making things move on the iphone

Making Things Moveon the iPhone

Keith Peterswww.bit-101.com

Wednesday, March 4, 2009

http://www.bit-101.com

http://www.bit-101.com

www.bit-101.com/360iDev/

presentation.zip


CoreAnimation


Background


Background

2005


Background

2007

2005


Background

20082007

2005


What is Animation?


Coded Animation


Coded AnimationApply a

rule



rule

Change something



rule

Change something

Updatethe screen


Make somethingto move


Make somethingto move

(project files: Animation101)


// interfaceUIImageView *ball;

// viewDidLoadball = [[UIImageView alloc] initWithImage: [UIImage imageNamed:@"ball.png"]];[self.view addSubview:ball];


NSTimer


NSTimer[NSTimer scheduledTimerWithTimeInterval:1.0/60.0 target:self selector:@selector(onTimer) userInfo:nil repeats:YES];


Moving UIViews


Moving UIViews

• view.center


Moving UIViews

• view.center

• view.transform


Moving UIViews

• view.center

• view.transform

• view.frame


// interfacefloat x;float y;

// viewDidLoadx = 50.0;y = 50.0;


ball.center = CGPointMake(x, y);x += 2.0;y += 3.0;


ball.frame = CGRectMake(x, y, width, height);x += 2.0;y += 3.0;


ball.transform = CGAffineTransformMakeTranslation(x, y);x += 2.0;y += 3.0;


ball.transform = CGAffineTransformTranslate( ball.transform, 2.0, 3.0);


Which is fastest?


Which is fastest?

• view.center


Which is fastest?

• view.center

• view.transform (~2-3x)


Which is fastest?

• view.center

• view.transform (~2-3x)

• view.frame (~2-3x)


Velocity

(project files: Velocity)


Velocity

+(project files: Velocity)


speedand

direction


speedand

direction

x velocity

y velocity


+ x velocity- x velocity

- y velocity

+ y velocity


// interface:float vx;float vy;



// viewDidLoad:vx = 2.0;vy = 3.0;



// viewDidLoad:vx = 2.0;vy = 3.0;

// onTimer:ball.center = CGPointMake(x, y);x += vx;y += vy;


speed

angle

(project files: AngularVelocity)


speed

x velocity = cos(angle) x speed

y velocity=

sin(angle)x

speed

angle

(project files: AngularVelocity)


// interface:float angle;float speed;



// viewDidLoad:angle = 45.0;speed = 4.0;



// viewDidLoad:angle = 45.0;speed = 4.0;

// onTimer:ball.center = CGPointMake(x, y);x += cos(angle * M_PI / 180.0) * speed;y += sin(angle * M_PI / 180.0) * speed;


Acceleration

(project files: Acceleration)


Acceleration

+(project files: Acceleration)


// interface:float ax;float ay;



// viewDidLoad:ax = 0.07;ay = 0.1;



// viewDidLoad:ax = 0.07;ay = 0.1;

// onTimer:ball.center = CGPointMake(x, y);x += vx;y += vy;vx += ax;vy += ay;


Bouncing

(project files: Bouncing)


x velocity

-x velocity

y velocity

y velocity


// interface:float bounce;


// interface:float bounce;

// viewDidLoad:bounce = -1.0;


ball.center = CGPointMake(x, y); x += vx;y += vy;if(x > 300) // 320 - radius (20){ x = 300; vx *= bounce;}else if(x < 20) // 0 + radius{ x = 20; vx *= bounce;}


if(y > 440) // 460 - radius{ y = 440; vy *= bounce;}else if(y < 20) // 0 + radius{ y = 20; vy *= bounce;}


Gravity

acceleration(+y)


// interface:float gravity;



// viewDidLoad:gravity = 0.5;



// viewDidLoad:gravity = 0.5;

// onTimer:vy += gravity;


acceleration.y

acceleration.x


@interface GravityViewController : UIViewController <UIAccelerometerDelegate>{ UIImageView *ball; float x; float y; float vx; float vy; float bounce; CGPoint gravity;}


// viewDidLoadgravity = CGPointZero;[[UIAccelerometer sharedAccelerometer] setDelegate:self];



- (void)accelerometer:(UIAccelerometer *)accelerometer didAccelerate:(UIAcceleration *)acceleration{ gravity = CGPointMake(acceleration.x, -acceleration.y);}



- (void)accelerometer:(UIAccelerometer *)accelerometer didAccelerate:(UIAcceleration *)acceleration{ gravity = CGPointMake(acceleration.x, -acceleration.y);}

// onTimervx += gravity.x;vy += gravity.y;


Do we still have time?


Dragging and Throwing


// interfaceBOOL dragging;



// viewDidLoaddragging = NO;



// viewDidLoaddragging = NO;

- (void)onTimer{ if(!dragging) { ... }}


- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{ UITouch *touch = [touches anyObject]; CGPoint point = [touch locationInView:self.view]; float dx = point.x - x; float dy = point.y - y; float dist = sqrt(dx * dx + dy * dy); if(dist < 20) { dragging = YES; x = point.x; y = point.y; vx = 0; vy = 0; }}


- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{ dragging = NO;}


- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{ if(dragging) { UITouch *touch = [touches anyObject]; CGPoint point = [touch locationInView:self.view]; vx = point.x - x; vy = point.y - y; x = point.x; y = point.y; ball.center = point; }}


Thank you

• Keith Peters

• [email protected]

• www.bit-101.com

• www.wickedpissahgames.com

• www.bit-101.com/360iDev/presentation.zip


making things move on the iphone

Technology

float ax float

float angle float speed

speed y

float vx float vy viewdidload

float speed speed

y velocity x velocity

x view

float bounce viewdidload