I know how to do shake for the iPhone has been asked a million times on here, but I can't seem to find anything useful regarding the accelerometer with Cocos2D. Everything i have found involves using views and I don't think i am using any views in Cocos2D, if I am they are hidden from me I think. I want to be able to tell when any sort of shake has occured within a CCLayer class?
I figured it out. In the layer class you need to put these lines;
self.isAccelerometerEnabled = YES;
[[UIAccelerometer sharedAccelerometer] setUpdateInterval:1/60];
shake_once = false;
Then implement this function in the layer class;
-(void) accelerometer:(UIAccelerometer *)accelerometer didAccelerate:(UIAcceleration *)acceleration {
float THRESHOLD = 2;
if (acceleration.x > THRESHOLD || acceleration.x < -THRESHOLD ||
acceleration.y > THRESHOLD || acceleration.y < -THRESHOLD ||
acceleration.z > THRESHOLD || acceleration.z < -THRESHOLD) {
if (!shake_once) {
int derp = 22/7;
shake_once = true;
}
}
else {
shake_once = false;
}
}
shake_once is just a boolean to stop one shake from being registered more than once.
Related
I am writing an iPhone camera App. When user is about to take a picture, I would like to check if the iPhone is shaking and wait for the moment that there is no shaking and then capture the phone.
How can I do it?
Anit-shake feature is quite a complicated feature to pull off. I reckon it's a combination of some powerful blur detection/removal algorithms, and the gyroscope on iPhone.
You may start by looking into how to detect motion with the iPhone, and see what kind of results you can get with that. If it's not enough, start looking into shift/blur direction detection algorithms. This is not a trivial problem, but is something that you could probably accomplish given enough time. Hope that Helps!
// Ensures the shake is strong enough on at least two axes before declaring it a shake.
// "Strong enough" means "greater than a client-supplied threshold" in G's.
static BOOL L0AccelerationIsShaking(UIAcceleration* last, UIAcceleration* current, double threshold) {
double
deltaX = fabs(last.x - current.x),
deltaY = fabs(last.y - current.y),
deltaZ = fabs(last.z - current.z);
return
(deltaX > threshold && deltaY > threshold) ||
(deltaX > threshold && deltaZ > threshold) ||
(deltaY > threshold && deltaZ > threshold);
}
#interface L0AppDelegate : NSObject <UIApplicationDelegate> {
BOOL histeresisExcited;
UIAcceleration* lastAcceleration;
}
#property(retain) UIAcceleration* lastAcceleration;
#end
#implementation L0AppDelegate
- (void)applicationDidFinishLaunching:(UIApplication *)application {
[UIAccelerometer sharedAccelerometer].delegate = self;
}
- (void) accelerometer:(UIAccelerometer *)accelerometer didAccelerate:(UIAcceleration *)acceleration {
if (self.lastAcceleration) {
if (!histeresisExcited && L0AccelerationIsShaking(self.lastAcceleration, acceleration, 0.7)) {
histeresisExcited = YES;
/* SHAKE DETECTED. DO HERE WHAT YOU WANT. */
} else if (histeresisExcited && !L0AccelerationIsShaking(self.lastAcceleration, acceleration, 0.2)) {
histeresisExcited = NO;
}
}
self.lastAcceleration = acceleration;
}
// and proper #synthesize and -dealloc boilerplate code
#end
I Googled it and found at How do I detect when someone shakes an iPhone?
i am currently writing a game with a number of rectangles (say 30), if a user clicks on one of the four sides a certain action will need to be taken. Trouble is each card will have the same side which will perform this action. For example with rectangle 1 the side which will perform this action will be the left, but rectangle 3 the side will be the top side. My guess is a pixel collision detection is needed here. What do you guys think? Also is there a good example on pixel collision using cocos2s out there?
You can simply use following code
if (CGRectIntersectsRect(Rect1, Rect2))
{
//Your code ...
}
USING above CGRectIntersectsRect you can detect the collision pixels within a rectangular area.
yes good point, the solution was a little messy but it worked, this is what i did: I subclassed CCSprite and created a new attribute called state saving the current position if rotated relative to that rotation. Depending on what side was touched i would use that information to determine which side of the rectangle was touched. –
if((spriteCentre1.x < spriteCentre2.x) && (xAxisDiff < yAxisDiff))
{
[HelloWorldLayer whichSideTouched:sprite1 sideTouched:kStateRightPlus touchingSprite:sprite2];
}
+(int)whichSideTouched:(SpriteCard *)sprite sideTouched:(int)touched touchingSprite:(SpriteCard *)sprite2
{
switch (sprite.state) {
case kStateUpPlus:
case kStateUpMinus:
if(touched == kStateDownPlus)
{
NSLog(# "touched up ");
[sprite setTop:sprite2];
retValue = kStateUpPlus;
}
else if(touched == kStateRightPlus)
{
NSLog(# "touch left");
[sprite setRight:sprite2];
retValue = kStateLeftPlus;
}
}
Thanks for that Dhaval, here is the code i wrote a future reference for anyone who wishes to do similar, it can be further fine tuned, if i figure out a more accurate way of doing this i will update this thread accordingly
-(void)touchWhichSide:(CCSprite *)sprite1 collidingSprite:(CCSprite *)sprite2
{
BOOL retValue = NO;
CGPoint spriteCentre1 = sprite1.position;
CGPoint spriteCentre2 = sprite2.position;
NSLog(#"X %f",spriteCentre2.x - spriteCentre1.x);
NSLog(#"Y %f",spriteCentre1.y - spriteCentre2.y);
float xAxisDiff = spriteCentre1.x - spriteCentre2.x;
float yAxisDiff = spriteCentre1.y - spriteCentre2.y;
NSLog(#"x axis %f",xAxisDiff);
NSLog(#"y axis %f",yAxisDiff);
if((spriteCentre1.x < spriteCentre2.x) && (xAxisDiff < yAxisDiff))
{
NSLog(#"right touch");
}
else if((spriteCentre2.x < spriteCentre1.x) && (xAxisDiff > yAxisDiff))
{
NSLog(#"left touch");
}
else if((spriteCentre2.y < spriteCentre1.y) && (yAxisDiff > xAxisDiff))
{
NSLog(#"Bottom touch");
}
else if((spriteCentre1.y < spriteCentre2.y) && (yAxisDiff < xAxisDiff))
{
NSLog(#"Top touch");
}
}
Ok, so I have these powerups that I want to slow/speed up the movement of the other objects in the game for a few seconds.
I have an array of objects that I have a variable called spawnInterval that gets faster and faster as the game progresses, making the ame get harder after a few mins.
But I can't really grasp how to make it so the character in the game will react differently to different objects as in when the fastPowerUp is hit by the character sprite, the spawn interval doesn't change.
And vice versa with the slowPowerUp.
the code I have at the moment is this in a move sequence method that gets called in an update method:
-
(void) updateObstacles:(ccTime)delta{
for (int i = 0; i < 20; i++) {
//int randomizer = CCRANDOM_0_1() * [obstacles count];
//NSLog(#"randomizer: %i",randomizer);
CCSprite* randomObject = [obstacles randomObject];
currentObject = [obstacles indexOfObject:randomObject];
if ([randomObject numberOfRunningActions] == 0) {
[self runObstacleMoveSequence:randomObject withTimer:delta];
break;
}
}
}
-(void) runObstacleMoveSequence:(CCSprite *)object withTimer:(ccTime)delta{
static int time;
//Slowly increase object speed
numObstaclesMoved++;
if (!slowPowerUp && !fastPowerUp) {
time += delta;
if (numObstaclesMoved % 17 == 0 && obstacleMoveDuration > 2.0f) {
obstacleMoveDuration -= 0.2f;
if (spawnInterval > 0.1f) {
[self unschedule:#selector(updateObstacles:)];
[self schedule:#selector(updateObstacles:) interval:spawnInterval];
spawnInterval-=0.1f;
NSLog(#"interval: %f",spawnInterval);
}
}
}else if (slowPowerUp && !fastPowerUp) {
if (numObstaclesMoved % 17 == 0 && obstacleMoveDuration > 2.0f) {
obstacleMoveDuration += 3.0f;
if (spawnInterval > 0.1f) {
[self unschedule:#selector(updateObstacles:)];
[self schedule:#selector(updateObstacles:) interval:spawnInterval];
spawnInterval-=0.1f;
NSLog(#"interval: %f",spawnInterval);
if (time >= (delta + 3)) {
slowPowerUp = NO;
obstacleMoveDuration -= 3.0f;
}
}
}
}else if (!slowPowerUp && fastPowerUp) {
if (numObstaclesMoved % 17 == 0 && obstacleMoveDuration > 2.0f) {
obstacleMoveDuration -= 3.0f;
if (spawnInterval > 0.1f) {
[self unschedule:#selector(updateObstacles:)];
[self schedule:#selector(updateObstacles:) interval:spawnInterval];
spawnInterval-=0.1f;
NSLog(#"interval: %f",spawnInterval);
if (time >= (delta + 3)) {
fastPowerUp = NO;
obstacleMoveDuration += 3.0f;
}
}
}
}
CGSize screenSize = [[CCDirector sharedDirector]winSize];
CGPoint aboveScreenPosition = CGPointMake(object.position.x, screenSize.height - object.position.y);
int rotations = (CCRANDOM_0_1()*3) * 360;
float duration = (CCRANDOM_0_1()*5.0f) + 8.0f;
CCMoveTo* move = [CCMoveTo actionWithDuration:obstacleMoveDuration position:aboveScreenPosition];
CCRotateTo* rotate = [CCRotateBy actionWithDuration:duration angle:rotations];
CCSpawn* moveRotate = [CCSpawn actions: move, rotate, nil];
CCCallFuncN* call = [CCCallFuncN actionWithTarget:self selector:#selector(objectAboveScreen:)];
CCSequence* sequence = [CCSequence actions:moveRotate, call, nil];
[object runAction:sequence];
if (time >= (delta + 3)) {
fastPowerUp = NO;
}
}
-(void) objectAboveScreen:(id) sender{
//make sure sender is actually of the right class
NSAssert([sender isKindOfClass:[CCSprite class]], #"sender is not a CCSprite!");
CCSprite* obstacle = (CCSprite*)sender;
//move the back to the bottom of the screen
CGPoint pos = obstacle.position;
CGSize screenSize = [[CCDirector sharedDirector]winSize];
pos.y = (-screenSize.height - [obstacle texture].contentSize.height);
pos.x = CCRANDOM_0_1() * screenSize.width;
obstacle.position = pos;
}
I really just don't know where to go from here... Should I make the powerUps a different class? If so, how would I implement something like this? I really hate trying to ask for someone to solve my question, but I really just can't rack my brain around this and I'm rather new... if it were explained to me, then I know I would be able to implement it in future games on my own...
Thanks in advance, and let me know if more information is needed...
I'd do something like
in the .h file
float speedModifier;
-(void)resetPowerUp;
in the .m
-(void)resetPowerUp
{
speedModifier = 1;
}
wherever you are initializing the level
[self resetPowerUp];
upon collision with powerup:
speedModifier = 2;
[self performSelector:#selector(resetPowerUp) withObject:nil afterDelay:5];
then wherever you are moving whatever it is which speed should be effected by the powerup mode, multiply the speed of the animation (or divide the duration it takes for it to get wherever it's going) by speedModified
hope that helps
So I a little backstory. I wanted to implement a particle effect and sound effect that both last about 3 sec or so when the user shakes their iDevice. But first issue arrived when the build in UIEvent for shakes refused to work. So I took the advice of a few Cocos veterans to just use some script to get "violent" accelerometer inputs as shakes. Worked great until now.
The problem is that if you keep shaking it just stacks the particle and sounds over and over. Now this wouldn't be that big of a deal except it happens even if you are careful to try and not do so. So what I am hoping to do is disable the accelerometer when the particle effect/sound effect start and then reenable it as soon as they finish. Now I don't know if I should do this by schedule, NStimer, or some other function. I am open to ALL suggestions. here is my current "shake" code.
- (void)accelerometer:(UIAccelerometer *)accelerometer didAccelerate:(UIAcceleration *)acceleration {
const float violence = 1;
static BOOL beenhere;
BOOL shake = FALSE;
if (beenhere) return;
beenhere = TRUE;
if (acceleration.x > violence * 1.5 || acceleration.x < (-1.5* violence))
shake = TRUE;
if (acceleration.y > violence * 2 || acceleration.y < (-2 * violence))
shake = TRUE;
if (acceleration.z > violence * 3 || acceleration.z < (-3 * violence))
shake = TRUE;
if (shake) {
id particleSystem = [CCParticleSystemQuad particleWithFile:#"particle.plist"];
[self addChild: particleSystem];
// Super simple Audio playback for sound effects!
[[SimpleAudioEngine sharedEngine] playEffect:#"Sound.mp3"];
shake = FALSE;
}
beenhere = FALSE;
}
UIAcceleration has a timestamp property. I would modify your code to save the current timestamp on a succesful shake in a static variable (perhaps static NSTimeInterval timestampOfLastShake?). Then modify if (shake) to if (shake && acceleration.timestamp - 3.0f >= timestampOfLastShake)
resulting code:
static NSTimeInterval timestampOfLastShake = 0.0f;
if (shake && acceleration.timestamp - 3.0f >= timestampOfLastShake ) {
timestampOfLastShake = acceleration.timestamp;
id particleSystem = [CCParticleSystemQuad particleWithFile:#"particle.plist"];
[self addChild: particleSystem];
// Super simple Audio playback for sound effects!
[[SimpleAudioEngine sharedEngine] playEffect:#"Sound.mp3"];
shake = FALSE;
}
You realize that you are doing single axis acceleration checks and you are not ensuring the acceleration is repeated (i.e. shake). In other words, if you drop your phone, your code will think it's someone shaking the device back-and-fourth few times (which is what a shake is) and fire many times a second. So, either apply multi-axis checks against time or simply use the shake UIEvent. All you will need to do is in your UIView (or UIWindow better yet), implement - (void)motionEnded:(UIEventSubtype)motion withEvent:(UIEvent *)event making sure the view becomes first responder. This will take care of all acceleration filtering, etc. and app won't be bombarded by all the acceleration noise (you can drop your phone on the table and it won't mistake that for a shake).
Go here for doc: http://developer.apple.com/library/ios/#documentation/EventHandling/Conceptual/EventHandlingiPhoneOS/MotionEvents/MotionEvents.html
Or:
- (BOOL)canBecomeFirstResponder {
return YES;
}
// Now call [self becomeFirstResponder]; somewhere, say in viewDidAppear of the controller.
- (void)motionBegan:(UIEventSubtype)motion withEvent:(UIEvent *)event
{
}
- (void)motionEnded:(UIEventSubtype)motion withEvent:(UIEvent *)event
{
if (event.subtype == UIEventSubtypeMotionShake) {
// You've got a shake, do something
}
}
- (void)motionCancelled:(UIEventSubtype)motion withEvent:(UIEvent *)event
{
}
hi i want iphone detect shake gesture only one time .
after iphone had been shaken and html files showed , then i want iphone doesn't detect shake anymore .
here is my code :
- (void)accelerometer:(UIAccelerometer *)accelerometer
didAccelerate:(UIAcceleration *)acceleration {
{
if (acceleration.x > kAccelerationThreshold
|| acceleration.y > kAccelerationThreshold
|| acceleration.z > kAccelerationThreshold) {
}
}
}
Remove the delegate:
[UIAccelerometer sharedAccelerometer].delegate = nil;