gets touched, and invokes triggerRoll().
To prevent the user from touching the button while we are in progress, which put us into a state where the roll counter never got to zero, I hide the button. (I'll figure how to properly put in in disabled state later.)
The timer is set. It fires every .1 second (within limits), and is set to repeat. (until .invalidate ). And it "calls" the function doFancyDiceRoll via the selector: attribute.
So, the big change as previously noted is that doFancy..Roll() no longer loops. It excites a single instance up updating the images. It checks the counter, and if we reach the limit, we kill the timer, which stops the timer (invalidate). (And I unhide the button, making it available again.)
So, a few things I am concerned/wondering about: I get the value of timers for other things that need to happen periodically (take health away every second, check a GPS position every 10 seconds, etc.). It's seems a odd construct to force a screen refresh.
Frankly, I would have expected to see see something like this:
func doFancyDiceRoll() {
for x in 1...100 {
Die1.image = PipsImg[RollOne()] // and 2 and 3 of course.....
VIewController.forceRedraw <<=== something like this, or maybe
ViewController.wait(.05) <<== this?? I dunno ;-)
}
}
instead we end up with about 20 extra lines or so. I'd be interested in knowing if there other approaches that could work keeping the loop intact.
Anyway, assuming this is the one true way to go, I guess my followup to this is how do I pass parameters, since this is not a "real" function call. Trying
selector: "doFancyDiceRoll(40)"
was not objected to by the IDE, but failed in execution.
I had exactly same problem back in days, entire loop is finished before the view is refreshed as #doctordoder mentioned. Solved with using NSTimer
var rollCount = 0
let arrayOfImages = ["image01", "image02", "image03"]
var timer = NSTimer.scheduledTimerWithTimeInterval(0.1, target: self, selector: Selector("doFancyDiceRoll"), userInfo: nil, repeats: true)
func doFancyDiceRoll() {
if rollCount == 100 {
timer.invalidate
rollCount = 0
{
else {
//get images from array arrayOfImages[rollCount]
rollCount++
}
}
there could be typos, since I have no Xcode right now.
I have basically the same answer as above :(, but I thought I'd post it anyway.
var timer : NSTimer? = nil
var rolls : Int = 0
func doFancyDiceRoll() {
timer = NSTimer.scheduledTimerWithTimeInterval(0.10, target: self, selector: "roll", userInfo: nil, repeats: true);
}
func roll() {
println("rolling")
Die1.image = PipsImg[RollOne()]
Die2.image = PipsImg[RollOne()]
Die3.image = PipsImg[RollOne()]
if (++rolls > 100)
{
timer?.invalidate()
timer = nil
}
}
Rather than NSTimer and invalidating, you can use dispatch_after to do the work for you.
func rollDice(howManyTimes: Int) {
die1.image = PipsImg[RollOne()]
die2.image = PipsImg[RollOne()]
die3.image = PipsImg[RollOne()]
if howManyTimes > 0 {
let delayTime = dispatch_time(DISPATCH_TIME_NOW, Int64(Double(NSEC_PER_SEC) / 10.0))
dispatch_after(delayTime, dispatch_get_main_queue()) {
self.rollDice(howManyTimes - 1)
}
}
}
This will run the code for the number of times specified, delaying each time by 0.1 seconds. It works like this: First it sets the images on each die, then, if there are more iterations, it does a dispatch_after to call itself with rollDice(howManyTimes - 1)
With this, you don't need to maintain a NSTimer and it is pretty self contained.
I use: MPMoviePlayerController to show video.
Below I put list of thumbs from the video.
When pressing a thumb I want to jump to a specific place in the video using: setCurrentPlaybackTime.
I also have a timer updating the selected thumb according to the location of the video using: currentPlaybackTime.
My problem: when calling: setCurrentPlaybackTime, the player keeps giving the seconds before seeking to the specific second. It take few seconds to the player to reflect the new seconds. In the mean time the experience of the user is bad: Pressing a thumb shows it selected for a show time, then the timer updates to the previous thumb, then it jumps back to the thumb I selected.
I tried using (in the timer):
if (moviePlayer.playbackState != MPMoviePlaybackStatePlaying && !(moviePlayer.loadState & MPMovieLoadStatePlaythroughOK)) return;
In order to prevent from the timer to update the selected thumb as long the player is in a transition phase between showing the previous thumb and the new thumb, but it doesn't seem to work. The "playbackState" and "loadState" seems to be totally inconstant and unpredictable.
For solving this issue, this how I have implemented this nasty state coverage in one of my projects. This is nasty and fragile but worked good enough for me.
I used two flags and two time intervals;
BOOL seekInProgress_;
BOOL seekRecoveryInProgress_;
NSTimeInterval seekingTowards_;
NSTimeInterval seekingRecoverySince_;
All of the above should be defaulted to NO and 0.0.
When initiating the seek:
//are we supposed to seek?
if (movieController_.currentPlaybackTime != seekToTime)
{ //yes->
movieController_.currentPlaybackTime = seekToTime;
seekingTowards_ = seekToTime;
seekInProgress_ = YES;
}
Within the timer callback:
//are we currently seeking?
if (seekInProgress_)
{ //yes->did the playback-time change since the seeking has been triggered?
if (seekingTowards_ != movieController_.currentPlaybackTime)
{ //yes->we are now in seek-recovery state
seekingRecoverySince_ = movieController_.currentPlaybackTime;
seekRecoveryInProgress_ = YES;
seekInProgress_ = NO;
seekingTowards_ = 0.0;
}
}
//are we currently recovering from seeking?
else if (seekRecoveryInProgress_)
{ //yes->did the playback-time change since the seeking-recovery has been triggered?
if (seekingRecoverySince_ != movieController_.currentPlaybackTime)
{ //yes->seek recovery done!
seekRecoveryInProgress_ = NO;
seekingRecoverySince_ = 0.0;
}
}
In the end, MPMoviePlayerController simply is not really meant for such "micro-management". I had to throw in at least half a dozen flags for state coverage in all kinds of situations and I would never recommend to repeat this within other projects. Once you reach this level, it might be a great idea to think about using AVPlayer instead.
I use a sound each time a key is pressed to fire a missile. But it doesn't sound nice. I guess it's because the the sound is repeated so many times while the key is pressed down and that the code is within the Update method. I'm looking for a simple solution to just play the sound once when key is pressed? (I have tested to use a boolean variable to be true the first time and then false after det the sound has been played, but this didn't worked well because, when and where should I set it to true again) Help is preciated!
// Fire
if (keyboardState.IsKeyDown(Keys.Space))
{
missile.launchMissile(spaceship.spaceshipPosition, spaceship.spaceshipDirection);
soundExplosion.Play();
}
EDIT New code that isn't working!?
KeyboardState keyboardState = Keyboard.GetState();
KeyboardState prevKeyboardState;
prevKeyboardState = keyboardState;
keyboardState = Keyboard.GetState();
if (keyboardState.IsKeyDown(Keys.Space) && prevKeyboardState.IsKeyUp(Keys.Space))
{
missile.launchMissile(spaceship.spaceshipPosition, spaceship.spaceshipDirection);
soundExplosion.Play();
}
Store your previous keyboard state as well
KeyBoardState prevKeyboardState;
then in your update
prevKeyboardState = keyboardState;
keyboardState = Keyboard.GetState();
if (keyboardState.IsKeyDown(Keys.Space) && prevKeyboardState.IsKeyUp(Keys.Space))
{
//your code
}
You're basically just triggering the sound tons of times every second making it sound awful.